I had WAY too many FTEs today.  I went through 300 rounds today and had roughly 15-20 FTE.   The cases were stuck in the breach.  I was firing I.M.G. 5.56 surplus ammo. (brass, not steal)

Most of the time, I would drop the magazine and let the bolt carrier fly home, then pull the charging handle to extract the round.  On a couple of occasions, it was necessary to use a cleaning rod to push the case out.

I'm not sure if:
1) I need a new extractor, extractor spring
2) If I need to switch ammo.  The ammo I was using I've never used before and I've never had this problem.
3) If I messed up something when I installed the YHM FF rail.

I have a ArmaLite M4C.

On a side note, I'm not 100% on the reliability of my M4C after today.  I'm especially worried that  since I have a VLTOR stock, I have no place for a cleaning rod, therefore if I had to extract a case the way I had to today, I'd be SOL.

None of the brass cases were damaged that I could see.

Any ideas?

Thanks in advance
Hardwarz

Give your extractor a good once over.  You are looking for chipped or broken pieces on the 'claw' (that's the part that grabs the rim).  If that's alright, when was the last time to took apart your bolt and cleaned under the extractor and/or checked out your extractor spring?  Is the little rubber insert still inside your extractor spring?

Some guys have gotten good results by putting a small rubber o-ring around the extractor spring to give it a tigher grip on the case rim.  You should be able to get a small o-ring from Loews / Home Depot to fit around the extractor spring but make sure that you get one that can tolerate high temps.

Your big issue is holding too many parameters in your troubleshooting as variables. Try some ammo you used before the switch, and see if that works.

If it's not the ammo, my guess would be that in the course of installing your rail, you may have disrupted carbon deposts sealing your gas system, or may have incorrectly assembled some components. Perhaps debris worked its way into your gas system. If you have a gasblock, it may be misaligned.

Isolate variables, then test.

I won't be able to get to the range for a couple days.

I looked at the extractor, it looks good.

I have no more ammo that I use to use that was good in my gun.

I'm going to try adding the little D-ring onto the extractor and see if that works.  I'll also pick up some ammo, maybe Winchester White box.

Today, my rail came loose and was spinning.  The locking ring/jam nut and the rail were spinning together.  I might have to pick up some red LocTite too.

Hardwarz

Quoted: I won't be able to get to the range for a couple days. I looked at the extractor, it looks good. I have no more ammo that I use to use that was good in my gun. I'm going to try adding the little D-ring onto the extractor and see if that works.  I'll also pick up some ammo, maybe Winchester White box. Today, my rail came loose and was spinning.  The locking ring/jam nut and the rail were spinning together.  I might have to pick up some red LocTite too. Hardwarz

Use a tool to hold the jam nut in place, and use a strap wrench to torque the FF rail into position.  This is a good way to be sure it is tight enough, and loctite has not ben necessary on either of the two I have.  Of course, YHM now comes out with a model that uses locking screws.....

One question.

How is your Front sight base/Gas Block installed?  Taper Pin? Set Screw?

It could be that you didn't align in properly when you reinstalled it and some of the gas port is blocked, thus causing FTEs.

Here's the current build of my ArmaLite M4C

http://www.hardwarz.com/images/m4c_w_rail.jpg

Later this week, I'll get it to the range and try factory ammo instead of surplus ammo and see if I have any more extract problems.

Hardwarz

Quoted: I won't be able to get to the range for a couple days. I looked at the extractor, it looks good. I have no more ammo that I use to use that was good in my gun. I'm going to try adding the little D-ring onto the extractor and see if that works.  I'll also pick up some ammo, maybe Winchester White box. Today, my rail came loose and was spinning.  The locking ring/jam nut and the rail were spinning together.  I might have to pick up some red LocTite too. Hardwarz

You need to use blue loctite not red

Quoted: You need to use blue loctite not red

Too late.

I tried blue LocTite, but it came loose when I was trying to hold the rail and tighten the flash hider.  Switched over to red LocTite.

Hardwarz

tag...

Getting ready to install a YHM FF rail...

Sounds like a crimped gas tube to me. Restricted flow will give you FTE's I think... but I could be wrong. Won't be the first or last time either.

I note you still haven't answered my question on the Front Sight base...  Odds are that is where your problem is.

Quoted: One question. How is your Front sight base/Gas Block installed?  Taper Pin? Set Screw? It could be that you didn't align in properly when you reinstalled it and some of the gas port is blocked, thus causing FTEs.

2 pins, not tapered.  FSB seems to be in correctly as does the gas tube.  It doesn't seem to be off to the left or right in the upper.

Hardwarz

You were holding the handguard to tighten the flashhider? Get yourself some vise blocks if you plan on working on AR's very much.

You could just have a very fouled chamber too.  If the ammo was swollen at all, it probably caused the problem. We've had a bad run with PMC lately (some of the last crap we bought from them last year) in trying to get rid of it. Several rifles have cases sticking in the chamber with the case rim being ripped off by the extractor. Just like you, using a rod to get the cases out.

If the bolt is coming rearward and the case is still in the chamber, you've got enough gas to work with.  If you're working a 20" gun, the extractor spring buffer should be blue. Anything shorter than 20" should get black. Those and the wolf extractor springs are cheap to get.

Your extractor, when turned claw down and pulled across your finger tip, should feel like it has two little cat's teeth (one on each side.) If it doesn't, replace it.

Good luck.