So I built the entire PSA 10 gun from parts. The bolt catch will lock the bolt back on the PMags only the. DPMS ones won’t work. But when I pull the mag out the bolt slams forward. I thought that I have a AR15 bolt catch but its a AR10 one and I put a AR15 in it to see if it will work and it locks the bolt if I hold the catch down only. Whats wrong?
Sounds like the bolt is locking back on the DPMS mag’s follower.
Remove the upper from the lower and insert a DPMS mag and see if it properly actuates the bolt catch. Compare that to how the MagPul actuates it.
As a long time AR10 owner,
All I can say is the P Mags have really been an improvement.
I see no reason to continue using magazines with 60s/70s era tech that have flat black followers.
My problem is not the mag its the catch not working after the mag is dropped. The 308 both catch wont work without a mag in the gun to hold it up. The 223 catch will hold the bolt open when I force it to but it wont stay that way without me putting my fingers on the latch to keep the bolt from going forward when I don’t want it to
Dude, impossible.
If the bolt catch was actually activated the friction from the bolt face would hold it in place.
I have seen this with a couple of .308 ARs, and heard about it on some others. Mag compatibility is obviously an issue to take into consideration. I am not a gunsmith, and can’t say for certain why this happens, but based on my hunch and from what more knowledgeable people have suggested, it could be the bolt catch only coming up part of the way to catch the bolt. This means it is barely engaging the bolt, so dropping the mag or bumping the rifle can make the bolt catch lose contact with the bolt.
It has been mentioned also that the PA-10 was designed around pmags and that PSA has said that it may not work with other LR308/Knight’s pattern magazines. My suggestion is to contact them for yourself.
Another thing to keep in mind is that even when just talking about PMags Magpul’s change from their LR/SR Gen 2 to Gen 3 altered some of the dimensions like the follower height relative to other parts.
Talking to guys with the DPMS G2 308 rifles,this means that the bolt catch actuating tab (not sure if this is the technical term) on the Gen 3 follower sits lower than that of the Gen 2, and thus sometimes only partially engages the bolt catch. Filing down the follower would probably alleviate this.
What are you using for buffer and tube. Psa used a longer tube with standard carbine buffer. With the upper removed make sure you can slide the bolt back far enough that it goes past the bolt catch. On the complete rifle can you manually lock the bolt open with no mag?
I’m using a random tube I had laying around in my 308 bin. I am using a PSA black buffer and I think its a Standard 308 spring. Again this was my parts I had laying around stuff. I bought the barrel and U/L receivers along with trigger group. Using the 308 catch it won’t stay open unless I hold the catch. Using a 223 one if I hold it down without a mag in it it will hold open. Only the 223 will manually lock open. 308 catch only works 25% of the time with a mag in it; otherwise it won’t work without a mag or finger keeping the catch up.
Sounds like you need a 308 buffer. The standard ar15 is longer and won’t allow the bolt to travel back as far. Psa does not sell a 308 buffer. They use an a5 length tube with standard ar15 buffer.