Anybody have any safe and accurate loads for the above combination?

They're intended for a 16-inch carbine, and I'm having trouble finding any loads for R10x designed for bullets heavier than 55gr.

I'd use another powder, but this is all I have for the moment, and I don't have the funds for anything different. Run what you brung and all that.

To paraphrase my IT friends, RL-10X is suboptimal for the heavier bullets (IOW, over 60gr).



Buy lighter bullets.



 

There is a reason you can't find any loadings for 10X with 77 gr. bullets.  10X is way too fast burning for optimal results.  You won't get near the velocity you can get with slower powders.  Not that you can't get an accurate load with 10X, but your velocity will be way below what you would expect.




alliant.reloading[at]atk.com

I appreciate it guys.

As I stated, I don't have the funds to get another power at the moment (had to replace a stolen laptop. fu|<ing thieves.) This powder was actually purchased for me by a friend in exchange for loaded rounds, since I ran out of WC844.

I have lighter bullets, but he wants the 77gr SMKs. Hence I have to work with what I have.

I personally have not loaded the 77 MKS as have a 1-9 twist. I started working with the Speer 70 grain SP bullet with Benchmark and H322 and IMR 3031. I found the accuracy to be not what I wanted, and found 3031 to run through my measure with a sub par result. In looking over Alliant's burn rate chart found 10x to be very close to A-2230 and x-terminator  and found a load with both, using a 70 grain Barns bullet with a max of 22 grains of A-2230. Using this data and starting load of 19 grains of 10x with the 70 Speer SP to 22 grains as a finnish. I am very happy with the result of the 22 grain load as it is very accurate in my 5.56 x45 chamber in a 16 inch barrel, at the same time I do not have any crono-data to go with it, I t could be on the slow side.  In emails with Alliant in discussing 10x with the 70 SP they think that Reloader 15 would be a better choice, I agree, and now am working up a load with Reloader 15. In working with both, Hornady and Sierra in 60 grains I found the Sierra to exhibit "Classic Pressure" signs at a lower amount of powder, I.E. a grain less when using the Sierra. At that rate, one could try the same thing and work up a load, or try Reloader 15 with full support provided by Alliant.