I've just about had it with this thing. Won't feed at all. Here are the specs on it. DPMS lower with LPK, RRA upper w/ RRA bolt. 16" chrome lined barrel from Del-Ton. I can't run a full mag through it without it jamming. I've been using a Bushmaster 30rd mag( only one I had at the time). I bought a Pmag, ran 30rds through it, jammed twice. Loaded 30 more rds and tried it. It would close on an empty chamber after firing each time. I think it may have to do with the buffer spring. I got the stock from cheaperthandirt(came with spring) if that makes a difference. Anyone got any ideas?

Zack

What kind of jam? Is it a stove pipe type or is the new round not chambering? If its a stovepipe type then your gun probably isn't getting enough gas

It would close on an empty chamber after firing each time. I think it may have to do with the buffer spring.

Zack

That sounds like a bolt hold open problem.

Edit....nevermind....you're short stroking....

Let me guess, wolf ammo?

In addition to the others' questions already asked...

What buffer and stock (pics/link?) are you using?

How well oiled is the bolt carrier inside the upper?

Carbine or midlength gas system?

Just a few guesses here.

If the bolt is closing on an empty chamber then it is not traveling rearward enough during its cycle. Things to look at are the buffer spring, stock weight, not a heavy buffer, ammo (wolf is notoriously underpowered but every rifle should be able to shoot it), and gas system (not enough gas getting to bolt to push it rearward).

Easiest to change will be ammo followed by spring. Shoot some good brass cased ammo and see if the problem persists. If it goes away, then you know you have a power issue. Check into getting a lighter buffer spring, then try it again. Problems persist, then its time to check into the gas system, making sure the gas port in the fsb is aligned properly, etc.

Again, just a guess.

edit: Scott replied while I was typing and brings up a good point, lube. AR's like to be run wet. If you are just starting out it probably isn't lubed enough and friction could very well be giving you problems.

No Wolf here. All i've been shooting is Remington and Federal. The gun has probably had around 200-300 rounds through it. It's a mid-length gas system that Del-Ton installed themselves. Sometimes the bullet will get stuck trying to chamber, and the bullet will gouge the casing of the bullet. Other times the bolt closes on an empty chamber. Won't even chamber the round. The stock is the 6pos stock from cheaperthandirt. I keep my guns well oiled, and prior to shooting today, I made sure everything was clean and oiled.

Zack

Have you checked your gas key screws to make sure they haven't worked themselves loose?

Since I'll probably fall asleep before this diagnosis gets far:

Oil it till it's soggy. You can't hurt it with oil, just make sure you've got safety glasses and old clothes when you go to shoot it, 'cause if it's way over-oiled, it'll spit on you.

Go here: http://www.ar15.com/forums/topic.html?b=3&f=62&t=378850 and look up what your buffer specs and spring length "should" be for your stock. There's a chart and pics about a third of the way down the first page of that thread, with good info.

Once you've verified that you have the right spring/buffer/stock combo, get some known-good ammo and go shoot it.

If you have a rifle spring in a carbine stock, that *could* be enough to prevent it from cycling, but I've never actually tried that swap myself. If I have a few minutes free, I'll try it in the morning and see.

Edit: Was typing the above while the two posts above it were being posted, sorry, some of it's redundant now.

Have you checked your gas key screws to make sure they haven't worked themselves loose?

Maybe it's time to ante up for the $200 carrier key tactical staking tool.

:p

gas screws are tight, nothing loose in there. Just to clarify, these are the allen bolts on top of the bolt correct? If so, then they are tight.

edit: very quick responses, thanks guys. From looking at the thread from barfcom it looks like I have the AR15 Car Buffer H. I got the stock, buffer, and buffer spring in one complete package.

Maybe it's time to ante up for the $200 carrier key tactical staking tool.

:p

Uhh, hello? $200 tactical staking tools are so like last year and stuff.

$0.50 Harbor Freight 1/4" F-stamps are where it's at now, bitches.

edit: very quick responses, thanks guys. From looking at the thread from barfcom it looks like I have the AR15 Car Buffer H. I got the stock, buffer, and buffer spring in one complete package.

If you have an H buffer, I'd swap it out for a standard carbine buffer (should be under $20 at any local gunshop any more, or if you don't care to get this done *this weekend*, PM Aloharover, he's got pretty good deals on parts, just not local to you) and try that; I'm not sure exactly how much difference it'll make, but IMO, it's worth a few bucks to try (or better, borrow one from a friend, if you have a friend that has a standard carbine buffer).

And TRH is right, you really should F-stake those carrier key screws before you have a catastrophic screw-loosening. :laughing:

alright, so maybe its the buffer, I'll see if I cant get another one and try it out. I'll PM Pete and see what he's got.

Zack

Just remembered to check; a rifle spring at bind is ~3/8" longer than a carbine spring at full retract (not sure if the carbine spring is at bind, or if the carbine buffer is bottoming into the back of the stock, at that point). The rifle spring at bind, is ~1/4" too long to allow the bolt hold open to function; the bolt lugs stop on top of the hold open, instead of behind it. Should be easy enough to check that; if your bolt hold open works at all, you don't have the wrong spring. If you can't pull the charging handle back far enough to engage the bolt hold open with an empty magazine in place (or pushing in on the bottom corner of the bolt hold open with your finger) then you do have the wrong spring, and it should be changed.

Not sure what'd happen with the converse, a carbine spring in a rifle stock with a rifle buffer... I think it'd work, just not reliably close the bolt all the way. I can't readily try it and see.

the bolt open works perfectly fine. I can pull the charging handle all the way back and lock the bolt open. I can also put enough sideways pressure on the charging handle without the bolt open on and put enough pressure on it to hold it open. I'm pretty sure that the buffer is right as on the box it states CAR buffer spring.

Zack

When it's doing this, are you trying to fire as fast as you can, or slowly? I know that my Bushy HBAR w/ a rifle buffer and fixed stock will short stroke if I try to fire it to quickly. My CMMG with the same stock you have and the CAR "H" buffer will send em flying as fast as I can pull the trigger. Both are Carbine length, though the CMMG has M4 Feed ramps and the Bushy doesn't. Like others have said, a lighter / shorter buffer should solve your problems.

Crap, I just looked at that link to AR15.com, and realized why my Bushy is short stroking. Damn rifle length buffer in a carbine. Thanks for bringing this up, now I know what's wrong with my gun. Though it does shoot sweet as long as I keep it slow.

damn.... that sucks!

BUT! it sounds ALOT like you have to heavy of a buffer or buffer spring (or inside of the reciever extension doesnt have a light coating of lube) and a combination of shitty mags. Both of which are cheap and easy fixes :D I kinda doubt if its the gas block and the barrels port being misaligned... expecially if its a factory made upper. Pete could easily get you a standard carbine buffer/spring and you'll know its right.

Get some C-Products mags in the future. Theyre the only ones I buy now days and every one I have purchased has ran flawlessly. http://www.cproductsllc.com/

So it does eject the old fired case?

If the bolt will lock back with the BHD then its not too long of a spring. If the bolt is locked to the rear and you insert a fresh mag, then hit the BHD it will feed a round?

Ensure the gas ring gaps are off set.

ENsure the carrier key screws are tight.

Sounds short stroking.
check to make sure gas tube is pinned and not loose.
gas rings have gaps offset

is it a pinned or set screw gas block?

It has a pinned gas block. I had Del-Ton install the barrel and gas system for me when I stopped by their shop. It does eject the old fired case. If I lock the bolt back, insert a fresh mag, and hit the BHD, it WILL feed a new case. I'm shooting at a pretty slow rate, nothing too fast. I know TRH hates magpul, but I thought that they had a pretty good magazines. I only have two mags for it, a Pmag and a Bushmaster.

Zack

Get HK mags :flipoff2:

Get HK mags :flipoff2:

The only mag as homo as the fagpul one.

Do you have a standard Front Sight Base on the rifle, or an aftermarket bolt on RAil/Flatop/some other BS on it?

Order spring and buffer from my store.
I will send them out.
If they work then I will charge.
If they dont solve the problem, send them back.
or send me your upper :D

There is a 1/4" of travel between ejecting and picking up the new round.

sounds like a plan Pete, I'll be sending you a PM.

Zack

Took it to a local gun shop near me today. Apparently when Del-Ton installed the gas tube with the barrel, they tweaked the gas tube to the left. This caused the gas key to constantly rub the side of the bevel on the gas tube. Now where it should be beveled, there is a nice smooth spot. So we changed out gas tube, and its still doing the same thing. Now we think that its the actual gas key thats to loose around the tube. I left it with him so it "should" be fixed by the weekend.

Zack