Binding of new brass without sizing die for .280AI

[williaada]

I am working on reloading prior to going out west and today at the range I noticed my .280AI bolt was tough to close when chambering a new round. So this evening I have taken new brass (nosler) resized the new brass and it is a tight fit to close the bolt. I then took some already once fired brass resized a piece and tried to chamber the empty brass. The once fired brass work much betters. Can anyone provide some insight as to why this is occurring?

 

[TaperPin]

Didn’t the 280 AI have a change in length when it became a SAAMI standardized cartridge?

My understanding is the older AI chamber is slightly longer than the saami version. Older dies wont push the shoulder back, and older new brass will be on the long side.

 

[BrBa]

What dies are you using?

The piece of fire formed brass that you resized fits your chamber, but the new Nosler brass is a tight fit even after sizing? Sounds like your new brass might be out of spec, or maybe it had an unusual amount of spring back after sizing. Weird. Can you load any of your fire formed cases that haven't been resized?

 

[williaada]

What dies are you using?

The piece of fire formed brass that you resized fits your chamber, but the new Nosler brass is a tight fit even after sizing? Sounds like your new brass might be out of spec, or maybe it had an unusual amount of spring back after sizing. Weird. Can you load any of your fire formed cases that haven't been resized?

The fired form brass fits ok, I am resizing all of the new brass prior to reloading for this .280ai.

 

[Trogon]

Can you not just bump the shoulder back a bit more when resizing?

 

[BrBa]

Have you measured your old and new brass for comparison? Could be the shoulder needs bumped, or maybe the rim is oversized. Your caliper will tell you what's what.

 

[Unckebob]

Can you not just bump the shoulder back a bit more when resizing?

I had the same problem. I discovered my chamber was at the Saami minimum and absolutely hated Nosler brass. It seems their brass thickness doesn't work well with my "match" chamber.

Switching to Hornady 280AI and fire formed 280 REM Norma brass solved my problem.