.308 Norma Magnum

leojlafrog

leojlafrog

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Hi, I acquired a old browning safari with a Belgian proofed replacement barrel last year and have yet to shoot it. I have acquired dies and brass for it and chose some barnes tsx 168gr bullets for my hunting needs. While is was looking for info on handloading on this cartridge, I found some mention of a long leade with this cartridge. I made some dummy rounds and with some black marker, I found the lands with the cartridge @ 3.54" coal and the 168 gr barnes. Is this normal to have such a long leade or was this chamber cut long?

Anybody have some valuable info they would like to share or have about handloading the .308 Norma magnum? FWIW, I was going to try my first set of rounds using H4831.


Thanks, Joel
 
This is the formula I have been using for my Schultz 308 Norma Mag for a few years now and no hiccups.
Bullets........Hornady 165 gr sp i/l #3040
Powder.......IMR 4350......67.5 grs
Should come out at +- 2950 fps
C.O.L. 3.285 +-

I have tried a bit more powder, but the pattern opens up a bit.
For hunting rounds, these work.
I have never been a big fan of neck sizing only for hunting rounds.
Learned my lesson the hard way.
 
When I started reloading for my 308Norma Magnum, I 'cheated' a little. What Sierra used as a rifle for their load testing was the same as what I had just purchased. A model 65DL Schultz & Larsen.

SchultzLarsenM-65DL308NM.jpg


So, rather than re-inventing the wheel, I chose the same as what they had found best and listed it for their accuracy loads. IMR 4350. One of my most accurate loads was with their 200gr SPBT and IMR 4350. The C.O.A.L. Sierra suggests is 3.250" but I found the accuracy improved if I minimized the freebore. So, I extended the bullet out and my C.O.A.L. is 3.355".

308NormaMag.jpg


I'm changing over to Barnes TTSX in a number of calibers including the 308NM and quite likely, I'll stick with IMR 4350 and plan to use the Barnes 168gr TTSX.
 
With 72gr of RE#19 and a Barnes TSX 168gr mine shoots nice 1/2 MOA groups and zipped through both sides of a moose last fall.You will have a 1-12 twist in that gun as I have it's twin. With 71.5gr of IMR 4350 and a 150gr bullet all go into one ragged hole. 72gr of either H4831 or RE#19 and a 180gr bullet also 1/2 MOA. For brass FL size .300 win mag with the expander button removed and lubed only to where the NM shoulder will be and inside case neck.Trim to length ,chamfer neck inside and out ,run through FL die with expander re-installed load and shoot.Once fired .300 win mag range brass of the same brand is free and works great............Harold
 
mbogo3 said:
With 72gr of RE#19 and a Barnes TSX 168gr mine shoots nice 1/2 MOA groups and zipped through both sides of a moose last fall.You will have a 1-12 twist in that gun as I have it's twin. With 71.5gr of IMR 4350 and a 150gr bullet all go into one ragged hole. 72gr of either H4831 or RE#19 and a 180gr bullet also 1/2 MOA. For brass FL size .300 win mag with the expander button removed and lubed only to where the NM shoulder will be and inside case neck.Trim to length ,chamfer neck inside and out ,run through FL die with expander re-installed load and shoot.Once fired .300 win mag range brass of the same brand is free and works great............Harold
Click to expand...

In my Schultz, the 1-10" twist explains why it 'likes' bullets like the 200gr Sierra SBT. Personally for brass I try, if at all possible, to get the correct brass. Saves the possibility of down the road 'confusion' and accidental use in another firearm of the headstamped caliber. Where it is the only solution, yes, such as what I have to do for my 219 Donaldson Wasp, where I form brass from 30-30. With 308NM, rarely do I go to a gun show where there isn't a box or two of brass and/or factory loads available. A couple of good sources for some of the less than common brass are site sponsors like Henry at Budget Shooter Supply and Jerry at Mystic Precision.
 
I have 90 pieces of brass that I've scrounged up at gun shows. It's not a lot but enough for the time being. So, thinking imr4350 may be the powder to try first. Anybody have some coal's for 168 tsx that you're using? I'm thinking this rifle has a long freebore cut but not sure as information is limited so far.
 
leojlafrog said:
I have 90 pieces of brass that I've scrounged up at gun shows. It's not a lot but enough for the time being. So, thinking imr4350 may be the powder to try first. Anybody have some coal's for 168 tsx that you're using? I'm thinking this rifle has a long freebore cut but not sure as information is limited so far.
Click to expand...

90 brass will get you going alright. To my way of thinking, there are two primary considerations that will determine the C.O.A.L. for your rifle with your bullet of choice. The first, maximum length & freebore, has been made mention of already and you've stated in your rifle with the Barnes 168gr TTSX the C.O.A.L. is 3.54". The other governing factor is the maximun length your magazine will accept.
 
I agree with the IMR/H-4350 powders, including the H414/W760 and the IMR/H-4831 for the caliber. RL19 and RL17 are also a good choice, while RL19 usually is a splendid performer, I find it a bit too temperature sensitive to my liking.

As for throat lenght, it is very possible and likely, as the .308 NM was thought with 180/200 grains range in mind.

You can use .300 WM brass as a "genuine brass" replacement, but most of us use .338 WM and 7mm RM brass instead, as you just have to resize, prime, throw powder, seat a bullet and shoot.
 
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