Pro Carbine not recocking

[Murdoc555]

Really scratching my head on this one. Had a big game day and loaned it 2 years ago, was very busy at the time and didn’t notice all the paint that had gotten busted up inside of it until now. Before tear down, I put some air in it just to see what it was doing and was shooting incredibly hot. Didn’t have a chrono, but well over 300 fps in my estimation based on the curve balls and bark it was tearing off trees
despite the velocity screw being all the way in ( in case that’s a clue of something) but still recocked.

Doesn’t seem to be a low air issue. Same tanks on other blow backs are allowing function.

Orings are not for specific pro carb rebuild; spare cocker rings on bolt and valve ring, all else are for a 98c.

Post tear down and rebuild, it fires, but won’t recook itself. Still shooting hard, maybe slightly less than before. Any advice is appreciated, thank you.

[Chappy]

Your front bolt oring is likely too large, causing bolt stick.

[Murdoc555]

The front bolt oring appeared to be the same size as the old original and it seems to be seated well within the grooves sufficiently. I did find a similar post from a few years back and after sticking a squeegee down the barrel and firing, the gun will cycle. According to this post, it’s providing back pressure, but I’m unsure how to get that to work as a permanent solution.

https://www.mcarterbrown.com/forum/p...ut-wont-recock

[Chappy]

They shouldn’t beed back pressure to recoil.
Just try without a bolt oring. It’s worth a shot. I’ve had the same problem with the same perception.

[Murdoc555]

I tried again without an oring and it didn’t work. Was able to refire with the barrel plugged with a squeegee though.

[Sdawg]

Man, I have been having the same problem with a pro carbine I bought recently for nostalgia.

I am using a 684 bigshot so maybe the oring getting stuck is the problem as well on mine.

[Murdoc555]

I’ve tried it multiple ways with varying sizes or no oring, still not working. The only ground I’ve made to get it to cycle was sticking a squeegee down the barrel and according to the OP from the link I posted, provides needed back pressure. So somewhat diagnosed, but no remedy unless we get some further ideas here. I’m still waiting to hear back from them.

[Chappy]

Have you tried with paint? If the squeegee does it does paint ? I have one procarb that needs back pressure and it has a lightened hammer but paint does the job. What barrel you using?

[Murdoc555]

Yeah, it shoots fine. And through all my tinkering was able to get my original velocity issue down it seems. 690 Lapco Bigshot.

Edit: it was also cycling the same paint prior to the tear down.

[Sdawg]

Back pressure definitely helps. But back in the day, I had a procarbine that would cycle with no back pressure at 650psi HPA. or I think it did.

[Murdoc555]

Of all things holy I got it. It’s back to driving nails. A mere Hammer o ring replacement. I’m pretty sure I could Major Payne this bitch and assemble it blind folded hanging upside down before my knows starts to bleed.