I can lock the bolt back to the rear manually when pulling the charging handle, but when I fire the last round (various ammo) the bolt fails to lock back. I contacted PWS and they told me to replace the rubber dead blow stopper at the end of the tube with a metal insert they sent me in the mail.  PWS stated the the glue that holds the rubber stopper sometimes fails and can cause the stopper to dislodge. I installed the metal insert and I'm still having the problem. PWS informed me that the rifle should not be fired without the rubber or metal stopper in place due to the end of the buffer tube wall being thin (to accommodate the stopper). Anyone else have a similar experience?

When I manually hold the bolt back as far as it can go I noticed the space between the Bolt Catch and Bolt face is almost nonexistent. The bolt is just barely able to come back far enough for the Bolt Catch to rise up and lock the bolt back. I couldn't fit a hair in there if I wanted to. I compared this to another AR I have with a mil-spec "normal" buffer tube and there is a good quarter-inch or more of space. Plenty of travel.

In trying to think of a solution I could only come up with two ideas. Either shave some rubber off the end if the buffer itself OR cut some coils off the buffer spring. Thoughts?

I'm running the Spike's ST-2 buffer with carbine buffer spring. The Spikes buffer is standard length.

Standard works, enhanced does not work.
Some aftermarket enhancements seem like good ideas, this not so much.
I would not cut coils on the spring just on general principle. YMMV

Pull the metal insert and run it with nothing.  That's what I did. PWS really jacked up the tube by adding the buffer to fix a non-existant problem.

If you have more than one AR you might have accidentally put a rifle
length buffer spring in, pull your spring out and check it just to be sure

I have the PWS on my LaRue but I'm running a standard carbine buffer.  Swap the ST-2 with a normal carbine buffer and see if that solves your problem.

The Spikes buffer is on a 11.5" SBR. Should a carbine buffer be in that?

I have no experience with SBRs.   Can't help with that.  I'm running mine on a 16" middy.

It's that rubber buffer inside the PWS tube that is limiting your rearward movement. Get a long flat screw driver and pry it out. It's just glued in place. Once it is removed, it'll cycle properly.

The new PWS tubes do not even have this rubber buffer in them anymore. They've broken free under recoil and jammed up the recoil spring.

Correct. I spoke with a tech at PWS and he said if I don't put anything where the rubber buffer was in place the gas key "block" on top of the carrier could be damaged inside the receiver extension (buffer tube) because it would travel too far back. I wasn't following what he was saying at all. Does this make sense to anyone? What would it hit...the top opening of the buffer tube?

Does your gas key "block" hit the top opening of your buffer tube now that you removed the insert? It may be traveling too far back.

The "tech" at PWS that I spoke with said it was absolutely fine to run the tube without the rubber insert.  At this point i'm ready to pull the crap tube all together and install a mil-spec one... what a headache.

As you can see, the gas key "block" comes close to hitting the top of the receiver extension, but there is a gap. I also live fired with various ammo and didn't see any marks from it hitting. In this picture I'm pushing the BCG back as hard as I possibly can. No insert in place.

This is what I would do.  If it isnt broke dont try to fix it...

MAHA

same as this.

my roommate had to have the fancy fluted tube, i tried to talk him out of it (his first build/ar) he got it anyway. that tube looks cool and has some nice features in theory but in reailty they are a pain in the ass. roommate had the same issues with his, i talked him into trying a mil spec tube and immediately it ran 100%. id take that turd off and put on whats supposed to be there.

I got it to prevent any carrier tilt that MIGHT occur when running my piston operated SIG516.

What about the POF-USA tube?





 

Looks promising. I'd have to buy a castle nut and stake it in place. I'm going to see what PWS has to say first. I might be shipping them my lower to have them correct the problem.

Have you resolved this problem I was thinking of purchasing one of these buffer tube setups.

Sorry for the delay. I sent my lower to PWS and they installed their current version of their enhanced buffer tube. The inside end of the tube looks like a new design. I haven't had the chance to shoot it yet, but PWS did test fire using my mags and various ammo and said it functions 100%.

Thanks for the update. Let everyone know what happens when you take your carbine back out to the range.