M14 gas system shims

brownells sells the good ones.... maybe fulton armory as well.

or you could roll peen the buttress forward and never need shims again. Very easy permanent fix for aligning gas port and tightening up the system.
 
If you dont have the SOCOM 18 w/ the gas lock front site, and you've tried flipping your gas lock to no avail, I have a spare one I can swap you if you want.

Another CGN'r hooked me up with a spare a while back and I have no immediate use for it (but I would like to keep an extra) It'll give you 2 more chances at good timing.

PM me if interested.
 
shims don't address gas port alignment.
shims are for lazy people who aren't even paying attention to port alignment when they blindly add shims to solve a loose gas lock and then wonder later why thier rifle is still shooting +3moa.

no, I'm not "Hungry/Tactical Teacher" LOL (too lazy to use bold for azzkissing cool power)

but there is a better way and in my world, gas cylinder shims are a waste of money and a gimmick.

not trying to be a #### but some of you need to quit running to Barney and learn to do some simple things to your rifles that "will" improve them and increase potential and more importantly repeatable accuracy.
I tuned a few hundred of these rifles both professionally and non professionally and got paid good money to do so. Gas cylinder shims were an item you could not find in my shop even today. It's a simple process and if you wrap and tape the cylinder assembly up by the flash hider, you do not need to remove the flash hider. Unlike shims where the barrel must be naked.
Shimming assumes all the dimensions are correct between the buttress and the port. I've guaged 100's of norinco barrels and this dimension is often no in spec and when people shim, they are actually closing of a portion of the gas port. This affects your rifle and it's accuracy as well as reliable function due to gas port fouling.
Now, it's a simple thing to lay the buttress at an angle on a steel surface and gently tap it with a hammer as you evenly rotate the barrel. The light hammer strikes should be made with a steel hammer with a light sweeping motion to the hit, it the direction the buttress needs to go. You are creating a shoulder that when the gas lock is tightened, will crush form behind the cylinder, negating the need for shims.
Work slow, trial fit often and stop when the gas lock comes hand tight at 4'oclock. Then tighten with gas lock wrench to 6:eek:clock. Back off the gas lock and ensure that it now comes hand tight at 4:30 to 5 oclock. It should stay at that tension for many thousand rounds VS shims that tend to degrade and pound out over a much shorter time.
It's a fix it and forget it method to never needing shims again.
Now if one does shimming or roll peening and isn't using a port alignment device to see what is happening in there.... the whole process, either one, is a waste of time.
My method...... Roll peen (or shim if you must) the gas cylinder barrel buttress untill perfect gas port alignment is achieved, then chose an appropriate gas lock that comes hand tight at 4:30/5oclock.
it's that simple.
 
Last edited:
well the first thing I tried was flipping over the lock,no better. its a USGI kit from wolverine, everything is in good shape,but my lock ring is tight at about 11 oclock. with gas block pushed back all the way the port is lined up perfect. ive thought about removeing a bit off the lock to let it spin on further, to lock up tight. not sure if this will throw other things out however with the gas plug to piston fit.
 
45ACPKING said:
shims don't address gas port alignment.
shims are for lazy people who aren't even paying attention to port alignment when they blindly add shims to solve a loose gas lock and then wonder later why thier rifle is still shooting +3moa.

no, I'm not "Hungry/Tactical Teacher" LOL (too lazy to use bold for azzkissing cool power)

but there is a better way and in my world, gas cylinder shims are a waste of money and a gimmick.

not trying to be a #### but some of you need to quit running to Barney and learn to do some simple things to your rifles that "will" improve them and increase potential and more importantly repeatable accuracy.
I tuned a few hundred of these rifles both professionally and non professionally and got paid good money to do so. Gas cylinder shims were an item you could not find in my shop even today. It's a simple process and if you wrap and tape the cylinder assembly up by the flash hider, you do not need to remove the flash hider. Unlike shims where the barrel must be naked.
Shimming assumes all the dimensions are correct between the buttress and the port. I've guaged 100's of norinco barrels and this dimension is often no in spec and when people shim, they are actually closing of a portion of the gas port. This affects your rifle and it's accuracy as well as reliable function due to gas port fouling.
Now, it's a simple thing to lay the buttress at an angle on a steel surface and gently tap it with a hammer as you evenly rotate the barrel. The light hammer strikes should be made with a steel hammer with a light sweeping motion to the hit, it the direction the buttress needs to go. You are creating a shoulder that when the gas lock is tightened, will crush form behind the cylinder, negating the need for shims.
Work slow, trial fit often and stop when the gas lock comes hand tight at 4'oclock. Then tighten with gas lock wrench to 6:eek:clock. Back off the gas lock and ensure that it now comes hand tight at 4:30 to 5 oclock. It should stay at that tension for many thousand rounds VS shims that tend to degrade and pound out over a much shorter time.
It's a fix it and forget it method to never needing shims again.
Now if one does shimming or roll peening and isn't using a port alignment device to see what is happening in there.... the whole process, either one, is a waste of time.
My method...... Roll peen (or shim if you must) the gas cylinder barrel buttress untill perfect gas port alignment is achieved, then chose an appropriate gas lock that comes hand tight at 4:30/5oclock.
it's that simple.
Click to expand...

soooo in the end you have swelled the buttres to let the gasblock lock up tight, forcing the block further ahead the same as a set of shims would do? yet shims are no good you say? would your method not have the exact same affect as the shims, pushing the block ahead and closeing off part of the gas port?
 
sure, shims accomplish this task if you prefer and were made for this purpose but rifle builders find new and improved ways to do things. i did not invent the idea of roll peening thegas cylinder buttress and learned about the practice from one of the US's many long time m14 smiths.
If you have the good quality stainless shims that come in many thicknesses you can stack them to fill the gap. I have found it hard to find those even at brownells. Sage Int supplies the ones I'm talking about (or used to) , with thier chassis kits. The Brownells ones I've seen come in a package with 4 shims connected together. The stainless is cheap and soft.

so ya, if you want to go the route of shims and can find those hardened stainless ones, put your gas assembly plate on backwards, reassemble the cylinder with port alignment rod (drill rod) and measure the gap between the buttress and plate. Shim accordingly with appropriate thicknesses.
at least this method observes gas port alignment vs stressing on shimming to get a tight gas lock which most people i see on cgn have been doing.... shimming to get a tight gas lock

also for those who have welded on flash hiders and want to shim..... you either have to cut the shims and manipulate it on .... what's the point?
roll peening the buttress seems to be a simple solution to a problem and saves having to purchase more stuff and and pay for more shipping....

but hey..... to each his own ;)
 
OK about what I thought. So my question is if the ports line up with the gas system bottomed out without shims , what would be. Wrong with removing a few thou off the locking ring to make it come tight at 530 position ?
 
Beater said:
OK about what I thought. So my question is if the ports line up with the gas system bottomed out without shims , what would be. Wrong with removing a few thou off the locking ring to make it come tight at 530 position ?
Click to expand...

problem with removing material from the gas lock is that you are now shrinking the internal volume of the gas cylinder because the plug now threads in deeper. Probably only a few thou but still not adviseable
 
Thinkin maybe ill remive the same amout off the bottom of the gas plug. If volume makes a big diff by removeing a few though of ether oll put the gasplug in the mill and deepen the hole by the same amout. No shims no hammering on a barrel ether
 
i suppose you could try that , let us know
Roll peening the shoulder on the gas cylinder barrel buttress is such a simple process. Gun smiths have been roll peening barrels with recess shoulders since time began. There is an appropriate way to do these things so hammering away on the barrel is not necessary.
If you were here in front of me and saw it done you would understand how simple and safe the practice is and if done with care, the adjustment would be barely noticeable visually. You don't hammer the whole buttress, just the very edge the gas cylinder butts against, creating a recess shoulder.

anyhow, was just trying to help, I'm not trying to preach, was just offering a simple proven technique that would save folks time and money , especially those with welded on flash hiders that don't want to hammer thier FH off.

in your case..... I would just get another gas lock or two find the one that fits the best and sell the others in the EE.
or..... try the milling machine adjustments and let us know how things go.
I've deepened the gas plug recess on a few problematic rifles that were short stroking and all other possible remedies were satisfied and still problems. added a bit more gas volume to the cylinder to increase dwell time a fraction and voila..... no more short stroking in those particular rifles.
So try the gas lock adjustment, then test fire with a few weights of ammo. If dwell time has been seriously affected by the plug being set deeper..... you will know. If it has, deepening the plug would be the way to go. I'd be hesitant to mill off the hardened surfaces of the mouth of the plug tho as the piston might peen it out and who knows?

I should add a note in edit here.
I came to my knowledge and understanding of the M14 gas cylinder and it's function and affect on repeatable accuracy from both the writings/posts and direct conversations on the phone with Gus Fischer, Tim of warbird customs and a few others. Also the kuhnhaussen shop manual for technical reference for US spec parts.
I took the advice from these folks and applied it the best I could to the chinese rifles and I did so quite successfully I think.
So in the end, I can only give the best advice I can and folks can take it or leave it.
 
Last edited:
45ACPKING said:
i suppose you could try that , let us know
Roll peening the shoulder on the gas cylinder barrel buttress is such a simple process. Gun smiths have been roll peening barrels with recess shoulders since time began. There is an appropriate way to do these things so hammering away on the barrel is not necessary.
If you were here in front of me and saw it done you would understand how simple and safe the practice is and if done with care, the adjustment would be barely noticeable visually. You don't hammer the whole buttress, just the very edge the gas cylinder butts against, creating a recess shoulder.

anyhow, was just trying to help, I'm not trying to preach, was just offering a simple proven technique that would save folks time and money , especially those with welded on flash hiders that don't want to hammer thier FH off.

in your case..... I would just get another gas lock or two find the one that fits the best and sell the others in the EE.
or..... try the milling machine adjustments and let us know how things go.
I've deepened the gas plug recess on a few problematic rifles that were short stroking and all other possible remedies were satisfied and still problems. added a bit more gas volume to the cylinder to increase dwell time a fraction and voila..... no more short stroking in those particular rifles.
So try the gas lock adjustment, then test fire with a few weights of ammo. If dwell time has been seriously affected by the plug being set deeper..... you will know. If it has, deepening the plug would be the way to go. I'd be hesitant to mill off the hardened surfaces of the mouth of the plug tho as the piston might peen it out and who knows?

I should add a note in edit here.
I came to my knowledge and understanding of the M14 gas cylinder and it's function and affect on repeatable accuracy from both the writings/posts and direct conversations on the phone with Gus Fischer, Tim of warbird customs and a few others. Also the kuhnhaussen shop manual for technical reference for US spec parts.
I took the advice from these folks and applied it the best I could to the chinese rifles and I did so quite successfully I think.
So in the end, I can only give the best advice I can and folks can take it or leave it.
Click to expand...

many have benefited from your reservoir of knowledge, I look forward to your technical insights. thank you.
 
45ACPKING said:
i suppose you could try that , let us know
Roll peening the shoulder on the gas cylinder barrel buttress is such a simple process. Gun smiths have been roll peening barrels with recess shoulders since time began. There is an appropriate way to do these things so hammering away on the barrel is not necessary.
If you were here in front of me and saw it done you would understand how simple and safe the practice is and if done with care, the adjustment would be barely noticeable visually. You don't hammer the whole buttress, just the very edge the gas cylinder butts against, creating a recess shoulder.

anyhow, was just trying to help, I'm not trying to preach, was just offering a simple proven technique that would save folks time and money , especially those with welded on flash hiders that don't want to hammer thier FH off.

in your case..... I would just get another gas lock or two find the one that fits the best and sell the others in the EE.
or..... try the milling machine adjustments and let us know how things go.
I've deepened the gas plug recess on a few problematic rifles that were short stroking and all other possible remedies were satisfied and still problems. added a bit more gas volume to the cylinder to increase dwell time a fraction and voila..... no more short stroking in those particular rifles.
So try the gas lock adjustment, then test fire with a few weights of ammo. If dwell time has been seriously affected by the plug being set deeper..... you will know. If it has, deepening the plug would be the way to go. I'd be hesitant to mill off the hardened surfaces of the mouth of the plug tho as the piston might peen it out and who knows?

I should add a note in edit here.
I came to my knowledge and understanding of the M14 gas cylinder and it's function and affect on repeatable accuracy from both the writings/posts and direct conversations on the phone with Gus Fischer, Tim of warbird customs and a few others. Also the kuhnhaussen shop manual for technical reference for US spec parts.
I took the advice from these folks and applied it the best I could to the chinese rifles and I did so quite successfully I think.
So in the end, I can only give the best advice I can and folks can take it or leave it.
Click to expand...

I took Mr 45s advice and got out my fav 1 lb flat faced hammer and proceded to try swelling the buttress. I gotta say I learned something and it worked well. thanks a bunch
 
You must log in or register to reply here.
Back
Top Bottom