Not Cycling

[skooter525]

I have been loading some .308 for my M1A. I tried a few of these out, the gun didn't eject the spent round, but did go bang. Ejection by hand no problem. Could I have loaded the round too light? I used a few 10th's above minimum

 

[lee2]

it is possible. how does the recoil feel?

 

[John from MD]

I have been loading some .308 for my M1A. I tried a few of these out, the gun didn't eject the spent round, but did go bang. Ejection by hand no problem. Could I have loaded the round too light? I used a few 10th's above minimum

Yes. All gas systems have different tolerances. The best thing to do when working up loads for a gas gun is to make two cartridges .2 grains apart from the lower to the middle of the given loads for that powder bullet combo. Then, after you learn the minimum loads it will cycle, you can start working up loads for accuracy.

This saves wasting lead.

Regards,

John

 

[HogCommander]

Skooter...what powder, charge weight, bullet, COAL, etc are you using? I load for M1A with Varget and BLC-2 and use 168 grain bullets. Happy to help if possible.

 

[Clippers69]

I've been loading for my M1A with both 150 fmj from Hornady with 2520 at 42.5 and 2.700 loa. I have loaded up to 44.0, but it was not accurate in my rifle. I also load 168 Hornady match and Nosler match with 42.5 - 43.5 with 2.795 loa. I am using the Hornady and Nosler reloading manuals. The supposed go-to load is 41.5-42.0 grains of IMR4895 and the 168 grain bullet. That's from a gunsmith who knows alot about military guns and specs.

 

[amoebicmagician]

.308 autoloaders are exceedingly hard to load for

part of the reason that AR-10s are not a bigger deal.

The .308 is an incredibly versatile cartridge, it's got a lot of potential, and a lot of potential uses, as well as a large swathe of territory in which you can put your load and still have it be safe.

The problem is that the margin for reliably cycling an autoloader is much narrower. You can always overdo it, but that causes it's own problems likely to be much more of a pain in the ass than a simple failure to cycle.

Once you find something that works, stick with it.

You will be surprised the amount of FACOTRY ammo that will be finicky through most .308 autoloaders.

Just for emphasis, the M-14 was designed to fire a specific cartridge, not a range of them, and that cartridge or derivations thereof were all withing a very tight and finite set of values

 

[skooter525]

Skooter...what powder, charge weight, bullet, COAL, etc are you using? I load for M1A with Varget and BLC-2 and use 168 grain bullets. Happy to help if possible.

Using Reloader10X 39.5 grains with a 150 gr BT, Federal 200 primer I believe COAL was 2.750

 

[byf43]

Using Reloader10X 39.5 grains with a 150 gr BT, Federal 200 primer I believe COAL was 2.750

Where did you get the reloading data?????

 

[Second Amendment]

Darn, from the title, I thought this was an anti-bicycle thread.

 

[DaemonAssassin]

.308 autoloaders are exceedingly hard to load for

part of the reason that AR-10s are not a bigger deal.

The .308 is an incredibly versatile cartridge, it's got a lot of potential, and a lot of potential uses, as well as a large swathe of territory in which you can put your load and still have it be safe.

The problem is that the margin for reliably cycling an autoloader is much narrower. You can always overdo it, but that causes it's own problems likely to be much more of a pain in the ass than a simple failure to cycle.

Once you find something that works, stick with it.

You will be surprised the amount of FACOTRY ammo that will be finicky through most .308 autoloaders.

Just for emphasis, the M-14 was designed to fire a specific cartridge, not a range of them, and that cartridge or derivations thereof were all withing a very tight and finite set of values

AE 150gr doesn't cycle worth a damn in my LAR-8. Trying to make has loads for it has been a PITA too. It is a lot of trial and error to find the specs your 308 autoloader likes.

 

[stu929]

Im pulling from memory here but i believe my accuracy load for my M1A is 42.1 IMR under a 155 Nosler Custom Comp at 2.84 COAL???

I would make sure everything is greased well and tight you could be leaking some gas pressure. Gas cylinder tight?

As always work up your own loads but thats a pretty standard load for the M1A. Im not as in tune with the M1A as with the M1 but they were designed with specific powders in mind and I try to stick to those to protect myself and my investment.

 

[skooter525]

Where did you get the reloading data?????

From the Alliant web site

 

[skooter525]

Sound like a lot more field testing is in order :-)

 

[10xclean]

first thing to check is the gas shut off valve (the screw on the gas system). If it's on (should be vertical or pependicular to the barrel), pull the oprod back and lock it with the bolt stop, tilt the rifle up and down and listen for the gas piston.

 

[skooter525]

first thing to check is the gas shut off valve (the screw on the gas system). If it's on (should be vertical or pependicular to the barrel), pull the oprod back and lock it with the bolt stop, tilt the rifle up and down and listen for the gas piston.

This is something that I didn't know, Thank you

 

[HogCommander]

Ashamed I didn't think of this before but 10xclean's post reminded me...verify that the gas plug is tight/screwed all the way in. Mine worked its way loose after about 1000 rounds and the rifle wouldn't cycle. After figuring this out, screwed it all the way in and that fixed the problem immediately.

Other than a loose gas plug, never had cycling problems with either factory ammo or handloads. If it turns out to not be the gas plug, would try some factory rounds and see if that changes anything. If factory rounds cycle but handloads don't, would definitely focus on the loads you're using.

Separate issue but one of those "how did that happen" things is that the screws that keep tension on my rear sight knobs loosened while I was trying to get a 200 yard zero. For the life of me couldn't figure out why I couldn't get a decent group but luckily was shooting with an experienced M1A guy. Another easy fix.

 

[Winterborn]

Good article about this very isse in Guns and Ammo this month.

Most manuals (my Hornady 9th does) have different loads for 308 and for the M1A and M1 Garand, simply due to the limitations of the gas system.

Use the powders recommended because they produce more gas per load and will cycle your rifle more reliably.

300 blackout subsonic shooters face the same issues.

 

[amoebicmagician]

Ashamed I didn't think of this before but 10xclean's post reminded me...verify that the gas plug is tight/screwed all the way in. Mine worked its way loose after about 1000 rounds and the rifle wouldn't cycle. After figuring this out, screwed it all the way in and that fixed the problem immediately.

Other than a loose gas plug, never had cycling problems with either factory ammo or handloads. If it turns out to not be the gas plug, would try some factory rounds and see if that changes anything. If factory rounds cycle but handloads don't, would definitely focus on the loads you're using.

Separate issue but one of those "how did that happen" things is that the screws that keep tension on my rear sight knobs loosened while I was trying to get a 200 yard zero. For the life of me couldn't figure out why I couldn't get a decent group but luckily was shooting with an experienced M1A guy. Another easy fix.

I've had problems like this, and others on other guns, and have been wondering if any of you guys have some idea of a solution this.

I've been looking for a non permanent high temperature thread locker, but it seems that all the good ones are red permanent threadlock, not blue hand tool removable.

obviously I'm hesitant to use the red. Loctite you can usually get free with some heat and a lot of work, but the permatex red thread lock I've broken many a screw trying to un-bugger. When they say permanent they mean it!

So, not to derail the thread, but since I'm not eager to never be able to take my rifle all the way down again, is there a non permanent medium strength hi temp threadlock out there that I've just been missing?

 

[Jerry M]

Before you try anything above, get your self a small base die. You are not sizing the brass enough. This was a common problem when M1-A and M-14s were shot accross-the-course.

Good luck

Jerry

 

[stu929]

Mine runs just fine with full length dies.