Reduced Power Loads for 7.62x51 in an M1A


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cal30_sniper
February 3, 2013, 01:54 AM
I've been doing some thinking and reading on the forum, and I'm ready for some thoughts and input. Who all out there has tried reduced loads in an M1A, and how do you like them. Apparently they are moderately popular for NM shooting at the closer range.

I'd been wanting to get a Mini 30 for quite a while, but this buying scare has gotten in the way and has me thinking about alternatives. I figured since I already had an M1A Bush Rifle set up the way I want it, I could just as well turn it into a rifle in the same performance class with some creative reloading.

What I'd like to do, is create a load for .308 that gets as close to 7.62x39/.30-30 performance and still work reliably with reduced recoil. I would really like to get something very similar in performance to the 115grn, 2500fps 7.62x51 CETME load. As an added benefit, bullets would be cheaper, and I would use less powder. Win-Win. I'm looking to do this with no more modifications to the gun than sighting it in. I'd want to be able to switch back to my full power 150 grn loads in a heart beat.

I have a lot of H4895 and IMR4895 around, so that would likely be my powder of choice. I also have a lot of 'HC' stamped 7.62x51 brass. I think the smaller capacity of the military brass would be a benefit in this instance, as it should increase powder burn consistency with the reduced loads by keeping the charge density up.

I was looking at bullets in the 110-125grn range. There are Varmint offerings from both Sierra and Speer that look appealing. I've used the 85grn Varminters a lot in my 6.5x55 (that's actually what got me to thinking on this, I love the lack of recoil with those things). I'd like to try the Sierra 110 grn with minimum book starting load, or perhaps a few grains below that. Who here has actually tried that? Is there any way to make that light of a bullet cycle the operating system reliably?

Also, what are thoughts on feeding reliability with flat-nosed bullets made for .30-30? Those lighter flat nose bullets should be pretty devastating on game at short ranges, and they are a lot easier to find in today's market than spitzer bullets are.

Thoughts? Concerns? Ideas on something I'm leaving out here?

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Fatelvis
February 3, 2013, 02:18 PM
http://castboolits.gunloads.com/showthread.php?3558-7-62x51-NATO-(-308-WCF)-in-the-Springfield-M1A
This thread has just about everything you want to read about cast boolits in an M1A. A good read, written by a guy who really did his homework!

oldpapps
February 3, 2013, 06:27 PM
"... out there has tried reduced loads in an M1A, and how do you like them...

... a load for .308 that gets as close to 7.62x39/.30-30 performance and still work reliably with reduced recoil...

... smaller capacity of the military brass would be a benefit in this instance...

... looking at bullets in the 110-125grn range... the Sierra 110 grn... that light of a bullet cycle the operating system reliably?..."

I started with a different desire. Had a Remington Model 600 in .308 Win (18.5 inch with 1 in 10 twist) and talk about kick! The dumb thing was just too light and pumped out over 17 foot pounds of free recoil energy!

At the time I had a M1A with a 22 inch barrel with 1 in 11 twist.

I worked out some loads for the 600 to make it shootable and tried them in the M1A.

All velocities are taken at 10 feet and are a running total average of not less than 15 test shots.

Columns are:
cal, bullet type, bullet weight, powder type, powder charge, velocity, weapon

308 JSP 150 748 41.8 2548 M1A
308 JSP 150 748 41.8 2380 Rem 600
308 JSP 150 748 42.2 2570 M1A
308 JSP 150 748 42.2 2335 Rem 600
308 JSP 150 748 42.6 2502 M1A
308 JSP 150 748 42.6 2381 Rem 600
308 JSP 150 748 43 2629 M1A
308 FMJ 147 748 43 2468 Rem 600
308 FMJ 147 748 43 2677 M1A

Note, the FMJs are military pulls.
All loads fully functioned the M1A.

Along the same line, I worked on some 110 grain V-Max.

308 V-MAX 110 H4895 41.5 2684 M1A
308 V-MAX 110 H4895 41.5 2635 Rem 600
308 V-MAX 110 H4895 46 3103 M1A
308 V-MAX 110 H4895 46 2961 Rem 600

Again, they fully functioned the M1A.

Hope this helps a little.

As always, these loads were safe in my weapons, with my components. I am not implying that this information is safe in your weapon with your components.

cal30_sniper
February 3, 2013, 06:47 PM
That 110 grn load moving at ~2700 fps looks good. With the gas system and weight of the M1A, the recoil ought to feel like shooting a Mini-14.

That might be a good way to use up some of the H4895 I have laying around.

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