7.62x51 NATO (.308 WCF) in the Springfield M1A

[cbrick]

Thanks Tomme, I can look into that but right now I have a few thousand #34's to wring out. I suspect based on Bruce's testing using them they will be fine, just need to shoot & find out.

Rick

[winelover]

I've been following this thread for quite a while. It got me interested in loading cast for my Armalite AR-10 carbine. I have put thousands of rounds through it. I have settled on heat treating all my boolits. Even the light loadings, show a preference for harder boolits. I tested air cooled and water dropped versions of my alloy, an approximation of WW's.

I normally use CCI 200 large rifle primers but occasionally go to CCI 250 magnums. With AA4350, I am getting slightly better groups with the magnum primers. So Gear, if your not using CCI #34 military primers with IMR4350, you might want to give the magnum primer a try.

Bruce, my usual sight is a Trijicon Reflex with chevron recticle, no magnification. When doing load development @100 yards, I switch to a older inexpensive (Japanese) Weaver V-9 (3 x 9) variable. It takes a licking and keeps on ticking. My 1894 Marlin (44 Mag) is harder on riflescopes. I recently had to send a lighted Leupold Var X III (1.5 X 5) for a cracked front lens. Had to be recoil related since the scope was never dropped. Anyways, Leupold repaired it , no questions asked.

Winelover

[popper]

Cbrick - gone through the same with LR-308 & 300 BO mags. I know, not M1A. I got long scratches on the 308 brass till I deburred the bottom of the lips. Lots of over-ride jams til I widened the lips at the front, once the shoulder is started into the chamber, the base needs to pop up to the bolt surface. Tight or longer than needed front of lips prevents this. Moving the edge back on Pmags (BO) solved the 'tilt' problem. Per the army, the bolt moves 4-8 MPH when cycling. That 'tilt' will dent the nose or shoulder. Definitly clean up the base with a file or other to prevent over-run jams. Rough rim will pull lower cases forward - instant jam.

[26Charlie]

But- I sold my boat, motor, and trailer, so finally had the money to buy the M1A. Nostalgic maybe, since I trained with the M14 when they were new to the Marines 50 years ago. Kudos to Bruce B. for doing all the work on this thread for cast. I sighted in and shot some hardball at 200 yards last weekend, then just had to try cast - loads I had on hand from a bolt gun. so here's my two cents worth. A load of 12 gr. HERCO with a RCBS 120 RNGC failed to function the action at all - no surprise, but it is a light pest load. Next, tried the RCBS 180 gr. FNGC ahead if 28 gr. 4895. Five functioned the action, but one failed to feed the next round from the magazine. All the other loads in my stash are lighter charges of 4198 or 4227, and I can predict they will not function the action.
Since the weather turned cold, it is 15 degrees out, and I was leaning over the suburban hood, I didn't pursue accuracy too strongly - but they hit where the sights were at 30 yards. The snowplow has given me a berm at the end of my dooryard for a backstop and I decided to take advantage of it for a couple of trial groups.

[fcvan]

I'm shooting the NOE 309-150 SP from a SA M1A and a Sig Sauropod 716 Patrol Rifle (AR 10 variant). Gas checks are made from aluminum with a CheckMaker die, powder coated, and sized to .311 diameter. I started out with 24 grains of IMR 4227 and got %95 functioning. Full functioning at 25 grains, and settled on 28 grains. Lyman 49 says 20-30 grains and 28 grains is %95 load density.

Last week, I measured the velocity at 15 feet at 2050-2065 fps, the lowest spread I've ever recorded. I've only been shooting .308 since September, and picked these rifles up 2 days apart. I found the M1A as a consignment for $1000, and a buddy gave me a deal on the Sig I couldn't pass up. The SA was a field gun, used but not abused, and the Sig had 20 rounds through it.

Both rifles have seen several hundred rounds apiece between load development and my current load. The powder coating leaves nothing in the bore but burned gunpowder residue. I started using 4227 in the 5,56 (Mini 14 and AR 15) with PCd Lyman 225-415, and then 300 blk (pistol and carbine). It worked so well that trying it in the .308 rifles was a no brainier. I've already burned up 12 lbs, and have just cracked into another 8 lb jug. I love the consistent performance of the powder, and really enjoy shooting the .308 rifles.

My brother has 2 M1A rifles (National Match he bought in the mid 80s, and a Scout Squad be bought a few years ago. His has beautiful wood stocks, and mine is composite. The M1A is just an awesome, natural handling rifle. I also like that I can load 50 rounds for less than $10. Good times!

[Lindenwood]

I can elaborate more if anyone is interested, but here are my findings so far.

This is a 16"-barreled DPMS LR308 Oracle with some upgrades (FF handguard, trigger, gas block, stock). All reduced loadings utilized dacron over the powder. All bullets were 150gr FMJBT.

1) the rifle will function down to about 26gr of LVR. ES was about 200fps though with velocities averaging about 1600fps. This powder is relatively slow (2 steps past BLC2). Accuracy is pretty bad (6-8" at 100 yards), for the velocity variation and likely also due to poor engraving from the low pressures.

2) IMR 4320 was much more consistent, but would not function reliably until 31gr of powder. At 26gr, velocities were in the high 1400s (ES around 100) with 8 out of 10 not ejecting and the other two jamming. 28gr had velocities around 1600fps, ES around 80, with most ejecting but not stripping a new round. 30gr was about 80% good, with one jam, one failure to strip, and no lock-open. 32gr gave averages around 1975fps with roughly a 75fps ES. Accuracy was better with these loads, now about 4" at 100 yards.

I can infer that the low pressures with J-word bullets were a lot of the accuracy problems, based on my successes with Unique loads at higher presures. However, with the successful functioning at such mild velocities, I am comfortable running cast bullets and actually being able to get them to function.

Btw, I have all this data written down but not with me, so I am going by memory. If anyone wants more specifics, just ask. And If I misremembered something I'll fix that also.

[winelover]

I can elaborate more if anyone is interested, but here are my findings so far.

This is a 16"-barreled DPMS LR308 Oracle with some upgrades (FF handguard, trigger, gas block, stock). All reduced loadings utilized dacron over the powder. All bullets were 150gr FMJBT.

1) the rifle will function down to about 26gr of LVR. ES was about 200fps though with velocities averaging about 1600fps. This powder is relatively slow (2 steps past BLC2). Accuracy is pretty bad (6-8" at 100 yards), for the velocity variation and likely also due to poor engraving from the low pressures.

2) IMR 4320 was much more consistent, but would not function reliably until 31gr of powder. At 26gr, velocities were in the high 1400s (ES around 100) with 8 out of 10 not ejecting and the other two jamming. 28gr had velocities around 1600fps, ES around 80, with most ejecting but not stripping a new round. 30gr was about 80% good, with one jam, one failure to strip, and no lock-open. 20gr gave averages around 1975fps with roughly a 75fps ES. Accuracy was better with these loads, now about 4" at 100 yards.

I can infer that the low pressures with J-word bullets were a lot of the accuracy problems, based on my successes with Unique loads at higher presures. However, with the successful functioning at such mild velocities, I am comfortable running cast bullets and actually being able to get them to function.

Btw, I have all this data written down but not with me, so I am going by memory. If anyone wants more specifics, just ask. And If I misremembered something I'll fix that also.

How did this thread morph to Jacketed from Cast? And why would anybody want to shoot low pressure Jacketed loads and risk a bullet getting stuck in a barrel??

Winelover

[cbrick]

I thought so too, nearly 300 posts on shooting cast in the M1A.

But anyway Lindenwood, welcome to CastBoolits.

Rick

[ShooterAZ]

I have been using the Lee C312-155 boolit in my M1A, also with IMR4227 and having very good results. I have one of the older Springfields with a GI chrome lined barrel, and get no leading at all. I size to .311, use Hornady gas checks, and lube with BAC. The brass I use is Australian AAF from surplus, it's very thick, durable brass. I use CCI 34 primers, just cause. The bore is bright & shiny after hundreds and hundreds of rounds. No signs of lead in the gas cylinder, just the normal soot. I just spray the soot out with Gun Scrubber. The flash hider needs to get sprayed out too, from lube residue. I love my M1A as well, and thanks to this site I have been able to get it up & running like a clock with cast boolits.

[Lindenwood]

The focus of this thread, I thought, was getting mild loads to function in a service rifle. Sure, the objective was to be able to shoot cast bullets well, but again the focus was how to do it while maintaining normal functioning. I don't have any cast .30-cal bullets to test but wanted to see if I could get similar functional results with my AR10-platform as Bruce found with his M1A. But, sorry if mentioning jacketed bullets was so offensive as to blind everyone from the entire focus of my post, which was to provide a little data on low-pressure function in this platform. The only reason I specified bullet type was, again, to provide data.

Like I said, I intend to shoot cast through this rifle but wanted to verify it would cycle before getting too excited.

And no, I wasn't anywhere close to sticking a bullet. In my experience you have to get down in the 600-700fps before it becomes a real risk, which would take a lot less than 25gr of powder. Otherwise, all those people shooting subsonic 200+gr J-word bullets would be blowing up guns left and right, no?

[cbrick]

Now don't get your feather ruffled up. It is a thread about cast in the M1A but no one here is offended. I'd be willing to bet if you asked there would be someone here more than willing to send you some cast to try them out. But be warned it will be a game changer and you'll never be the same again. It will make you into a dedicated leadhead and you'll end up pouring your own for everything you shoot.

Rick

[Lindenwood]

Heh, no worries. And actually, I have been shooting almost exclusively cast bullets in handguns and pistol-cal carbines for years . I was going to start shooting cast bullets through this rifle as well, but did not expect to be able to load anything powerful enough to cycle the action. Having to manually cycle the action with each shot takes a lot of the fun out of shooting for my wife (for whom these reduced-recoil loads are largely made). So, I also needed something that would both cycle and be accurate without leading. I know pushing cast bullets to service velocities without issues (like Bruce was seeing toward the top end of his loads) isn't easy, but with Bruce's results I thought Id see if my rifle would also cycle with reduced loads more appropriate for cast bullets. Now that I know it can, picking up some cast bullets is certainly the next step.

[BruceB]

As far as shooting jacketed bullets goes, in the very first posts on this thread I was mentioning my Sierra Matchking loads which I used to break-in the new M1A.

Also, I will freely admit that my "ready-use" ammo (old Navy term, there) is loaded with jacketed bullets.

Of course, it would be very easy to stash cast-bullet loads as well, or instead, and those would easily equal factory 7.62X39, or even be a good bit more powerful.

This thread has wandered a bit over its surprisingly-long life. and it's ALL about shooting our beloved M1A rifles. What's not to like?

Thread drift can be VERY EDUCATIONAL, and thread drift is something I like very much about our CB website..... nobody leaps reflexively to stamp out the heathens who DARE to post something that's just a wee mite off the main topic. We often learn things from thread drift, and that's great in my estimation.

I'm sure tickled that my efforts on this subject are bearing fruit with so many people; that's exactly what I hoped would happen. It was the intent of the project to develop reasonable baselines from which other m1A shooters could work, and it's proving-up rather nicely....

[ShooterAZ]

The great thing about cast boolits in the M1A, is that you don't have to have "service rifle" velocities to get full function and very good accuracy with reduced recoil. It's perfect for practice, plinking, and general good fun.

[DisinterestedThirdParty]

....... Next, tried the RCBS 180 gr. FNGC ahead if 28 gr. 4895. Five functioned the action, but one failed to feed the next round from the magazine. .....

I was just looking through my molds and I have that RCBS 180gr FNGC and was just wondering if it would feed through my M1a (If it ever gets here...). I'm very happy to see it will..

[DisinterestedThirdParty]

The great thing about cast boolits in the M1A, is that you don't have to have "service rifle" velocities to get full function and very good accuracy with reduced recoil. It's perfect for practice, plinking, and general good fun.

I'm just thrilled to be reading that cast boolits function well in this weapon. I've been looking at ammo/reloading costs for this rifle and shuddering. With 20-35 cents for the jacketed bullet, 4 cents for the primer and whatever for the powder (when you can find it..), that's an expensive day at the range.
Thank you and please keep the information coming...

[geargnasher]

Will keep adding as I generate pertinent data.

Gear

[trapper9260]

I know someone that have a M1A and had him test some fed ammo for me that was given me problems in my DPMS LR308 and it did not want to cycle all the time in my gun , he test it in his and he said it was low on powder and the company did not want to hear it. So I load some cast for my and end up use data from jacket for my cast and it was the 173gr lyman with GC and use IMR 4064 and I weight each boolit and then did some test at first to have the gun cycle with out problems and the weight I use is the one I had the most of with the most weight and end up that for the data is of the jack but for what the boolit weight on the mold and what it was was different and I end up with it weight with WW and lube and GC to 182gr.and shot on center at 43yards for test.So what it all come to for the M1A is if it can cycle in my DPMS it will do ok in the M1A ,but if it dose not shoot well in the M1A then it will be worst in the DPMS.Because of the CBC ammo shoots fine in both type of guns and also the Russian ammo also.

[A pause for the COZ]

Wow!!! What a valuable resource this thread is. Glad it did not get locked back there around page 11.
New to the 308 in Semi Auto thing.
All my guns must shoot cast boolits or they wont be my guns long.
I am using HM2 312 155-2 mold


Trying them out of Palmetto PTAC Tac10 AR10.
So far so good.
I have H4227 working around 22.5gr and WC844 working ok at 30gr.
Good thread!!!

[popper]

I studied this thread before loading for my LR308 (gasp, jacketed) now it's cast only. I don't have an M1A but the info is valid for me. I have found 4227 to have very low ES in 300BO. 335 seems to give me better groups ans fps than 4895 in the gas gun.