308 Norma Mag VS 300 WM

[Cowsearshooter]

Assuming a 26" barrel (lately a virgin 30-06) with a 1:10" twist, can someone convince me of the merits of the 300 WM over the 308 NM?

I plan to handload in either case and I don't work for anyone who can wizard up some free 300 WM for me. So, from the research I've done it seems like the minor edge in cartridge efficiency and design (as in a longer neck) gives the 308 NM a win in my book.

Does anyone have experience with both of these cartridges that can recommend one or the other?

 

[MTyotehunter]

Re: 308 Norma Mag VS 300 WM

I have a 308 norma magnum built on a custom Mouser 98. 24" 1in10 long throat. 180 accubonds with 76gr H4831 max is around 3080 fps. The long throat tipicaly gives me 3-3.5gr more powder before I hit max. Groups in the .2s and the shorter case gives you more room for seating out bullets.

1 vote 308 Norma Magnum

 

[Cowsearshooter]

Re: 308 Norma Mag VS 300 WM

I like those numbers. This will be on a Winchester 70 Marksman and about 2" more barrel--hopefully that can improve it a little bit.

Have you tried any RL22 or anything in the 4350 burn rate (RL17, IMR, AA, H4350)?

What OAL length are you running for the 180 grain bullets?

 

[MTyotehunter]

Re: 308 Norma Mag VS 300 WM

funny you should ask, my most accurate load with this gun and the accubond is 72gr of H4350 running 3060 and throws them in one tattered hole. I have not tried a slower powder, I might if I go to hevier bullets tho.

My OAL is 3.51

 

[Cowsearshooter]

Re: 308 Norma Mag VS 300 WM

That's running 'em long, but it still should fit in an AICS magazine. I'm having CDI put on some bottom metal and tuning up 300 WM magazines for 30-06. I suppose I should have them do a set for 308 Norma too...