450 Bushmaster FTF

[sbrville]

Brother dropped off his 450 AR before deer season for me to look at. Said shooting at target it works pretty good but every time he shoots a deer it has a failure to feed. I've never had an issue with an ar FTF but maybe a different weight buffer? I initially thought mag but he is using factory mag(spring seems very stiff) and a PMAG i converted for him(spring seems pretty soft) and they both act the same. Using both Hornady loaded ammo and some handloads i made for him and having problems with both. Thanks SB

 

[M67]

for 450s I'd use a Lancer mag over a PMAG, there's no ridge in the front of a Lancer, you just have to fit the single shot followers to either.

How old is his 450BM? And factory mag like factory Bushmaster/Remington mag? If so, pop the thing open and check the spring out and look at it. I saw a couple that were made in the post Newtown rush that were absolutely horrible, looks like they took a 60rd spring and crammed the thing in there. Never seen one of those mags work right.

The other, is it lubed and how does the chamber look?

 

[indiana hillbilly]

I have a 450. I have never had a FTF, but mine would stovepipe every couple of rounds. I installed a heavier buffer and it fixed the problem. I would ask if he has a .223 sized buffer or something heavier. .450's are known for having mag issues. I say check the mags first?

 

[T755]

Make sure you cut a clearance cut on the front. The best mags for these are the all stainless L80 mags that came in years ago. Take a sanding drum from a dremel and clearance cut the front of the magazine. Bout the size of the round. Also make sure you are using a blue single shot follower in the magazine. You can get these from Fulton Armory and the like.

 

[bobjones223]

Brother dropped off his 450 AR before deer season for me to look at. Said shooting at target it works pretty good but every time he shoots a deer it has a failure to feed. I've never had an issue with an ar FTF but maybe a different weight buffer? I initially thought mag but he is using factory mag(spring seems very stiff) and a PMAG i converted for him(spring seems pretty soft) and they both act the same. Using both Hornady loaded ammo and some handloads i made for him and having problems with both. Thanks SB

Sooooo I am going too spin this a different direction due to the first part of the post!

You said he never has failures at the range but shoots deer and gets a FTF. To me I am thinking weather related? Is there a chance that the lube that he is using doesn't like the cold and isn't allowing the bolt to fully cycle?

Just a thought?

 

[Ggreen]

I shoot .50 Beowulf and noticed that pmag's fail to feed on a regular basis with the .50. I switched to some CAA mags and the ftf problem went away. I still ftf the last round of every magazine, but I'm sure that is due to using a standard AR follower, pushing the round at a very awkward angle. The main difference I could see between the two mags was that the CAA is made of a stiffer polymer and doesn't flex out like the pmag does. I am waiting on caliber specific mags which are metal.