- Location
- Jameson, SK
Reverse osmosis. It's a thing from 10 years ago.
Lapua brass. Prep???
- Thread starter Brianma65
- Start date
Reverse osmosis. It's a thing from 10 years ago.
- Location
- Jameson, SK
A guy says he finds beer disgusting, as i post, from my brewery!!! F-Ing hell!!!
Ron - you have more to offer than you realize, or let on. A common sense, unbiased approach is sometimes what a world filled with rhetoric needs....
I think the expander mandrels are common between 21st and KM, so you should be able to get either TiNi and slot them in - I THINK. Call before you buy.
I royal lube when I FL resize the shoulder, neck, and body, and expand the neck prior to turning, but that's it.
It's a metallurgic dry hump from then on......
Ron - you have more to offer than you realize, or let on. A common sense, unbiased approach is sometimes what a world filled with rhetoric needs....
I think the expander mandrels are common between 21st and KM, so you should be able to get either TiNi and slot them in - I THINK. Call before you buy.
I royal lube when I FL resize the shoulder, neck, and body, and expand the neck prior to turning, but that's it.
It's a metallurgic dry hump from then on......
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Lapua 260Rem has a tight neck, run it through the E26 expander with powder lube, that's it. Pretty sure Lapua drill the flash hole instead of punching so leave that alone.
If I was going to going through the 10 (or is that 11) case prep steps no point paying premium for Lapua.
PS. WTF is a small group? Is that 1/2, 1/4, 1/8 MOA?
PS2. Case preping sucks.
PS3. Like MP's method of prep, esp. COW method to "not strain the web area...".
If I was going to going through the 10 (or is that 11) case prep steps no point paying premium for Lapua.
PS. WTF is a small group? Is that 1/2, 1/4, 1/8 MOA?
PS2. Case preping sucks.
PS3. Like MP's method of prep, esp. COW method to "not strain the web area...".
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
The question was thin necks in a large chamber... lead to bad things... my answer, doesn't do anything except maybe lead to neck splits if necks get brittle (anneal the necks and you will be amazed at how much stretch it has). Bullet is well down the bore before the neck expands to ID 1 thou larger then the bullet diameter.
How much energy does it take to seat that bullet? I bet the pressure from all that burning powder is a wee bit more. We know the force of a primer can and does move a bullet forward.
So I think we have beat the neck turning thing to death.. for those that want to do the work, and all the other steps, it can be a very positive thing. For those, that don't want to bother... the bullet will leave the muzzle too.
Problem with 1 bullet over another may have nothing to do with bullet weight but how that weight is distributed in the bullet shape. Bearing surface vs ogive. If you have a long throat and the bullet cannot fully engrave into the bearing surface before the bearing surface leaves the case neck, accuracy will suck.
You are correct that without proper support for both ends of the bullet, it will be pushed into the rifling cockeyed and that is not good for accuracy. By definition, this is what a worn out barrel wrt to throat means.
So let's reverse your concern.. you shoot 62's and the barrel is no longer working. Moving to the 68's just got you a "new" barrel. Shooters can extend the life of the barrel by chasing the lands with OAL and/or switching to a heavier bullet.. assuming the twist is fast enough to work with the heavier bullets.
All those 308 shooters using 10 twist can now stand up and cheer... from 155 to 210's, you can chase the throat close to 1/2". Now if the rifling doesn't break off the barrel, you can indeed retain very good accuracy until the heaviest bullet for your twist no longer has any throat to engage into.
WRT to runout, if all the steps are taken to prep and assemble the ammo using properly formed and sized cases, the odds of runout is slim to nil. AND measuring on a proper runout gauge is relevent to the runout wrt to the bore... unless you have a chamber that is not aligned with the bore and then you have bigger problems.
Many, and I do mean many, bullets are very tolerant of runout and still shoot accurately. we all want near zero runout but I have competed with ammo around 5 thou without any loss in score or X count out to 1000yds. More can cause issues but then you really haven't paid much attention to the steps to make the ammo in the first place... or the ammo box gets banged around way too much.
If all the proper steps are done to assemble the ammo for a properly built rifle, the bullet bore axis WILL BE ALIGNED with the boreline of the barrel. Even from a mag fed rifle, the bullet should still be plenty straight to get the job done....and if not, fix the rifle.
I know many jam and if that works for you or the bullet, by all means. it works. Some match shooters use a soft jam and will literally set that OAL based on the throat of the rifle. The only problem is if you have a cease fire and have to extract that rd.... yeah, that can get messy.
I have found that EVERY match bullet shape used today can be set OFF the lands and work superbly.. it takes some fine tuning of OAL and powder charge... no different then if you went with a jam.
Sizing the entire neck length is up to the shooter and if less works for you, fly at it. BUT I may require the ammo to live a bumpy life so having all the support on the bullet bearing surface can be a very good thing... think mag fed ammo.. in a semi. Just be aware of case bulges that may restrict proper chambering.. it is risky and not ideal if your chamber can get dirty.
In F class and PRS type shooting, I fully expect my chambers to get very dirty... and wet. My case neck to chamber wall have plenty of room.
Guns still shoot just fine....
Jerry
- Location
- Jameson, SK
Lapua does drill not punch. Doesn't mean that there aren't any burrs.
A small group is smaller than anyone else you know has ever shot. If you hang out with a bunch of gang-bangers, sub 20MOA. If you have regular, respectful conversations with Jerry, Jefferson, Yodave, Bsand, skypilot, furtaker, biged, Ron, Tomochan, etc, etc then under 1/2MOA had better be your norm.
Case prepping does suck, but like anything high-end in life, shooting is 90% planning, prep, and mentation. Squeezing the trigger is just the icing.
Case prep is a situation where the returns diminish more and more with the work that you do. In many cases 1/2moa is achieved with virtually no special case prep other than proper sizing, trimming cases when required, and chamfering case mouths. The extra work like deburring flash holes and turning necks, usually improves accuracy by so little that you have to look hard to notice it.
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I suspect that most jams over 0.005" do exactly that. They really don't jam 0.010 or 0.020". They slide back in the neck. Consider also that neck tension is not always what you might think it is. Brass yields at about 0.001" interference in the neck, and while more than that makes you feel good, you are not really adding much real tension because the extra interference is just causing more yielding, with not much extra tension. For example going from a target load 0.001" interference to a hunting load 0.003" interference will not give you three times the neck holding force. It might give you 30% more or so. The point is that those who think they are holding the bullet in the neck while jamming with extra interference, probably are not really. The bullet still slides back.
The issue with this jam theory is that some bullets don't shoot with a jam. You can dream up all the theory that you want, but the target is the truth teller in the end. I have not used them, but I gather Berger VLD's like a jump, and sometimes a fairly large jump. They however are quite long bullets to start with, and perhaps are less susceptible to getting skewed in the bore off the hop.
My issue with neck turning in a factory SAAMI chamber is that it increases neck clearance. And if you combine that with full length resizing of the cartridge, and the complete neck, you have lost control of the back end of the cartridge. It flops around in the chamber, even if you jam the ogive of the bullet. I would not worry about neck cracking as the 0.001" or so that you may trim off a Lapua cartridge to make the thickness uniform is not going to change things much. It is still going to expand to chamber neck diameter every time you pull the trigger. If it cracked it would likely crack at the thin point anyway, and you are not taking much if any off that part.
Some will say that pro shooters FL size every case. Yes, some do, but in most cases those FL dies are not standard off the shelf dies. The neck is custom sized, and even the body may be sized based on the reamer used in their chamber. It is comparing apples to oranges when you compare the cartridges from those dies to ones formed in an off the shelf FL die. In these custom die and custom chambered guns the neck clearance can be as tight as 0.001 to 0.002". They don't flop around!
Jamming has issues and I know about them by finding out the hard way. But I have used Berger 80's, Berger 69's, Berger 68's, and Bart's Ultra 68's in my 6BR. I tested every one at various jumps and jams. All produced the smallest groups at 0.010" jam. Could be gun specific, but that is what the targets say. But, it has a factory CIP chamber. Those with the tight neck chamber and neck turned brass, may find the jump works better than a jam, as they have control of the bullet concentricity to the bore due to the tight neck, and don't have to rely on the bullet jam...
Just my thoughts!
Lapua refers to the manufacturing of flash holes as "piercing". There is a small amount of burrs inside the case which some remove. Some very top FClass users of Lapua brass take "high spots" off with neck turning and have customer chambers with dies made with same reamer.
Best regards,
Peter
Lapua in Canada
Best regards,
Peter
Lapua in Canada
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- Location
- Jameson, SK
......and those little improvement are what win competitions.......with anything in life.
GGG
Pretty sure you, me and the OP are not in that category so all that prep work is purely educational.
Exactly what I was getting at in asking WTF is small group.
Akin to "How do I get rich?" "Buy low, sell high"
You prove the point in that until one is specific on what is a small group and if it achievable by the firearm and shooter all this prep may simply be a waste of time. Folks need to be specific and measurable to determine if the goal is achievable or exercise in futility.
Exactly what I was getting at in asking WTF is small group.
Akin to "How do I get rich?" "Buy low, sell high"
You prove the point in that until one is specific on what is a small group and if it achievable by the firearm and shooter all this prep may simply be a waste of time. Folks need to be specific and measurable to determine if the goal is achievable or exercise in futility.
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
"What do you think?" "What is best?" " What should I build?" and one of my favorites "what is best for LR shooting?"... and on and on.
The internet and this forum is filled with extremely vague questions looking for very precise information. Until there is a specific question to solve specific goals/needs, discussion typically ends up in a choas of personal opinion mixed in with wild guessing. Everyone is "right", everyone is "wrong"... big waste of time and the person that asked the question is likely no further ahead.
Formulate a goal, budget and application FIRST... the parts are easy and process clear cause there is actually a destination.
If a small case doesn't move a bullet fast enough, use a larger case and burn more powder.
Elevated pressures that some use can lead to more problems they it solves. Speed is not everything... accuracy is.
YMMV
Jerry
The internet and this forum is filled with extremely vague questions looking for very precise information. Until there is a specific question to solve specific goals/needs, discussion typically ends up in a choas of personal opinion mixed in with wild guessing. Everyone is "right", everyone is "wrong"... big waste of time and the person that asked the question is likely no further ahead.
Formulate a goal, budget and application FIRST... the parts are easy and process clear cause there is actually a destination.
If a small case doesn't move a bullet fast enough, use a larger case and burn more powder.
Elevated pressures that some use can lead to more problems they it solves. Speed is not everything... accuracy is.
YMMV
Jerry
Yes Jerry, I know what your saying.
I'm just wondering how much velocity the 20 in barrel is gonna cost me.
Just curious is all.
I think I should be able to push the 123 scenars at about 2750 fps,without causing any over presure.
I've tryed a couple of ballistic apps,but they won't allow me to enter my barrel length.
I read about an experiment,where the guy kept cutting down his barrel,inch at a time.
Lost a little over 120 fps from 26 to 20.
How do you figure out when the bullit stops going supersonic?
I'm just wondering how much velocity the 20 in barrel is gonna cost me.
Just curious is all.
I think I should be able to push the 123 scenars at about 2750 fps,without causing any over presure.
I've tryed a couple of ballistic apps,but they won't allow me to enter my barrel length.
I read about an experiment,where the guy kept cutting down his barrel,inch at a time.
Lost a little over 120 fps from 26 to 20.
How do you figure out when the bullit stops going supersonic?
Brian, you should probably chrono your load. Then plug in that info to your ballistic software. It should tell you when that bullet will drop below supersonic. (With all of the inputs entered, of course.) Otherwise, all people are doing is guessing.
iSnipe will give you speeds over distances.
iSnipe will give you speeds over distances.
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You don't need to enter the length. After you get your speed, enter that with all of the other variables and fixed inputs. Set your distance (s), and get your chart. Easy.
Edit: sorry to join the off topic crowd. To the OP, I usually just neck size new Lapua brass. After that, brass prep is done as to what it calls for (calibre, times fired, etc.).
Edit: sorry to join the off topic crowd. To the OP, I usually just neck size new Lapua brass. After that, brass prep is done as to what it calls for (calibre, times fired, etc.).
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Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
There is no answer until you launch some lead. I have had 223 "short" barrels run as fast a long ones. no one will have any idea where the best load tuning will be for any barrel without testing. When you have your most accurate load, chronie it and that is the speed you live with.
Given target turrets on scopes and ballistic apps, initial muzzle velocity isn't all that important anymore. With a twirl of an elevation turrent, everything shoots flat
Build the load for accuracy, the speed will sort itself out... and it might be faster then you think
Jerry
