Long-range build caliber .284 Win (7mm)
- Thread starter Ruthless
- Start date
That is correct the trend is to use the smallest case that allows a full powder charge (to get to the desired velocities) with the least amount of air space ala 6PPC. It seems everyone is trying to make larger cases following the 6PPC as a base model. When i looked at the 7mm as a platform I looked at the 280 but shy'd away because it based on longer case. I have been reading too many PS articles and was concerned that ignition would not be as consistant as with the shorter fatter cases. That included looking at the old 7x61 Sharpe & Hart the original not the updated version.
The other case of interest was/is the 7mm SAUM it is more then capable of running with the 284 and had the added advantage of reaching 3000+ FPS
The interesting turn of events these past few months is the new powder reloader 17 there have been more then a few reports of people getting 3000FPS out of the 284 without any pressure signs and with the accuracy node being in the 3030 - 3070 range it will easily surpass the 6.5-284 ability to cut the wind.
The other case of interest was/is the 7mm SAUM it is more then capable of running with the 284 and had the added advantage of reaching 3000+ FPS
The interesting turn of events these past few months is the new powder reloader 17 there have been more then a few reports of people getting 3000FPS out of the 284 without any pressure signs and with the accuracy node being in the 3030 - 3070 range it will easily surpass the 6.5-284 ability to cut the wind.
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I think I understand this,
In my rifle the reamer was made from a sample 7mmWSM case, with a seated 180gn Berger VLD, hence with this custom reamer the delta L problem probably does not exist.
Presumably, if I understand this issue correctly, this problem can also be corrected r after fireforming to the chamber, and then neck sizing.
Am I correct?
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
The situation of small chamber and big brass is common to ANY min spec chamber and especially common in match rifles that have undersized chamber necks.
Since we reload, this becomes a non issue. I always match my sizing with the chamber. I treat any chamber as a wildcat and work up loads accordingly. If need be, I make a chamber cast just to ensure I know I have clearance when I pull that trigger.
Take a new piece of brass. Try and chamber it. If it doesn't go in, get out the sizing die and move things around until it does. Voila, problem bye bye.
If you ever decide to make a custom reamer, start by getting your sizing die. SIZE the brass and use this to work off.
Many dream up a reamer ($$$) then find there are no dies that work with it leaving 'custom' reamers the only solution ($$$$$).
Jerry
Since we reload, this becomes a non issue. I always match my sizing with the chamber. I treat any chamber as a wildcat and work up loads accordingly. If need be, I make a chamber cast just to ensure I know I have clearance when I pull that trigger.
Take a new piece of brass. Try and chamber it. If it doesn't go in, get out the sizing die and move things around until it does. Voila, problem bye bye.
If you ever decide to make a custom reamer, start by getting your sizing die. SIZE the brass and use this to work off.
Many dream up a reamer ($$$) then find there are no dies that work with it leaving 'custom' reamers the only solution ($$$$$).
Jerry
For the
vast majority of shooters that works. There is still nothing like a custom neck die that squeezes the entire case 2-3 thou all around when looking for that last little bit.
I have used Redding dies and they are OK until I got my custom sizing die. After it was seasoned by sizing cases with Imperial wax I can now size brass with no effort without any lube. I throw some lube on the first case after every relay and the rest go in dry.
vast majority of shooters that works. There is still nothing like a custom neck die that squeezes the entire case 2-3 thou all around when looking for that last little bit.
I have used Redding dies and they are OK until I got my custom sizing die. After it was seasoned by sizing cases with Imperial wax I can now size brass with no effort without any lube. I throw some lube on the first case after every relay and the rest go in dry.
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Since there was a mention of 'no pressure signs' with very high velocity, I just wanted newbies to understand this little statement...
There is no free lunch.
Not until more of the fancy new gen powders get released.
I did some research and found the following:
Lee Second Edition pg.363 284Win, 378 - 7RSAUM, 381 - 7WSM
useful case capacity: 284 - 3.97cc, 7 RSAUM - 4.67cc, 7 WSM - 5.02cc
With long seating bullets in the 284, might increase to say 4.1 to 4.2cc
We can also estimate that pressure/velocity tests are done in 24" barrels and most will gain up to 25fps per inch of barrel. 30" barrel can gain up to 150fps
H4831SC loads for 175gr bullets is: 7RSAUM 58gr max 2760fps at 62900psi. 7WSM 57.5gr max 2733fps at 63900psi This is also SAAMI Max pressure levels.
So we can estimate that in a 30" pipe, max velocity is around 2900fps.
Now we make this level of performance with a heavier 180gr long bearing surface bullet in a case that is 10 to 20% smaller 'with no pressure signs'.
Ummmm, makes you wonder. I would like to see a pressure test on these loads - no one seems to ever do a strain guage test.
I have cases from factory proof loads that show no outward signs of pressure. You can do a google on proof loads and see how this test protocol affects the lifespan of an action. Bottom line, it is not good for your actions to be running at these pressures levels especially in a large case/bolt face chambering.
My comment about a trend to the smallest case to do the job was not meant to be a positive thing. In fact, it is approaching dangerous levels. Modern zero tolerance custom actions are so well machined that scary high pressures are handled with pinky light bolt lift and no outward signs on the fired case.
That is helping many dive into and beyond proof pressure levels in search of ever increasing velocities from undersized cases. The use of small rifle primers enhances this too. Hopefully, no one gets hurt.
Now I am the first to support running at SAAMI magnum pressure levels because that is where modern extruded powders perform their best. Also, every component is stressed for this level of combustion. But when only super strong brass can withstand repeated firings, maybe the load is telling us something?
Why not just use a slightly larger case and eliminate any problems/risks?
OK, so much for all the 'sky is falling' rant. There is another more practical reason why toasty loads should be avoided - they can be very fussy over wide ambient conditions.
The 6PPC is a prime example of this. Ever wonder why ammo is loaded at the match?
For F class, loading ammo between matches is not always possible nor practical. The ammo you have must work whether the weather is hot or cold, dry or wet.
Running at the highest levels of pressures can lead to flyers if ambient conditions push your loads over the top. Worst yet, you can blow a primer and lock up your action. At best, you can't complete a relay and loose a match.
Quickload data of my 6.5 mystic loads shows I am in the 58,000 to 60,000psi range. Firmly into magnum pressure range. The loads shoots great, consistently and reliably from 0C to 35C.
This load is not the fastest I can extract from this case volume but it is the most reliable. I can get another 100fps with excellent accuracy. Brass life is poor and I wouldn't want this load to peak higher or other nasty things will happen.
YMMV....rant off.
Jerry
PS all the factory released data I have seen showed that re17 DID NOT provide anymore velocity out of typical cases and pressures. That is not to say you can't but.....
Yes, I will be getting my hands on some to test and see for myself.
There is no free lunch.
Not until more of the fancy new gen powders get released.
I did some research and found the following:
Lee Second Edition pg.363 284Win, 378 - 7RSAUM, 381 - 7WSM
useful case capacity: 284 - 3.97cc, 7 RSAUM - 4.67cc, 7 WSM - 5.02cc
With long seating bullets in the 284, might increase to say 4.1 to 4.2cc
We can also estimate that pressure/velocity tests are done in 24" barrels and most will gain up to 25fps per inch of barrel. 30" barrel can gain up to 150fps
H4831SC loads for 175gr bullets is: 7RSAUM 58gr max 2760fps at 62900psi. 7WSM 57.5gr max 2733fps at 63900psi This is also SAAMI Max pressure levels.
So we can estimate that in a 30" pipe, max velocity is around 2900fps.
Now we make this level of performance with a heavier 180gr long bearing surface bullet in a case that is 10 to 20% smaller 'with no pressure signs'.
Ummmm, makes you wonder. I would like to see a pressure test on these loads - no one seems to ever do a strain guage test.
I have cases from factory proof loads that show no outward signs of pressure. You can do a google on proof loads and see how this test protocol affects the lifespan of an action. Bottom line, it is not good for your actions to be running at these pressures levels especially in a large case/bolt face chambering.
My comment about a trend to the smallest case to do the job was not meant to be a positive thing. In fact, it is approaching dangerous levels. Modern zero tolerance custom actions are so well machined that scary high pressures are handled with pinky light bolt lift and no outward signs on the fired case.
That is helping many dive into and beyond proof pressure levels in search of ever increasing velocities from undersized cases. The use of small rifle primers enhances this too. Hopefully, no one gets hurt.
Now I am the first to support running at SAAMI magnum pressure levels because that is where modern extruded powders perform their best. Also, every component is stressed for this level of combustion. But when only super strong brass can withstand repeated firings, maybe the load is telling us something?
Why not just use a slightly larger case and eliminate any problems/risks?
OK, so much for all the 'sky is falling' rant. There is another more practical reason why toasty loads should be avoided - they can be very fussy over wide ambient conditions.
The 6PPC is a prime example of this. Ever wonder why ammo is loaded at the match?
For F class, loading ammo between matches is not always possible nor practical. The ammo you have must work whether the weather is hot or cold, dry or wet.
Running at the highest levels of pressures can lead to flyers if ambient conditions push your loads over the top. Worst yet, you can blow a primer and lock up your action. At best, you can't complete a relay and loose a match.
Quickload data of my 6.5 mystic loads shows I am in the 58,000 to 60,000psi range. Firmly into magnum pressure range. The loads shoots great, consistently and reliably from 0C to 35C.
This load is not the fastest I can extract from this case volume but it is the most reliable. I can get another 100fps with excellent accuracy. Brass life is poor and I wouldn't want this load to peak higher or other nasty things will happen.
YMMV....rant off.
Jerry
PS all the factory released data I have seen showed that re17 DID NOT provide anymore velocity out of typical cases and pressures. That is not to say you can't but.....
Yes, I will be getting my hands on some to test and see for myself.
Wow, I'm glad I'm a part of such a rich community, so much info for me to retain
As far as 7mm goes, I feel that I can take the beating of 25rds twise a day
, What Jerry wrote about the pressure does bring up a little concern with .284 Win. as I'm sure that most F-Class shooters run on a fine line of very High pressure with they .284's
I will start buying the parts in December will keep updating, for now will start with action and stock, so that caliber can be picked last
for now back to my .308 reloading process
(will be testing first loads this weekend with 155, 168 Scenars, 155 A-max, 155 Palma all over Varget at 200yrds)
As far as 7mm goes, I feel that I can take the beating of 25rds twise a day
, What Jerry wrote about the pressure does bring up a little concern with .284 Win. as I'm sure that most F-Class shooters run on a fine line of very High pressure with they .284's I will start buying the parts in December will keep updating, for now will start with action and stock, so that caliber can be picked last
for now back to my .308 reloading process
(will be testing first loads this weekend with 155, 168 Scenars, 155 A-max, 155 Palma all over Varget at 200yrds)
I think it was in about 1978 that Bob Hobbs decided the 284 would make a perfect long range round. I don't remember if I or Art Bourne chambered the rifle for him (I kind of think it was Art). In any case, it was nearly thirty years ahead of the current re-discovery of the cartridge.
At that time the best available bullets were the Hornady 162 and the Sierra 168. Using 4831, Bob was just able to approach around 2950 with the 162's. There were no signs of excessive pressures but the addition of one grain of powder blew the primer right out! The project was abandoned after some further testing as it just didn't meet expectations. At the same time, Art was shooting a 7x64 Improved (think 280AI) which would just reach 3000 fps with the same bullets IIRC.
A 284 with 180's has to kick about the same as a 30/06 with 180's. One would want to maximize rifle weight to make it comfortable to shoot. Regards, Bill.
At that time the best available bullets were the Hornady 162 and the Sierra 168. Using 4831, Bob was just able to approach around 2950 with the 162's. There were no signs of excessive pressures but the addition of one grain of powder blew the primer right out! The project was abandoned after some further testing as it just didn't meet expectations. At the same time, Art was shooting a 7x64 Improved (think 280AI) which would just reach 3000 fps with the same bullets IIRC.
A 284 with 180's has to kick about the same as a 30/06 with 180's. One would want to maximize rifle weight to make it comfortable to shoot. Regards, Bill.
Now this is so neat info
You guys were working on a round, while I wasn't even born yet
From all the test and results 7mm seems to be a potent round that I think will soon be discovered and then.....go try to find brass for it
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Most everything has been tried many times over BEFORE the 80's. Except for a few new cases like the WSM, every known case has been pushed and pulled in every conceivable direction with most done during the 50's and 60's.
I wonder how many reloaders have heard the term wildcatting?
In the hey days of PO Ackley, Gibbs and such, some really cool chamberings were invented. Some went on to become factory chamberings like the 22/250, 25-06, 300RUM, 7-08, 260, etc, etc, etc.
The new tech is in bullets and powders. New High bc bullets are allowing old case designs to become novel and hot. The 6.5X47L/Creedmore/XC and similar are based on wildcats developed during the 70's.
To continue on some of the craziness now being popularised, two of the scariest loads I have heard of lately are from F(TR) shooters.
One is pushing the 155gr bullet to 3150fps. The other is pushing the 210gr VLD's to 2700fps. All with 308's and 30" barrels.
Take a quick look through your reloading manual and try and find cases that will deliver this level of performance. I bet you will find them in cases a whole lot bigger and use ALOT more powder.
Yet still operate at magnum pressures.
Of course, neither load showed any pressure signs.....
Jerry
I wonder how many reloaders have heard the term wildcatting?
In the hey days of PO Ackley, Gibbs and such, some really cool chamberings were invented. Some went on to become factory chamberings like the 22/250, 25-06, 300RUM, 7-08, 260, etc, etc, etc.
The new tech is in bullets and powders. New High bc bullets are allowing old case designs to become novel and hot. The 6.5X47L/Creedmore/XC and similar are based on wildcats developed during the 70's.
To continue on some of the craziness now being popularised, two of the scariest loads I have heard of lately are from F(TR) shooters.
One is pushing the 155gr bullet to 3150fps. The other is pushing the 210gr VLD's to 2700fps. All with 308's and 30" barrels.
Take a quick look through your reloading manual and try and find cases that will deliver this level of performance. I bet you will find them in cases a whole lot bigger and use ALOT more powder.
Yet still operate at magnum pressures.
Of course, neither load showed any pressure signs.....
Jerry
That's my favourite, since I keep sneaking around forums looking for load for my 10FP .308 and some people post very high load for 155gr with 47gr+ Varget and no pressure signs
