I recently had the opportunity to run my PWS piston conversion AR upper through the Viking Tactics Street Fighter class taught by Kyle Lamb.
Right side of gas block with Daniel Defense Lite 9.5 FSP rail
Round count for carbine in the class was slightly less than 800 rounds. The PWS upper performed impressively for the first two days of the class without a single malfunction shooting crappy Brown Bear Classic .223. Despite being shot from a variety of positions including in variations of prone where plenty of dirt and debris were being kicked up. I had fired an estimated 400 rounds on two different range days prior to this class.
On Day 3 the problems began when I was attempting to complete a shooting drill around vehicles. I shot it strong hand only with no problems but when I went to shoot support hand only, it appeared that the weapon was short stroking, I would fire a round and then manually cycle the bolt before firing again, still doing this with just my support hand. The drill also required a single magazine change which I completed but the multiple repeated malfunction clearances took a toll on me. At one point I had to “mortar” the weapon in order to get the charging handle to go back.
It was frustrating and much of the drill’s value was lost as I had to fight the weapon to complete the drill. I cleared the weapon and took it off the line to investigate and found that the gas block was loose, enough that it would wiggle with just finger pressure.
Note scratched to barrel due to shooting around vehicles and barricades
I emailed PWS that evening and they immediately offered to have it sent in for repair. The plan is to install a taper pin to keep the gas block fixed. So far all 3 problems I’ve had with this weapon have been related to the gas system. The first time PWS opened up the gas port, the second time they stated that their was a subtle taper to the barrel and finally, the gas block was shot loose. I suspect the Daniel Defense Lite 9.5 FSP rail may be making it difficult for them to properly secure the gas block using the set screws. I may have them change it out to a Larue 7.0 rail when I send it in to see if that makes it easier.
I remain extremely impressed by the customer service at PWS but am starting to lose confidence in their system, both in design and execution. I look forward to getting my upper back and running the gun through its paces. I hope that PWS can finally resolve these teething issues to deliver the enhanced reliability it was advertised for.
Tags: Daniel Defense Lite 9.5 FSP, gas piston AR, HK416, LWRC, pi, piston, Piston conversion, PWS, PWS piston conversion, Viking Tactics, VTAC, VTAC Street Fighter
Man, that sucks. I hope they can get things right this time. At least it sounds like there’s minimal hassle while dealing with these issues, but I can only imagine how frustrating it is to be without your rifle during all these repair periods. Good luck!
Very interesting. I’m glad I found this. I had my Wilson Combat M4TAQ converted to the PWS system over a year ago. I still haven’t had a chance to really put it to the test. That will all change over the coming weekend. I am attending a class with a round count around 600. I know that is probably less than would go through a gun in a single, real-world firefight. Hopefully I can get extra rounds through the gun. I will keep an eye out for the problems you’ve had. My conversion was installed by PWS before they farmed that task off to dealers. I’ll come back and give you an update if you are interested. I would like to know how your gun is working out as well. Also, any issues with carrier tilt?
No evidence of carrier tilt yet but then it hasn’t been consistent long enough to show wear.
I tried it again this past weekend at a class and made it to about 600 rounds before it went single shot on me again.
I will most likely send it back to PWS for a refund at this point.
Thanks for the reply. Here’s my update …
I didn’t even make it to the class. As soon as I typed out my earlier comment, I went downstairs to check my rifle one more time. Guess what? The gas block was loose. It didn’t seem like much, almost unnoticeable but still a very slight wiggle with just a little finger pressure. I contacted PWS and they told me to send it back. They said they would check it and pin it if necessary. Right now I am waiting to hear back from them. When it comes back, I will be putting this thing through the wringer.
What disappointed me was that I hardly had enough rounds through the system to even warrant a cleaning. I have to admit that I didn’t have a malfunction/stoppage. I only caught it because of the information you posted.
I’ll update after it returns.
That’s unfortunate that its loose, I suspect it may or may not work depending on ammunition selection. They pinned the gas block after the last return but it didn’t stop the carbine from going single shot on me.
I also had them switch out the DD 9.5 FSP Lite rail for a Laure 7.0 rail so that I would be able to detect the gas block shooting loose in the future.
If they haven’t already given it to you, ask them for the UPS shipping #, I sent mine out via 3 Day select and they sent it back UPS Ground so turnaround time was dragged out a bit.
I’ll update the blog when I get time to upload pics.
Please do let me know if they are able to fix your PWS upper.
[...] is someone else's story (my experience is shared in the comment section of this guy's blog) … Part One Part Two Our experiences have been with the conversion kit and not with a complete PWS rifle [...]