.408 Cheytac 400 grain bullet load

[jbs2014]

So I did some load development with 400 grain bullets and Retumbo. I went from 133-136 grains of powder. The ES on the 136 grain load was 13fps. I did not see any pressure signs and no bolt lift issues. I am told that 136 grains is too hot. Anyone have any experience loading 400 grain Bullets and Retumbo? Is this load too hot?

Primer is fed 215m

Thank you for your time

 

[Bravo 4]

What brass you using? Your rifle/chamber and load will be different than others so let the rifle tell you what it wants. In the .408 I had, the Jamison brass wouldn't have made it to 136 grains of Retumbo without pressure signs (415 grain Cutting Edge MTH) and Bertram brass would take about 2 grains more.

 

[jbs2014]

Peterson brass.

Is it possible that I have a slow lot of Retumbo?

Thank you so much for the response

 

[jbs2014]

how much powder did you use with that MTH? How fast did you get it?

 

[Bravo 4]

Don't have my data book, sold the rifle about two years back. Going off memory but I'd bet money it was 132 grains of Retumbo and 129 of RL-25 got 2900 +/- of few. RL-33 gave me that with a mild-ish load, ran it up to almost 3100 before pressure signs showed but accuracy was phenomenal @ the lower load.

 

[THEIS]

Hi,

JBS...couple questions.

1. What chamber spec are you using?
2. What rifling profile are you using?
3. What muzzle brake are you using?

Sincerely,
Theis

 

[jbs2014]

Unfortunately I do not know, it's a Lawton, if that helps
It's not the lost river bore, so standard rifling
Standard Lawton muzzle break

It's an older gun, built in 2008.

 

[jbs2014]

Don't have my data book, sold the rifle about two years back. Going off memory but I'd bet money it was 132 grains of Retumbo and 129 of RL-25 got 2900 +/- of few. RL-33 gave me that with a mild-ish load, ran it up to almost 3100 before pressure signs showed but accuracy was phenomenal @ the lower load.

What barrel length did you have? What charge of RL 33 did you use?

 

[Bravo 4]

28" Lawton
147 grains RL-33 for 2900 FPS
153 grains gave 3080 fps with ejector swipe

 

[jbs2014]

Thank you, should I start with 147 grains?

Merry Christmas BTW

 

[jbs2014]

28" Lawton
147 grains RL-33 for 2900 FPS
153 grains gave 3080 fps with ejector swipe

Did that Lawton give you headaches? Mine did, it wasn't till Joel Russo fixed it that it became fun to shoot, and submoa

 

[Bravo 4]

I would advise to start about 140, I started at 136. I went up 1 grain at a time until I hit pressure then dropped several and started accuracy testing in reverse. Besides, at 140 grains each grain is way less than 1% charge weight.

 

[jbs2014]

Ok thank you. I have RL 33 on hand

 

[Bravo 4]

Did that Lawton give you headaches? Mine did, it wasn't till Joel Russo fixed it that it became fun to shoot, and submoa

What kind of fix did it need?
Mine shot exceptionally well, to almost 2500 yards.