Building/selecting components for 450B uppers

[mtnhuntsman]

I'm not new to assembling custom uppers for bottleneck catridges. However, straight wall cases like the 450 Bushmaster cause me to ask the question about upper receivers. Is the forward assist absolutely essential? I've never had to use it on my other uppers. Clean rifles and clean burning ammo seem to work for me everytime. Yeah, I know about the stealth closing of the bolt senario.

A couple of my choices for an upper do not have forward assist, ejection port cover, case deflector. You know the ones. I'm wandering if those of you are actually shooting the 450 Bushmaster, whoever built the upper, are experiencing problems chambering factory or reloaded ammo.

I've been getting after Bushmaster and Remington about selling parts (barrels & bolts) to parties wishing to do their own thing. I received a very nice response from Bushmaster stating I should check back mid-summer. Talked with the folks at MGI who are just as frustrated as I am with the lack of barrels and bolts to sell and for me to buy. The forum points to MGI but they don't really have any. A couple of "AR Barrel Manufactures" don't really make AR barrels. What? Just big orders to contract specs for major companies. So where are the assembled barrels and more importantly the proper bolts?

I don't know about you, but I don't need a chrome lined bore and chamber. Stainless would be okay. A good moly steel would be my preferance. I'm not into muzzle devices on this project. Look at Remington's 18" fluted barrel with target crown. Sweet!

I'd love to hear your comments on component choices.

[45r]

I have a upper and lower on order from Delta Arms Company.It will have a LAR Grissly side charge with CM 20 inch barrel,midlength tube,AR performance locking system,sampson handguard,and Ross MB.The LAR lower will have Ergo 93 BS,Moe PG & TG.You get a better trigger pull when you get a lower from them also.I talked about the build with Aaron,he is very knowledgable about big-bore AR's and I went with his suggestions.He sells barrels I think,you might want to give him a call.He says I'll like my rifle a lot.