M4 miss loading
 

So I have a G&G m4 commando that had pneumatic blowback (I altered it to not be anymore). When I was trying out some .25 gram bbs every third shot or so would shoot 2 bbs out. I have tried with two different brand of mags and both do this. I also noticed with .20's or .25's three or so bbs would get stuck in the mag well when I take a mag out. Any help would be much appreciated.

Do you mean 2 or 3 bbs fall out when you remove the mag?
Thats normal on most aegs. Sometimes even 4 or 5.

As for the missfeeding. What kind of bbs are you using. Crappy bbs will do that

Sounds to me that you are not getting enough compression to push out the bbs. How did you disable blowback?? Did you change the cylinder? if you are still using the same cylinder...did you seal the port that directs air for the blowback piston? I had did the same to my G&G Commando M4. You must ensure that the hole on the cylinder is leak proof or else you will lose compression and therefore, your bbs will drop out of the barrel.

Also helps if you chrono the gun and see if you're getting the desired fps.

The brand of 25's are firepower. To disable the blowback I did plug the port. Perhaps I did a crappy job on sealing it.

If you don't mind me asking...How did you seal the port?

I used silicone sealant.

might be interfering with the O-ring of the piston head preventing it from sealing at that point?

Crappy BB's. Use good BB's and either your problem will be solved, or you already damaged your hopup rubber and you have to get it replaced, then use only good BB's.

Sounds like your problem is crappy BB's, and you will continue to have issues even if you replace your hopup rubber.

is BB Bastard a good brand? I thought I heard from somewhere that it is Canadian.

yes and yes

I once build a custom AR for a friend... When I test it with my King Arms BBs, everything was fine. When he play with firepower BBs, he have a very bad jamming problem...
Haven't try those firepower BBs myself but sounds like they are not very good.

I tried firepower BBs when they first came out, just freaking awful.
I used to use flying colors, despite them jamming everyone elses gun, they never jammed any of my 6.03 tightbores, but had 10% less accuracy than KSC perfects.
firepower was 20% less accurate than KSC perfect
metaltechs were 10% less accurate than KSC, and it's the only BB I've ever seen jam a mag.