M1A Problem

[Grumulkin]

I've recently been having trouble with my M1A using the same loads I've used for years. It now frequently fails to chamber another cartridge when I shoot it or even fails to cycle at all. What I've done:

1. I replaced the gas plug and the piston with new ones when simply cleaning the old ones didn't seem to help.

2. I cleaned out carbon (there was some) with special tools from Brownell's.

3. I tried a different magazine.

I'm wondering if I have a bent op rod. Ideas on fixing the problem would be welcomed.

On a slightly different subject, I've noticed that when cases are ejected manually when the action fails to cycle, they are quite cool unlike cases that come out hot when the action cycles as it should. Those that are ejected don't go as far as they used to. Also, when the action fails to cycle, the bullets hit lower on the target.

 

[sinister]

I've recently been having trouble with my M1A using the same loads I've used for years.

How many rounds do you have from this barrel? What is your load?

The Brownell's tools -- do you have and use both piston and gas plug reamers?

 

[Grumulkin]

I've used a number of loads over the years the current one being 43.0 grains of IMR 4064 under 168 grain Nosler match bullets. This load has worked well for me in the past in this gun. As far as number of rounds down the barrel; I would have to say it has probably been between 1,000 and 2,000; maybe a little more.

And yes, I have both the piston and gas plug reamers. Actually, they look more like drill bits than reamers.

 

[mescalito]

You should not need to replace the plug and piston after so few rounds. It is definitely your gas system.

 

[BCP]

Cock the weapon and keep the bolt back (cock it with an empty mag or use the bolt hold open) and point the barrel up, then down. you should hear the piston moving back and forth. If you don't hear it moving you need to use those drill pits to clean ALL the gunk out of where the piston goes and inside the gas plug. Look up on youtube for M14 tilt test and M14 gas piston cleaning to see what I'm talking about.

 

[Name Enough]

Make sure the gas Cylinder (the tube the piston goes in) is correctly aligned. Sadlak makes a tool to hold this while you are removing the gas plug so you don't move it off line and this is a common problem.
Make sure the spindle valve is in the upright position this is the one with the notch in it.
Make sure the gas cylinder lock is tightened locked down correctly. If not it can block the gas port. Best thing to do is to shim it so that the lock will hand tighten to the 4:00 oclock position then tighten it with a wrench to the 6:00 position. Shims cost 10 bucks on Gunbroker or $5 at the gunsmith. This will also improve accuracy.
Make sure the bolt and the operating rod are not binding. When correctly lubricated it should cycle smoothly.
I have been shooting those M14 and M1a for some time now. First thing I do is to buy a Sadlak Titanium coated piston, Schuster Adjustable Gas plug and then a National Match Spring guide. These enhancements cost about $150 for all three. My current M1a a Squad Scout has about 1000 rounds down the tube and I have not cleaned the gas cylinder yet.

 

[ArmyJerry]

If its a Springfield send it in to them they will fix it under warranty and have it back to you in a few weeks.

 

[Grumulkin]

Cock the weapon and keep the bolt back (cock it with an empty mag or use the bolt hold open) and point the barrel up, then down. you should hear the piston moving back and forth. If you don't hear it moving you need to use those drill pits to clean ALL the gunk out of where the piston goes and inside the gas plug. Look up on youtube for M14 tilt test and M14 gas piston cleaning to see what I'm talking about.

I have used the drill bits to remove all the gunk. I also did the tilt test and I can hear the piston moving back and forth.

In regards to the suggestions posted by Name Enough, the ONLY thing I did with the gas system was to remove the gas plug and piston and clean the system with the tools I obtained from Brownell's so I don't think anything I did could have misaligned anything. I don't think the operating rod and bolt are binding but I'll check that again. The action seems smooth when I cycle it manually. I may very well buy the Sadlak titanium coated piston and the adjustable gas plug; it's a National Match M1A so should already have the National Match spring guide.

In regards to the suggestion posted by ArmyJerry, it is a Springfield Armory M1A and I may return it to Springfield Armory if I can't fix the problem myself. At least according to their web site, their warranty is only good to the original purchaser; I did buy the gun new but that was close to 30 years ago so after a number of moves, I'm not sure I could provide the needed documentation. Also, the Springfield Armory warranty has so many exclusions such as not using handloads, they would probably try to get out of providing warranty service.

Thanks for all the suggestions.

 

[ArmyJerry]

My experience as well as many others is they have those exclusions there for extreme situations. You are the original purchaser, they will take care of you. They wont ask you for documentation, only a serial number. They sent mine back with a USGI Bolt because the original was out of spec, even though it shot perfect for 13 years.

 

[mescalito]

Having a bent op rod sounds extreme. If it passes the tilt test then it is not bent. Put the old gas plug and piston back in after a thorough cleaning. You can be overly aggressive with gc bits. You only want to remove residue, not gc material. Call SAI, it is the easiest warranty experience you'll ever have.

 

[mescalito]

Is this cross posted on teamm14.com? There are some extremely experienced individuals helping to troubleshoot a similar situation.

http://www.teamm14.com/showthread.php?14769-M1A-fail-Help!!&p=94269#post94269

 

[Daniel Hall]

The problem you describe sounds like insufficient gas to the piston. First make sure the slot in your spindle valve is in the vertical position ( i believe someone else also said to check it). Next, remove the gas piston. Look at your front band and see if it close to the shoulder on the barrel. If it is try to insert an .075 drill bit thru the vent hole in the bottom of the gas cylinder and into the port in the barrel. The brill bit should go thru and be visible as you look down the bore. A 1/16" allen wrench will work also. I have fixed a number of M14 and M1A rifles over the years that were not functioning properly. The gas plug and piston had been taken out for cleaning. as the rifle was handled and turned the figure eight not would loosen. When the piston and gas plug were installed the gas cylinder would be pulled forward fully or partially covering the gas pot in the barrel cutting the gas supply to the piston. Other common problems are not cleaning the chamber and improper handloads. If reloading you need to check the headspace of your fired casing and size your fired based on that dimension - .002. An RCBS case mic or a comparator ring and dial caliper should be used to check casings. I hope this helps, if not please contact me and I will try to assist you. I have built and maintained a good number of rifles. I also was a very proficient with the M14 and earned one of the first NRA Highmaster classifications with it. Dan

 

[Grumulkin]

Thank-you all for the additional suggestions. When I get a little free time I'll try them.

 

[superjc]

I'm not sure the right way (or really how to) clean the actual gas port at the top of the barrel but that could possibly gummed up). Sounds like not getting enough gas.

 

[nicholst55]

Make certain that the gas cylinder lock is threaded fully on. It's not difficult to stop one thread early, and then install the gas cylinder plug - I've seen it done more than once.

 

[Rapidrob]

An obvious question but, what the heck.... The gas piston and gas cylinder has to be bone dry. No oil or bore cleaner what so ever on either part.
Any kinks in the op-rod spring? How's the roller bearing on the bolt? Is it lubed? Has anything changed in the ammo or reloading components? How are the threads on the gas port plug side? Wrap the gas plug flange and gas cylinder where the two mate up with masking-tape ( not going over the gas vent hole). Fire the rifle. Is the tape blown off? If so the threads are eroded venting high pressure gas.