300 Norma vs 300 Norma Improved real world velocity

[cb4128]

I'm looking at both of these to shoot the 245gr Berger Elite hunters. I can also shoot the 230gr hybrids but really want to shoot the 245's for their BC.

With that in mind, in a 27" barrel, what kind of velocity can I expect in both with H1000, Retumbo, N565 powders? Not interested in shooting N570 and burning up the throat as this will be a fairly high volume shooter.

Trying to decide if it's worth the extra effort for the improved version…

Thanks!

 

[E4aker]

Improving the Norma mag will not see the gains as say the 338 lapua improved.

The body at the shoulder is only getting blown out .005-.007 in most of the variants out there.

What you will see is less case growth with the improved shoulder angle.

The only obstacle to overcome is sourcing a full length die for the 300 NMI. Just be careful who you order your die from, and make sure they understand what you need. The 300NMI brass does not react to sizing like smaller cases and needs more sizing at the base to avoid clickers.

The Norma improved is one of my favorite big 30s right now, and would be my choice of the two if I had plans for the 245s.

 

[cb4128]

Thanks for the reply - do I need a different sizing due for the improved version? I see bullet central sells a 300 Norma sizing die but I've never seen an improved version for sale…

 

[E4aker]

Bullet central has some versions that are not on the website. You would need to call them to see what they have available.

You will need a sizing die made for the reamer your gunsmith uses. Some gunsmith will offer custom dies with their wildcats. I make them occasionally but they are not cost effective by the time you buy a resize reamer, ream the die, and then have it nitrided.

I'd recommend hornady for custom dies if using a print and/or fired brass. This delays the process some depending on how big of a hurry you are to get shooting.

A non improved version is definitely the easy button.

 

[cb4128]

awesome thanks for the info