77smk 8208xbr what velocities to expect?

[Djstorm100]

Out of a 18" rifle? Going to do a load development test this weekend, if the weather holds out.

[markm]

I get 2700 out of a 20" barrel. XBR is moody and can vary by lot. My current load is 23.4 gr. Work up carefully.

[rjacobs]

I want to say I chrono'd right around 2600 with 23.2g out of my 18" krieger barrel. I cant remember the exactly number, but it was 26 something, which matches what Mark is getting out of a 20".

[markm]

Yeah. XBR will shoot awesome with 77s. But if high velocity is critical, a powder like TAC is going to get you closer to Mk262 velocities.

[Djstorm100]

I did a quick load development because 8208 is just easy to load for. My older barrel (rainier arms) was at 2750 at 23.6 grain. I was expecting at least 2700 but dumbfounded when it was 2660.

[markm]

I did a quick load development because 8208 is just easy to load for. My older barrel (rainier arms) was at 2750 at 23.6 grain. I was expecting at least 2700 but dumbfounded when it was 2660.

Same lot of powder? I've had lot changes where I started getting a lot of popped primers all of the sudden... with the same old 23.8 grains. That's why I just dropped my load to 23.4.

[P2000]

This is with tmk's

https://www.m4carbine.net/showthread.php?t=184967

Sent from my XT1565 using Tapatalk