PSA Glock Carbine Jamming on 1st Round

[Boss1622]

I thought I would give PCC a try so I picked up a PSA Glock Mag Carbine. The gun ran 100% for the first 500 rounds with everything stock. I then changed out the Trigger to a Hyperfire 24C and added the Blitzkrieg Hydraulic Buffer with a JP 308 spring. and bought 5 new Glock 33 round mags and 2 21 round pmags. I ran 500 rounds of Winchester White box 115 gn without a single problem. 

( i know this round is hotter then I need but I was trying to keep it simple and get ready for the Area 4 match). 

So I get to the Match Saturday and on the load and make ready for the first stage jams a round into the top of the barrel and the bolt is not closed all the way. I didn't notice this until the BEEP, A quick mag change and fresh 33 round Glock magazine (downloaded to 31)and I was running. On the next stage I had the same issue (using the Glock Mag that had just worked) but I noticed it on the load and make ready this time the round was jammed nose up and the bolt was 1/2" from closing. This continued on all but 2 initial loads of the weekend.

Saturday Night I stripped everything down and cleaned everything very well, Paying a lot of attention to the chamber and Bolt face. 

Same story on Sunday, so I made sure to lock the bolt back when I pulled the flag out and I dropped the bolt after seating the magazine. I down loaded the 33 rounders to 28 and the Pmag 21s to 18. I made sure the mag was seated and was tight. Nothing helped. 

I know about the short chamber issue with these barrels but these rounds are not long and they are not making it into the chamber at all. 

Any suggestions? 

 

 

[Aircooled6racer]

Hello: The lead on the barrel tends to be on the small size on those barrels. It may need more of a chamfer on it to help with the feeding. The other thing is to change out the 308 spring with a 223 spring or with the other buffer setup you had before and try it out. Another thing to check is the rail that the hammer rides on. Check near the chamber end for a burr at the 90 degree angle. Thanks, Eric

[Flatland Shooter]

My first two PSA uppers run like scalded dogs.  The third one has the same problem as yours.  It only happens on the first round.  All three have the older Version 1 barrels (short lead requiring me to load short).  If I try to slingshot the first round into the chamber, its sure to jam.  If I lock the bolt back and release the bolt catch to load the first round, then it jams maybe 50% of the time. Once I shooting, it runs just fine.

 

I've isolated it to just this upper.  Ran the "problem" upper on each of three different (all PSA) lowers and tried several different bolts (PSA and Spinta) and it still has problems with the first round.

 

I'm hoping that with a little more break-in, it will resolve itself.  If not, I plan on pulling the barrel and see if PSA will take a look at it and tell me what's wrong.  If another barrel on this upper receiver does not help, then there is something (small)  wrong with it.

 

Let us know if you find a solution.  I'm all ears on good ideas.

 

Edit to add:  Two of the lowers have Hiperfire 24c triggers and the third has a JP roller trigger and a stock AR hammer and disconnector.

 

Edited September 11, 2017 by Flatland Shooter

[TRUBL]

try this once.......when loading the first round......tip the bottom of the mag forward

 

[Flatland Shooter]

42 minutes ago, TRUBL said:

try this once.......when loading the first round......tip the bottom of the mag forward

 

 

If that helps, would your Glock Lower Feedramp be the solution?

[nickbfishn]

34 minutes ago, Flatland Shooter said:

 

If that helps, would your Glock Lower Feedramp be the solution?

I sure hope so because I ordered one today!

[Boss1622]

Thank you for the input, I will try the Buffer Spring and the Mag Tilt tonight and let you know what I see.

[wyliearms]

 If it continues, message me your order number or email. The barrel was revised and as you stated will run great in it's stock configuration. Just about every issue that we see come back recently pertains to either too light or too heavy buffering. We went through several variants of weights and springs before we went with what it actually ships with and we know it is reliable in that configuration.

[nickbfishn]

5 minutes ago, wyliearms said:

 If it continues, message me your order number or email. The barrel was revised and as you stated will run great in it's stock configuration. Just about every issue that we see come back recently pertains to either too light or too heavy buffering. We went through several variants of weights and springs before we went with what it actually ships with and we know it is reliable in that configuration.

I'm curious, you say you went through "several variants of weights and springs....we know it is reliable in that configuration" --should I assume this is using some brand of factory ammo?  IF so, mind sharing what ammo you used and the data?  Also, what spring and buffer di you land on for the factory ammo use?

 

Also, have you guys considered testing your barrels / buffer combinations to figure out what suits competition shooters who will likely be shooting ammo that is considerably lower power factor (typically in the 130-140pf range) to that of most factory ammo (typically over 145pf) from 16" barrels, and also longer loaded?  It would be a great service if a company like yours with all of your resources available to do some testing and then be able to market certain setups directly to the competitive realm as opposed to just general builders and Timmey tactical +P folks.

[Flatland Shooter]

21 hours ago, TRUBL said:

try this once.......when loading the first round......tip the bottom of the mag forward

 

 

Unfortunately it did not help.

 

Tried it at the range with three different bullets (147 gr RN plated, 125 gr RN coated and 98 gr RN coated).  These loads work fine with all my other 9mm uppers.

[Aircooled6racer]

Hello: Here is one of the problems I have seen around here with some of the barrels. The one on the left is a Wilson Arms, the JP is similar  and the other is another brand which I don't remember who's. Notice the lead angle on the one on the left. It feeds great with multiple uppers I have tried and also Colt and Glock mag lowers. Thanks, Eric

[Flatland Shooter]

Question about the barrel on the right.  Is that a feed ramp there at 3 o'clock or is it just a discoloration in the picture?

 

If its a ramp, did you do that or did it come from the factory like that?

 

Thanks.

[Aircooled6racer]

9 hours ago, Flatland Shooter said:

Question about the barrel on the right.  Is that a feed ramp there at 3 o'clock or is it just a discoloration in the picture?

 

If its a ramp, did you do that or did it come from the factory like that?

 

Thanks.

Hello: It is not a feed ramp but is a stain and rub mark from the extractor and extractor hole. Thanks, Eric

[Boss1622]

 

Problem Resolved: I tried tilting the Magazine as TRUBL suggested and it did not appear to help. Then I pulled out the 308 buffer spring that came with the Blitzkrieg Hydraulic Buffer and put the original PSA spring back in as Eric suggested and the problem was gone. The gun now loads and feeds 100% of the time. I tested the Magpul 21 round as well as the Glock 33 Round magazines fully loaded and it is back to loading flawlessly. I would like to thank everyone that chimed in on this issue the knowledge base on this forum is amazing. I just found out that my JP GMR-15  shipped yesterday so it looks like I get to do the New Gun thing all over again. At least this time I'm not rushing to get it ready for a Major Mach.

 

                                     Brian