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GriffonSec
6 May 2009, 08:37
After tinkering with my first AR the last couple of months, I managed to run into a friend selling one at what I thought was an absolutely great price. He and my father are very close friends, and he purchased the rifle from him in the mid 80's when my father held his FFL. I actually remember this and another coming into the house. I was 15-16 at the time, so there's a bit of cool factor to me in this also.

SGW CAR-AR, 16" barrel, hard chromed BCG, A-1 upper (rifle stock added, which the tech question will explain) :

http://i624.photobucket.com/albums/tt323/griffonsec/sgw1.jpg

http://i624.photobucket.com/albums/tt323/griffonsec/sgw3.jpg

http://i624.photobucket.com/albums/tt323/griffonsec/sgw2.jpg

http://i624.photobucket.com/albums/tt323/griffonsec/wevo1.jpg

Now, initially, at the price purchased, I considered it somewhat "investment" and had thought to simply hold on to it for a bit and sell it. However, that's changed. There's something to the simplicity of it that I really like, and after tearing it down, the fit and finish for a 25 year old rifle is ridiculously tight. There is no 'creep' in the trigger, and it's very crisp, much better than my current 'new' rifle. I'm considering a full Magpul MOE kit for this, and simply leave it at that.

Here's my question in this. Talking with him, he added the rifle stock because occasionally the bolt will not lock back on an empty magazine with the collapsible stock/buffer (there are no FTE, FTFs). He did try an extra power buffer spring but it did not alleviate the issue. While not having a specific round count on the barrel, there's most likely 3k + through it. Acts the same on different BCGs also. I'm thinking the rifle weight buffer is a fix for the problem, and that a H-3 buffer in the carbine stock will also correct this. I would like to find what the problem exactly is. We both discussed the possibility of gas port erosion, and the system is being 'over-gassed'. There are no issues with accuracy with this rifle whatsoever. I guess what I'm asking is aside from trying different buffer weights is there a solution to the problem aside from changing the barrel, and if I decide to keep this barrel (which I really would like to do as it's still damn accurate) is the gas port erosion an issue?

Thanks-
Steve

Stickman
6 May 2009, 09:56
What magazines are being used?

Check that your carrier keys are tight, and staked. Check your gas rings as well.

My first guess would be the mags, and that weak ammo was bringing out early symptoms.

103m 95g
6 May 2009, 10:14
Could be something as simple as the leg on the bolt catch is a little short and the follower on that particular mag being used does not push the bolt catch up to lock the bolt to the rear. you said occasionally
so the issue might not have anything to do with the stock.

Id start with Stick's recommendations but would add check the SIZE of the gas port hole to see if it falls within the acceptable range for a carbine.

GriffonSec
6 May 2009, 10:30
I do know that he has several NHMTG mags with green followers. However, he did say he has tried several different magazines. I don't think I'll have a chance today to try my PMAGs out, but I'll put that on the list of things to do. I'll also need to put the collapsible stock on, since it does not have any issues with lock back on the rifle stock.

I also initially leaned towards the gas key/rings thought process until he had tried other bolt carrier groups and that did not solve the problem. When I try out the PMAGs, I'll swap my Armalite BCG and LMT bcg and see what happens. That encouraged an idea, I may just try different bolts with different carriers also.
The staking on the key is different than what I'm used to seeing, it appears to be something like a round press on each screw, and 'melds' the key and screw together, and screws are red loctite. I need another set of AA batteries and I'll get a pic up of it.

When I did ask about ammo, he stated it's only seen 55gr and up, never any wolf or questionable quality. Knowing him, I buy that too.

Edit: 103 - I posted this answer prior to seeing your post. It is occasional, so I'm looking to other causes also. I'm hoping to solve it without having to take the FSB off because that would be a new one for me, but I picked up the rifle knowing the issue, and don't mind doing some garage/bench learning to fix a problem, especially if it's occasional.

Lancelot
6 May 2009, 13:25
Nice Rifle.

Great minds........

http://coloradoshooting.org/v-web/gallery/albums/bbadmin-Album-1/CMT_CAR_025.sized.jpg



.

GriffonSec
6 May 2009, 13:38
Lancelot - Thanks. I'm starting to really like the Old School look with the A1 upper, I've just never been quite comfortable with the rifle stock. I had considered an A3/M4 flat top receiver, but there's really no need to, as I won't be doing any kind of optic on this, and I do like the stock irons on this.

BCG pics -

Staking - While not 2 sided, it appears to be fairly substantial, but I'll take input on this also. It's definitely more than the old punch/hammer combo anyway. (the discoloration by the way is not rust, even though it may appear so in the pic)

http://i624.photobucket.com/albums/tt323/griffonsec/stake.jpg

Here's the lower side of the carrier -

http://i624.photobucket.com/albums/tt323/griffonsec/carrier.jpg

and a pic of the bolt itself. I'm going to go ahead and put new rings on, it won't hurt. While movement is free, it's more of a smooth resistance, but definitely not loose, versus the new LMT bolt I just received which almost has a drag it's so tight right now.

http://i624.photobucket.com/albums/tt323/griffonsec/bolt.jpg

and the group:

http://i624.photobucket.com/albums/tt323/griffonsec/bcg.jpg

I really appreciate the input on this. I think the rifle is going to be a keeper.

Eric
6 May 2009, 17:18
Here's my question in this. Talking with him, he added the rifle stock because occasionally the bolt will not lock back on an empty magazine with the collapsible stock/buffer (there are no FTE, FTFs). He did try an extra power buffer spring but it did not alleviate the issue. While not having a specific round count on the barrel, there's most likely 3k + through it. Acts the same on different BCGs also. I'm thinking the rifle weight buffer is a fix for the problem, and that a H-3 buffer in the carbine stock will also correct this. I would like to find what the problem exactly is. We both discussed the possibility of gas port erosion, and the system is being 'over-gassed'. There are no issues with accuracy with this rifle whatsoever. I guess what I'm asking is aside from trying different buffer weights is there a solution to the problem aside from changing the barrel, and if I decide to keep this barrel (which I really would like to do as it's still damn accurate) is the gas port erosion an issue?
The BCG looks bone dry. I would start with a thorough cleaning and lubrication. Here's a great resource that covers the lube points: http://www.ar15.com/forums/topic.html?b=3&f=7&t=433730
For the most part, if the bolt does not lock back after the last round, you're looking at a short-stroking issue. Adding a heavier spring or buffer will tend to make the situation worse. Underpowered ammo can also induce a short-stroke condition.

To check for worn gas rings: field strip the BCG, insert only bolt into the carrier, grasp the bolt by the lugs and see if the inserted bolt will support the weight of the carrier. If it drops free, time for new rings.

As previously listed, ensure that the gas key is torqued and staked. Make sure there isn't an obstruction in the gas key (cotton swab tips like to hide in there). While not that common, the gas tube can clog and if that is the case, don't bother trying to clean it out, just replace it. Make sure the BCG is able to retract all the way into receiver extension without binding. When retracted all the way, the bolt should just about be at the rear of the ejection port.

GriffonSec
6 May 2009, 18:14
Eric, Thanks. I did the gas ring check and here's what happened (and to help me along, I did this with all 3 BCG's I have):

The SGW would hold, however any shake to it and the carrier would drop free.
The Armalite I have took 2-3 light shakes before the carrier would drop.
The LMT wouldn't drop free at all unless violently shaking it.
Again, I went through all 3 so I could see the differences. Gas rings are cheap enough, so that's on the 'fix' list.

I know the BCG looks dry, but there is a light film on it. Actually, there's more oil on the entire weapon than I actually prefer, but it has been stored a while. I don't know why it came out looking dry in the pics.
Pipe cleaner gave the gas key the OK for obstructions, and I did check the tube for any kinks/dents, but didn't think that it may be clogged. Another cheap enough fix and easy to remedy, add that to the list.

The only reason I was questioning the buffer weight was I am under the impression that the rifle buffer weighs more than the standard H or CAR buffers, and the rifle buffer/spring eliminated the issue.

All of this back and forth into the receiver has me noticing other things, and begs another question. The edge of the bolt release that actually catches the bolt has some obvious wear, along with a couple of minor notches. Would it be possible for a bolt release to wear down enough to not function properly? If that's an off the wall question, let me know, it's just something I noticed while watching it interact with an empty magazine.

GriffonSec
7 May 2009, 15:07
Ok, an update.

To try to duplicate the problem, I needed to put the CAR tube and stock back on. I had another tube that I had removed from my Armalite that did not have the finish wear the one that came with it did, so I installed it instead of the old one. I also had a new buffer spring and buffer that I installed. After reassembly and a moderate amount of oil, I tried several single shots through a PMAG (about 20). I then tried another 10 singles through the NHMTG mag that I have, and one of my 2 CProducts mags with the orange Magpul follwers. Ammo was the last of a bit of Remington Soft Points I had, along with a few Georgia Arms reloads with some factory 55gr Remington FMJ. I could not get the problem to duplicate itself, bolt locked back on an empty mag every time. I then tried 2 rounds in the mag and double tapping, still the bolt locked on the empty. Weird.

I called the previous owner to ask just how occassional the problem was, and he stated maybe 2 times in 5 it would occur, some attempts with various different springs/buffers would either worsen or improve it, but 2 in 5 was average.

It almosts begs the question would the tube itself have been a problem? That's the only thing changed aside from a new standard spring and new buffer. Again, weird.

I was very very please firing the rifle as a side note. Very accurate considering who was firing it. I mentioned that also to the previous owner and he then told me it did have a stainless barrel, and had always shot well for him. Stainless barrel? Bonus I think...

The way it sits now, and of course, any further input would be appreciated.

http://i624.photobucket.com/albums/tt323/griffonsec/sgw-car.jpg

Thanks-
Steve

Eric
8 May 2009, 06:54
Action springs (AKA buffer springs) do wear out. The spec for the springs:
CARBINE: 10 1/16 inches (25.56 cm) minimum to 11 1/4 inches (28.58 cm) maximum.
It's not common for the receiver extension (AKA buffer tube) to go bad, but stuff happens.

I like the A1 upper on your carbine. I prefer the ruggedness and simplicity of the rear sight for most applications.

GriffonSec
8 May 2009, 16:29
I ran a couple of more mags through today. I really enjoy shooting this rifle. I did have a couple of issues, but I honestly believe it was magazine related. I fired one full PMAG without issue, and one full Cproducts mag (not just single shot to check for lock back). I had 3 FTFs with the Cproducts mag. I loaded the magazine again and hand unloaded it, and it felt as if I was pushing rounds through gravel. I'm sure it was the mag. I'm trying to decide whether or not to chuck the 2 Cprod mags I have at the turtles in my lake, or level out a coffee table with them. Ran another PMAG through with no issues. Chalk that up to a bad magazine.

I do really appreciate everyone's input on this particular carbine. Thanks!

Steve