300 Win Mag vs 300 PRC

[FEENIX]

Got scorching velocity with the 180 grain Berger and the 300 Win Mag with Magpro powder.

MagPro is one of those sleeper powders. I have used it with excellent results on various calibers/chamberings for a while. I took advantage of it and snagged a few when my local Scheels was selling it for $28/lb; nowadays, they are in the $50+ range when available.

 

[DustThroughaFan]

I've been looking at retumbo for my winmag lately but I've got a lot of magpro to burn up first.

 

[MarkInPA]

 

[Alibiiv]

I have loaded belted cases in 5+ decades and have never had case separation.

I have had the same experience with my son's 300 WinMag, but I headspace off the shoulder with a .002 bump. I'm curious if headspacing off the belt causes the separation?

 

[Stevenstl86]

I have had the same experience with my son's 300 WinMag, but I headspace off the shoulder with a .002 bump. I'm curious if headspacing off the belt causes the separation?

I also agree but will sizing off the shoulder of any belted case size the area right above the belt or leave any small area of the brass untouched?l

 

[Alibiiv]

I also agree but will sizing off the shoulder of any belted case size the area right above the belt or leave any small area of the brass untouched?l

Good question. It "may" but .002+-?? All I can say about it is based upon my experience. Never any chambering issues, and no case separation.

 

[MarkInPA]

This might be a good place to mention the Larry Willis, "Belted Magnum Collet Resizing Die". I personally don't have a lot of experience reloading for belted magnums even though I do own a few. If I were to load for the belted magnum, I would certainly look into this. I do know that you want to avoid sizing the brass to headspace off of the belt and headspace off of the shoulder instead.

Innovative Technologies - Reloading Equipment

Our patented resizing die can reload Winchester, Remington and Weatherby belted magnums up to 20 times, instead of just 2 or 3 times and the top of the die is a chamber width gauge.

www.larrywillis.com

Our patented Belted Magnum Collet Resizing Die solves this problem and has other unique features. The top of this die is a case width gauge that shows when a little "extra" case resizing is required. This resizing die is used to eliminate the case bulge above the belt, after using your full length (or) neck sizing die. Our collet die ensures that your belted magnum ammo will always chamber properly and your cases are now able to last for up to 20 firings, even when using the hottest handloads. Our resizing die uses a collet that fits over the cartridge case, until it bottoms against the belt. The case is then pressed into the sizing die. The collet allows your case to go farther into the die where it only reduces the area "just above" the belt.

 

[MT-Shooter]

It is a myth.
The ONLY cause of case head separation is from HANDLOADERS SIZING TOO MUCH….
I have numerous batches of 300WM, 264WM, 270 Bee, 300 Bee, 340 Bee & 375 Bee brass that have exceeded 20 sizings
I can show you a case on it's tenth firing sectioned and prove that no stretching takes place if you don't induce excessive headspace with your die.

OK, but aren't you supposed to run the case completely into the sizing die?

 

[FEENIX]

This might be a good place to mention the Larry Willis, "Belted Magnum Collet Resizing Die". I personally don't have a lot of experience reloading for belted magnums even though I do own a few. If I were to load for the belted magnum, I would certainly look into this. I do know that you want to avoid sizing the brass to headspace off of the belt and headspace off of the shoulder instead.

Innovative Technologies - Reloading Equipment

Our patented resizing die can reload Winchester, Remington and Weatherby belted magnums up to 20 times, instead of just 2 or 3 times and the top of the die is a chamber width gauge.

www.larrywillis.com

View attachment 625092
Our patented Belted Magnum Collet Resizing Die solves this problem and has other unique features. The top of this die is a case width gauge that shows when a little "extra" case resizing is required. This resizing die is used to eliminate the case bulge above the belt, after using your full length (or) neck sizing die. Our collet die ensures that your belted magnum ammo will always chamber properly and your cases are now able to last for up to 20 firings, even when using the hottest handloads. Our resizing die uses a collet that fits over the cartridge case, until it bottoms against the belt. The case is then pressed into the sizing die. The collet allows your case to go farther into the die where it only reduces the area "just above" the belt.

I purchased mine some time ago but have not yet found the need to use it. All of mine are head-spaced from the belt.