This is a discussion on M1A feeding problems within the The M14 forums, part of the M14 M1A Forum category; My M1A is having problems with feeding by short stroking. I checked the gas plug it feels tight so I removed the op spring and ...
My M1A is having problems with feeding by short stroking. I checked the gas plug it feels tight so I removed the op spring and ran the bolt back and forth to look for any excess friction. I found a lot so much that the bolt will not slide freely on its own. The bottom of the bolt appears to be getting stuck on the hammer and the top of the hammer is showing sings of wear. Is this normal and if it is what’s causing my problem how should I fix it. I think adding heavy grease to the area might help but I would like to think that my rifle would work without it.
The bolt needs to contact the hammer to reset the trigger. That being said maybe u can use a polishing stone to smooth it out, thats what my uncle did to my AR bcg cause it rides over the brass casings and was getting fouled up. Just throwing it out there, dunno if it would mess with the bolt integrity or not. Btw I'm having the same problem, but it seems to mot happen when I use heavier ammo 168gr etc.
Yes, the underside of the bolt will slide in the grooved section at the front corner of the hammer; it pushes the hammer down that far to ensure that the disconnector captures the hooks. I lightly grease that bolt contact point on the hammer. You'll need to remove the trigger assembly to get a true idea of how much the bolt & op rod are binding, if at all.
The bolt should contact and depress the hammer some when the hammer is held by the disconnector. When fired the trigger is holds the hammer after the bolt pushes it down. When the trigger is released the hammer takes a slightly higher position and is caught by the disconnector. The disconnector will hold the hammer slightly higher than the depressed trigger. The bolt has to push the hammer far enough for trigger to catch it when firing, therefore the disconnector must hold the hammer slightly higher because the depressed trigger hook is lower than the free disconnector. If the bolt didn't contact and push the hammer when it is being held by the disconnector, the depressed trigger would never be able to catch the hammer while firing. You can hold the trigger back and pull the op rod back to cock the hammer. Keep hold on the trigger, do not release it. Then see how much the bolt contacts the hammer. It should still contact it and depress it but not as much as when the trigger is not held and the hammer is held by the disconnector. Also check for free movement with the trigger housing removed.
Does your M1A have a Springfield synthetic stock on it ? There have been a few problems as of late, with stock fitment issues. Trigger group issues also. If the stock overall thickness is too shy, it might cause more drag. The TG should bottom out in the receiver at the splineway, and have very little gap at the top of the TG to receiver fit. If for some reason, yours is out of spec in this meeting area, the entire TG would ride higher in the receiver, and also cause more contact or drag. The other place to look, would be the curved roof of the receiver, or bolt raceway. See if the bolt is dragging on the top of the receiver excessively. See if the bolt saddle at the receiver safety bridge is cut too low or too high and letting the bolt ride lower or higher also. I have been seeing a lot of SAI's lately with 1.631 chambers and the least bit of fouling has been causing feed and eject problems. What kind of ammo are you shooting ?
I thinking more and more it’s the ammo causing the short stroking.
I was using 42 gr of AA 2520 with match 168 gr Noslers. I know other people who use this load so I’m guessing its the brass. I used a partial resizing method that appeared to work find when testing.