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Maybe not reloading, but ammo related.
- Thread starter P5 Guy
- Start date
I have no direct knowledge of this situation, although I shoot a Garand in .30-06 and am familiar with the powder restrictions. Similar cartridges and operating pressures; I suspect the same caveats about powders (aka a narrow acceptable range of burning rates) applies here as well.
When the US Navy and Army ordered a bunch of 7.62 NATO chamberd Garand barrels from Springfield Armory in MA, they all came with the following gas port sizes (.30-06 one's listed for comparison):
30-06 Garand - .0790" +.0015"
Original 7.62 Garand - .0790" +.0015" (same as .30-06)
The shops rebuilding 30 caliber M1's to 7.62 NATO quickly learned the port pressure of a 7.62 NATO round was lower than that of the .30-06. So they experimented with larger sizes. Here's what they ended up using:
7.62 Army M1 - .1050" +.0015"
7.62 Navy M1 - .1065" +.0015"
I've watched the 'smiths at the USN unit drill out gas ports in the 7.62 chambered SA barrels they were fitting to Garands.
Yes, one must not use too slow a powder in properly ported 7.62 Garand barrels. The USN and USAF rifle teams used 44 grains of IMR4320 under Sierra 190's in their 7.62 Garands for a long range load. It had the upper limit of port pressure. Op rods had to be perfectly shaped and fit to withstand the shock from the gas cylinder for such loads. And folks shooting that load could easily hear the difference in sounds of the metal parts slamming around when the M1 cycled.
Some folks used IMR4320 under 180-gr. Sierra match bullets in their .30-06 M1 rifles without a hitch, but their op rods had to be the same as those used on 7.62 ones. Very few 'smiths had the skills and knowledge to do them right so they would last for the lives of several barrels.
Unless your Garand's op rod was shaped and fit by one of 3 or 4 folks still around to do it right, I would use no powder slower than IMR4064. If the op rod was fit by one of these few, no powder slower than IMR4320.
30-06 Garand - .0790" +.0015"
Original 7.62 Garand - .0790" +.0015" (same as .30-06)
The shops rebuilding 30 caliber M1's to 7.62 NATO quickly learned the port pressure of a 7.62 NATO round was lower than that of the .30-06. So they experimented with larger sizes. Here's what they ended up using:
7.62 Army M1 - .1050" +.0015"
7.62 Navy M1 - .1065" +.0015"
I've watched the 'smiths at the USN unit drill out gas ports in the 7.62 chambered SA barrels they were fitting to Garands.
Yes, one must not use too slow a powder in properly ported 7.62 Garand barrels. The USN and USAF rifle teams used 44 grains of IMR4320 under Sierra 190's in their 7.62 Garands for a long range load. It had the upper limit of port pressure. Op rods had to be perfectly shaped and fit to withstand the shock from the gas cylinder for such loads. And folks shooting that load could easily hear the difference in sounds of the metal parts slamming around when the M1 cycled.
Some folks used IMR4320 under 180-gr. Sierra match bullets in their .30-06 M1 rifles without a hitch, but their op rods had to be the same as those used on 7.62 ones. Very few 'smiths had the skills and knowledge to do them right so they would last for the lives of several barrels.
Unless your Garand's op rod was shaped and fit by one of 3 or 4 folks still around to do it right, I would use no powder slower than IMR4064. If the op rod was fit by one of these few, no powder slower than IMR4320.
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Do the same restrictions apply using a commercial hunting round in the M1 Rifle chambered in .308 Winchester?
I'm asking for a friend that does not handload. From what you say I'm going to caution him to not take his M1 hunting
Look for 165gr bullets with a velocity between 2550 and 2650 fps, or 150gr bullets between 2650 and 2750 fps. It doesn't tell you what the powder used is, but most of the problems with commercial hunting ammo in M1A/M1 have ballistics outside of the M118/M852/M80 ball ballistic range.
It isn't a guarantee, but it is where I would start. For me, I'd drop 165gr Hornady BTSP over 42gr of IMR4064 in LC brass with a #34 primer. I know that isn't an option for your friend, but it might be in the future.
Jimro
Wow, what an eye-opener.
Factors like this are among the reasons why my desire for a self-loader is practically nonexistent, whatever the legalities. But I'm starting to understand now why Hornady's reloading manual has separate entries for service rifle loads in 5.56, 7.62 and .30-06 that are separate from the .223 Remington, .308 and "standard" .30-06 entries!!
Factors like this are among the reasons why my desire for a self-loader is practically nonexistent, whatever the legalities. But I'm starting to understand now why Hornady's reloading manual has separate entries for service rifle loads in 5.56, 7.62 and .30-06 that are separate from the .223 Remington, .308 and "standard" .30-06 entries!!
Jimro says most of the problems with commercial hunting ammo in M1A/M1 have ballistics outside of the M118/M852/M80 ball ballistic range.
I don't know what his reference is for M118/M852/M80 ammo ballistic range is. Having shot commercial ammo, both hunting and match types, from 7.62 NATO M1's and M1A's noting its trajectory for bullets in the 150 to 180 grain range matched what the government ammo produced through 600 yards. Remington's .308 Win. match ammo with their 168-gr. bullet had the same charge weight of IMR4895 as did their 165-gr. hunting ammo as confirmed by a Remington field rep. And Lake City Arsenal's M118 and M852 ammo had IMR4895 powder charges within a couple tenths grains of what Remington's match ammo had.
Both Hornady and Federal's .308 Win. 168-gr. bulleted match ammo was formulated with the same powders and charge weights used in their hunting ammo with 165-gr. bullets. At least that's what their reps told me when they were queried. Comparing each make and type showed identical powders by visual observations.
I don't think the ballistics between most commercial ammo and arsenal stuff is very much with medium weight bullets in these semiautos. No more than what would be observed across all sorts of rifles shooting the same make, type and lot of either ammo type.
I don't know what his reference is for M118/M852/M80 ammo ballistic range is. Having shot commercial ammo, both hunting and match types, from 7.62 NATO M1's and M1A's noting its trajectory for bullets in the 150 to 180 grain range matched what the government ammo produced through 600 yards. Remington's .308 Win. match ammo with their 168-gr. bullet had the same charge weight of IMR4895 as did their 165-gr. hunting ammo as confirmed by a Remington field rep. And Lake City Arsenal's M118 and M852 ammo had IMR4895 powder charges within a couple tenths grains of what Remington's match ammo had.
Both Hornady and Federal's .308 Win. 168-gr. bulleted match ammo was formulated with the same powders and charge weights used in their hunting ammo with 165-gr. bullets. At least that's what their reps told me when they were queried. Comparing each make and type showed identical powders by visual observations.
I don't think the ballistics between most commercial ammo and arsenal stuff is very much with medium weight bullets in these semiautos. No more than what would be observed across all sorts of rifles shooting the same make, type and lot of either ammo type.
The only caveat is to watch out for changes. One fellow on another board observed that a particular Remington load he'd used since the 80's has had at least three visibly different powders in it over the years, from spherical to stick. I've forgotten the chambering. The main thing is that SAAMI standards include chamber pressure and velocity windows, but the military also has gas port pressure windows. Board member Hummer90 describes two lots of bulk grade WC852 (H380 in canister grade for hand loading) being tested and one being qualified for M2 ball and M2AP for the Garand's gas system, but the other being disqualified for the Garand and qualified only for machine guns. You can see them as entries 193 and 214 in this relative burn rate chart.
Probably the easiest thing to do is to get the expanded volume gas port plug. No adjustments are required. It works with all commercial ammo.
Probably the easiest thing to do is to get the expanded volume gas port plug. No adjustments are required. It works with all commercial ammo.
I don't know what his reference is for M118/M852/M80 ammo ballistic range is. Having shot commercial ammo, both hunting and match types, from 7.62 NATO M1's and M1A's noting its trajectory for bullets in the 150 to 180 grain range matched what the government ammo produced through 600 yards. Remington's .308 Win. match ammo with their 168-gr. bullet had the same charge weight of IMR4895 as did their 165-gr. hunting ammo as confirmed by a Remington field rep. And Lake City Arsenal's M118 and M852 ammo had IMR4895 powder charges within a couple tenths grains of what Remington's match ammo had.
Things like Hornady Light and Heavy Magnum and Superformance ammunition. Advertised as 100 toi 200 fps faster than "standard offerings" are loads that should not be fired in M1s, M1As, or AR-10s.
M118, M118SB, M118LR, and M118LR Mk316 Mod 0 used a number of propellants, IMR5895, WC750, WC846, and IMR4064, but the velocity was between 2550 and 2640 fps, and it all seemed to shoot safely through M1s, M1As, and AR-10s. Two bullets, the M72 match bullet and 175 SMK. The M852 match bullet used the 168 SMK and IMR4895.
M80 Ball has used WC846 under a 147FMJ, around 2,700 fps.
So anything heavier than 175gr and faster than 2650 fps is "outside the ballistic range" of M118 by any variant, and anything heavier than 150gr going faster than 2,733 fps is "outside the ballistic range" of M80 ball. I recommend avoiding those loads.
However, just because you use a load in the same projectile weight and velocity range as good military loads, there is no guarantee of having the right port pressure. But the odds are much better.
I hope this clarifies.
Jimro
Jimro, thanks for mentioning Hornady Light and Heavy Magnum and Superformance ammunition as somthing that's not good for the semiautos covered in this thread. I totally forgot about them
More than a few Garands bought from the DCM decades ago shooting handloads with favorite bolt gun loads, a case full of 4831, and their op rods bent. There's been a few reports of M1 receiver humps being cracked by the bolt slamming into them like a freight train plowing into a tower of stacked playing cards.
More than a few Garands bought from the DCM decades ago shooting handloads with favorite bolt gun loads, a case full of 4831, and their op rods bent. There's been a few reports of M1 receiver humps being cracked by the bolt slamming into them like a freight train plowing into a tower of stacked playing cards.
I have shown the above replies and they have convinced Pete (the friend that asked) to stick with his 270 for shooting a couple feral hogs while vacationing in the GunShine State. Hopefully pork in the freezer next month.
I really was wondering why he'd want to carry a 9 1/2 pound rifle around when he has lighter bolt guns.
I'm looking forward to seeing that new .308 Garand.
Thanks again!
I really was wondering why he'd want to carry a 9 1/2 pound rifle around when he has lighter bolt guns.
I'm looking forward to seeing that new .308 Garand.
Thanks again!