AR-9 build

[KnotRight]

Sorta new to the forum and was directed here from a couple others.

I built an AR-9 using a PSA Glock lower and bolt. The other parts have come from a number of different vendors. I have used a mil-spec trigger that I have polished using Mother's Polish to a mirror finish. I used a Dremel with a cloth wheel only. Also, installed an ALG trigger and a drop-in trigger with a 3.5 break.

The gun with the mil-spec trigger and the drop-in trigger would go fully auto. I emptied a 31 round clip with 4 quick trigger pulls. The ALG trigger worked fine except the break was about 5.5 pounds. That is the reason I bought the drop in. With the upper off, I tested the trigger lock-up and it would after I pulled and held the trigger.

I even changed the buffer spring that I got from a new AR-15. The buffer is made for the 9 mm action and is heavier than the normal AR-15 buffer.

Any ideas why the gun would go fully auto?

Thanks,

[fallenromeo]

If you want to get answers to this, I recommend you PM a mod and ask them to move this to the Technical discussion.

[KnotRight]

Thanks

[KnotRight]

Made it to the range today with the ALG trigger. This is after the smith replaced the spring in the bolt and the gun ran the way it was suppose to. After 75 rounds I was going to drop the ALG trigger and put the drop-in but I forgot the allen wrench to get the hand grip off the lower. I could not get the trigger in.