I purchased a Springfield National Match M1A, after researching the web I see everybody talks about reloading for them but theres a lot of talking without saying anything. All I need to know is what is the starting load for 168 SMK with Varget and RL15 in commercial cases.
Whats the deal with loading for an M1A?
- Thread starter startrek
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Re: Whats the deal with loading for an M1A?
http://radomski.us/njhp/cart_tech.htm
has varget but not RL15
http://radomski.us/njhp/cart_tech.htm
has varget but not RL15
Re: Whats the deal with loading for an M1A?
Well,
There is alot of info on reloading for the M1a, but alot of it is for the 4064 and 4895 powders.
The reason for that is that the M1a/M14 is gas operated via an op rod. The pressure profile for the m14 is pretty specific and no one should use a powder any slower than 4064 without possibly damaging the op rod. From what I have read it is more of a problem on the M1 Garand, but I don't deviate from the 4064 for loading for my M1a.
Here is another post regarding this topic.
http://www.snipershide.com/forum/ubbthre...513#Post1849513
Looking at burn rates, Varget looks like it would work, but Rel-15 is slower than 4064 and is not advised.
Hope that helps,
madd0c
Well,
There is alot of info on reloading for the M1a, but alot of it is for the 4064 and 4895 powders.
The reason for that is that the M1a/M14 is gas operated via an op rod. The pressure profile for the m14 is pretty specific and no one should use a powder any slower than 4064 without possibly damaging the op rod. From what I have read it is more of a problem on the M1 Garand, but I don't deviate from the 4064 for loading for my M1a.
Here is another post regarding this topic.
http://www.snipershide.com/forum/ubbthre...513#Post1849513
Looking at burn rates, Varget looks like it would work, but Rel-15 is slower than 4064 and is not advised.
Hope that helps,
madd0c
Re: Whats the deal with loading for an M1A?
What Mad said...the fact that it's a gas gun makes it a bit more picky about what one should shoot through it because of the specific pressures needed to make it run smoothly without doing damage in the long run. All gas guns are the same to a greater or lesser extent (I load for an HK 91 and an L1A1 as well), but the M1A seems to be a bit more picky. In my experience, 4895 is the way to go, and the 168 SMK will serve you well.
My 2 cents
What Mad said...the fact that it's a gas gun makes it a bit more picky about what one should shoot through it because of the specific pressures needed to make it run smoothly without doing damage in the long run. All gas guns are the same to a greater or lesser extent (I load for an HK 91 and an L1A1 as well), but the M1A seems to be a bit more picky. In my experience, 4895 is the way to go, and the 168 SMK will serve you well.
My 2 cents
Re: Whats the deal with loading for an M1A?
http://www.zediker.com/downloads/oncefired.pdf
http://www.zediker.com/downloads/m14.htm
These are some pretty good reads on the M1A.
http://www.zediker.com/downloads/oncefired.pdf
http://www.zediker.com/downloads/m14.htm
These are some pretty good reads on the M1A.
Re: Whats the deal with loading for an M1A?
I use only 4895 and 168 grain match Sierra or Hornady projos in my M1A match. Accurate and never had a single problem.
I use only 4895 and 168 grain match Sierra or Hornady projos in my M1A match. Accurate and never had a single problem.
Re: Whats the deal with loading for an M1A?
Slow burning powder (IMR4350 for example) will break op rods in the M1A. About 30 years ago I broke mine (cracked it), had it welded up and then cracked it again near the first crack. Then I read about slow burning powder issues in M1A's and gave up on getting the accuracy I was searching for.
Don't take the above to say an M1A can't be accurate. Accuracy is a relative thing. Mine does fine for its intended use but its not a Remington M700 Varmint Special.
Slow burning powder (IMR4350 for example) will break op rods in the M1A. About 30 years ago I broke mine (cracked it), had it welded up and then cracked it again near the first crack. Then I read about slow burning powder issues in M1A's and gave up on getting the accuracy I was searching for.
Don't take the above to say an M1A can't be accurate. Accuracy is a relative thing. Mine does fine for its intended use but its not a Remington M700 Varmint Special.
Re: Whats the deal with loading for an M1A?
Sierra suggests 42gr of RL 15 for the 168gr SMK HPBT bullet.
The critical key to making my M1A SuperMatch happy is to use a small base die- as with any semi-auto (in my opinion). Also make sure that your rounds are dead-on when it come to their overall length.
Just my $.02
J
Sierra suggests 42gr of RL 15 for the 168gr SMK HPBT bullet.
The critical key to making my M1A SuperMatch happy is to use a small base die- as with any semi-auto (in my opinion). Also make sure that your rounds are dead-on when it come to their overall length.
Just my $.02
J
Re: Whats the deal with loading for an M1A?
The M1A gas system is designed for a port pressure of 12,500 PSI, measured in CUP back in those days.
Tolerance is +/- 2,000 psi.
Bullet travel is about 12.5 inches to clear the gas port which is about 14-1/8 inches from the breechface.
Cross-referencing some (rare) published data which included both chamber pressure and port pressure on various reloads (I think it was the C.E. Harris 1983 article in American Rifleman), certain loads tested there, and my own current loads and QuickLOAD, they tend to agree on velocity, but pressures look a bit higher--until I remember that QuickLOAD predicts piezo transducer PSI, which often gives a higher NUMBER.
There's no hard and fast correlation or curve to match or formula to "convert" between CUP and piezo PSI, but in .308 using bullets from 150 to 190 grains, it *appears* that QuickLOAD's PSI figures on port pressure are about 1,800 or so higher on the number than the CUP number for identical loads.
Powders no slower than 4064 or Varget peak chamber pressure for every load I've looked at BEFORE the port pressure gets out of hand. I'll have to re-examine RE-15. I tested a great load with that and 175 SMKs, but thought the port pressure was too high based on the predictions. That was when I was not doing any loads more than 14,000 PSI predicted port pressure per QuickLOAD, before I compared with other known data (all using LC cases, BTW).
I've also had three dies and two barrels and NEVER any need to use a small base die.
The M1A gas system is designed for a port pressure of 12,500 PSI, measured in CUP back in those days.
Tolerance is +/- 2,000 psi.
Bullet travel is about 12.5 inches to clear the gas port which is about 14-1/8 inches from the breechface.
Cross-referencing some (rare) published data which included both chamber pressure and port pressure on various reloads (I think it was the C.E. Harris 1983 article in American Rifleman), certain loads tested there, and my own current loads and QuickLOAD, they tend to agree on velocity, but pressures look a bit higher--until I remember that QuickLOAD predicts piezo transducer PSI, which often gives a higher NUMBER.
There's no hard and fast correlation or curve to match or formula to "convert" between CUP and piezo PSI, but in .308 using bullets from 150 to 190 grains, it *appears* that QuickLOAD's PSI figures on port pressure are about 1,800 or so higher on the number than the CUP number for identical loads.
Powders no slower than 4064 or Varget peak chamber pressure for every load I've looked at BEFORE the port pressure gets out of hand. I'll have to re-examine RE-15. I tested a great load with that and 175 SMKs, but thought the port pressure was too high based on the predictions. That was when I was not doing any loads more than 14,000 PSI predicted port pressure per QuickLOAD, before I compared with other known data (all using LC cases, BTW).
I've also had three dies and two barrels and NEVER any need to use a small base die.
Re: Whats the deal with loading for an M1A?
As mentioned, powder selection is one element that has to be right.
You might want to obtain measuring tools for case diameter and headspace, two more important elements with the M1A. Last thing you want to do is press the trigger on a round that's only 95% into the chamber. Results of that event are impressive.
If you adjust your size die to provide 0.0015 to 0.002 headspace AND check the case diameter just above the web, you might not ever need a small base die, and brass life will be greatly extended. I have one RCBS Jr. press with a size die locked firmly in place just to size for the Supermatch chamber and nothing else.
I run 175 matchkings in mine with H4895 at 2550fps with zero issues, and also run them with Varget at 2600 for 1000 yard shooting, again with no issues WITH the caveat that I employ a Schuster adjustable relief valve to manage op rod speed, which has the secondary benefit of reducing brass stretch by significantly slowing action cycle speed.
All in all, the M1A just requires that you think about what you're doing, which you should be doing anyway, right?
As mentioned, powder selection is one element that has to be right.
You might want to obtain measuring tools for case diameter and headspace, two more important elements with the M1A. Last thing you want to do is press the trigger on a round that's only 95% into the chamber. Results of that event are impressive.
If you adjust your size die to provide 0.0015 to 0.002 headspace AND check the case diameter just above the web, you might not ever need a small base die, and brass life will be greatly extended. I have one RCBS Jr. press with a size die locked firmly in place just to size for the Supermatch chamber and nothing else.
I run 175 matchkings in mine with H4895 at 2550fps with zero issues, and also run them with Varget at 2600 for 1000 yard shooting, again with no issues WITH the caveat that I employ a Schuster adjustable relief valve to manage op rod speed, which has the secondary benefit of reducing brass stretch by significantly slowing action cycle speed.
All in all, the M1A just requires that you think about what you're doing, which you should be doing anyway, right?
