I’m going to be loading up some 350 grain MTAC’s for a .375 cheytac. Anyone have recommendations for what powder to use?
Recommended powder for .375 cheytac
- Thread starter AZ_tactical
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I’ve heard lots of recommendations for retumbo. It must be good cuz it’s sold out everywhere!
Hang tight. I've heard that it should be back on shelves in the next few weeks. There was supposed to be a shipment arriving this month according to Hodgdon.
Going to try US 869 and RL33 in my 375 SnipeTac. Have plenty of Retumbo on hand and will experiment with that as well. Will post results when I get around to it.
N570 should work but for lighter like something in the 350 grain range i think i would use Retumbo. I use Retumbo for the 350 SMK's I used for break in and to get close on my zero and they shot very well.
Mine was also 125 gr of retumbo and the avg fps was 2861. I could have gone more but for barrel break in and getting close on paper for zoning I didnt see the need. I have shot them out to 2100 yards and they did pretty good.
350 SMK can be loaded to 130 with retumbo in Peterson brass for 3000+ FPS, and 132 in Bertram for a touch more speed. N570 can be loaded a couple grains more, and brings with it 50-100 fps more speed.
...and this is why I can't find Retumbo for the 300PRC...because you guys are shoving an entire bottle behind a 350gr bullet 
Man, I am jealous of sending something that big...at that speed...and then the low SD you guys are getting...jeazzz....my wallet hurts just thinking about my soon to be 2000+ Yard rifle build.
Man, I am jealous of sending something that big...at that speed...and then the low SD you guys are getting...jeazzz....my wallet hurts just thinking about my soon to be 2000+ Yard rifle build.
Decided to go with rl33. Mostly due to availability. Anyone have a good starting load for the 350 MTAC’s with rl33?
Anyone use 24N41? It seems like a better, faster choice than RL50. Nothing else available.. no retumbo, RL33, N570 left in the world. I have RL50 and use it in my 416 but it looks slower and seems temp sensitive and dirty. Just curious why I can't find anyone using 24N41.
There is a guy on accurateshooter that is using it. I recall he had good results too
Performed OCW with both 24N41 and BMG 50 for the 400 gr Flatlines in 375 SnipeTAC. Had very good results with 24N41 which provided low ES and good groups. BMG 50 provided about 80fps more velocity but was showing some pressure signs where it grouped best. The 24N41 was about 80fps slower than the BMG where both produced the best groups. Best results were with 142 gr of 24N41 and 146 gr of BMG50. Peterson brass and 215M primers.
- Mar 15, 2018
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I have not seen Retumbo or RL33 in over a year; this includes the Wholesalers as well. If I hadn't been shooting Retumbo in my .338LM a few years ago I would be skeptical of its very existence. I have no expectation it will be available anytime this year either.
So...while I have been patiently waiting for my dies to come in, the best information I have for any powder that I have been able to find is for IMR 8133. I should have the dies very soon (again, full disclosure I have not yet fired a single round from my CDX40) but I have the Brass (Peterson), Primers (Fed215M), Powder (IMR 8133) and Bullets (Sierra 350gr HPBT's) ready to go.
My plan is to start at 125gr's and work up from there in 1 grain increments. Right now I am going off a single source and my QuickLoad data.
P.s. If I was going with a heavier bullet I think I would have gone down the H50BMG path, which does seem to be readily available.
So...while I have been patiently waiting for my dies to come in, the best information I have for any powder that I have been able to find is for IMR 8133. I should have the dies very soon (again, full disclosure I have not yet fired a single round from my CDX40) but I have the Brass (Peterson), Primers (Fed215M), Powder (IMR 8133) and Bullets (Sierra 350gr HPBT's) ready to go.
My plan is to start at 125gr's and work up from there in 1 grain increments. Right now I am going off a single source and my QuickLoad data.
P.s. If I was going with a heavier bullet I think I would have gone down the H50BMG path, which does seem to be readily available.
Yea
I think it’s been two years since I saw retumbo.
Have you considered N570 and 24n41
- Mar 15, 2018
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N570 is non-existent as well (the Cadex guys recommended this as well). I'm going to check on 24n41, thanks!
- Mar 15, 2018
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Yup, found it, thanks! I think I might still work through the 8133 first and see how that goes, but it's nice to have some choices.
- Mar 15, 2018
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I didn’t like it, the closest I got to a decent load was;
Peterson brass
Trimmed: 3.019”
Primer: Fed215M
Powder: 8133/129.2 grains
CBTO: 3.330”
COL: 4.200”
Bullet: 350gr SMK
That shot a decent group, sub MOA at a 100 yards, ES: 19, SD: 7.8
Before I could really tweak it I found Retumbo, like a shit load of it and never went back to the 8133. The 8133 seemed very inconsistent, but to be fair, I probably didn’t give it a fair chance.
- Mar 15, 2018
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Yup. I ended up at:
Peterson brass
Trimmed: 3.006”
Primer: Fed215M
Powder: Retumbo/130.0 grains
CBTO: 3.357” (should have been .001" off lands in my rifle)
Bullet: 350gr SMK
FPS (avg): 3067 (you can push this harder, but I was happy with anything over 3,000)
ES: 6 (repeatable, I shot 10, 5 rounds groups with an ES: <10)
SD: 2.19
MOA: .43
