I received my piston upper back from PWS after the last round of problems and was looking forward to seeing if they were able to resolve the short stroking issues. Unfortunately I wasn’t able to get out to the range prior to taking another carbine class with it. I was slightly disappointed that PWS chose to send the upper through UPS Ground rather than 3 Day Select which added to the delay.
Change of rail from DD Lite 9.5 FSP to older Larue 7.0
Upon initial inspection I noticed a few changes beyond the specified rail replacement. I chose a Larue 7.0 rail to replace the Daniel Defense Lite 9.5 FSP after reading on the internet that Wes Grant of MSTN, an authorized PWS installer, refused to use those types of rails for the PWS conversion because he felt the rail obstructed access to the set screws.
Gas block pin- note front site is mounted backwards and gas block has been refinished
The most obvious discrepancy was that the folks at PWS installed the Centurion HK style Diopter back up iron sights on backwards. Next I noticed that the gas block was now pinned which was the proposed solution for the most recent problems I had. The gas block itself no longer had the etched PWS logo on there and by the looks of it they refinished the gas block entirely in a black finish.
I took the sights off and reinstalled them with loc-tite but did not have a chance to test fire it prior to the Bennie Cooley carbine class.
I was able to zero the rifle with no issues using an Eotech 516 and Wolf 62 grain hollow point.
It was downhill from there as I managed to make it through about half a day of training and probably less than 400 rounds before it began having failures to extract again which was the same problems I have had with the two previous returns to PWS.
Closer view of pin through barrel
I swapped out the carbine in it’s entirety and used another DI (Direct Impingement) carbine for the duration of the course. I will most likely take it to the range to confirm the short stroking issues before returning it to PWS for a refund.
Tags: Bennie Cooley, gas piston AR, HK416, Piston conversion, PWS
My upper came back from PWS yesterday. Just finished looking it over (I was on shift yesterday when it arrived). They tightened the set screws and it is now pinned as well. I don’t have a heavy barrel like yours. It’s more of an M4 profile. I will be getting this out to the range in the coming days for some testing. I’m crossing my fingers. By the way, I noticed mine still has the etched PWS logo on both sides.
Hardly an endurance test. I got out last week and the focus was on sighting in the EOTech and BUIS for an upcoming match. I only got 74 rounds of .223 through the gun. Everything looks tight still and there were no malfunctions. I’ll post more after the match on Nov 1. I plan on sharing the gun with two other shooters as well as using some 5.56. I should know more after that.
Well … I went to the match as well as two more range trips this month (last one yesterday). I’m not sure of the exact round count since the “repair” but it’s close to 400 rounds. Not a single malfunction and everything appears to be tight as a drum. No cleanings but I have added a drop of oil here and there on top of the militec grease (BCG only … not the piston parts). I also introduced a new component (one that I thought was necessary) into the mix. I added an anti carrier tilt buffer assembly.
I finally took everything apart this evening for a cleaning and closer inspection. Everything still looks good. I did notice some scuffs and dings on my rail from the removal/installation process when PWS worked on the upper. Other than that, it looks and works good. However, it will be a while before I place this as a front line rifle I would trust. I have a lot more range trips and classes/matches to go before I will trust this one. In the meantime, that duty falls to my LWRC.
I would still like to know how your rifle is working and how PWS is taking care of you.
I don’t know if you or anyone still reads this but I will post this final comment in case anyone comes across this seeking more information.
The rifle has not had any issues since I got it back in October. There’s been several range trips and a couple matches since then. The most recent match was completed in 95 degree heat without a hiccup. I don’t know how it would stand up to a true endurance test of hard combat in a tough environment but for now, it’s slowly earning my trust back. (I would also like to do some prolonged shooting with 5.56 as opposed to the .223 I’ve been using recently.)
Wild Deuce, sorry I’ve been busy with work and the blog has been on the back burner.
PWS gave up on trying to repair the conversion upper since the gas port was too big. They offered to “trade in” my old upper and they would reassemble a “new” upper using as many of my existing parts as possible. So they used the upper receiver, charging handle and BCG but gave me a new barrel and their new rail system.
I took it out the last weekend in June and put a few hundred rounds through it with no problems.
This past weekend I had it in a Carbine class and it died on me once again. This time the carrier key screws sheared! I sent an email to PWS and am waiting to hear back.
I’ll update my blog with pictures and a new post once I sort it all out.
Wow! Bummer!
I’m watching mine like a hawk. So far no problems. I’ve been taking it to a match once a month. My original plan was to shoot it at the monthly multi-gun match until the end of the season and see where I’m at without any cleaning (lube only). I had to clean it after the June match when I shot one whole stage in a torrential downpour (we got close to 3 inches in a half hour). The system worked fine but I had to break the rifle down afterwards to avoid rusting issues. I’m going to continue with the matches and end the season with an extended range session. I’ll let you know how it ends.
Now I know to keep an eye on those key screws … something else to worry about. Gas block is still tight as a drum.
Hopefully PWS will make things right by giving you the option of walking away from this “disaster” at minimal cost to you (I assume you are at that stage?). Keep us posted.