Home Forums Reloading Big Game Rifles 375-308 Velocities?

Does anyone have chronographed 375-308 load data?

I am thinking of building a 20 inch 375-308 and am interested in 235 and 270 grain bullet weights.

Google has not been my friend for this. I can find all sorts of talking about this wildcat, yet so far no data. The closest I have come is some limited discussion on the 375 Jaguar.

Based off of my experience with the 358 Winchester, I'd think you'd be in the 2000 to 2250 fps range.

I am still looking for 375-308 load data if anyone has some to share.

This afternoon I seated some .375 bullets in necked up 358 Winchester brass. If the link works, they are on my Picasa web site at the link below.

[img]https://picasaweb.google.com/lh/photo/yiYrg0cXlFsqgpVIJp6TNg?feat=directlink[/img]

The first picture is (above, left to right) a Remington 270 SP 375 H&H, a Hornady 300 DGS 375 Ruger, a 270 Steel Jacketed 9.5 MS, a Winchester 300 FMJ 375-308, a Barnes 270 TSX 375-308, a Nosler 260 Partition 375-308, a Nosler 260 AccuBond 375-308, and a Barnes 235 TSX 375-308.

All of the 375-308 dummy rounds are seated to 2.80 inch overall length.

[img]https://picasaweb.google.com/lh/photo/K3QiqpET4Mt5VgQRw1R8ig?feat=directlink[/img]

The second picture shows all of the bullets lined up by their cannelures (above). The idea is to get a feel for how far below the neck the bullets protrude. The 9.5 MS is shown for comparison. Note that the 270 grain bullet of the 9.5 MS does not protrude below the shoulder.

[img]https://picasaweb.google.com/lh/photo/XKij6CouFO2022bqZZgZ7Q?feat=directlink[/img]

The third picture lines all of the cannelures up for the 375-308, 9.5 MS, 375 Ruger, and the 375 H&H (above, left to right).

(I don't like using the Picasa site very much. If someone has a better way, please PM me!)

It's been quite awhile since I sold mine ... yet to get around to building another. I was getting about 2450fps from a custom made 190gr projectile. The guy I sold it to loaded it hotter to about 2600fps with a 200gr projectile. I tried AR2207 (H4198) thinking it'd be perfect but it was too fast, but the guy I sold it to shifted to AR2206H (H4895) and got much better speeds.

He called the rifle "Little Bitch" as I sent it in a tupperware stock and 20" barrel so it weighed in at about mid 6lb weight. It could wallop you good when loaded hot. It was used on management hunts for pigs and did well enough that the guy was to build another. Only issue was the custom 200gr pills were coming apart as they were designed as 'varmint pills' in the 375H&H. Not sure if he got around to it, but he too was going to load a 270gr RN Woodleigh and spank a buffalo with it.

It's a remarkably good little cartridge ... but I've had Woodleigh 9.3mm RN 286gr drawn down to 0.358" ... and these in a 358Win do exactly the same thing as the 375-08.

One thing I found a pleasant surprise, most Rem700s run short in magazine length. The short fat 375cal projectile made the 375-08 an absolute dream to hav efit as my lengths were closer to 2.7" ... but I'd have to check.
Cheers...
Con
PS: I made brass from 243Win / 308Win and 358Win. Jeez it was a fun rifle.

Con,

Thanks. After seating the bullets in the dummy rounds, I think the 235 TSX and the 260 Partition are the two that I will try to work up after I get the rifle built. I originally hoped to get at least 2300fps with the TSX and at least 2200fps with the Partition in a 20" barrel. Sort of a higher-pressure 9.5 MS.

I have looked long and hard at the 358 Winchester. Especially since several people are drawing down .366" bullets. In many ways it would be better, being a factory cartridge and all.

What is your 358 barrel length? I would be interested to know what kind of velocities you are getting with those drawn-down 286 grain bullets.

Today, I drank way too much rifle loony juice! I have one of the Ruger M77-GS (Gunsite Scout) rifles in 308 Winchester with a 16.5" barrel. I kept looking at those 375-308s and the rifle...

You ever given thought to a 9.3x57 on a '98 action? Seems like it'd do about what you're looking for here?

efw,

I have thought a lot about the 9.3x57. I think it can do anything the 375-308 is capable of. However, another project that I have in progress is a 9.5x57. I am fond of the .375s.

I plan to build a 375-308 and a 9.5x57. I have 375 H&H and 375 Ruger rifles, bolt and single shot. If I were starting all over, the various 9.3s would get serious consideration. I read somewhere on here that Sisk has built 9.3-308. Then there is the 9.3x57, 9.3x62, and 9.3x66.

There is also the 358 Winchester and the 35 Whelen. In some ways they would be more practical. Especially since the 9.3 bullets can be drawn down.

I just bought a 9.3x57 mauser and have started working up loads for it. Using 270gr Speer right now and can't wait to shoot a big attacking doe this fall. May even try some of the heavy bullets (296 IIRC). Brass is a little spendy and I'm not going to use 8mm as I reload that also.

FWIW I asked quickload to let me put a 235 grain 375 cal bullet into a win 358 case. It came up with alot of powders that it thought would do 2370-2400 fps at 60k pressure and a 20" barrel. If you have more questions feel free to pm me.