I built this AR and it failed. AR15 scientist help much appreciated!!!

[SpentCasing]

The other issue you may be having is the fact that the barrel is an 18" with a midlength gas system. This is the same issue that people see with carbine length systems. The carbine system was designed around a 14.5" barrel but the barrels ended up being lengthened to 16" for civilian use. This can affect bolt dwell time because the bullet is in the barrel a little bit longer after it passes the gas port keeping the chamber pressure up, and making it harder for the bolt to extract the case.

Bold type is incorrect. Carbine gas was actually designed for 10.5" and then kept for use in the 14.5" in the M4 system. Thats why many people find the midlength gas for 14.5"+ the ideal length. Also why many, myself included, find it sub-optimal for the even longer 16" civilian legal bbl. One of the (several) reasons I prefer many other options first over Colt. But thats probably best left for another thread .

 

[Mohave-Tec]

Marshall, my gut has been telling me this from the beginning. I've repaired more machinery with feel and sense than with books and wrenches.

 

[Mohave-Tec]

ObsceneJesster, The BCM BCG was the first thing I bought/traded.

 

[Mohave-Tec]

Walkalong, Ramone...thanks a bunch. I'm hoping this will be a winner. It does look very nice and shoots extremely straight.

 

[MarshallDodge]

Bold type is incorrect. Carbine gas was actually designed for 10.5" and then kept for use in the 14.5" in the M4 system. Thats why many people find the midlength gas for 14.5"+ the ideal length. Also why many, myself included, find it sub-optimal for the even longer 16" civilian legal bbl. One of the (several) reasons I prefer many other options first over Colt. But thats probably best left for another thread

You are correct.

My thoughts were based on the present M4 vs. civilian "M4" where issue is still something to consider.

I don't own a Colt AR either. Nothing really against them but I am a fan of the midlength gas system on a 14.5 or 16" barrel and they don't offer one.

 

[Mohave-Tec]

Spent, just to let you know, I bought your buffer weight. http://www.aimsurplus.com/product.as...er&groupid=576
It makes all the sense in the world to me and the weight seems logical as best I can process it in my mind. The rifle is working well now but I think I'd like to find some more traditional middle ground by having the buffer regulate the cycling for the most part then having the adjustable gas block to fine tune with. I'm trying not to introduce a gas line restiction as much as possible.

I bought a new Aimpoint Pro for $385 brand new this morning. No tax. No delivery. MIAD pistol grip instead of the MOE and some BUIS and I'm good to go. This will be a really beautiful rifle.

 

[SpentCasing]

Good deal bud. Im sure youll be happy. Enjoy your new stick.

 

[itsa pain]

it is funny the mini 14 is supposed to be junk compared to the much pampered ARs but I have seen them with barrels from 12-26 inches and everything in between never jam. no issues with weights springs buffers gas system barrel length and the bolts do not need every molecue gone over with a microscope