Loading for the new .375...

[Guy Miner]

I'll need to scope this rifle to do some serious load evaluation, but am starting to learn a bit about it already.

The rifle magazine & chamber accept factory loaded .375's just fine, but won't take most of the ammo I've loaded for the Ruger Number One. The Ruger has a very long throat, and I've been loading the cartridges long for that rifle. They just don't even fit in the magazine of the Model 70:


But, I do have some 300 gr Sierras loaded to factory length:


If I'm going to run it this season, for bear, elk, or even (ahem) deer, I'll need to get something loaded up quickly. On hand I've got a pile of bullets, notably a lot of Hornady 270 & 300 gr bullets, as well as a smattering of Sierras, Speers and Nosler bullets.

H4350 has proven excellent with the 300's and good with the 270's.

RL-15 has been superb with the 260 gr Noslers.

But those results were loaded long, and fired from the Ruger. Looking forward to exploring the capabilities of this Model 70!

Guy

 

[Oldtrader3]

I had really good luck with IMR 4350 in my .375 H&H. However, that was a while ago.

 

[DrMike]

I do believe you will be pleased with this rifle, Guy. It is assuredly a handsome rifle, that's for sure.

 

[Oldtrader3]

Typically, custom rifles are built to shoot with a particular load and are guaranteed some level of accuracy with that load. Since the Stockmaker/Smith is still around, maybe he can tell you what he optimized for loads?

 

[SJB358]

Guy, I would bet your RL15/260 AB load will shoot just fine, if you can shorten them up enough to fit the mag box. Although, that 300 grain Sierra looks like a super bullet as well, and might just be enough for those enormous deer you have out West! :twisted:

I am looking forward to seeing what that big 375 does though. It just looks all class. I can't imagine it doesn't shoot excellent, and I haven't heard of many 375 barrels being worn out, so I am betting it won't take much to get it up and running.

 

[Guy Miner]

Thanks guys. I'm going to try that RL-15 load, with 260 & 270 gr bullets soon, just shortening the cartridge up to fit the Winchester's magazine. It's already at Nosler's minimum recommended powder charge, so I should be plenty safe.

Am thinking my 300 gr Rockchuck loads will do for deer or bear, maybe even elk, if the shot is carefully placed... Wouldn't want to over-stress the Sierra Boat Tail bullet now... :grin:

Guy

 

[Oldtrader3]

I don't know but you might wan to stick to Partitions for large Rock Chucks! The Sierra's may blow up!

 

[boomer68]

Guy, let us know what you're starting and max charge of RL15 ends up being.

Sent from my LG-E971 using Tapatalk 4

 

[JD338]

Guy,

I agree with Scotty. I would try your proven load with RL 15 and the 260 gr AB and just seat the bullets to cycle through your magazine.

JD338

 

[Guy Miner]

boomer68, I doubt I go to "max" level loads.

Nosler's minimum of 69 gr RL-15 and their 260 AccuBond is good for 2620 fps from my Number One. That's still a bit over 4,000 ft lbs of energy at the muzzle. Sighted in at 200 yards, it's about 9" low at 300 and dumped a black bear quickly at that range. It's also sub MOA out of the Ruger, which I didn't expect, though the .375 is noted for accuracy.

I won't be surprised if I just end up sticking to about 69 or 70 grains of RL-15 and the 260 AccuBond for a lighter bullet load. There's quite a bit more velocity to be had, but I really like the way that load shoots.

75 gr H4350 moves a 300 grainer at over 2500 fps from that Number One and is also gratifyingly accurate.

Those are my two proven, regular .375 loads. I'll likely give them both a try in the Model 70 before messing around with anything else. Did get a tip to try the standard 210 large rifle primer, rather than the 215 I've been using. I might just try that.

OT3, I haven't seen a rockchuck in a month or so. I think it got too hot for them over here and they went back underground... But if I do, I'll try for a repeat on that 300 gr Rockchuck adventure! :grin:

Regards, Guy