Project - Machine Turned Solids
- Thread starter Brobee
- Start date
Jason: I'm not certain just how concentric a bullet tip really needs to be. Keep in mind that the bullet is rotating at a high velocity and any non-concentric features will be spread out around the bullet's center of rotation. It has long been known that damage to a bullet nose does not significantly affect the accuracy of that bullet.
Delrin does machine fairly well as does nylon. However machining something as small as a bullet tip is going to be difficult because the material will want to bend away from the cutting tool.
I'm not sure what configuration you have for your .224 bullets but I can provide a large field or two full of gophers for terminal testing if you are interested in that kind of thing.
Very interesting Jason although turned bullets offer better balistics than than the traditional swaged bullets they[turned bullets] have some issues that are hard to resolvle.Swaged bullets offer better accuracy and less barrel fouling over turned bullets why ?,Swaged bullets conform better to the bore than turned bullets thus improving accuracy and less fouling in the bore and at long range this alone is a deciding factor over the ballisticly superior turned bullets
drew:
I spent quite a bit of time talking with Dave Corbin about the polymer tips...if I recall the conversation right his impression is that the big boys for the most part injection mold their tips from some sort of polyacrylic resin and then press them into the tips of their bullets when swaging the final nose shape. He looked into doing the same to make tips commercially available to his custom bullet manufacturer clients and was struggling with the ultra high tooling costs of high volume molds. In the interim he was bidding machine shops for machine turned tips from either brass/bronze or aluminum.
trevj:
The broach is set up on a live center and then inserted into the pilot hole while both the part and broach are spinning.
The bronze alloys you reference, specifically ones that are set up for precision machining, all have lead in them. Were it not for their lead content I would have likely gone this route. California has recently banned lead ina bunch of stuff (like plumbing fittings); material foundries are responding with lead free brasses/bronses however they are quite expensive and not yet readily available. I will try to keep a pulse on this and re-evaluate if the situation changes.
Re obsolete tech - the screw machines in question are all CNC integrated and hold mega-tight tolerances...they are commercially available today as state-of-the-art high precision/high volume small parts machines.
M A T T:
As mentionned above, aluminum would only be considered as a replacement for the polymer material I used in the tips, never as a candidate for bullet body construction.
bigstickpilot:
How do you like the GS Custom bullets? Did you go with their flat nose design? What are your impressions of their performance?
suputin:
Re accuracy and tip geometry - I don't have much experience in this world however have read stuff that indicate you're right about tip damage not impacting accuracy very much. As an aside, these same sources indicate that bullet base geometry/uniformity is much more important which influenced heavily the selection of a machine capable of turning both the tip and the base with no partoff nipple (as is seen on the base of barnes's machine turned solids). I was more worried about concentricity from the perspective of longer range stability rather than overall accuracy. As these are longer for the same SD as compared to converntional jacketed lead bullets stability can be a real issue. Recognizing there are lots of variables at play here (twist rate, velocity, non-axial engagement of rifling due to possible OAL constraints et al, concentricity) my hope was to make the tips as concentric as possible to minimize one possible contributor to tumbling at longer range resulting from stability issues.
Re .224 - I have no current plans to do a hollow point solid .224 bullet as I don't believe there is much of a big game market for it. The lead-free-seeking gopher crowd is likely better served (IMHO) with things like the barnes varmint grenade (which is a conventional jacketed bullet swaged with a powdered copper/zinc core). I'll still do the FMJ solid so I have fodder for shooting at steel on my 500 meter range and practice for service rifle.
To all those looking to help out with testing:
This is something I would like to do, however while I have lots of .308 solids on hand I only have a couple hundred hollow points which is not enough to sell to folks in sufficient quantity for them to work up a load and then go shoot something with it. I've already sent some of the solids to a couple folks, so if you're interested in purchasing some solids for participating in testing send me a pm and we'll work something out. Back to the hollow points - I need to complete my gelatin testing before I run some more but once I do if folks are willing I'll make them available for limited purchase for the purpose of testing. For the time being these will be .308 155gr only.
Savage:
I don't believe that turned homogeneous copper solids can ever be ballistically superior to conventional jacketed lead core swaged bullets simply because of the difference in material density. Ergo the bullets I'm making will always be at a long range disadvantage to traditional bullets however folks might still want them because they are lead free. Vis a vis short and medium range accuracy, I don't know if I buy your statement that conventional bullets are intrinsically more accurate as in my own accuracy testing (across three different bolt guns) the machine turned projectiles perform measurably better than my best Sierra HPBT match loads. Whether or not this is because my bullet is better or some other combination of the myriad of different handloading variables I can't really say and I likely won't ever have enough info to know for sure but what I do know is that at 300 yards on a windless day the machine turned projectiles are every bit as accurate as the Sierras.
I did have some early fouling issues however I think we've got that sorted out as well...
Cheers,
Brobee
I spent quite a bit of time talking with Dave Corbin about the polymer tips...if I recall the conversation right his impression is that the big boys for the most part injection mold their tips from some sort of polyacrylic resin and then press them into the tips of their bullets when swaging the final nose shape. He looked into doing the same to make tips commercially available to his custom bullet manufacturer clients and was struggling with the ultra high tooling costs of high volume molds. In the interim he was bidding machine shops for machine turned tips from either brass/bronze or aluminum.
trevj:
The broach is set up on a live center and then inserted into the pilot hole while both the part and broach are spinning.
The bronze alloys you reference, specifically ones that are set up for precision machining, all have lead in them. Were it not for their lead content I would have likely gone this route. California has recently banned lead ina bunch of stuff (like plumbing fittings); material foundries are responding with lead free brasses/bronses however they are quite expensive and not yet readily available. I will try to keep a pulse on this and re-evaluate if the situation changes.
Re obsolete tech - the screw machines in question are all CNC integrated and hold mega-tight tolerances...they are commercially available today as state-of-the-art high precision/high volume small parts machines.
M A T T:
As mentionned above, aluminum would only be considered as a replacement for the polymer material I used in the tips, never as a candidate for bullet body construction.
bigstickpilot:
How do you like the GS Custom bullets? Did you go with their flat nose design? What are your impressions of their performance?
suputin:
Re accuracy and tip geometry - I don't have much experience in this world however have read stuff that indicate you're right about tip damage not impacting accuracy very much. As an aside, these same sources indicate that bullet base geometry/uniformity is much more important which influenced heavily the selection of a machine capable of turning both the tip and the base with no partoff nipple (as is seen on the base of barnes's machine turned solids). I was more worried about concentricity from the perspective of longer range stability rather than overall accuracy. As these are longer for the same SD as compared to converntional jacketed lead bullets stability can be a real issue. Recognizing there are lots of variables at play here (twist rate, velocity, non-axial engagement of rifling due to possible OAL constraints et al, concentricity) my hope was to make the tips as concentric as possible to minimize one possible contributor to tumbling at longer range resulting from stability issues.
Re .224 - I have no current plans to do a hollow point solid .224 bullet as I don't believe there is much of a big game market for it. The lead-free-seeking gopher crowd is likely better served (IMHO) with things like the barnes varmint grenade (which is a conventional jacketed bullet swaged with a powdered copper/zinc core). I'll still do the FMJ solid so I have fodder for shooting at steel on my 500 meter range and practice for service rifle.
To all those looking to help out with testing:
This is something I would like to do, however while I have lots of .308 solids on hand I only have a couple hundred hollow points which is not enough to sell to folks in sufficient quantity for them to work up a load and then go shoot something with it. I've already sent some of the solids to a couple folks, so if you're interested in purchasing some solids for participating in testing send me a pm and we'll work something out. Back to the hollow points - I need to complete my gelatin testing before I run some more but once I do if folks are willing I'll make them available for limited purchase for the purpose of testing. For the time being these will be .308 155gr only.
Savage:
I don't believe that turned homogeneous copper solids can ever be ballistically superior to conventional jacketed lead core swaged bullets simply because of the difference in material density. Ergo the bullets I'm making will always be at a long range disadvantage to traditional bullets however folks might still want them because they are lead free. Vis a vis short and medium range accuracy, I don't know if I buy your statement that conventional bullets are intrinsically more accurate as in my own accuracy testing (across three different bolt guns) the machine turned projectiles perform measurably better than my best Sierra HPBT match loads. Whether or not this is because my bullet is better or some other combination of the myriad of different handloading variables I can't really say and I likely won't ever have enough info to know for sure but what I do know is that at 300 yards on a windless day the machine turned projectiles are every bit as accurate as the Sierras.
I did have some early fouling issues however I think we've got that sorted out as well...
Cheers,
Brobee
Update!
The ballistic gelatin arrived just before christmas; I spent the past few days making jello and managed to get out to the range to shoot some this morning. Results were dissapointing (yet very interesting). We fired a total of three rounds into the gelatin and all recovered projectiles look about the same. I neglected to take the camera to the range and was dissapointed enough that I tossed the gelatin on the way home, so I apologize for their not being any backlit photographs of the gelatin.
Observations:
- petals shear early (within 1 inch of gelatin penetration)
- petals shear along broach lines and continue to tear to total cavity depth
- petals then tear/fracture off the bullet shank, the tear initiating exactly at the corner created by the tip of the dril bit used to bore the hollow point - strangely the 6 petals tear off somehat asymetcially in time which then causes the bullet to deflect/deviate off original trajectory. Both the petal shedding and deflection is BAD. The fracture evidence is interesting - I suspect this is related to the tellurium addition and resulting alloy properties - I'm speculating that chipping charracteristics desirable in machining are somewhat contradictory to desirable plasticity/elasticity of material required for good peeling hollow point bullet charracteristics. More thoughts on this in a bit.
- what's left after the petals shear off mushroom slightly...encouraging that there is some material plasticity and the basis for the flat metplate dangerous game style design I'm going to try as a part of the next batch we're getting set to run.
- fouling bands are of sufficient depth
- decent, but not ideal engagement of driving bands. Rifling scoring is not really deep. Sufficient for good spin stability though as gelatin showed good rotational stretch cavity tearing which could only be caused by spinning projectile. Also, projectile is accurate at extended range which could only happen if it was sufficiently stabilitzed.
- some lateral displacement of rifling-diplaced material - suggests that the projectile is slightly undersized to the bore of this specific test gun. Not a show-stopper, as velocity is on par with other projectiles I've tested from same gun with same propellant quantity/projectile weight. Also, I'd be scared to make the bullets with an OD any larger than .308! The 150gr barnes bullet we also tested for control/comparison exhibited the same phenomenon on it's driving bands.
- no ill effects observed at all relating to rebated boat tail.
- little bits of blue plastic visible on leading edge of bullet are from the blue tarp I had placed underneath the gelatin block. The bullets all deflected sufficiently that they exited the second block (blocks were 9"x9"x18", two placed end on end for a total of 32 inches of potential penetration witness capability)
- deflection did not start until approximately 14 inches of penatration.
- two of the three bullets exited the side of the gelatin blocks after approximately 22 inches of penetration. The third was recovered, but only because it exited the bottom of the block and deflected off the table to then travel another 4 inches inside the gelatin.
- temporary stretch cavity, while massive, was not as developped or as long as one produced by a 150gr barnes ### we used for control/comparision.
So while very interesting, as one of my initial goals was 100% weight retention and little-to-no deflection in homogeneous media, the projectile tested gets an F grade and is not something I will be producing commercially in it's current design.
Regarding the tearing of the petals....the copper/tellurium alloy was chosen as a material primarily because of it's machining charracteristics. From what I understand, pure copper does not machine very well and gets pushed around by the cutting tools something analagous to slightly warm butter sticking to your butter knife. By alloying the copper with trace amounts of tellurium the ductility of the copper is changed such that it now chips sufficiently to be machinable.
While an expanding-hollow-point-spitzer style bullet made by precision high speed machining (as compared to swaging) might be an un-solvable problem relating to the copper/tellurium alloy's malleability properties, it got me thinking about one of the disciplines in my oilpatch work world : pressure vessel design. Flat caps to a cylindrical pressure vessel concentrate force at the intersection between the cylinder and the cap - when over-pressured the material will fail right at the corner - typically where the cap was welded onto the cylinder. Proper pressure vessel construction utilizes parabolic shaped caps on the end of the vessel cylinder. These distribute the force evenly and longitudionally down the pressure vessel body. Consequently this type of pressure vessel design can withstand several times more pressure than one built by welding a steel plate to the end of a cylinder (with both vessels being made from the same thickness and grade of material).
So before giving up on the machine-turned hollow-point-spitzer-style hunting bullet I'll investigate having a parabolic-shaped drill bit made for boring the hollow point. I'll also try reducing the number of petals by using a phillips broach instead of a hex broach. If the V2 prototypes still have their tips shear I'll throw in the towel on the spitzer style hunting bullet just make the solids for use on my lead free range.
I have enough gelatin left over that I can also do some testing of the flat-metplate design....so when spinning up V2 of the hollow points we'll also run some "dangerous-game" style solids in the 155gr and 168gr range. Will report back in 6 to 12 weeks or so!
Hope the holiday season is treating you guys well!
Cheers,
Brobee
The ballistic gelatin arrived just before christmas; I spent the past few days making jello and managed to get out to the range to shoot some this morning. Results were dissapointing (yet very interesting). We fired a total of three rounds into the gelatin and all recovered projectiles look about the same. I neglected to take the camera to the range and was dissapointed enough that I tossed the gelatin on the way home, so I apologize for their not being any backlit photographs of the gelatin.
Observations:
- petals shear early (within 1 inch of gelatin penetration)
- petals shear along broach lines and continue to tear to total cavity depth
- petals then tear/fracture off the bullet shank, the tear initiating exactly at the corner created by the tip of the dril bit used to bore the hollow point - strangely the 6 petals tear off somehat asymetcially in time which then causes the bullet to deflect/deviate off original trajectory. Both the petal shedding and deflection is BAD. The fracture evidence is interesting - I suspect this is related to the tellurium addition and resulting alloy properties - I'm speculating that chipping charracteristics desirable in machining are somewhat contradictory to desirable plasticity/elasticity of material required for good peeling hollow point bullet charracteristics. More thoughts on this in a bit.
- what's left after the petals shear off mushroom slightly...encouraging that there is some material plasticity and the basis for the flat metplate dangerous game style design I'm going to try as a part of the next batch we're getting set to run.
- fouling bands are of sufficient depth
- decent, but not ideal engagement of driving bands. Rifling scoring is not really deep. Sufficient for good spin stability though as gelatin showed good rotational stretch cavity tearing which could only be caused by spinning projectile. Also, projectile is accurate at extended range which could only happen if it was sufficiently stabilitzed.
- some lateral displacement of rifling-diplaced material - suggests that the projectile is slightly undersized to the bore of this specific test gun. Not a show-stopper, as velocity is on par with other projectiles I've tested from same gun with same propellant quantity/projectile weight. Also, I'd be scared to make the bullets with an OD any larger than .308! The 150gr barnes bullet we also tested for control/comparison exhibited the same phenomenon on it's driving bands.
- no ill effects observed at all relating to rebated boat tail.
- little bits of blue plastic visible on leading edge of bullet are from the blue tarp I had placed underneath the gelatin block. The bullets all deflected sufficiently that they exited the second block (blocks were 9"x9"x18", two placed end on end for a total of 32 inches of potential penetration witness capability)
- deflection did not start until approximately 14 inches of penatration.
- two of the three bullets exited the side of the gelatin blocks after approximately 22 inches of penetration. The third was recovered, but only because it exited the bottom of the block and deflected off the table to then travel another 4 inches inside the gelatin.
- temporary stretch cavity, while massive, was not as developped or as long as one produced by a 150gr barnes ### we used for control/comparision.
So while very interesting, as one of my initial goals was 100% weight retention and little-to-no deflection in homogeneous media, the projectile tested gets an F grade and is not something I will be producing commercially in it's current design.
Regarding the tearing of the petals....the copper/tellurium alloy was chosen as a material primarily because of it's machining charracteristics. From what I understand, pure copper does not machine very well and gets pushed around by the cutting tools something analagous to slightly warm butter sticking to your butter knife. By alloying the copper with trace amounts of tellurium the ductility of the copper is changed such that it now chips sufficiently to be machinable.
While an expanding-hollow-point-spitzer style bullet made by precision high speed machining (as compared to swaging) might be an un-solvable problem relating to the copper/tellurium alloy's malleability properties, it got me thinking about one of the disciplines in my oilpatch work world : pressure vessel design. Flat caps to a cylindrical pressure vessel concentrate force at the intersection between the cylinder and the cap - when over-pressured the material will fail right at the corner - typically where the cap was welded onto the cylinder. Proper pressure vessel construction utilizes parabolic shaped caps on the end of the vessel cylinder. These distribute the force evenly and longitudionally down the pressure vessel body. Consequently this type of pressure vessel design can withstand several times more pressure than one built by welding a steel plate to the end of a cylinder (with both vessels being made from the same thickness and grade of material).
So before giving up on the machine-turned hollow-point-spitzer-style hunting bullet I'll investigate having a parabolic-shaped drill bit made for boring the hollow point. I'll also try reducing the number of petals by using a phillips broach instead of a hex broach. If the V2 prototypes still have their tips shear I'll throw in the towel on the spitzer style hunting bullet just make the solids for use on my lead free range.
I have enough gelatin left over that I can also do some testing of the flat-metplate design....so when spinning up V2 of the hollow points we'll also run some "dangerous-game" style solids in the 155gr and 168gr range. Will report back in 6 to 12 weeks or so!
Hope the holiday season is treating you guys well!
Cheers,
Brobee
That was the first thing I thought of too. Cut them in a full hard state to take advantage of the cutting properties of the work hardened rod, then anneal them to soft to see if you can get the peelback you need rather than breaking.
You chucked you gelatin? I thought that the stuff was reusable? Not the stuff you got? I've seen repeated written articles where the author heated the gel to molten again, then re-cast it for re-use.
Cheers
Trev
You chucked you gelatin? I thought that the stuff was reusable? Not the stuff you got? I've seen repeated written articles where the author heated the gel to molten again, then re-cast it for re-use.
Cheers
Trev
bcsteve & trevj - I will definately do some learning with respect to annealing....maybe even look for a material lab that has the ability to measure ductility.malleability charracteristics & hardness with some degree of scientific rigor other than my basic garage tests where I simply drop a heavy steel bar from a known height onto the bullet which is sitting in a steel block with a .310 hole deep enough to swallow 2/3 of the shank. When doing this simple test I can detect no difference in the deformation/plasticity charracteristics between the machine turned bullets and the variety of barnes solid copper bullets I have on hand; admittedly it is crude test so I'll look for a place to step it up a notch as well as do some research regarding annealing temperatures/atmospheres/soak times. My main worry about annealing is that at temperatures hot enough to change the chrystalline structure of the metal there might be some small amount of shape deformation which could possibly defeat the uniformity benefits of machining them rather than swaging them.
trevj - chucking gelatin - I do have a protocol for cubing up, gently melting down (via double-boiler), and then re-casting the gelatin however it is very time intensive and majorly stinks up the kitchen when I do it (not to mention the rest of the house). Consequently, She-Who-Must-Be-Obeyed has outlawed the process. Additionally, previous testing I've done and gone public with that used the re-use protocol has received significant critisim from various professionals in the terminal ballistics community. Lastly, even though I'm using a pretty serious mold inhibitor, it's unlikely the gelatin would remain mold free for the probable 12 weeks (or more) it will take me to get the V2 projectiles spun up and ready for testing.
broncoo - ball mill - excellent idea and something I will pursue if unable to get a custom parabolic shaped cutter made.
Brobee
trevj - chucking gelatin - I do have a protocol for cubing up, gently melting down (via double-boiler), and then re-casting the gelatin however it is very time intensive and majorly stinks up the kitchen when I do it (not to mention the rest of the house). Consequently, She-Who-Must-Be-Obeyed has outlawed the process. Additionally, previous testing I've done and gone public with that used the re-use protocol has received significant critisim from various professionals in the terminal ballistics community. Lastly, even though I'm using a pretty serious mold inhibitor, it's unlikely the gelatin would remain mold free for the probable 12 weeks (or more) it will take me to get the V2 projectiles spun up and ready for testing.
broncoo - ball mill - excellent idea and something I will pursue if unable to get a custom parabolic shaped cutter made.
Brobee
Have you look at the bullet test tube? http://www.thebullettesttube.com/ Not that expensive and maybe worth for you if you want to look a wound caracteristics. Way easier to melt and re-cast, may even past the test of She-Who-Must-Be-Obeyed. 
Jordan Smith
CGN Ultra frequent flyer
- Location
- Calgary, AB
Shearing the petals off is a good thing in regards to killing power. I think many people would be drawn to your bullets if they penetrated like a Barnes TSX, but killed and fragmented a little bit more like an Accubond. If you could anneal the alloy a little bit so that the petals didn't shear off until after 6" or so of penetration, that would be ideal. Then you would have copper fragments doing the killing, and the flat meplat "solid" doing some serious penetrating. It would also probably penetrate in a straighter line after annealing, due to consistent ductility, and therefore more consistent petal shearing.
Very interesting testing!
Very interesting testing!
Well, I can understand the point about the missus, but can't for the life of me figure out why some good old fashioned cut and try testing shouldn't be in order for the remainder of your batch of bullets.
I'd be looking up the full anneal temperatures and grabbing some Temp Stick Crayons and doing some heat treating with a propane torch to start out. It'd be far more brutal on the bullets as far as heat stressing them too, so you would be able to see if there was any movement, under worst case conditions. If there was no movement to measure, then a proper oven anneal should be safe enough, though it also would be worth trying.
But I'd run a straight comparison to start, using a torch to anneal (simple heat to beyond what the anneal temp was) and see if it made a difference in how the bullet behaved.
If it acts the same, you may be looking for a different alloy, or sticking to the target shooting market with this one, but to know soon is to move forward soon.
The professionals in the terminal ballistics community apparently have someone else paying their bills. For your needs, for now, I would say that being able to test new ideas fairly rapidly in a more or less standardized medium trumps the requirement to have perfect test medium every time. That's just me though. I'd be too hot to try a few different ideas quickly, to see if they were dead ends, to wait 12 weeks to do it!
Time to get a hot plate or other means to melt your jello down for reuse outside the kitchen. Maybe a water bath system with an electric water heater element.
Keep us posted!
Cheers
Trev
I'd be looking up the full anneal temperatures and grabbing some Temp Stick Crayons and doing some heat treating with a propane torch to start out. It'd be far more brutal on the bullets as far as heat stressing them too, so you would be able to see if there was any movement, under worst case conditions. If there was no movement to measure, then a proper oven anneal should be safe enough, though it also would be worth trying.
But I'd run a straight comparison to start, using a torch to anneal (simple heat to beyond what the anneal temp was) and see if it made a difference in how the bullet behaved.
If it acts the same, you may be looking for a different alloy, or sticking to the target shooting market with this one, but to know soon is to move forward soon.
The professionals in the terminal ballistics community apparently have someone else paying their bills. For your needs, for now, I would say that being able to test new ideas fairly rapidly in a more or less standardized medium trumps the requirement to have perfect test medium every time. That's just me though. I'd be too hot to try a few different ideas quickly, to see if they were dead ends, to wait 12 weeks to do it!
Time to get a hot plate or other means to melt your jello down for reuse outside the kitchen. Maybe a water bath system with an electric water heater element.
Keep us posted!
Cheers
Trev
Actually fractured petals might not be a bad thing if you can keep the main bullet body traveling straight..
Take a look at this thread starting with: michael458's post 24 Nov. 12:00
http://forums.accuratereloading.com/eve/forums/a/tpc/f/4711043/m/2861098911/p/6
Take a look at this thread starting with: michael458's post 24 Nov. 12:00
http://forums.accuratereloading.com/eve/forums/a/tpc/f/4711043/m/2861098911/p/6
Ok...so I now seriously regret tossing the gelatin. I will make up some more and go testing again after new years with the goal of more carefully documenting (with photographs and a bias towards recovering all the fragments).
What's also interesting is the developing discission on whether or not petal detachment is a bad thing or not. I went and made a post in the hunting section to try and solicit some opinion here, so if you guys would be so kind as to go participate over there I'd be really grateful.
http://www.canadiangunnutz.com/forum/showthread.php?t=421610
As I've progressed through my north american game hunting carreer I'm been gravitating more and more towards the camp that 100% weight retention and deep/straight penetration are more desirable than fragmentation, but that's been primarily an opinion based on stark contrasts such as the nosler 155gr ballistic tip vs the barnes 150gr tsx.
trevj - where would I get the heat crayons you mention? I will do as you suggest and take the torch to a couple.
Cheers,
Brobee
What's also interesting is the developing discission on whether or not petal detachment is a bad thing or not. I went and made a post in the hunting section to try and solicit some opinion here, so if you guys would be so kind as to go participate over there I'd be really grateful.
http://www.canadiangunnutz.com/forum/showthread.php?t=421610
As I've progressed through my north american game hunting carreer I'm been gravitating more and more towards the camp that 100% weight retention and deep/straight penetration are more desirable than fragmentation, but that's been primarily an opinion based on stark contrasts such as the nosler 155gr ballistic tip vs the barnes 150gr tsx.
trevj - where would I get the heat crayons you mention? I will do as you suggest and take the torch to a couple.
Cheers,
Brobee
Heat crayons.
Welding supply or industrial supply places. Acklands, etc.
http://www.tempil.com/closeup.asp?pid=185&cid=22&theme=2
Full kit is near $200, but if you figure out what temps you need, you should be able to buy them individually.
You in Canada, or on the US side of the line? In Canada look at the Princess Auto multimeter with temperature reading, Same one or close enough, is available from Harbour Freight. Reads degrees C with a K type thermocouple. If creatively used, it will give you a reasonably accurate temperature readout of a oven. A useable oven does not have to be fancy either. A toaster oven, some ceramic fiber insulation (optional), and if you want, drill a hole into it and feed it a slow trickle of welding shield gas for a non oxidizing environment, and you can be in business well enough to try out various temperatures. A controller equipped heat treat oven would be better, but they are stupid expensive for what you get, given that there is under $200 in materials to make a decent one.
Cheers
Trev
Welding supply or industrial supply places. Acklands, etc.
http://www.tempil.com/closeup.asp?pid=185&cid=22&theme=2
Full kit is near $200, but if you figure out what temps you need, you should be able to buy them individually.
You in Canada, or on the US side of the line? In Canada look at the Princess Auto multimeter with temperature reading, Same one or close enough, is available from Harbour Freight. Reads degrees C with a K type thermocouple. If creatively used, it will give you a reasonably accurate temperature readout of a oven. A useable oven does not have to be fancy either. A toaster oven, some ceramic fiber insulation (optional), and if you want, drill a hole into it and feed it a slow trickle of welding shield gas for a non oxidizing environment, and you can be in business well enough to try out various temperatures. A controller equipped heat treat oven would be better, but they are stupid expensive for what you get, given that there is under $200 in materials to make a decent one.
Cheers
Trev
notsorichguy
CGN Ultra frequent flyer
- Location
- The city that rhymes with fun
Brobee:
If you are looking for 'testers' who are willing to pay for the bullets they 'test'.....
I know a guy who is very interested in doing some testing for you.......
Great thread btw. I hope this works out.... I would definatly support a Canadian Bullet manufacturer.
Cheers!
If you are looking for 'testers' who are willing to pay for the bullets they 'test'.....
I know a guy who is very interested in doing some testing for you.......
Great thread btw. I hope this works out.... I would definatly support a Canadian Bullet manufacturer.
Cheers!
Getting ready to go re-test the projectiles in ballistic gelatin with an eye to way more thorough documentation, I've spent the past few days making gelatin and should have enough blocks for another test on Sunday...woohoo!
As per your guy's suggestions, I also been trying to learn as much as I can about annealing, and figured that in the spirit of trevj's posts I'd go for the quick and dirty crude test with the 'ol torch in the garage. The material data sheets indicate the annealing temperatures are between 425 to 650 degrees C...I don't know what happens if you heat beyond the 650 C or what kind of soaking time is required, but figured "what the heck!" and put the torch to a small batch.
I also had the camera out in the garage with me to take some photographs; they turned out to look quite intesting so I though I'd post some to share:
my 9x9x18 stainless steel gelatin mold I had made by a local tig welding artist. He did it several years ago the evening before new years, and he only let me pay him with a case of beer. It was the best deal ever!
If it turns out the annealing has a favorable effect and the machine shop costs come back relatively reasonable, my plan would be to get a pottery kiln (that's what I'll tell the wife it is! I just better make sure it works for clay too...) with a fancy-shmancy temperature controller, mildly modify the works for the addition of purge gas, and then try to sweettalk the Missus into making me a bunch of ceramic holders for standing up a thousand or two at a time.
Anyway...seems like I'm getting way ahead of myself! Back to the most immediate plan: I've got a flourescent light box all built and ready to backlight the gelatin after testing on Sunday evening. My plan is to test two of the non-annealed and two of the annealed (total of 6 blocks of gelatin - each shot consumes a block and a half...what a pain!). Will post photgraphs once I've got them...
Cheers, and Happy New Year!
Brobee
As per your guy's suggestions, I also been trying to learn as much as I can about annealing, and figured that in the spirit of trevj's posts I'd go for the quick and dirty crude test with the 'ol torch in the garage. The material data sheets indicate the annealing temperatures are between 425 to 650 degrees C...I don't know what happens if you heat beyond the 650 C or what kind of soaking time is required, but figured "what the heck!" and put the torch to a small batch.
I also had the camera out in the garage with me to take some photographs; they turned out to look quite intesting so I though I'd post some to share:
my 9x9x18 stainless steel gelatin mold I had made by a local tig welding artist. He did it several years ago the evening before new years, and he only let me pay him with a case of beer. It was the best deal ever!
If it turns out the annealing has a favorable effect and the machine shop costs come back relatively reasonable, my plan would be to get a pottery kiln (that's what I'll tell the wife it is! I just better make sure it works for clay too...
) with a fancy-shmancy temperature controller, mildly modify the works for the addition of purge gas, and then try to sweettalk the Missus into making me a bunch of ceramic holders for standing up a thousand or two at a time.Anyway...seems like I'm getting way ahead of myself! Back to the most immediate plan: I've got a flourescent light box all built and ready to backlight the gelatin after testing on Sunday evening. My plan is to test two of the non-annealed and two of the annealed (total of 6 blocks of gelatin - each shot consumes a block and a half...what a pain!). Will post photgraphs once I've got them...
Cheers, and Happy New Year!
Brobee
