375 CT load & experience- share w newbie

[Timsar]

Hi,
ELR Newbie here in Kalifornestan. 30 yrs of shooting experience and 20 yrs of Reloading experience. Able to hit 1400 yards with FGM 185gr, using a 80 yr old Mauser action, bartlein barrel by SAC.

Just received my used 375 CT in a Stiller tac408 1.6 repeater action, with Rock creek 1-10 twist 33′′ barrel, with a APA gen 2 brake installed from a SH, ELR member,(nice transaction) with apprix 500 rnds down the tube already.

Optics: vortex razor HD 4.5-27x with Eiley 200 moa adj base.
20-60x - 100mm spotting scope
Kestrel 5700
Applied ballistics $ sw app.

Press: Rcbs Ammomaster 2, Dies: C4HD
RCBS charge master w trickler and separate dig. Scale 0.001gr accuracy

Components:
Peterson brass- 200x
2k Fed gold 215 Mag primer,
4lbs of 24N41
100x 350 gr SMK
100x 353 gr Lehigh solids

Phase 1:
Load some basic ammo for sight in and then up to 1-1.5k yards.

Phase2: up to 2k yards.
Maybe change barrel if shot out.

Phase 3: 2 miles club

Phase 4: Sell and get into .22cal ELR.

So my questions:

Can you please share your load data (mild to med load).

Reloading Do's & Don't for 375.

Pressure and neck signs

Brass life

Annealing?


How to tell my barrel is kaput?

What barrel and Smith do you recommend?

Any other data or story you want to share..

Regards
Yosemite Sam

 

[GIXXER2000]

If you can find any Retumbo that is a better powder for the 350 to 360ish grain bullets. I am running a 34 in 1-7 twist and use 131.5 of N570. I am getting 3060 avg fps with Cutting Edge 400 grain lazers.
I anneal every firing and when you resize don't bump the shoulder until you need to so I will chamber. That advice was from Peterson Brass engineer at last years Shot Show. Feel free to drop me a PM if what to talk more I would be happy to help.
As for gunsmith Robert Vestal did my last barrel and I am very happy. At the SW ULR match I have made hits out to to 3090 on 40x40 plate.

 

[1moaoff]

A friend uses rl26, rl33, h1000 a.d a few others

 

[Timsar]

Finding any powder is nearly impossible, retumbo ranks as the holy grail. If you ran across some, plz let me know.

 

[ZiaHunter]

24n41 is a very good powder and run it a 375 SnipeTac. For the 400 Flatlines using 142 gr. with Peterson Brass and 215M primers. I started at 138 gr. based on QL data and worked up in 1.0 grain increments. Cheytac has less case capacity than the SnipeTac so a starting load would be less. I found while tuning the rifle with various powders they all performed best at near max loads.

 

[Geno C.]

24n41 is right in the burn rate you want to be at. With 350s I’d start around 135gr and work up from there. Mine being a Snipetac as well, won’t be a direct comparison but I’m running H50bmg with almost a full case with no pressure in 100*+ heat and running 3172 with an sd of 4 with the badlands 350gr. Had a friends running RL33 with good success as well. Retumbo is of course going to be prefect but hard to find and almost the same rate as the 24n41 that you have. Anneal every time. Some of my brass is on its 5th firing without needing to bump the shoulder.

Don’t wait to sell the big gun before you get an ELR 22. You’ll really want to be doing both

 

[Timsar]

Thank you for the info

 

[TexasGunSlinger]

Just took my new 375CT to the range and tried out some loads from Copper Creek as a starting point. My rifle really likes the CE 402gr MTAC at a very specific OAL. Very little reloading experience, but I have all my gear to reload and thinking I will replicate the loads I tried out and go from there. Achieved .25 inch groups at 100, but heard anecdotally that the 375CT is better at 200 zero than 100. Any thoughts on this?

I have a 6 mil mount with NF ATACR 7-35. With CE 402 going 3000, can I dial to 2 miles or will I be doing holdovers?

Peterson
Retumbo
Federal 215
CE 402gr MTAC

Thanks!

 

[Dogtown]

Have a look at Ramshot/Accurate LRT. It's a bit slower than RL33, meters really well because it's a ball powder, and is relatively new and not popular yet (ie you can find some at Midsouth right now).

 

[MOUNTIC]

Just took my new 375CT to the range and tried out some loads from Copper Creek as a starting point. My rifle really likes the CE 402gr MTAC at a very specific OAL. Very little reloading experience, but I have all my gear to reload and thinking I will replicate the loads I tried out and go from there. Achieved .25 inch groups at 100, but heard anecdotally that the 375CT is better at 200 zero than 100. Any thoughts on this?

I have a 6 mil mount with NF ATACR 7-35. With CE 402 going 3000, can I dial to 2 miles or will I be doing holdovers?

Peterson
Retumbo
Federal 215
CE 402gr MTAC

Thanks!

You will need a Charlie Tarac still.

 

[THEIS]

You will need a Charlie Tarac still.

Hi,

Or the NF Prism or any of the other cheaper adjustable mounts.

Sincerely,
Theis

 

[TexasGunSlinger]

Hi,

Or the NF Prism or any of the other cheaper adjustable mounts.

Sincerely,
Theis

50 or 100MOA version?

 

[Geno C.]

Go with the 100

 

[TexasGunSlinger]

thanks all!

 

[secondofangle2]

no substitute for 215M - otherwise hang fires in cold weather esp with n570

peterson brass, although there are a couple more grains capacity in Bertram

Retumbo/n570 best in the 350 weight classes, but n570 gets you about 50-100 fps faster at same pressure
I never had any luck with RL33 on 4 different barrels in terms of accuracy or superiority to the above
H1000 is waaaaay too fast burning
some guys are using the 50 BMG powders but case capacity may limit achieving top velocities. If i couldnt' find the others I'd try RL50 or 24n41

Yes, anneal every firing

There was a while ago a tale about not changing back and forth between solids and jacketed bullets without a thorough cleaning or accuracy suffers

My buddy whacked a whitetail deer this month at 2127 yards with a 350 SMK

The 390 A-tips will be a total game changer when they come out, I have 1000 of them on order

make sure to chrono every single shot preferably with labradar. FPS consistency is at least as important as accuracy at the super extreme ranges. a 1/2 MOA load with SD 12 is not as good as a 3/4 MOA load with SD 6, even though the former looks way better to show off on paper targets

 

[GIXXER2000]

I would never shoot at an animal at over 2000 yards. The chance wound and never find it. I find that not very ethical hunting. Just my 2 cents worth.
As for N570 never had a hang fire with a 210M.

 

[Dogtown]

But three dudes trying to setup a DShK...fair game.

 

[secondofangle2]

I would never shoot at an animal at over 2000 yards. The chance wound and never find it. I find that not very ethical hunting. Just my 2 cents worth.
As for N570 never had a hang fire with a 210M.

I would never hire a prostitute in Vegas, but I don't need to prove my moral superiority to others by stating it. The chance my wife would find out. It's just my personal standard and every other man has to face his own God. I suggest we not derail the thread into a mudsliging contest about "ethics". That was done 5 years ago on the same topic, same place, same caliber, same people. The point is the SMK is a worthy bullet far past a mile. So if an "ethical" hunter wants to sneak up from 2137 to 1999 yards (be careful your quarry doesn't hear you!) or whatever their personal ethical limit is, they can rest assured that the SMK will do its job. LOL

 

[KineticPerformance]

Just took my new 375CT to the range and tried out some loads from Copper Creek as a starting point. My rifle really likes the CE 402gr MTAC at a very specific OAL. Very little reloading experience, but I have all my gear to reload and thinking I will replicate the loads I tried out and go from there. Achieved .25 inch groups at 100, but heard anecdotally that the 375CT is better at 200 zero than 100. Any thoughts on this?

I have a 6 mil mount with NF ATACR 7-35. With CE 402 going 3000, can I dial to 2 miles or will I be doing holdovers?

Peterson
Retumbo
Federal 215
CE 402gr MTAC

Thanks!

I used a 60 MoA base on my .375 CT for Ko2M and had the full 30 MRAD I could dial which allowed 2400-2500yds depending on the load. Beyond that you will need either an adjustable base or prism (I used a 30mil Charlie TARAC).

You may also find that the MTAC doesn't shoot as well at long range as the Lazer.

 

[Turtle 🐢]

352 cutting edge lasers
Peterson brass
Federal match large bore primers
125 grains retumbo
Seat the copper right at the lands

352’s are a little light but I have a gain twist barrel
The retumbo is out there but u may have to sell a kidney...
Machtech knows the way - he helped me get my baby goin...

 

[Geno C.]

I do fine with 350s. My bc is about the same as Cutting edge 400s but I can run them faster