Fireform .375 RUM brass for .338 Edge?

[davewilson]

personally i feel that .002 clearance is just a bit snug with a 338 dia bullet. this is with a hunting rifle. if it was a 243 then yes, .002-.003 would be about right. with a 338, .003 would be about minimun with .004 or .005 being ideal, especially if you've never dealt with a tight neck before. i talked with Shawn about this once, it's been a while, but i'm pretty sure he told me most of his ran about .007 clearance. 365 inside of 372.

 

[TAP]

I had a .223AI that I was fireforming for. When I first started, I was just loading up some rounds and shooting them, but I was getting that same wierd shoulder shape. I wound up loading some rounds up with a mid range load of a medium powder for this cartridge and seated the bullets into the lands. When you do this it keeps the case tight to the bolt face when the rifle is fired. This also helps to keep the case stretching to a minimum so you won't have as many problems with head seperation. Worked like a charm. I also load my .257AI the same way as In had the same thing happen with it. The Nosler reloading manual explains how to do it under this same cartridge listing.

 

[RockyMtnMT]

Neck diameter

So when you turn the neck down, say .004" less than the chamber, is this dimension before seating a bullet or after seating the bullet? When I seat the bullet the neck expands beyond the full length sized case dimension. I'm guessing that I need to anticipate how much the neck size will change w/ seating and turn the neck accordingly.
Another question, should you turn the neck before necking down to caliber or after necking down?

Thanks, Steve

 

[geargrinder]

So when you turn the neck down, say .004" less than the chamber, is this dimension before seating a bullet or after seating the bullet? When I seat the bullet the neck expands beyond the full length sized case dimension. I'm guessing that I need to anticipate how much the neck size will change w/ seating and turn the neck accordingly.
Another question, should you turn the neck before necking down to caliber or after necking down?

Thanks, Steve

Seat the bullet then measure the neck diameter. Then you will know how much to take off.

You'll have to neck down prior to neck turning so you can measure with a seated bullet.

 

[RockyMtnMT]

OK. That makes sense, thats what I have been doing. Just needed conformation.

Thank you, Steve