77 SMK trial loads

[opeagle]

I'm just getting ready to load some 77 SMK's for a 20in 1/9 twist bolt gun.

I know the 77 may or may not like the 1/9 but I want to find out for sure. I have various cases and a few powders but I'm pondering using either a few hundred PMC or Federal cases and RE15. I know there's lots of info out there but I'm looking to first see if it will shot them, then see if I can come up with a nice easy to shoot load. I don't need to drive the bullet at top speed so can someone give me a decent starting point and any pointers with this combo at .223 pressures?

Later next week I'm got some 68 gr Horniday coming and I'm going to try those as well. Thinking of starting in the 24 grains of RE 15 for that one.

 

[opeagle]

Has anyone used 77's in a bolt gun? Maybe that a better question.

 

[BoilerUP]

Yes, 77s will stabilize just fine in a 1:9.

Can't help with RL15 but 24-24.5gr Varget or 23.2-23.8gr 8208XBR should work. I found best accuracy around 0.010 jump in two 1:9 Savages, but AR mag length was easily sub-MOA.

 

[OF&B]

Which brass you use will matter.

For PMC holding 30.5 grains of water after sizing.





The gun is a Mossberg MVP with a ton of freebore. The bullets won't contact the rifling until 2.400" and they're loaded to 2.260" to fit in the AR magazine. It's a 1:9 barrel and the stability calculates out to 1.4 where I'm at, usually ~28.5" of barometric pressure and 30 - 100 degrees. I only get 2740 fps from a 24" barrel.

The 77 smk seems to transition pretty well. I use this load for shooting an IDPA target at 1070 yards. 24.0 - 24.5 grains of Varget is one of the goto loads for this bullet, but you'll probably want to start in the 23.0 - 23.5 range.