375 ultra mag

[Poor_choices]

I've got a few questions about rebarrelling a Remington 700 I have from 300 rum. I got it to learn the ropes of elr with until I burned the barrel out then rechamber it for something more purpose built. At the time I was thinking 338 edge, but recently I wondered if I could go to 37 caliber and found this gem of a thread. I'm hoping to get some guidance on my first dedicated elr(600 out to, well however far I care to carry the steel for a day) rifle.

When I bought the rifle, I had a range that was 3 miles long in a canyon, so I could run targets as far as I cared to hike. I had a 6.5 creedmoor that I had taken to 1400 and wanted something that would pick up where it left off. I am currently single feeding, so I'm not worried about fitting in a mag. I will be keeping the factory action and bolt. Weight, recoil, muzzle blast and noise are not a concern.

I'd like one of the improved cases, what's out there in terms of something that keeps the rum bolt face and will fit in a rum action in 37 caliber? I know I've seen a few (375 bme? I think was one?, 375 Tejas?) I don't mind ordering custom dies, but I'm sure there's already reamers floating out there that are what I'm after.

Speaking of reamers, I was thinking of running either the 350 smk(tried and true, will probably be available forever), the 352 cutting edge, or the 377 mtac. I'd like to be seated out as long as possible. So who would I get in contact with for a reamer(hopefully a Smith with the reamer to do the barrel job) to do the chambering and guidance as to how to throat it.

And to the barrel. I'm planning on a 30 ish finished length, plus brake. The part I'm stuck on is the twist. Cutting edge recommends a 1:9 twist if shooting the 377 transonic, the 352 would require a 10. The question I have is, is the 377 going to be too heavy to be useful? If I did go with a 9 twist, could I still shoot the smk's or 352's if I didn't like the 377? Would a gain twist be helpful?

I've still got plenty of time left till I shoot out the 300 barrel, so looking for ideas

I stumbled onto this post and it made me laugh when you mentioned the 375 BME. The guy who came up with that one was a good friend who passed away about a year ago. That 375 BME project was a lot of fun and even more wasted money! lol I ended up with the barrel, brass, and dies with the hope of getting back to that project one of these days.

I haven't seen the 350gr SMK available for a few years. If you find a stash of them though, buy all you can afford. They were a great all-round bullet at a fair price.

 

[Nhyrum]

I stumbled onto this post and it made me laugh when you mentioned the 375 BME. The guy who came up with that one was a good friend who passed away about a year ago. That 375 BME project was a lot of fun and even more wasted money! lol I ended up with the barrel, brass, and dies with the hope of getting back to that project one of these days.

I haven't seen the 350gr SMK available for a few years. If you find a stash of them though, buy all you can afford. They were a great all-round bullet at a fair price.

Do you happen to know where the reamer is? Or a reamer?

 

[Poor_choices]

The only reamer I know of was traded off years ago. PTG made the original reamer and I still have a copy of the print. I don't think I'd recommend PTG if you wanted to have one made, they've been pretty hit and miss for the last 10 years. CH4D made 2 sets of dies for the BME, one set went to the guy who ended up with the original reamer and I have the other set on my shelf.

 

[Nhyrum]

The only reamer I know of was traded off years ago. PTG made the original reamer and I still have a copy of the print. I don't think I'd recommend PTG if you wanted to have one made, they've been pretty hit and miss for the last 10 years. CH4D made 2 sets of dies for the BME, one set went to the guy who ended up with the original reamer and I have the other set on my shelf.

Thanks for the print. I've got a few sets of ch4d pistol dies, they're just about all I use now.

Where would be the go to place to get a reamer made? Ptg is the only one I can remember.

 

[Poor_choices]

I’d look at either Manson or JGS for reamers.

 

[Chase723]

It that 2820 that you're getting with the 390 a tip?

Yes. W/ N570 I got 2849 at max and W/N565 I got 2827 at max. Accuracy was best seemingly around 2790-2825fps, so upper node just below max. 32” 1:8 twist K&P barrel.

 

[Nhyrum]

Yes. W/ N570 I got 2849 at max and W/N565 I got 2827 at max. Accuracy was best seemingly around 2790-2825fps, so upper node just below max. 32” 1:8 twist K&P barrel.

Was n570 the most accurate powder? Did you try other powders? I know 570 is unicorn dust for the big magnums, but wondering how things like retumbo,h1000, rl33,rl50, or imr 7828 might do.

With the 8 twist, have you tried other bullets, like the 352 or 377 cutting edge? I guess what I'm getting at, is the 1:8 twist going to be too much for bullets that require like a 10 twist.

If I could get 100 fps more, I'll be pretty darn close to where guys with a 375 ct are able to send them(2950-3000 ish). I think if I could have it throated to have them seated so the bottom of the bullet that's full caliber diameter is seated at the bottom of the neck and still have .100 jump, that might be the ticket to getting darn near CT velocities

 

[Frank in the Laurels]

..big thunder without question ! If that doesn't git' it done not sure what you could do but certainly not for the faint of heart by any stretch and not easy on the wallet either. Have you thought about the .338 Edge, a little easier on the body and wallet.

 

[Chase723]

It was a toss up between N570 and N565 for accuracy. It was 1/3 MOA. I stopped shooting it because of a couple things 1) My barrel is for a TL3 short action and while it’s a relatively stiff action, it damaged a couple scopes. So, I think I need a stiffer monolithic action like a Terminus. 2) I have pretty bad tinnitus from my time in the military and the concussion/blast when shooting undercover at the range was bothering me. 3) I moved and so I had to break down all of my reloading stuff and haven’t gotten it back up and running yet.

That said, I have a Terminus long action now, and a suppressor that is probably tough enough…so I may have it rethreaded/chambered for that. The other interesting thing though is that I think with H4350 or RL16 you might actually be able to shoot a max load and load it to mag length in a long action…I’d have to dig in and look back at my notes. So, I might actually cut it back to like 16 or 20”, suppress it, and build another dedicated rifle off of it.

Retumbo would probably work great. I didn’t have it at the time so didn’t try it.

The A-tip was pretty easy to get to shoot and is pretty economical comparatively, so didn’t try many others. I initially had it cut for the Badlands Super Bulldozers but couldn’t get them to shoot as accurately as I wanted so switched. Also, the 390gr A-tip leaves a great mark on steel and I bet if you were to use it on something like elk or brown bear it would work awesome.