Bump fire is the coolest! I especially like to do it underwater. 
C4
LMAO !
Grant, I may still send you my bolt carrier for you to stake it, and check everything out.
Sounds good.
C4
After doing some reading here http://www.ar15.com/lite/topic.html?b=3&f=66&t=266108&page=4 about gas tube alignment. I noticed that my gas tub is wearing on the bottom, and when you look at the tube on the carrier, you can see it is hitting it low. With all the parts out of the bolt. I can slide it towards the gas tube, and you can feel the resistance.
So Im going to try to tweak the tube like is mentioned there.
I take my time torquing barrels to upper receivers and then use a gas tube alignment tool to get the gas tube/barrel nut alignment perfect. If the barrel nut isnāt perfect it can cause the gas tube to bend slightly and engage the carrier key at slight angles wearing the gas tube a little quicker and leak gas, blowing it out of the carrier key and not into the carrier (because the gas tube isnāt sealing inside the the key as it should).
You can bend the tube to fix it a little but itās a bandaid fix instead of curing the problem. This is also why Iām anal and replace gas tubes when replacing carrier keys.
One of the tests to see if you gas key is straight is to remove your upper assy from the lower. Keep the CH and bolt assy in the upper, hold the upper assy so that itās pointing toward the floor at a 45 degree angle (muzzle down) and pull the carrier about 1/3 to 1/2 the way out (with the CH locked forward) and then release the bolt carrier assy, it should slide forward and close without binding. If itās too dry it may not, if itās too dry lube it and try again.
If you mean just slide up against the chamber, then it will now that I tweaked it some. But if you mean close completely, there is no way. It takes way too much force to push the bolt from its forward position, to the locked position. Itās really, really, stiff.
If you want for the cost of the return shipping Iād get it right for you.
I got 100 rounds of Federal XM193 from a friend. Iām going to try those before work. I took it back by the gun shop yesterday and compared it to a Bushmaster. The pins on the bushy were a lot harder to get out, but besides that, the buffer spring seemed to be much softer than the one in my gun.
Edit: Went out and tried the XM193. Gun shoots a lot better with it. Even just holding it by the carry handle, it will chamber the next round just fine. So I loaded up 20 more, and tried bump fire. It emptied all 20 FAST, and locked the bolt carrier back when empty.
Thanks for everything.
Now for a little gun porn of the subject in question:
Sounds good!
Now that youāve demonstrated that it works, youāll never have to bump fire again!
It was a shame to waste all that nice ammo 
Bump firing is how my 2nd child was concieved
I thought that was bumpinā uglies? 
Your wifeās lower reciever must be of high qualityā¦lol
AmmoTech,
Those magazines I sold you way back when, were they any good for you?
I am loving life right now, I have more magazines than I know what to do with, so if you need a few more, let me know!
I leave in 2 weeks, so it will probably have to wait a few months!
Tang419 , can you do me a favor and take apart your bolt and look at your extractor? Does it have a black insert and a Crane O-Ring installed?
I have been hearing reports that M&Pās are coming this way now.
C4
ā¦see post belowā¦
Nope, blue insert, no O-Ring.
I sent you an email about those parts.
Interesting. How old is your M&P?
C4
Not sure of exact date. I picked it up last week, as soon as it came off the UPS truck.
Know of anyway to tell by serial numbers ?
Iāve only been able to test 3 of them but they ran fine. I got a batch of new mags from BQ when I got back and Iāve been using them. Next range trip Iāll use some more of the ones you got me.
Good mags/Good price:
http://www.actiongear.com/cgi-bin/tame.exe/agcatalog/results.tam?rlk=3005319