Belted Magnums oversize brass reloading issue.

[gringop]

I've got a Ruger #1 rifle in 7mm Rem Magnum, bought it used 30 years ago. I've reloaded for it for with no issue for all those years. My brother got a Rem 700 in the same caliber and just started reloading for it using my Lyman 2 die set and his own Dillon 550. He is getting issues with some of his factory once fired brass being too big in diameter just above the belt, some work, some don't.

All new factory ammo loads OK.

Looking at some of the too large brass that he tried chambering, the chamber mouth is actually cutting into the brass and raising a burr. He found this Belted Magnum Collet Resizing Die, but it's kind of pricey.
https://www.larrywillis.com/

I'm looking for input from folks who have experience with Rem 700 chambers shaving brass and/or belted magnum reloading and/or experience with this Belted Magnum Collet Resizing Die.

My first thought is to;
A: deburr the chamber mouth,
B: Have a gunsmith ream the chamber
C: Buy this Collet Resizing Die
D: ?????

I have no issues with my #1 with these dies but being an old single shot it's not too picky re, bullet, crimp or other factors.


Help me Belted Magnum Obie Wans, you are my only hope.

Gringop

[secondstoryguy]

The Willis die you listed is the only thing that I have found that works.

It essentially smashes the bulge down so they will feed more reliably. I've only used it with .300 H&H, .375 H&H and .350 rem mags (all in bolt guns) but it works really well.

[Paul D]

I second the Willis die. I use it for my .458 Lott, .375 H&H and 300 WM. It works.

[entropy]

Third for the Willis die.

I use it on both .300winmag and 7mm RM.

It’s not the quickest procedure in the universe to use the die, but it does what it’s designed to do. Use a good case lube.

[gringop]

He has ordered the die and lube. He questioned if the 550 will have enough leverage to do the job.

I told him to enjoy his Christmas present.[emoji3]

Sent from my SM-A125U using Tapatalk

[entropy]

It should. I use a simple Lee Breachlock.

If you are ever so inclined to take a set of calipers to a belted magnum case, it’s quite enlightening.

Depending on the case manufacturer, I’ll belt size it every other, or very third loading. I have some RWS .300wm cases that seem to nearly be immune to it. Hornady so the other hand, are pretty soft and seem to stretch like balloons.