Ar Not Stripping Round

[TRG65]

When I have a full mag inserted with the bolt locked back, and I drop the bolt release, my rifle jams. All I have to do to clear is pull the bolt back a second time and let it fly but that seems to be a little much. The gun doesn't seem to be dirty, and has been repeatedly cleaned, this occurs regardless of recent cleaning. It indicates to me that the recoil spring has weakened.

The rifle only has less than 500 live rounds through it. Although I do dry fire it a good bit.

I'm not keen on the idea of using downloaded mags.

Can anyone recommend a good replacement spring? I was looking at the CS springs that are sold under Tubb's name.

Or is there some other solution I should look at.

Thanks

Seth

[benny hill]

Use ISMI mag springs & never load more than 29 in the mag.

[benny hill]

I also use the ISMI recoil spring because I try to leave nothing to chance.

[George]

No way the recoil spring is sacked at 500 rounds no matter what brand. ISMI is good stuff and replacing with them is a very proper race thing to do. But the stock ones worn already, no way!

If it reliably strips rounds from downloaded mags, you might check to see if the bolt is dragging excessively over an empty mag. Another indication of a too high mag causing dragging is if you have to slam your mags into place to keep them in. This indicates a too high mag catch ledge and stoning it until full mags "snap" into place under a closed bolt without much push is what is needed. This will also lower the mag a tad and reduce bolt scrubbing of the mag which reduces bolt speed and causes what you are seeing.

Another thing to check is the rear of the nag feed lips at the rear of the mag. If they are cracked and letting rounds sit higher because they are bent up a tad, this will explain it.

Clean is one thing, lubed properly is another and AR's do not want to be run dry in most cases. A too dry AR will also cause this type of malf.

Also possible is the underlug of the bolt face being worn/cracked off just enough so that it is barely snagging rounds on the way forward. The fully loaded mags won't work, but downloaded ones will because there is less tension on the round and thee lug doesn't just skip over the round instead of stripping it forward.

Thats all I can think of at the moment.

Yes, good springs are good things, but there is some other factor at work here. Last thought, is your recoil buffer and spring lubed enough to keep friction here from slowing the bolt. Once again, this area really doesn't want to be run dry.

--

Regards,

Edited September 13, 2005 by George

[John Dunn]

I agree with loading 28 or 29.

[kurtm]

George has it exactly right!! Look at all the things he mentioned!

There is NO reason that an AR can't be run with a full mag! The only case where this is not true is if you use an aluminum carrier with the low mass spring system AND run the ISMA heavy springs. Standard springs in the mag are the key here, and then they will run all day with full mags! BTW is this cabine a "shorty" or a "full size" ( if you can say that about a carbine ) The collapsable stocks seem to have this problem more often than the long stock version. KURT MILLER

[BSeevers]

I will say I have never downloaded or even considered downloading a stock mag. I have a 16 inch, reg stock and stock bolt. Always works. I try to clean and lube it too.

[chp5]

I always download by 1. Maybe I need a new recoil spring.

How long should a stock spring last?

[Patrick Sweeney]

You might take a look at the feed ramps area of the barrel extension. If you have heavy brassing on the edges, a bit of stoning could bring big dividends.

As for how long the springs last, I'll let you know when I wear one out. I have one rifle on its third barrel, with the origianl buffer spring.

[George]

Thanks Kurt. I used to believe that downloading 30's (and even 20's) was the way it had to be, but realize that if I won't accept that in my pistol, why should I accept it in my rifle!

All my AR's run 100% with full mags inserted under a closed bolt. If it won't, it's broke and needs to be fixed IMO.

--

Regards,

[TeamGE]

Ditto what George said!!!!!!!!

[redmercury2]

Dave tubbs recoil springs and BROWNELLS new ar mags have eliminated your same prob for me, the mags are definitely the bomb.

[TRG65]

I haven't had a chance to pull it out and make sure it is lubed up. I can seat a full mag under a closed bolt, but when I do I can't be gentle. I do tend to run my guns w/o much lube because I'm accustomed to Glocks, and I thought I had read somewhere that with gas op'ed like the AR and 1100's lube was an enemy because it gunked things up. Therefore I use a dry moly film lube.

I will look the rifle over probably tomorrow and repost.

[Patrick Sweeney]

Holy petroleum, Batman! Am I going to have to trail the next Billy Graham crusade, and pass out literature that YOU DO NOT RUN ARs OR 1100s DRY.

Dripping with lube, no. But lubricate the things, unless you are running them in a literal dustbowl of a country.

Gaston Glock may have designed a "no-lube" gun, but nobody else has.

[Paule]

Even dripping is good for the first 1k rounds or so. Makes things a lot slicker down the road. We do the break-in on nearly every upper we ship and they run awash in Kel-lube and FP10 (together) for the first 50-100 rounds. It makes a huge difference in getting things to smooth out quicker. Then we hose 'em down to get rid of all the gunk and lube more "normally". I even have a designated pair of shooting glasses to handle all the spray in my face!

[Patrick Sweeney]

I'd elect for a full face shield and tarp, were I doing that.

[George]

Yeah, I know that. I now have a white shooting shirt with Mobil 1 polkadots after helping a guy with a brand new upper who was trying to break it in dry this weekend ;-)

[Paule]

But a face shield would diminish my dubious "manly man" image! ha ha ha...

[TRG65]

Couldn't find my moly dry lube, must have gotten junked in the move. I washed the bolt with Rem oil spray, dried and then lightly sprayed. Problems have gone away. Closing is sluggish on a full mag, and much better on any reduced capacity.

Thanks all.

[benny hill]

LOTS of mobil 1- 10w30 everywhere. If it's dripping you'll be ripping.

[George]

If it's dripping you'll be ripping

Funny as hell, but true!

[scottmilk9]

I strongly disagree with downloading mags. I have all USGI mags, and never once downloaded them. matte of fact I usually put a barney bullet in. if you want to replace springs/followers, I like the magpul followers, but check other things first, definately try some other mags, different manufacturers or try your mags on another gun.

[Chris Rhines]

ARs like lots of lube in the upper. I paint the entire B/BC with Slide Glide or Miltec grease, which cuts down on the spatter.

- Chris