450Bushmaster.net

i look forward to shareing any info that i have pertaining to my new 450 bushmaster--i have been reloading since the 60's but always bolt action rifles--i rescently purchased a 450--my delima is i am attempting to use the 284 win brass that i have had for many years--whentriming to length and seating a bullet the case neck is around 481" and i read that 476 is what will work--my question is who makes a reamer that will ream the case necks the appropriate ammount and where can i get one--thank you for any help --Roger

Welcome Aboard Roger!

I tried that route many moons ago (2010) and eventually gave up due to the touch labor per case, getting everything just right. I gave my .284 brass and reamer to some member and bought 450b specific brass. Hornady and Starline make it.

Forster will make you a custom reamer for $57.00

Link I can't speak for their turn around time. A phone call would help.

IIRC, you want one that is .446 for cut down .284 cases already run through the 450b sizing die. Due to wall thickness, you're going to have to pick a bullet seating depth and ream in that far.

There are numerous threads here regarding what you are attempting to do. The embedded search engine here is so-so at finding all of them.

I recommend using Google's forum search engine with the search term Site://450bushmaster.net ".284"

Good Luck

Hoot

i realize now that that is very time consuming to use 284 brass to make 450s--i have orderd some factory ammo to get started --thank you for the help and the wonderful advice--Roger

Only advantage to using 284 brass is the large primer....I sized and used a lathe to get the proper bore size its time consuming.....

coyote wacker wrote:Only advantage to using 284 brass is the large primer....I sized and used a lathe to get the proper bore size its time consuming.....

Was there any velocity gains between the large primer vs the small primer?

I made a few... mostly ta see how it would be.

If it where me, and I had a quantity of 284 cases. Id sell and buy proper 450 Brass.

Might be slow selling here but try first. But places like the camp fire would likely sell very quick for ya. They have a huge selling board.

Welcome to the forum! Ya got some good replies and reading old posts will probably answer all questions.

CW

Al in Mi wrote:

coyote wacker wrote:Only advantage to using 284 brass is the large primer....I sized and used a lathe to get the proper bore size its time consuming.....

Was there any velocity gains between the large primer vs the small primer?

Actually 284 brass will have a smaller case capacity....