PWS Buffer tube issues?

[ktom300]

Wanted some opinions on this. I purchased an enhanced Mil Spec buffer tube from PWS and noticed during function tests that the bolt would not lock back on empty mag or even manually. This was happening because the bolt was not coming back far enough to clear the catch. Bolt is a BCM in an AA piston BCG.
After trying several combos (standard bolt, different spring, different buffer, different lower, upper, etc. I found that the PWS tube has a rubber stop glued into the bottom as a stop for the BCG/spring. I suspect this quiets the spring sound a bit?
Even with a standard BCG/Bolt, it was barely coming back far enough to clear the bolt catch. The spring in the piston BCG/Bolt seems to exacerbate the issue as if forces the bolt out all the way.
Anyway, I removed the rubber stop and cut ~1/8" of material and stuck it back in. Bolt now clears the catch easily
Has anyone else come across this? Possible I had an older rev from PWS?
I have not contacted PWS and this is not intended to criticize or bash the product. Just curious.

Thanks

[FeuerFrei]

The rubber bumper is there to reduce carrier speed.
The AA uses a spring on the bolt tail to address timing. Forces the bolt to move forward, normal.
Find out where the carrier is hitting. The PWS is designed to address carrier tilt and alignment issues.
The AA carrier already has built in skis to address carrier tilt.
Is this a AA kit you installed?

[ktom300]

The rubber bumper is there to reduce carrier speed.
The AA uses a spring on the bolt tail to address timing. Forces the bolt to move forward, normal.
Find out where the carrier is hitting. The PWS is designed to address carrier tilt and alignment issues.
The AA carrier already has built in skis to address carrier tilt.
Is this a AA kit you installed?

Yes it's an AA kit. The carrier was hitting on the rubber stop.
I supposed under live fire that rubber might compress and allow the bolt catch to function. The AA bolt spring might even compress some from inertia on the back stroke. However, it doesn't make much sense to have a carrier that can't be locked back manually.
Also note that I discovered my Spike's buffer spring is 1" longer than the generic carbine spring in my other AR. When I swapped springs during testing, the shorter spring made no difference but I'm still wondering if Spike's sent me the wrong spring.

[FeuerFrei]

Rifle length action spring in a carbine can mess this up.
Rifle = 11 1/4" - 13 1/2" acceptable.
Carbine = 10 1/16" - 11 1/4" acceptable.

Question; can the tube be backed out enough for clearance while retaining pin still holds it's place?
What buffer weight is being used? (measure the length too)

[ktom300]

Rifle length action spring in a carbine can mess this up.
Rifle = 11 1/4" - 13 1/2" acceptable.
Carbine = 10 1/16" - 11 1/4" acceptable.

Question; can the tube be backed out enough for clearance while retaining pin still holds it's place?
What buffer weight is being used? (measure the length too)

Buffer is a Spike's ST-T2. Spring measures 11.5"
Like I said, even with the shorter carbine spring, I still couldn't get the BCG to lock without pushing the bolt in with my finger.
If you're familiar with the PWS, it's an extended tube, with a hole for the spring retainer. Once it's "bottomed" on a modified end plate, you tighten set screws at the back instead of a castle nut.
The only downside I've found is that you have to make a complete rotation to find the retainer hole again. I ground the end plate on a belt sander to make it thinner so I could complete another rotation and have less gap between the set screw block on and the end plate.
We're talking maybe .050" of material so I don't see how that could've made a difference.
How much play is there at the end of the stroke on a standard tube? In other words, if you pull out the spring and buffer, how much over travel is there for the BCG?

[FeuerFrei]

Everything you have seems to be "correct" except my spider sense is telling me your buffer tube is the culprit. Too short or out of spec.
I would swap it out for a mil-spec carbine tube and check again.
AA kits on my pistols work great and using GSE 4" buffer assemblies. Golden.