Brass Shrinkage With Use

[gunnut]

Well, It's like this. With the heavy walled 284 cases and a tapper crimp, everything conforms to the outside specs. When the round is slamed into the chamber from a mag the bullet jumps forward. The base being slightly larger due to the tapper crimp, expands the case mouth and acts like a wedge anchor.
Pulling it out from the base using the charging handle only makes it tighter! The only way to get it out is to drop a cleaning rod down the barrel with the bolt unlocked to back the bullet up and the case will just drop out. Very scary!! With the bolt unlocked the firing pin is not long enough to hit the primer. Still, Very scary! Look at my post on "Stuck cases".
Inside reaming of the 284 cases helps, with the side crimp it eliminates it.
Try them with a Dummy round first!

[Hoot]

Yes, I found your thread about that very interesting. Before the 450b, I never gave it much thought since I reload all my bottle-neck cartridges to the lands. Luckily, I'm not rechambering the same round repeatedly, nor are my bullets real heavy and made of lead. I suspect one day, when I've contributed as much information as I've gleaned from this forum, I'll abandon the Hornady cases and go the route of .284 cases. That could change if some manufacturer comes out with reasonably priced brass. I perceive a buck a round, shipped, for Hornady brass to be a message that they'd just as soon not sell it. With all the lemmings buying guns and ammo, it appears the manufacturers are leaning away from making reloading brass that competes with their higher profit margin, complete ammunition. With all the price fixing going on, I'll be surprised if Remington decides to sell brass and it's cheaper than Hornady's.

It's a shame Bushmaster decided to line their bore and chamber with chrome. I seriously believe the brass would bind better during ignition to a SS or CM chamber, but what do I know?

Hoot

[Siringo]

Regarding 284 brass and the wedge anchor -- I size in the 450B die, expand and then size again -- after that sequence, I ream all my new brass to an ID of .445 inches --. Just enough to seat the 230 grain bullet. Drops in the chamber perfect!

After the first firing, I size and them ream the full length of the tool. At that point, the ID of the cases are pretty close to factory 450B cases.

[Siringo]

Regarding case shrinkage -- this happens even to macho rounds as the 450B when the barrel is very cold! Geeze -- that was bad!

Seriously though, I have notice on my cases that have shrunk that the lettering on the case head gets peened so bad that it gets hard to read it. Anyone else see that? But they have been fired well over a dozen times.

[gunnut]

The 284 cases are a BIG plus for the 450B. Not only can you make your own cases! You now have a choise between large and small primers. Just need to know how to do it. The brass is thicker. But, Boy do you get a lot of reloads out of them! I prefer my LiL "O" 230grn fmj the most. Same ones I shoot out of my 1911 & XD. Not much to stop the 450B now!

[Hoot]

In this thread I have posted the resulting shrinkage of brand new, unsized 284 brass.

Hoot