Jump to content
308AR.com Community
  • Visit Aero Precision
  • Visit Brownells
  • Visit EuroOptic
  • Visit Site
  • Visit Beachin Tactical
  • Visit Rainier Arms
  • Visit Ballistic Advantage
  • Visit Palmetto State Armory
  • Visit Cabelas
  • Visit Sportsmans Guide

Whoas and sadness with my first AR


jlaw

Recommended Posts

I looked in the chamber with my streamlight and can see it doesnt look like it was polished at all, looks just like holes that I ream for tapered pins with a very fine lenghtwise chatter marks, I spoke to a local gunsmith that a few of my friends use and he recommended lightly polishing with 800 grit paper on a wood dowel in the lathe. Sound good?

Link to comment
Share on other sites

  • Replies 68
  • Created
  • Last Reply

Top Posters In This Topic

...I spoke to a local gunsmith that a few of my friends use and he recommended lightly polishing with 800 grit paper on a wood dowel in the lathe.

Be VERY careful when doing this. Remember that when you're polishing, you are actually removing material and once removed, it can't be put back. If you've never done it before, I'd take the upper to the 'smith and let him do it while giving you a block of instruction on chamber gauging so you know when to say, "when." An out of spec chamber, either too small, too big, or out of round is a bad thing.

Link to comment
Share on other sites

Just like he told me I believe that fixed it, it didn't take very much polishing, I haven't shot it yet, but I can manually cycle a whole mag through it now without the bolt sticking closed once and all of the marks are gone from the back of the cases. We shall see how it goes when I make it to the range.

Link to comment
Share on other sites

  • 1 month later...

Hello ladies and gentlemen. Here is my long over due update. Sorry it took me so long been working my buns off as of latel, Found out I got a baby on the way, yadda yadda yadda so on and so fourth.

Sent the rifle back to CMMG, took about a week to get it back. Somewhat pleased with the work they did.. Shipping and return time was great and they were very pleasant to deal with.

They did a custom polish job on the feed ramp (very nice), Realigned the gas block, and lock-tighted the screws that hold the block in place.

I have had the riffle out to the range several times since I got it back.. Shoots great!!! about 300 rounds down range and not one failure to feed or eject! Makes me a very happy chappy. SO with that said I will attribute my FTF FTE to the crappy stock feed ramp job..

Gas block issues... They are persistent to say the least. First time taking the riffle out after getting it back from CMMG the gas block moved again... I'd readjust it.. It moves again. After about 4 range trips having this problem every time.. I noticed that not only is my block moving forward towards the muzzle brake a few milometers.. But so is the entire quad rail. It moves also is moving a few milometers from the upper. This movement has not cause one short stroke or failure.. 

So here is what I did, first stripped it down did a full inspection. I noticed that there were almost no dimples on the barrel to keep the gas block in place... So I guess CMMG did not notice this and just thought that loc-tight would keep it in place. I drilled dimples myself, seems to be a lot more stable now.

Every time I have broken this thing down and reassembled, I have noticed that when I install the FF quad rail it would never be aligned properly. Meaning that instead of the barrel being center it would be low, very low.. And I would be able to slightly move the rail left and right.. Seems my barrel nut was loose because I was able to remove it by hand without much man power... Figuring that is loose, correct me if i am wrong?

Sorry to go on and on guys...

Tightened the block up real good. Hopefully not over torqued, I don't have the proper tool so I had to use vice grips and a shimmy towel. When I tightened it to the max I was then unable to install my gas tube because there are little notches on the barrel nut that would get in the way... Dremel took care of that little notch reeeaaal quick. I then installed the Rail and drilled a very small dimple on the barrel nut to accommodate the screw from the rail that is supposed to hold the rail in place.. Tightened it down.. Feels great, better than it ever has and is now very stable. It wont budge no matter how hard I tug and pull.  So I'm thinking that the lack of dimples and the loose ass barrel nut was the fix on that.. I will update in the next couple of days..  Thank you everyone and have a great evening !  <thumbsup>

Link to comment
Share on other sites

Anyone know were I can find a flash enhancer for the .308?? I can only find them for .223..  ;D

An "enhancer"! :o You want your flash to be bigger? Just take off the muzzle device completely. Can't make a bigger flash than that. I'd suggest a thread protector in the mean time. They run about $5 in various places.

When I tightened it to the max I was then unable to install my gas tube because there are little notches on the barrel nut that would get in the way... Dremel took care of that little notch reeeaaal quick.

Uh... What? I think you made a very unnecessary (and irreversible) modification to your barrel nut. Those "little notches" are designed to line up with the gas tube hole. If you aren't lined up, you are either too tight or not tight enough... Based on your description you are probably the former rather than the latter.

Forgive me for not having time to read through pages and pages of posts. Can you post a current picture of your rifle? Maybe detail out the parts that aren't easily identifiable. Hard to help you figure out the problem if I don't know what I'm looking at.

Link to comment
Share on other sites

I certainly can post some pictures my brother.. I Always seem to post them to small and sideways and stuff. I haven't had to many posts on here so my apologies for that ahead of time. I really don't feel like taking the Rail off right this second, but I'll put up some picks of the new feed ramp and such..

Oh and the Flash Enhancer, I just want one for shoots and giggles... Reminds me off the fourth of July. <thumbsup>

I understand that those little notches align with the gas tube hole. It seemed like a twist to the right was to tight, and a twist to the left was to loose. At this point with all the garbage I've gone through with this beast.. I said to myself "screw it, if I muck it up I muck it up.. Amazon can have me one here in the mourning if need be lol.".

It doesn't seem like removing that single notch will affect the performance and you cant see it.. Will it? This is my first AR. If the barrel nut is to tight what will that do? Like I had said it really rock solid now. much better.

Really I'm just happy its shooting, now I'm actually part of the .308AR club.. Not the .308AR bolt action club.  ;D

PICS before and after ramp shots, .223 Flash Enhancer, and a few pictures of the rifle --->

post-1532-13629727359_thumb.jpg

post-1532-136297273592_thumb.jpg

post-1532-136297273594_thumb.jpg

post-1532-136297273596_thumb.jpg

post-1532-136297273599_thumb.jpg

post-1532-136297273601_thumb.jpg

Link to comment
Share on other sites

jlaw the typical barrel nut tightening is done three times tightening.

Tighten the nut pretty snug then back it off

Tighten it again approaching the notch where you plan on stopping. Back it off again

Tighten the final time on the desired notch.

You will be surprised how much incrementally further the nut goes with each torquing

Link to comment
Share on other sites

jlaw the typical barrel nut tightening is done three times tightening.

Tighten the nut pretty snug then back it off

Tighten it again approaching the notch where you plan on stopping. Back it off again

Tighten the final time on the desired notch.

You will be surprised how much incrementally further the nut goes with each torquing

Why is that? Does it have something to do with the barrel nut thread?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...