[gregj]

I recently had a smith put a new barrel in my RRA AR (Kreiger, 20" SS, 1:7.7), and it really seems to like 77gr, especially Federal Gold Match. I'm getting ready to work up some new new loads with 77gr SMK and already have some Varget and RE15.

The most common load for this combo (77gr and 1:7.7 barrel) seems to be 24.5gr of either powder. However, Hodgon lists a max of 23.7 compressed for Varget, and Reliant a max of 24.1 for RE15. Am I missing something here? Common loads over max? :confused:

I primarily shoot only out to 100yds, but may begin to try longer distances this winter.

[rcmodel]

Just a glance at Lyman #49 shows the MAX load with both powders is determined not by Max pressure limits.
But by "thats all you can stuff in the case and compress" limits.

They show:
Varget = 25.0C = 2,788 FPS - 44,500 PSI.
RX15 = 24.5C = 2,803 FPS - 46,400 PSI.

The same bullet using a couple slightly faster powders that are not compressed result in more pressure, & more velocity.
AA2230 = 24.2 = 2,880 FPS - 49,600 PSI.
H335 = 25.0 - 2,851 FPS - 51,200 PSI.

rc

[Pete D.]

I load RL-15 and the 77 SMK as my standard combo. I drop 24.0 grains. Good enough for me, accuracy wise. It allows me to shoot tens if I am up to the task.
Pete

[moxie]

What do your loadbooks say? Websites are a good supplement but don't take the place of manuals.

Having said that, the 24.1 RE-15 load you mention is right at max, and so is the 23.7 Varget load. 24.5 is over max for either powder. You should start at about 2.0 grains lower than max for each load and work up from there.

[gregj]

The numbers I posted were directly from the powder manufactures web sites. So I would assume the data to be good.

My Sierra manual lists 23.9gr max for Varget and 24.1 gr max for RE15. Which again, is why I was wondering why the "accepted" loads seem to be above max per the bullet mfgr as well as the powder mfgr.

I have a Lyman's but to be honest, I have tended to rely on my Sierra more than any other manual I have.

[1858]

I shot my way through two boxes (1,000 rounds) of 77gr SMKs with 25.0gr of Varget, CCI 400 primers and Remington brass (it's compressed for sure). That's a very accurate load out of my DPMS 24" stainless barrel. I never dropped a single primer, no split necks and as I said, very accurate with numerous five-shot groups way under 0.5 MOA at 100 yards with many in the 0.3 MOA range. Works great at 300 yards too!!

[moxie]

Greg,

Who knows where "accepted" loads come from?

Where there's a difference I always side with the published load data. In this case your Sierra and Alliant numbers would be my choice. Hard to see where another grain of powder would help much when you're already at or nearly at compressed. I've also had good luck with Sierra's numbers in the 55 grainers.

[dennymac]

Everybody and his brother loads RE15 for the .223/5.56. I use 24.0 to 24.5 grains for from 75 to 80 grain bullets. I shoot a service rifle and a match rifle. That load is fine. Twist is 1:7 and 1:8 DennyMac

[sleepercaprice1]

I shoot Hornady 75's with 24.0 of RE 15 out of a RRA 1/8 with very good results.