Questions...

[LSP972]

New to the board, thinking about a big-bore AR upper. I see BushMaster has theirs on sale. I have perused this board, and had some questions answered. But I would like clarification on a few things...

1. Can one reload this cartridge using .45 ACP pistol bullets (sized to .452) for bunny-fart practice loads... with success? I would use Hornady factory stuff "for real"...

2. I'm still not clear on how one modifies standard 30 round AR magazines to function reliably. Although, the new BM nine-rounder may make that point moot... anyone tried it yet?

3. Will your basic composite collapsible stock stand up to the recoil? I plan to put this on a stock BM lower. The lower is from four years ago, before Cerebus bought them out and QC began sliding.

I have been intrigued with this idea for some time, but am ready to pursue it now. Thanks for any suggestions/information.

.

[thatguy]

Not an authority in any means.. but Ill try to get this kicked off..

1) the bullets are typically made for the 45 Long Colt - not sure how that compares the the 45 ACP - Hornaday had the .452 bullets in 200/240/250/300 gr..

2) 30 rd AR GI mags typically dont work well with the 450B - the curved mag body causes the cartridge to bind up and not feed correctly.. To my knowledge the only 30 rd mags that work are the Sig 556 mags and they work without any modifications.

20 rd GI mags do work but you have to either 1) use a single stack follower , or 2) grind down the bullet shape on the follower. The problem is the 5.56 will double stack in the magazine while the 450 B needs to be in single file. The bullet shape on the follower will push the first round loaded to the side and it will catch under the mag lips and not feed. by removing this bullet shape the cartridge will now feed straight up.

You can also convert Pmags for 450B use but you have a couple more things to modify (its not hard either, I have done 2 so far). I can provide more details if you are interested.

3) I am using the CAA 6 pos stock and so far have not had any problems (30ish rds).. I have read that either some of the 50 Beowulf or 458 Socom guys have had the cheaper collapsible stocks fail.. The Magpul collapsible stocks do seem to hold up though..

I am guessing the BM sale will end on the 30th.. so you better act fast to save a lot of money..

I bought my upper in October and love it so far.. It has become my deer hunting rifle and I was able to take a decent size doe with it last week..

good luck

Brian