Need a load for 6mmTCU

[Rockydog]

I'm looking for a load for my 6mm TCU using a 93 Gr GC bullet, cast from Straight WW and water dropped. Lyman mold 245497. I'm loading this for my Contender Carbine and, yes, I know it's a bit heavy for the caliber but I really want to try the long bullet. Any suggestions at all for a starting load? If you are unfamiliar with this round it's a .223 case necked to 6mm and fireformed to blow out the shoulder. Case capacity is midway between the 6X45 and the 6X47. My primary use for this will be Prairie Dogs if I can get it to shoot. Don't know whether to look at a light load of fast powder (2400?) or a jacketed starting load of 4895 etc. Any advice appreciated. RD

[ktw]

Hodgdon site has data for 6x45 and jacketed bullets.

I started some load development work with a 6x45 Contender Carbine(20", 1 in 12" twist) last summer. Haven't gotten very far with the project yet.

To date I have tried both Lyman 245496 and RCBS 24-95-SP in oven heat treated WW alloy (25-27 BHN) using IMR4895 in the range of 16.0-23.0 grains The RCBS bullet has shot better for me than the lighter Lyman across the powder range.

Best performance to date has been with the RCBS in the range of 19.0-20.0 gr IMR4895 (1.0-1.5 MOA inside of 100 yards, 1925-2025 FPS)

-ktw

[JSH]

I would look at the length of the bearing surface of your CB. Compare it to a jacketed, though it will be "slicker" going down the bore. I would guess this is a 1-10 twist?
Powders. I have fooled with the 6-223 and the 6TCU's for several years, FLGC though. I have tried several different powders. H335 is always what I end up going back to for speed and accuracy in the 6's using the 223 case. I would suggest a start load for a FLGC, you may be pleasantly suprised at the speed, compared to what the FLGC does with the same amount of powder.
jeff

[Rockydog]

Gentlemen, Thank you for your input. For 75 Gr. V-max bullets I'm using 25.5 gr. of H322. I don't know if I can safely reduce that powder very much for cast use but might try it with start loads. The 4895 was one I was looking for. Thanks for the help. RD

[6.5 mike]

Rockydog, my load book shows imr-3031 loads with 100 gr sierra's.
21.4=2000 fps, 22.0=2050 fps, 22.6=2100 fps, & 23.2=2150(max).
Imr 3031 might be a little more user friendly in reduced loads.
I use 22.0 gr Imr-4198 & a speer 85 gr in my 14" contender when I want a
heavy bullet.