M14s / M305 cocking effort problem

Grizzlypeg

Grizzlypeg

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I have two new 2007 M14's from Marstar. One requires significantly more effort to #### after dropping the hammer. Its like the initial movement out of battery, or just after moving out of battery and beginning to #### the hammer is way more difficult. If I remove the trigger group, both are the same effort, so its not the recoil spring or guide. Both are very smooth after being cleaned and greased. What would cause more resistance at this initial phase of cocking the hammer / opening the bolt? Its a real thumb buster compared to the other gun.

The trigger group was thoroughly degreased, oiled with G96, then grease applied to the surface which bares against the bolt. Same with the bolt, cleaned, oiled with G96 and greased on bolt lugs, roller, bolt to hammer sides lugs, etc. I don't think its a lubrication / cleaning issue. Something to do with the bolt pushing back against the hammer.

I could try swapping trigger groups and see if the problem follows the trigger group or is cured.
 
I swapped trigger groups. Made no difference. As soon as the bolt rotates out of battery and begins to meet the resistance of the hammer, it feels like its locking up. Takes a very hard snap to get it past the starting point.

Problem with op rod???
 
:agree: , this might also be the culprit, and it would be most noticeable when oprod is in it's rear travel area. Check for index, then.... check the op rod guide on the barrel and be sure it is inline with the gas system and tighten it if it is loose
 
45ACPKING said:
does it still do this with a stock on it?
is the op rod binding on wood somewhere?
Click to expand...

I guess I can't really duplicate the problem without a stock, because I need the resistance of the trigger group to duplicate the problem. In stock, and no trigger group, or in stock and already cocked, it cycles quite smoothly.

Yes, the indexing as seen at op rod to gas cylinder is out slightly. Op rod guide I believe is tight, but I'll have to check that again.
 
Is it perhaps an issue of the portion of the Op Rod/Cocking handle binding in the raceway that exists on the right side of the reciever? Similarly is the bolt running up against rough spots or burrs on the inner left side of the reciever.

I had an older production M14S kit from SIR where the op rod required a tiny bit of filing on the portion that ran through the raceway on the right hand side of the receiver for it to #### under effort, after which I still had to #### it a couple hundred times with lapping compound to get it working more smoothly. Even with that there still remains some resistance from rough spots on the other side of the reciever with the bolt.
 
When I compare this rifle to my old Norinco, I see a noticeable difference in the op rod tightness in the groove in the right side of the receiver. On my old Norinco, when the bolt is in battery, I can wiggle the op rod handle up and down slightly, there is some play in the channel. But, on the new gun, when the bolt is closed, and the op rod fully forward, she's tight as a wedge in the groove in the receiver. No play up and down whatsoever. I wonder if it just needs to be broken in?

There is a small amount of movement of the op rod guide to barrel. Not much, but you can move it. As for indexing, the op rod end almost perfectly lines up with the gas system. Maybe a degree of misindexing.

I may just have to shoot the gun and see if there is any actual problem with cycling, and see if the wear of operation loosens things up.
 
Disregard the issue of the tight oprod in the receiver at battery. Guess what the cause was? The stock. When the op rod is fully forward, it wedges right tight into the stock, making it appear that there was no play. Bad news is that even operating the action outside the stock, the problem still exists of the "percieved" excessive cocking effort / bind.
 
45ACPKING said:
does it still do this with a stock on it?
is the op rod binding on wood somewhere?
Click to expand...

You were right, it was binding on wood, right at the battery position, forcing the op rod down. I didn't realize the gun could be cocked and operated without a stock in place. Its still very rough, even without the stock.
 
Back from the range. The gun performed flawlessly for 40 rounds. There is obviously no problem affecting function. Found most of my brass in the snow. Dialed it in at 100 yards, re-zero'd the elevation dial. No problem hitting the 200 yard gong, other than my fingers were getting cold and my patience wearing thin, glasses fogging up. I'm very happy with the gun. Can't give a proper report of group size. Too cold to get serious about it, but happy the gun functions properly. Do they make a winter trigger for the m14 or was that the Garand they made those for?
 
yes, there is a winter trigger as well- , actually 2 styles- one looks like a long lever that attaches to the trigger and when you grip the pistol grip, it pulls the trigger, the other is merely a trigger exension- and there's a "winter" safety as well- one simply clamps on the trigger( i beleive the garand winter trigger might also work) , the other requires drilling the stock
 
BTW, the multi-tool's big end works well for pushing the rounds out of the stripper clip into the rifle. I'm told that's the reason for the radius cut into it. Handy when your hands are cold.
 
yep- and you can use it either with the filler clip out of the rifle or the stripper clip guide in the rifle
 
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