Pre-64 Model 70 - 308 Norma - 20" Barrel - Need help with the load

[Floundertrap]

Hey Folks,

I'm new, thanks for having me. I've been reading posts from this site for years and finally have a question that I don't think has been asked/answered already. If it has please kindly direct me to it.

I've recently purchased what I think should've been an heirloom rifle out of California, guess the kids weren't into hunting. Serial# 390XXX, I believe 1956 built, but was rechambered with a custom barrel, marked on left with "XXXX" and 308N, on the right side with "JRB" over "APEX". Based on my research I believe this rifle was rechambered in the early 60s before the 300WM was introduced. It has pretty nice and very well inletted stock (fully floated barrel but very nice fit/gaps), really crisp trigger that's light with no creep, clean, sharp bore that I believe to be 1:10 twist and a really nice finish, matched bluing on barrel to original receiver bluing, wood in exc cond, etc. etc...

I really want to use this rifle for hunting whitetail in Eastern NC. I have a few hunting spots where my shot may be 500-700 yards and I would like to tune a round for this rifle for that range. I can find load data for the 308 Norma Mag, but everything I'm finding is out of a 26" barrel or longer. Just to get it out there, I am an experienced shooter and loader, and I am an ethical hunter, still a bit old school I suppose because I still like bullet weight retention and holes on both sides that leak, a lot. I'm hoping you guys can suggest a powder that will burn fast enough to get good, consistent speed out of my short barrel. On the shelf I have H1000, IMR4350 and H4350, IMR4895, H4831, Retumbo and RL22; but I'm not afraid to buy more. I plan to start with a 165gn Sierra TGK GameChanger and Norma Brass and WLRM primers and I have a paper-box RCBS Full Length die set.

What powders do you guys suggest? Load data would be awesome but I realize I have a rare bird here. Your help is greatly appreciated. Any info on that "JRB APEX" builder/barrel is appreciated as well.

BTW, the rifle will be topped with a Leupold LRP 6.5-20X50, not a 40 year old 2-8X Bushnell, lol.

 

[cody finch]

Mine has a 24inch barrel I use h4831 and 180 siearra boat tails old military Enfield that was sporterized by my father in the late 50s early 60s

 

[Floundertrap]

Mine has a 24inch barrel I use h4831 and 180 siearra boat tails old military Enfield that was sporterized by my father in the late 50s early 60s

What's your charge and speed (if you don't mind me asking)?

 

[Edd]

You don't choose powder based on your barrel length. For a 165 gr bullet, I would use H4831.

 

[cody finch]

2990 fps just look in the book for charge. Are you sure that you have a 308norma mag.you might want to do a chamber cast if not sure.

 

[Floundertrap]

You don't choose powder based on your barrel length. For a 165 gr bullet, I would use H4831.

Thanks for your interest, Edd. I would normally agree with you 100% if we were talking about standard length barrels, however I reason the thought that of available powders intended/tested for 308 Norma, there may be one that burns slightly faster than another. This may allow my bullet to benefit from more burn at 20" than another.

I run H1000 in my 300 WM (32" Krieger) pushing 225gn ELD-Ms consistently at 3010. I chose that powder because it's a slow burning powder, as a result that round benefits from plenty of pipe for the burn. Perhaps the opposite is worth considering with a short barrel.

 

[Edd]

If you get the best performance from your 32 inch barrel with H1000, it would still be the best powder to use if you cut the barrel down to 20 inches.

 

[Floundertrap]

2990 fps just look in the book for charge. Are you sure that you have a 308norma mag.you might want to do a chamber cast if not sure.

Thanks Cody, I have some 308 Norma brass and can confirm by some fairly rudimentary headspace, body and shoulder gauging that it is a .308 Norma Mag. It also has 308N stamped on the barrel.

Cool note, I did find "J.BOLLIN 1/61" stamped on the bottom of the barrel. Not sure if it's the previous owner or the smith who built it.

 

[ofbandg]

I use Rel 19 in my Magnum Mauser .308 Norma. The hard part was finding consistent brass. When I bought it I picked up an assortment of ammo at a gun show, all Norma of course, but it was in different bullets weights. I just wanted the brass anyway so I shot it off at the range (and discovered my rifle is a shooter) but when I went home to reload it, and returned the next day, it didn't shoot as well. Later I weighed the cases and found as much as 30gr. difference between them - the most I have ever seen even when weighing from different manufacturers. It was old brass but still usable. I separated it into lots according to weight and the accuracy returned but I will be ordering a new lot of brass from Norma. The performance is virtually identical to my .300 Win. Mags by the way but I like the European stock on this rifle.

 

[CliffM]

Hey Folks,

I'm new, thanks for having me. I've been reading posts from this site for years and finally have a question that I don't think has been asked/answered already. If it has please kindly direct me to it.

I've recently purchased what I think should've been an heirloom rifle out of California, guess the kids weren't into hunting. Serial# 390XXX, I believe 1956 built, but was rechambered with a custom barrel, marked on left with "XXXX" and 308N, on the right side with "JRB" over "APEX". Based on my research I believe this rifle was rechambered in the early 60s before the 300WM was introduced. It has pretty nice and very well inletted stock (fully floated barrel but very nice fit/gaps), really crisp trigger that's light with no creep, clean, sharp bore that I believe to be 1:10 twist and a really nice finish, matched bluing on barrel to original receiver bluing, wood in exc cond, etc. etc...

I really want to use this rifle for hunting whitetail in Eastern NC. I have a few hunting spots where my shot may be 500-700 yards and I would like to tune a round for this rifle for that range. I can find load data for the 308 Norma Mag, but everything I'm finding is out of a 26" barrel or longer. Just to get it out there, I am an experienced shooter and loader, and I am an ethical hunter, still a bit old school I suppose because I still like bullet weight retention and holes on both sides that leak, a lot. I'm hoping you guys can suggest a powder that will burn fast enough to get good, consistent speed out of my short barrel. On the shelf I have H1000, IMR4350 and H4350, IMR4895, H4831, Retumbo and RL22; but I'm not afraid to buy more. I plan to start with a 165gn Sierra TGK GameChanger and Norma Brass and WLRM primers and I have a paper-box RCBS Full Length die set.

What powders do you guys suggest? Load data would be awesome but I realize I have a rare bird here.

I cut a 30" barrel to 26" IMr 4350 lost 40fps, H4831 lost 60fps. with 180gr bullets, I would expect a 20' to lose the least with the faster powders. Reloder(i.e. rl17) powders are one of the few that will burn 100% in shorter barrels.

 

[Floundertrap]

CliffM, that's just what the doctor ordered right there! Thank you, Sir. I will work up some loads with RL17 as well as H4831 and see how they chrono those 165s and I want to try some 180s, if I can make up my mind which one to start with. Suggestions on a 500-750yd whitetail pill?

TK

 

[Floundertrap]

I use Rel 19 in my Magnum Mauser .308 Norma. The hard part was finding consistent brass. When I bought it I picked up an assortment of ammo at a gun show, all Norma of course, but it was in different bullets weights. I just wanted the brass anyway so I shot it off at the range (and discovered my rifle is a shooter) but when I went home to reload it, and returned the next day, it didn't shoot as well. Later I weighed the cases and found as much as 30gr. difference between them - the most I have ever seen even when weighing from different manufacturers. It was old brass but still usable. I separated it into lots according to weight and the accuracy returned but I will be ordering a new lot of brass from Norma. The performance is virtually identical to my .300 Win. Mags by the way but I like the European stock on this rifle.

The action and custom work really sold me on this rifle, not to mention the price ($500+$20 shipping ). It's the most comfortable and stable off-hand rig I've ever held. Now the challenge is finding good rings that put my LRP lower to the action since I've mounted a 20 MOA nightforce rail, which really matched the finish on the action and barrel nicely. The lowest standard duty NF rings I can get are .9, and the 1.0 rings I put on to start give me about a 3/8" gap between the bell and the barrel, not a fan.

 

[CliffM]

CliffM, that's just what the doctor ordered right there! Thank you, Sir. I will work up some loads with RL17 as well as H4831 and see how they chrono those 165s and I want to try some 180s, if I can make up my mind which one to start with. Suggestions on a 500-750yd whitetail pill?

TK

There are so many good bullets, the only ones I would pass on would be Barnes and Nosler Ballistic tips. I use Sierra, Hornady and Berger.
In 6.5 caliber Hammer bullets have been exellent, they should be good in 30 cal. on whitetail.
Cliff