Strange

Doing some reloading. I found 20 once fired Norma cases for 7 mm Rem Mag that I resurrected after 10 years. I noticed they wouldn't fit into a #5 she'll holder. Same I've always used for 7 Rem mag and 300 win mag. I looked and rim is thicker. I looked at some 300 win mag Norma cases and thinner like all other brands of 300 and 7 mag. I had to use a #38 for 300 RUM case to seat primers. No big. Only have 20 cases. They're probably 20 yrs old.
Another strange thing. I had some Winchester 300 win mag cases that were once fired. Shot them. One case the primer fell out of. Tried another primer. Same thing. I don't use my Hornady or Win. 300 Winnie cases for much. Use Gunwerks/ADG and Norma. Just thought strange after 2nd firing. Not hot load either.

Come to think of it I had a batch of Remington 300 RUM cases that wouldn't fit in the shell holder also. About 15 years ago. Just wondering if anybody else has experienced.

Crickets ...

Can't speak for # 5, but the older (at least 4-5 years old) Norma 7 Rem mag I have will work in #38 or #43.

Seems like your loose pockets are 'prime' for testing some of those new Bosnia primers....they are supposed to be a touch bigger diameter......

WYO300RUM,

Both situations are a bit odd!

The Win. 300 may be a bit more explainable…..factory load (?) perhaps a bit warm and perhaps perhaps you have a chamber of minimal size!

As to the 7 Mag. brass…….nutt'n to offer! memtb

wasskeet said:

Can't speak for # 5, but the older (at least 4-5 years old) Norma 7 Rem mag I have will work in #38 or #43.

Click to expand...

I had to use a #38 for RUM.
Thanks !

memtb said:

WYO300RUM,

Both situations are a bit odd!

The Win. 300 may be a bit more explainable…..factory load (?) perhaps a bit warm and perhaps perhaps you have a chamber of minimal size!

As to the 7 Mag. brass…….nutt'n to offer! memtb

Click to expand...

It was a new Win. case. I loaded it once . Not hot. Never ran it to that before but no big deal.
Thanks !

My friend gave me 200 Nosler 300 RUM brass because his Hornady shell holders would not fit. Fit fine in RCBS shell holders. There is .020 tolerance between the rim (.010) and extractor gap (.010) that might be contributing to it on the 300 RUM. Probably drives tool designers to drink.

I have some 65248 lapua brass that is tight fitting in shellholders...and another lot that slides right in.....
I doubt 'all' cuts are 1000% perfect...

Bob Wright said:

My friend gave me 200 Nosler 300 RUM brass because his Hornady shell holders would not fit. Fit fine in RCBS shell holders. There is .020 tolerance between the rim (.010) and extractor gap (.010) that might be contributing to it on the 300 RUM. Probably drives tool designers to drink.

Click to expand...

The problem I had was some 20 year old Norma 7 Rem mag brass wouldn't fit in #5 shell holder I use for 300 win mag and other 7 mag brass. Used #38 she'll holder for 300 RUM and it fit. Had new Norma 300 win mag and it fit in #5 fine.

Bad lot most likely. OAL good?

Hey stranger ! Yes. It was 20 cases I had from some factory loads about 20 years ago. I kind of remembered the problem when I tried to size them back then . Just wondered if anybody has experienced it with Norma cases before. I had some new Norma 300 win mag that fit fine in #5 shell holder. You can see the difference in rim thickness .