Ticks for loading a belted case

[Old Coach]

I need to start loading the 7mm Rem. Mag. and have not loaded for a belted case.
All brass will be used in one rifle.
Any tricks of the trade to share?
All help appreciated.

Coach

 

[AJ Peacock]

I ignore the belt and use the shoulder for headspace, just like any non-belted round. Otherwise, as you reload the brass repeatedly, they will have a tendency to stretch in front of the belt. This is due to pushing the shoulder back too much.

If you have a way to measure the shoulder to head length (like the hornady tools), it is an easy job to just touch the shoulder .001" or so and call it good.

AJ

 

[steve smith]

I would advise that you neck size for as long as the brass still chambers easily, then full length size to bump the shoulder back. This should give the longest case life and better acuracy than to full length size every time.
I anneal the case necks on all new brass then use a Lee collet neck sizer. This works very well for not over stressing the necks and giving very consistant neck tension. I can usualy load each piece 3-4 times before it becomes neccesary to full length size. Then the sequence starts all over. I have loaded some 300win mag brass some ten times before primer pockets got a little toooo loose! I've yet to loose one case to head separation.

 

[gbp]

i ignore the rim and the shoulder and load into the lands. fl size when it needs it to bump everything back to 'normal'. but i must admit i so not shoot a lot of belted mags. This is what has worked for me. your milage may vary

 

[mike33]

Be careful sizing you dont go to far. A lot of reloaders dont size a magnum properly.
mike

 

[boomtube]

A bottle necked case is a bottle necked case, size them to fit your chamber. A belted case is a bottle neck case, there are no tricks.

 

[30-06 boy]

i load a 300 wim mag. i neck size with lee collet dies. when the cases get "snug" in the chamber, i fl them just enough to get the bolt to"close" on them. i also anneaql every 5 shots.brass life extended this way.moderate loads will also extend brass life. jason

 

[Bart B]

Re: Tricks for loading a belted case

There's several ways to resize belted cases as the replys show. Depending on how one tests the results, any one of them will work to some degree. I prefer to do what has resulted in the best accuracy all the time; not a 3, 5 or even a 10-shot group. But best accuracy for at least 25 shots. Due to the statistical odds, any reloading process will produce great accuracy for a few shots once in a while.

Back in the 1960's and 1970's when belted magnums were used in 1000-yard matches, both top civilian and military competitors tried various full-length, partial-neck and neck-only sizing techniques. And bullet seating depth relative to the leade was varied along with neck tension. Best accuracy happened with new cases. None of these resizing techniques produced accuracy as good as what new cases would do. 25 or more consecutive shots into less than 7 to 8 inches at 1000 yards was only attained with new cases for both 28 and 30 caliber belted magnums.

Some folks finally did some critical measurements on the resized cases and found that a ridge a few thousandths of an inch in front of the belt wasn't sized down with a full-length die. For some reason, any fired belted case that didn't get its body full-length sized back to original diameter right in front of the belt didn't shoot too good. Neck-only sizing these fired cases tended to produce better accuracy than conventional full-length sizing does when this ridge is present.

By cutting off a full-length sizing die's bottom half inch or so and cutting off the top about half an inch below the shoulder, you end up with a body only sizing die. Smoothing the top and bottom edges lets a fired belted case be sized all the way to the belt eliminating that tiny shoulder in front of the belt. Some folks use a standard full-length die first (with its neck lapped out so expander ball isn't used) to set the fired case shoulder back about .003-inch then size again with this body only die. You end up with a belted case with virtually new dimensions. I've reloaded some cases 10 times using this method. Best I've done is 30 consecutive shots from a Kreiger-barreled M70 .30-.338 Keele well inside 7 inches at 1000.

Since then, a couple of folks started making these special dies; Innovative ??? (company name escapes me) has a collet version that works well but it's expensive.

Best suggestion? Simple. Do what works best for your techniques and hardware.