M1A match rifle not cycling

[DaveL]

Hello All,
My shooting buddy just bought a new Springfield M1A Match grade off Gunbroker. It has an odd (to me) cycling problem. The first few shots cycle correctly landing 6 feet or so at about a 45 degree angle forward. But as he continues to shoot the shells start landing closer and closer to the bench and the angle goes from forward at 45 degrees to 90 degrees to backwards at about 30 degrees and then stops cycling as the shells land on the bench. From here it short strokes and won't pick up the next round. I used to shoot High Power Matches with my M14SA so I am familiar with the cleaning and maintenance of these rifles. It's cleaned and lubed correctly. I've tried replacing the op-rod spring from the NM to a standard. That made things worse, it short stroked on the first round. I've checked the barrel gas hole for obstructions, found nothing out of the ordinary there. I've changed the op-rod spring guide from the NM to a standard. That had no effect. The piston is clean and dry and moves freely, but I replaced it with a standard piston anyway, which had no effect. Same problem. We have tried a number of ammo types including military white box match in 168 and 173 grain, my full length sized reloads I used when I competed, loaded with Sierra 168 grain HPBT Match Kings and IMR 3031 and 4895. All loads fail in the same way in this NM rifle but run perfectly in my M14SA. It almost acts as if the hammer is dragging on the bolt but I can see no excessive galling or ware on the bolt, the hammer or the receiver and if it was dragging, why would it get worse and worse as it's fired? I tried to lower the trigger group by shimming the trigger group between the group and the stock but it's so tight it only allows about .010 shim thickness. I haven't shot it like this but I expect that little bit won't help anyways.
Any thoughts as to where to go next? I'm at my wits end with this rifle and my buddy is about ready to bust it over a rock. I'm hoping someone out there has a fix.
HELP!!
Dave

[nf1e]

Could be the gas cylinder is out of spec. That would account for the changes as it warms up.

[DaveL]

nf1e,
Do you have the specs for the gas tube? I couldn't find them anywhere on the web. I guess my next step is to compare the gas hole and piston hole to my M14SA and see if they measures the same sizes, if no one has the specs. I am hoping someone has them and will respond.
Any other ideas out there?
Dave

[Sunray]

A new Springfield M1A Match(it's not an M-14 of any kind. No M1A is an M-14.) should go back to SA Inc. under warrantee. Assuming the Gunbroker seller was a retailer. Do not mention the use of reloaded ammo. Voids the warrantee.
Sounds like the gas cylinder is loose though. Or the gas valve may have been replaced with the wrong part.
Read response #8.
http://m14forum.com/m14/73388-stupid...as-system.html

[lyman]

sounds like something is restricting the gas flow, and it gets worse as it heats up,

so between rounds are you cleaning it or letting it cool while yall load mags, ponder etc?


and yes, if it is a SA built gun, call them for warranty work

[Dan Shapiro]

Send it back to SA. That's probably why it ended up on Gunbroker in the first place.

[Hecklerusp45]

I remember seeing 45 autos that would work great until they got hot. Come to find out that the bushing was expanding as it got hot. When it got tight enough, they would jam. Sounds to me like something is getting hot, expanding, then causing the problem. Gas system would be the first place I would look.

[DaveL]

Thanks for the replies guys. I will be looking a lot closer at the gas system.

[DaveL]

Update
Well, we couldn't find anything wrong with the gas system. Checked everything I know and found no problems. It's on it's way to Springfield. I'll post the outcome when he gets it back.
DaveL

[Richard H Brown Jr]

Dear Davet.

This is gonna sound stupid, but did you check the gas spindle? Normal operation position is perpendicular to the gas tube. The screw driver/ combination tool blade can be used to make sure it's in the up and down direction. If the spindle valve is in the proper position, shoot the rifle a few times, and see if the spindle valve orientation changes, if it does, the spindle valve or it's seat could be a bad part.

The -34 manual for the M-14 gives Short recoil as being (in decending order) A. Undersized or damaged Gas Piston B. Gas Cylinder oversized C. Operating Rod bent D. Damaged Operation Rod Guide E. Bolt binding receiver F. Restricted movement of Operating Rod G. Cartride Guide Clip Pin restricting Bolt movement.

TM 9-1005-223-35 Illustration B-29 on page 59 shows the exploded parts diagram withe the Gas Spindle Valve, and Gas Spindle Spring removed
from the Gas Cylinder. It may be worthwhile *CAREFULLY*driving the pin out on the other side of the Gas Spindle Valve and removing both parts and seeing if the port machined in the spindle isn't partially blocked.

Since you didn't say if the rifle was bought as brand new or used, it may be that if it was brand new out-of-the-box, the heavier preservative oils wasn't completely cleaned off the rifle. The Bolt Roller may be not rotating freely. Strip the bolt completely except for the roller bearing, and dump in a jar of mineral spirits to let every bit of preservation oils work out of the Roller. Clean and lightly oil all the bolt parts and reassemble, then hand pack the roller bearing with lubriplate grease or white lithium grease see page 10 of this lubrication aid: http://www.m14.ca/maintenance/M14_Lu...ictures_1_.pdf, there are also vid clips on youtube on how to pack grease in the roller bearing.

The most off the wall idea I can think of is, that once the barrel heats up, it's bending just enough to where the op rod isn't moving freely and is dragging on the barrel underside. So either the barrel is bent, or improperly aligned to the receiver face, or the Op rod is bent or machined wrong.

Since you said you've sent the rifle off to Sprinfield Armory, hopefully the can correct the problem, and they will include a description of what was wrong with the rifle. And you can post an update to what was the problem

R. Brown