1st M1A handloads - the aftermath.

[Battler]

43 gr IMR 4064 w/ 150gr flat bottom spitzer in new Winchester brass cut down to 1.995", oal 2.72.

I did 10, shot 7 on one target and 3 on another target (guy with a gun-rest/stand suggested I try it out but those things just don't work for me).


Of the 7, 1 flinched-off flyer 4 inches away, 6 inside a < 1.25" circle - optics are a 2x Aimpoint red dot.

This is my first 308 handload, I'm fairly new to rifle reloading in general, and the best I've EVER shot with ANYTHING - and WAY better than I've done with this gun before. Guess handloads meticulously measured to PRECISE powder charges and length must shoot better than my Radway Green 20 year old surplus.

BTW - this is a starting load rated for ~25xx fps - yet it shot TWO INCHES HIGHER than RG brit surplus. Is this normal? It didn't seem to kick any more than the surplus ammo (seemed lighter).


The rounds fed and functioned perfectly. However, most of the cases have dents in the case wall. On the milsurp I only ever saw almost imperceptible dents - don't know if this means thinner cases or lighter ejection. How much dent makes the case a writeoff? The cases are currently in for cleaning so I haven't resized yet. I realize the case will undent upon firing but I don't want to risk any rupture.

Also - pressure signs. One of the cases showed SLIGHT primer flattening (not truly flat, though, just tiny growth toward edges but still rounded at edges). Should I worry as going up thru loads? With the drastically shortened case necks the brass wouldn't have gone into the chamber - should I just suspect the primer itself, since it was only one?

Is there any diagnostic value to ejection pattern? I caught most of them with a rolled up shirt; but those that ejected a bit more forward hit the ground a couple of yards away, bounced off a wall.


I've pretty much found out that all my shooting so far (with surplus) I was selling myself short - while flinching would come and go, some of my otherwise perfect shots/groups were being hampered by the inconsistency of the surplus (don't get me wrong, I'm sure it would still do the job, and it's still handy for blasting practice).


thanks,
Battler.

 

[Art Eatman]

"BTW - this is a starting load rated for ~25xx fps - yet it shot TWO INCHES HIGHER than RG brit surplus. Is this normal?" Yeah; different bullet, different powder, you commonly get different "whip" or barrel vibrations.

The dents might come out when you resize. Civilian brass *is* a bit thinner than GI-type. They hold more powder, which is why you don't use civilian-type maximum loads in GI-brass reloads.

Excessive working of brass will harden it, so the cases might split after several reloads. (Depends on the severity of the dent.) I don't know about lowering/rounding/whatever on the edge which causes the dents, but that's the "why" of lowering the ejection port on Colt Government slides.

As far as any pressure sign on that one primer, I'd tend to trust the book. If it says your load is a "starter", I wouldn't worry about it. SFAIK, you ought to be able to get to around 2,700/2,800 ft/sec without hurting anything.

FWIW, Art

 

[HankL]

I would try reducing the load by 1 gr. and see where that takes me. The 43 gr of 4064 is a starting load in a bolt action rifle. Please do not load to 2800 fps with a 150 gr bullet in your M1A.
Regards

 

[John Marshall]

Now you've got me to wondering, HankL. How much will 3gr difference in bullet weight make? I have been shooting Winchester/USA 7.62 NATO 147gr fmj ammo in my M1A for some time and Winchester says this stuff is supposed to go out at 2800fps.

Are you saying that there will be enough pressure difference pushing a 150gr bullet at that speed to cause a catastrophic failure in a semi-auto?

 

[Zak Smith]

Here's another way the POI could be higher with the slower load: as the gun recoils, the muzzle climbs, right? If the bullet spends more time in the barrel, the muzzle will have climbed higher by the time the bullet exits the barrel.

-z

 

[HankL]

John, I stand corrected. The 147/150 grainers are supposed the be going 2750 fps. I usually work with the 168/173 grain bullets and that is where I confused myself.
I think of 2650 fps as being the velocity that is needed.
Sorry. The thought of catastrophic failure never entered my mind.

 

[BigG]

Welcome to the world of reloading!

It sounds like the first load is pretty dang good compared to the RG.

Smithz is correct about the slower bullet allowing impact to rise more due to longer time in bbl.

I usually clean my primer pockets with a little primer pocket cleaning tool similar to a flat screwdriver.

Some other guys could recommend loads for the M1A. I l believe it was loaded with ball powder by the armories. It may be OK to use stick powder like 4064 but the old Garand operating system had certain difficulties with loads that some members could clue you in on. I know the old NRA literature about match shooting used to specify loads.

Have fun!

 

[Battler]

HankL: Thanks - I think I know what you mean.

I am not using a chronograph - I know, if I get my gun to shoot as fast as the test boltaction to which the book refers I would probably be using more powder/more pressure.

I'm going to take it slow and stay well within the max.


BigG: I am VERY pleased with this setup - I didn't even think that, with these optics (dot covers 2 inches, low zoom) and my skill that this was even possible.

they speak well of the 4064 powder on this thread:
http://yarchive.net/gun/ammo/308_loads.html

Everywhere I hear of people going for accuracy they use a 168gr bullet - I think I'll have to try that next (observing proper loading data for the different round, of course). Gives me goosebumps to think that there's even better accuracy to be had than this


Art Eatman: The dents persist after sizing; but shrunk a bit.



Battler.

 

[Big Bunny]

Sounds a good potential outfit! Congrats are in order.

The Swedes put a rubber buffer on their AG42B Ljungman ejection port to prevent this type of case damage, as they reloaded using a wet berdan de-capping process.

The mil case is a LOT thicker than the civie one.

Also mate, I would load DOWN rather than up, the speed of ejection sounds a bit "iffy" to me!

BB

 

[BigG]

Hi Battler,

I used IMR 4064 in 30'06 and 375 H&H. It is super for those applications, too. Have not reloaded the 308. I have a couple a cases of milsurp yet to go. At 10c a shot or so, it don't make sense to reload for me, yet...

Grear luck on future endeavors.

 

[Cheapo]

Battler, the M1A's gas system tends to be self-regulating, unlike the M1's direct gas impingement system. Slow powders and high port pressure cause fewer problems, because the piston cuts off the gas upon moving back a bit.

Plus, 4064 is "fast" enough for even the M1. More so for the M1A, as long as you STOP at 190-gr bullets. IMO, 175-180 grains is a more realistic upper limit for bullet weight in the typical M1A 12-twist barrel.

Comments above hint that someone may believe the gas system bleeds off enough gas to make velocities slower. Tests show no statistically reliable or repeatable difference greater than 5-10 fps, where there was a velocity loss at all.

Bolt gun vs. M1A makes no difference in velocity, aside from barrel length--22 inches on the M1A. The trend (exceptions abound!) is something like only 25 fps velocity loss per inch of barrel, in lengths ranging from 18 to 26 inches.

US "commercial" brass vs. Lake City (GI) brass DOES make a difference in charge weights and velocity. Search the forum and you'll undoubtedly find some good, factual info from actual reloader experience (with a chrono, no less!).

 

[HankB]

My M1A is the only rifle I've got in which powder type makes a significant difference in accuracy. The "traditional" powder for M1A target loads is IMR4895 . . . but I found that IMR4064 significantly shrinks groups with the 168 grain Sierra Matchking bullet. I've also read that Federal Gold Match ammo uses IMR4064 powder, though in a non-cannister grade.

Be aware that commercial cases have significantly more internal volume than military - when switching from commercial to military cases, this means you must reduce the powder charge.

 

[MIKE14]

Battler, I spent hours last winter trying to find the right load for my M1A loaded. I used 168 gr sierra MK's, Hornady 168 gr Match, 147gr FMJ's all kinds of stuff. I used IMR 4895, Varget, BL-C2 Win 748 and IMR4064. I used a chronograph and took notes on every string I shot and then transfered the notes to a log book. I could not get the groups I expected with the 168 gr stuff at 100 yards I bought some 155gr Sierra Palma HPBT MK's took a load recipie form Sierras manual and used 46.1 grains of IMR4064 in a Black Hills Match case with a Federal 210M primer. This load shot consistantly in the high 27's and low 28's. With this load out of a cold barrel I can get 1/2 inch three shot groups at 100 yds. After the second or third string it will open up to 1 inch to 1-1/4 inch let the barrel cool and clean the bore and it will go back to the sub moa groups. With this load I can take this rifle out of the case and know exactly where it is going to hit. I just got 100 new Federal GM brass cases and a 100 Nosler 155gr J-4's to try I hope they work as well as the Sierra's do they are a couple of bucks cheaper on the 100 rd box. Good luck and be safe!

 

[Peter M. Eick]

I have several M1A's, so I will figured a few comments might help. First I only use gold medal brass and cci c-34 primers. I do not want to mess up my m1a's with a slam fire.

I have found that the supermatch likes 4895 with 168 seirra's while the nationalmatch likes 4064 and 155 palma's. If you swap rounds groups will open up, swap the loads, groups open up.

Interesting problem, but it shows that each one is unique.

 

[Dave P]

Aimpoint

Battler, tell me about your Aimpoint setup. Is that the model 5000, with the 1.5" dot size? (saw one for $240!)I have just started looking for one for my M1A, since my accuracy without scope is marginal. What kind of mount are you using?

Thanks

 

[Battler]

Yeah, the old 5000 model - I suggest you hodl out for one of the new ones that JUST came out - batteries last 30 times as long or something.

Arms # 18 mount, rings that came with the Aimpoint.


I'm using it because I want a tiny bit of zoom; but not give up quick aiming - it's a good balance, and as a red dot it is amazing in crappy light.


Battler.

 

[Jamie Young]

nationalmatch likes 4064 and 155 palma's.

Peter what load are you using?

 

[Gewehr98]

That 155gr Sierra Palma bullet is a pleasant surprise.

I had the same experience using that bullet in my Navy Trophy M1 Garand. 168gr MatchKings shot well enough, but the 155 Palma's? Oh, my! My M14NM likes them a lot, too, using Lapua 7.62x51 brass and IMR4895.