Reloading belted cases


Q: I am about to start reloading for my .300 Winchester Magnum and since this is my first attempt at reloading a belted case, I have a few queries. 

I have read that it is best to neck-resize cases until they get a bit tight to chamber and then to set the full-length die to bump the shoulder back only 0.001” or 0.002” (0.025-0.05mm) so that it head-spaces on the shoulder (I have purchased a Hornady Lock-N-Load headspace gauge). I have heard that this can eventually result in the cases bulging just above the belt, causing chambering problems. I would appreciate your thoughts on this.

I am loading 175gn Atomic 29 projectiles using AR2213sc. Any suggestions for a starting load for this combo?

Bruce Doyle

A: Reloading belted cases does require a little more care than does rimless cases. You could neck-size only until the bolt closes very hard on a reloaded round — usually after two or three full-power reloads — and then full-length size the cases and check their length. If they are 2.62” (66.5mm) long, trim them back to 2.61” (66.3).

I have never had any belted cases that started bulging just above the belt: no idea where this came from. The main point to remember is never set the die down hard against the shell holder until you are certain that the die and the chamber have the same dimensions at that setting.

Head-to-shoulder length is critical. Forget the belt and ensure that the case head-spaces on the shoulder like a rimless case does. 

This is done by unscrewing the die body until it just fails to touch the shoulder on a fired case, run the case into the die then try to chamber it. If it is tight or won’t enter the chamber fully, screw the die body down a half-turn and try again. 

Repeat this process, slowly turning the die down a little at a time until the case will enter the chamber with a slight feel. This tells you that the case is actually head-spacing on the shoulder. 

Lock the die in this position and you can be sure that your .300 Win Mag cases are not being lengthened and shortened each time they are fired, something that can cause case head separations.

One other thing: I suggest you buy a separate neck-sizing die as problems can arise from partially sizing cases in a full-length die.

For a starting load, I suggest working up from 69gn to a possible maximum 75gn, which gets 2966fps with the 175gn Atomic 29.

 

 

 


Like it? Share with your friends!

What's Your Reaction?

super super
13
super
fail fail
4
fail
fun fun
3
fun
bad bad
20
bad
hate hate
18
hate
lol lol
16
lol
love love
15
love
omg omg
10
omg
Nick Harvey

The late Nick Harvey (1931-2024) was one of the world's most experienced and knowledgeable gun writers, a true legend of the business. He wrote about firearms and hunting for about 70 years, published many books and uncounted articles, and travelled the world to hunt and shoot. His reloading manuals are highly sought after, and his knowledge of the subject was unmatched. He was Sporting Shooter's Technical Editor for almost 50 years. His work lives on here as part of his legacy to us all.

0 Comments