300 blk and trail boss

[2manyguns]

hello i am looking for some load data for the 300 blk with a 208 cast and i would like to burn trail boss , because i have 5 cans of it , if any one can give me a starting load i would like that a lot thx also would like any thing on the 7.62x39 with T B or lil. gun

[BK7saum]

So you have a single shot or bolt gun. I dont have my data in front of me, but it isn't much. Someone will be along shortly, I'm sure.

[2manyguns]

they are both bolt guns blk is a ruger american and the 7.62x39 is a howa mini thx for your help

[41cal]

Follow the 3 steps outline here to find your starting point
For any cartridge.

273731

[Gamsek]

https://uploads.tapatalk-cdn.com/20201222/0fae8a752e588851b0c02bcd3b94b810.jpg
With bore rider MP 311-235 (base of bullet not protruding into powder space) which is 218grs with no GC, that I used,
- 6grs of TrailBoss = 270m/s,
- 7grs (slightly compressed) I got 300 m/s and only 1-2 m/s velocity variance.

Hope it helps, again it’s 218grs and with it, I have almost all the space for powder below neck.
https://uploads.tapatalk-cdn.com/20201222/de0cd6655466c5252809b8a8ddb4c212.jpg

7grs.
https://uploads.tapatalk-cdn.com/20201222/55cad6759ab913c0453f5a15fd3ecd54.jpg
https://uploads.tapatalk-cdn.com/20201222/e5c77577d95c7f167bb4e15b8f8b4b1e.jpg

[2manyguns]

https://uploads.tapatalk-cdn.com/20201222/0fae8a752e588851b0c02bcd3b94b810.jpg
With bore rider MP 311-235 (base of bullet not protruding into powder space) which is 218grs with no GC, that I used,
- 6grs of TrailBoss = 270m/s,
- 7grs (slightly compressed) I got 300 m/s and only 1-2 m/s velocity variance.

Hope it helps, again it’s 218grs and with it, I have almost all the space for powder below neck.
https://uploads.tapatalk-cdn.com/20201222/de0cd6655466c5252809b8a8ddb4c212.jpg

7grs.
https://uploads.tapatalk-cdn.com/20201222/55cad6759ab913c0453f5a15fd3ecd54.jpg
https://uploads.tapatalk-cdn.com/20201222/e5c77577d95c7f167bb4e15b8f8b4b1e.jpg
this is what im looking for , i am getting great accuracy with a 208 cast with a gc and 11.8 of h4198 @ 1170fps so i will work out something off your load , thx

[Gamsek]

this is what im looking for , i am getting great accuracy with a 208 cact with a gc and 11.8 of h4198 @ 1170fps so i will work out something off your load , thx

https://uploads.tapatalk-cdn.com/20201223/2d5cc61e83057b569816d19f4e44a3e4.jpg
Results with 7grs TB a and no GC. I got 20-25 m/s LESS velocity when I used a GC bullet and much more variation. I used pistol primer for TB, Murom small pistol. I don’t know how much TB can you squeeze into case and still seat bullet that goes deep into case. 7grs is max for my bullet and 6grs gives very low velocity, good for plinking and nice accuracy although. Good luck.
It was +3 degrees Celsius on that day.

[Lloyd Smale]

why use expensive trail boss. I load 130 grain cast in my american with 4 grains of unique. its accurate and with a suppressor sounds about like a pellet rifle going off. I use have the powder and a powder thats a heck of alot cheaper to start with. Even cheaper yet is when i do it with surplus br2 (which is aa2) But i like saving that for my semi auto pistols and 9s for my ar15s.