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This is a discussion on Shim(s) within the Accuracy forums, part of the M14 M1A Forum category; I'm thinking I need to shim my Socom, easy enough to do from what Tony and others have shown. I reached this decision due to ...


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Old April 21st, 2017, 10:22 PM   #1
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Shim(s)

I'm thinking I need to shim my Socom, easy enough to do from what Tony and others have shown.

I reached this decision due to fact I am able to turn gas lock to 9 o'clock before it even begins to tighten up plus every time I clean barrel with wet patch solvent leaks between gas lock and cylinder band.

Shooting this evening did a slow motion video of gases exiting barrel and could definitely see flash where I have cleaned carbon build-up, same location between cylinder band and gas lock.

If you look close you can see a sliver of flame set back like it is in muzzle ports. Any of you Socom owners shim and notice a difference in accuracy?


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Old April 22nd, 2017, 04:20 AM   #2
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Due to the short SOCOM barrel you're bound to get flash unless a fast burning propellant or ammo designed for short barrels is used.

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Old April 22nd, 2017, 05:08 AM   #3
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Leaking gas

That may be a case of a poor fitting rear gas cyl ring, shims wil not change that condition, only the gas direction.. ... Art

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Old April 22nd, 2017, 06:20 AM   #4
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Nearly M14 gas locks don't tighten up until the 9 or 10 o'clock position, then get backed down to the 6 for gas plug installation. That is the way they were designed, most likely to allow for metal expansion when hot. When you tighten the gas plug, you are "pulling" the gas cylinder forward against the gas lock. That is why gas locks are snug when being removed and loose when being installed.

The gas lock "timing" thing is relatively new, most likely influenced by folks selling shims. Whether or not shims actually help accurize the rifle is debatable. At the very least, the shooter "thinks" his rifle is more accurate and his shooting habits improve. The end is the same, putting rounds in the black. Whatever helps you sleep at night. It is a small investment to see if it helps.

I use shims simply to keep the front band and handguard from rattling, if needed. I only use enough to barely finger tighten the gas lock. Anything more may keep the metal from being allowed to expand. It can even distort barrel harmonics and raise point of impact.

Carbon builds up in the Socom muzzle because there is some breathing room between the actual barrel muzzle and the brake. It's the nature of the beast. The parts are not hand fitted, as it is not intended to be a precision rifle.

Judging by your photo, I can make two suggestions:

1. Get a new gas plug and use only a 6 point box wrench on it. You are rounding off the corners on the current one.

2. Get a new gas cylinder. The ones made by SEI are state of the art. They are usually very snug on the barrel and don't allow any leaks. I have not tried the ones by Bula, as they are more expensive.

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Old April 22nd, 2017, 06:57 AM   #5
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If guys like gun guru Tony Ben do it I'm confident that it has some effect on improving accuracy and not just a feel good endeavor for peace of mind so thats why I did my Standard. It's an easy enough procedure and cost very little to do so why not. To tell the truth it's hard for me to tell from group to group if it shoots tighter. My rifle is irons only and my eyes aren't what they used to be. Hey if it even closes groups a 1/4" it's worth it for me.

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Old April 22nd, 2017, 08:20 AM   #6
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Quote:
Originally Posted by Redneck Yankee View Post
Due to the short SOCOM barrel you're bound to get flash unless a fast burning propellant or ammo designed for short barrels is used.
Thanks. I've used up several pounds since December of IMR 3031, which is a fast burning powder, a pound of TAC and one or two more of IMR 4895.

Muzzle flash is not my concern, even with fast powders it's hard to get away from with the Socom short barrel.

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Old April 22nd, 2017, 09:59 AM   #7
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I shimmed my 2012 Scout about 300 rounds after I bought it.

I "think" it helped with the accuracy.

I know my groups improved but some of the improvement may have been due to range time with a new rifle.

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Old May 1st, 2017, 07:45 AM   #8
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National match rifles always snugged up the barrel band... Marines welded... Army screwed and glued. It's easier and simpler to just shim. So it has merit in increasing accuracy if done right.

Cheaper place for shims and more of then we just found and posted in this accurizing sub form:
http://www.badgerridgeind.com/store/p56/450BMshim

Sent from my SM-G920P using Tapatalk

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Old May 1st, 2017, 08:51 AM   #9
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Quote:
Originally Posted by topprop View Post
National match rifles always snugged up the barrel band... Marines welded... Army screwed and glued. It's easier and simpler to just shim. So it has merit in increasing accuracy if done right.

Cheaper place for shims and more of then we just found and posted in this accurizing sub form:
http://www.badgerridgeind.com/store/p56/450BMshim

Sent from my SM-G920P using Tapatalk
Thanks. I was just looking for shims, and most were more money for fewer shims.

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Old May 1st, 2017, 06:31 PM   #10
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Adding shims to my SOCOM tightened its groups. HTH

This fellow offers a nice assortment of 5 shims at a reasonable price:

http://www.gunbroker.com/item/642358868

I was able to get a good combination of them to do the job right.

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