Hello everyone I have a psa gen 2 billet glock lower and need to know if my new upper will work with it. The upper described as psa gen 4 10.5" 9mm sku 51655104635B. I am removing my gen 3 psa 4" 9mm sku 51655447524. I noticed that the gen 3 upper has a ramped barrel and the gen 4 does not. Will this cause problems? Thanks for the info.
All of our PSA 9mm uppers and lowers will work together across Generations, with the exception of the AR-V. The AR-V uppers and lowers will only work with the corresponding AR-V receiver.
Where are you seeing that the Gen 4 does not have a ramped barrel? I will double check with someone in our manufacturing facility, but I’m pretty sure they are.
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Is he referring to the barrel ya’ll used to make/sell that had the extra cut on the ramp (instead of the standard cone feed ramp)?
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Guitar guy is correct that is what I’m asking.
I stand corrected. We just had someone verify it. Our newer barrels do not have the additional ramp cut, just the standard cone. This upper should still work with your lower though. All of our Upper Receivers are test fired during manufacturing before they are sent out to the customers. If for some reason it gives you issues, we cover all of our PSA products with a lifetime warranty and will fix the issue.
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Ok today I tested this new upper with the gen 4 bolt and my ar was shooting full auto. Any ideas why? Or what I should try?
Bcg and fire control issue. 9mm’s are super finicky. Is it a factory built lower or did you build it up?
Everything is factory as discribed in the first paragraph. It is all psa uppers and lowers. The only difference I see in the bottom of the bolts are the ramps that push the trigger back down. I forgot how to post image if someone could remind me. Thanks
I believe I am also using a AR9 heavy buffer. This is used for the 4" barrel upper. Should I try a lighter buffer when running the 10.5" upper? Maybe not letting the bolt back far enough to reset the trigger. Can I use AR15 buffers?
You need a heavier 9mm buffer, and the ramped bcg will be an issue. 9mm have different hammers for the fcg and ramped bcgs. Not having the right can mess you up.
We recommend our 8 oz 9mm buffer for the AR9. this is a lot heavier than a traditional heavy or h3.
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I am running the Guntec AR9 8.2oz buffer. Does PSA sell gen 3 bolts still?
@oconnell406 I do not believe we sell the Gen 3 BCG’s anymore. The Gen 4 is compatible with our older Generations though. If you could, PM me your order number and a good mailing address. We will get some replacement parts sent out to you to try and solve this issue. If this doesn’t take care of it, we will bring it into our Repairs Department under the Lifetime Warranty to make sure the issue gets resolved and your firearm is safe to use.
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PM sent
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