I have a Bushmaster Lower with a 10.5 inch Delton Upper. The entire upper is Delton. I use this rifle at work on the SWAT team and had to requalify with it today. There was a little problem.
Some history. I have put about 500 to 600 rounds through this setup since I SBR'd it last summer. the only time it jammed was the first time I qualified with it for work. The last 2 rounds I had to fire FTE and the spent case got stuck above the bolt carrier. The new round was partially chambered. I had to dig the spent casing out with a knife.
Today I fired the first few strings of fire without a hitch, roughly 20 rounds. After that my gun would FTE and jam everytime i tried to shoot. I tried different mags (the old military ones i use for practice, the brownells mags with magpul internals and even my team leaders magazines) with the same effect. Twice when my team leader was shooting his gun jammed. Then we went onto ammo. I had some FMJ I use at 3 gun competitions, my duty ammo and some of the American Eagle FMJ we were using to qualify with and all 3 types did the exact same thing. We then pulled the rifle apart to check the extractor. It appeared to be in good shape. I think we have eliminated magazine malfunctions and ammunition. I am going to have a new extractor put in tomorrow and bring my other AR to the range on Thursday to see if swapping out the bolt carrier groups helps. That is if the new extractor doesn't fix the problem.
Does anyone know if the extractor springs have to be beefed up or not? I read on Brownells that a drop in kit with 4 times the strength of the factory spring is made especially for short barelled AR's.
Anyone have this problem and know how to fix it?
Thankyou for all the help
Cole
Some history. I have put about 500 to 600 rounds through this setup since I SBR'd it last summer. the only time it jammed was the first time I qualified with it for work. The last 2 rounds I had to fire FTE and the spent case got stuck above the bolt carrier. The new round was partially chambered. I had to dig the spent casing out with a knife.
Today I fired the first few strings of fire without a hitch, roughly 20 rounds. After that my gun would FTE and jam everytime i tried to shoot. I tried different mags (the old military ones i use for practice, the brownells mags with magpul internals and even my team leaders magazines) with the same effect. Twice when my team leader was shooting his gun jammed. Then we went onto ammo. I had some FMJ I use at 3 gun competitions, my duty ammo and some of the American Eagle FMJ we were using to qualify with and all 3 types did the exact same thing. We then pulled the rifle apart to check the extractor. It appeared to be in good shape. I think we have eliminated magazine malfunctions and ammunition. I am going to have a new extractor put in tomorrow and bring my other AR to the range on Thursday to see if swapping out the bolt carrier groups helps. That is if the new extractor doesn't fix the problem.
Does anyone know if the extractor springs have to be beefed up or not? I read on Brownells that a drop in kit with 4 times the strength of the factory spring is made especially for short barelled AR's.
Anyone have this problem and know how to fix it?
Thankyou for all the help
Cole