Load data for 77 TMK in 223

[mustelid_master]

Howa Mini .223, factory barrel cut down to 16”.

LC once fired
F205 primers
2.004” CBTO
77TMK
Lever

23*f outside, loaded in 65* house

No signs of pressure other than slightest primer cratering at 27. No heavy or sticky bolt lift or ejector swipes or anything.

Shot groups of 5 at 25,25.5,26 and they started getting real interesting at 26g. Will load up 10 each at 26,26.3,26.5 for next range session.

View attachment 828317

Man that is haulig the mail

 

[KyleR1985]

Man that is haulig the mail

At 27g:

When I run it in quickload, with the default .223 case water capacity at 28.8, it shows 69,000psi, 2800fps

When I update it for my actual measured case capacity of 31.2, pressure drops below 55,000psi, 2650fps.


Load was not crunchy, but I’m certain is compressed.


Not sure what to make of it. Brass and bolt didn’t give me any sign.

But I liked what happened around 26g anyway