375 Cheytac Powder Testing and Load Dev Data- Unknown Munitions

[Unknown Munitions]

Hey Rokslide, I wanted to post some info that can help to make the right choice when looking for data on 375 Cheytac. I tried searching for load data on multiple powder types before starting this project but could not find anything comprehensive. I'll continue to post results in this thread as the project continues.

A little background, this rifle is a Cadex Defense CDX-40 Shadow 32" 1:10 twist barrel. The customer's goal is to hit 3 miles at some point. We opted to shoot the 350 Grain Lazer from Cutting Edge Bullets. This bullet seems like a great match with the twist rate and has the proven ability to reach out a long ways. We fired 50 rounds to break the barrel in and took this opportunity for a powder shoot out and see where we would go from here. The following are the results:

Peterson Brass, trimmed to 3.016"
350 SMK @ 3.235" BTO
FED215M Primers
Powder and charge rate as shown in the graph:

 

[maliclipse]

You guys should try retumbo for bullets around the 350gr weight in the CT. H50 is too slow and works better once you hit the 377gr or heavier (like the MTAC/Laser).

 

[powerspc]

Holding out for Retumbo in the hope that it will eventually return to the shelves (haven't seen any in about a year). Also suggested to me was VV N570 (also non-existent), both powders would be over a 350gr SMK. In any case, assuming either powder does become available, any reliable load data? I will also be shooting CDX-40 Shadow, 32" barrel, 1:10 twist using FED215M Match primers and Peterson brass. Thanks!

 

[maliclipse]

RET is out there if you look for it and willing to pay. You're looking at a starting load of about 125gr and 400 shots out of a 8lb jug. N570 is a popular powder but is temp sensitive from what i've heard.

 

[powerspc]

Brilliant! Thank you for the response; I think somewhere along the way I had seen 130gr's of Retumbo so 125gr's sounds like and excellent and safe place to start. I've seen Retumbo on places like GunBroker for stupid money (I think one guy had an 8lb. jug listed at $700) WTF! Other than that I check daily at Graf's, Crow, Black Hills, Powder Valley, etc. It's gotta get back to some kind of normal at some point (I hope!). Thanks again!

 

[maliclipse]

No problem.

Just so you know normal people can't ship powder easy anymore. I'm a FFL and i bulk ordered a ton of powder recently. I sell local mostly (DFW area) but I have a few people I've known who have moved out of state. One guy wanted 6 x 8lb jugs of H50 (we're a bunch of ELR shooters). I had to get DOT certified by FedEx to be able to ship the powder or use a hazmat broker (for what i want/need to do those guys are a waste of time and money).

What you're paying for isn't gouging, its supply / demand as well as a high LOE (level of effort) to get the powder shipped.

 

[powerspc]

No problem.

Just so you know normal people can't ship powder easy anymore. I'm a FFL and i bulk ordered a ton of powder recently. I sell local mostly (DFW area) but I have a few people I've known who have moved out of state. One guy wanted 6 x 8lb jugs of H50 (we're a bunch of ELR shooters). I had to get DOT certified by FedEx to be able to ship the powder or use a hazmat broker (for what i want/need to do those guys are a waste of time and money).

What you're paying for isn't gouging, its supply / demand as well as a high LOE (level of effort) to get the powder shipped.

Thanks, I appreciate the insight; I'll keep haunting my local gun stores, I'd rather they got the business anyway!

 

[pbcarch]

Any new results from this ? Just starting my 375 CT build

 

[Catalyst]

I would like to revive this thread unless a better is available. I have a good amount of data to share...

 

[Catalyst]

I have been working with the CEB 375 gr. Lazer in the 375 Cheytac with Retumbo.

125 - 2898
126 - 2916
127 - 2931
128 - 2952
129 - 2974
130 - 2995

At 130 gr. there are signs of ejector marks on the Peterson brass. However 130 seems to be what the gun is shooting the best...

My lab radar results very closely mirror the load data that CEB has for the 377 mtac.

Anyone else have some results to collaborate on?

 

[Catalyst]

Did some more testing with the 125 grain Retumbo load and 375 gr Lazers and was pretty happy with the consistency. Great group size and right at the 2900 fps range with an SD of 5 fps. Definitely not a light load as the 'factory' offering from Desert Tech is 2925 fps with a 352 grain bullet from my 32" Shadow.

I don't like the ejector marks at the 130 gr. Range, so if I do any more experiments I will try to stick between 125-128 maybe with a ladder test. Then pick a final load and start looking for a range and really stretch it out.

 

[Catalyst]

375 Cheytac Update

H50BMG tests with the 375 gr. Lazers

131 - 2845
133 - 2875
135 - 2930 *
138 - 2975
140 - 3025 **

* 135 gr. had an SD of just 1.7 fps

** 140 gr. is too much for my gun, I started seeing ejector marks and light catering of the primers.

- 140 is very near max case fill without being compressed (my guess is 141)

- I will be testing more between 131-138 gr.

 

[Catalyst]

Tested more groups in the 375 CT @ 500 yds
Weather: 30°F and 5-10 mph crosswinds

375 gr. Lazers with H50BMG

5 shots @ 135 gr - 2922 fps | SD 4.1 | 4.0"
5 shots @ 138 gr - 2980 fps | SD 5.2 | 4.7"

 

[Catalyst]

Interestingly I got a new lot of H50BMG and it's a full 2 grains slower than my previous lot.

 

[Catalyst]

375 gr Lazers with a new (slower) lot of H50BMG

5 Shots @ 137 gr - 2930 fps | SD 5.1

-

I also picked up some 390 gr Atips

5 shots @ 135 gr - 2900 fps | SD 6.0

 

[Fotis]

Nice . This is my 375 BAS Chey improved.

 

[Catalyst]

Wow nice looking rig

I see you have (what I think is) the same barrel as my shadow: 7 twist 32"

I honestly haven't gotten mine to shoot that well yet, but looking at your load and speed I haven't yet chased the upper end of the load spectrum and perhaps I need to...

I have tested almost exclusively at 500 yards and always shoot 5 shot groups. Best has been around the 3.5-4.0" but seems more like 4.5" is common. This is obviously in real world conditions with wind and mirage, etc.. so it's not bad per say, just not quite what I'm looking to achieve. If I could consistently get 3.5-4.0 I would quit load development.

 

[Fotis]

Yes sir 1:7 32"

You should be able to coax close to 3100 fps with yours. They do like hot loads!

 

[Catalyst]

I ran the 375 lazer up to just over 3000 fps but started getting some case head ejector shiny swipes so I stopped there with Peterson Brass. Maybe I should have pushed a little further...

I definitely have struggled at lower powder charges to find an accurate load. Would have really liked to find a 2900s load if possible for brass life.

Any issues pushing that hot yet?

 

[Fotis]

no sir not at all. What make is your barrel?