AR 450 Bushmaster Mag Issues

[cwlongshot]

Its more than just mag dumps. HEAT KILLS barrels faster, excessive heat should be avoided. But come even close to compressed and watchout! Hang fires and pressure spikes are on your addenda. Been there...

LIL Gun is for chasing every last FPS. I dont play that game.

[missionary5155]

CW Again thanks ACC #9 is a bunch slower than I was thinking..... I wonder how Blue dot or 4227 might get along ?
I also do not need much over 1600 FPS. I hunt river bottoms and my longest shot weather flintlock of center fire is a whopping 33 yards. Most are very close with 5-10 yards the normal. 55# recurve gets alot of use.

[cwlongshot]

AA#9 is a faster powder then lil Gun or 4227. (Unsure why this is a concern)

Or if its velocity that worries you.... My top 200g FTX load closes in on 2600 fps....

4227 is good RE7 too but enough gas for M$R is questionable but Id steer clear of Blue Dot in the 450Bushy. I LOVE IT, BUT It can be a "funny" powder too. I have tried most of these even some "vhitavoree" powders but 5744/#9 have been the cream for four different barrels.

CW

[SeabeeMan]

I run the Tromix followers with Lancer 10 rounders, giving me a 4+1 setup for hunting with the stop removed. 100's of rounds, never had a FTF.

[BD]

Caviat: I put this .450B AR together 12 years ago and haven't had to mess with it much at all since, so the info is based on what was available then. I use the older blue "single round loading" .223 hi-power followers in any mag and they all work fine. The plastic Sig 20 round mags also feed just fine with the stock followers. Lil Gun works great but does burn very hot. I primarily use surplus WC297 in cut down .284 brass with large primers. Mostly because I have a lot of it and it was cheap at the time. It burns clean and consistently and groups well with the 250 grain FTXs. Not so well with cast. 2" groups at 100 are about as good as I can do with cast. I often have 3 very close, with a couple of flyers. The FTXs are excellent. I once put 50 rounds into 1" at an 80 yard range in upstate NY while doing load work up with FTX and LilGun, and the last 10 where shot by another guy who was at the bench next to me and couldn't believe what he was seeing, (big bore ARs where not very common then). And I've shot quite a few 300 yd groups under 2" with the FTXs. Once I retire I will go back after the cast in the .450B to see if I can't cure the flyers, but for now I'm staying with what works.

[missionary5155]

Thank you everyone for all the input.
Looks like mags are the big issue. While we are in Peru this time will get a couple "real" 450 mags ordered. 4-5 rounds is all I will need as this rifle will be for hunting.
But we are 9 days from leaving back to Peru so today that barrel was oiled and wrapped and goes into storage tomorrow with a pile of other items.
So again thank you all for all the good info and discussion. I learned alot and I do appreciate your sharing with e and everyone else who was reading along the wealth and value of what is already written.
Mike

[Gtek]

I spent many an hour staring into magazines and working with just about everyone on the market. If scarring/chiseling long lines on brass does not bother you and working a little radius up front I would suggest the Lancer mags and polish bottom of lips and it is what it is. A.500" case sitting up between two lips that are supposed to have .378" cases alternating under each creates a little issue. What I have done and have been using for several years dare I say flawlessly off the bench and hunting and they also feed the Socom just fine, three rounds magic, four rounds pushing it and don't use. Take a PMAG plastic 10 rounder, disassemble and now the fun begins. I took a very sharp wood chisel and removed front separating rib on front internal wall of magazine to almost flush. Then wrapped 320 on pop stick and finished polish to flush. Wrap a 30-06 case or equivalent case diameter with the 320 and radius front top of magazine down in at 30 degrees in to a depth of .1875"/3/16", shooting for a .250" radius. Here is where a mill really helps with next and final, secure up follower (take spring off) level/level in vise. Then run down longitudinal center with a .500" ball bit to as close as you dare to deck height of follower. Yes it makes holes through in places on bottom and interior wall of ridge but does not affect operation in any way. Clean up scraping and sanding to personal needs, took an Exacto and scraped a chamfer in created holes and used 30-06 case wrapped with paper to polish and clean up top. Three round loading as said has been flawless, four really wanting to pop overriding plastic tension of mag top but can slap in and will run.
I walk in loaded with three in mag and two more mags on the front of me, nine rounds of that and a 1911 on my hip. If I cannot get out of stand and back to the airboat with that I guess it ain't my day!