What are the best and where do I find load data?

I noticed shooters world SBR, blackout, and buffalo rifle can ve used, but they don't publish data. Seems kinda odd they do that.

Trail Boss is commonly used for subsonic loads...  The minimum charge is a load density of 70%.  From the TB mfgr website  >>>

"1) Find where the base of the bullet to be loaded is located in the case and make a mark on the outside of the case at this location. Then fill the case to that mark with Trail Boss, pour into the scale pan and weigh. This is your maximum load. Pressures will be below the maximum allowed for this cartridge and perfectly safe to use!

2) Take 70% of this powder charge weight (multiply the maximum load from step 1 by .7), and that is your starting load.

3) Start with this beginning load and work up to your maximum charge, all the while searching for the most accurate reduced load. Once found, the fun begins!"

In a 308, 100% load density is about 14 grains, 70% is about 10 grains...  so in a 308, you start at 10 grains and work your way up paying close attention to your chrono data.  The speed of sound is temperature dependent...@ 32 degrees F, the speed of sound is 1,087 fps.  @ 68 degrees F, the speed of sound is 1,125 fps.  Pick whichever maximum MV you like and work up a load that will give what you need.  Typically, most sub-sonic loads use bullets that are on the heavy side for caliber.  In my 308, I have developed a recipe for a 180 grain bullet...  next, I will work up a load for a 200 grain bullet and a 220 grainer as well...  then I will pick the one I like the best and standardize on it.

Since you are also running a 0.308 diameter and your case is smaller than the 308, your minimum charge will be less and your projectile could also be lighter that what I am using...  ~150 grain?.   Also be sure to pay attention to your twist rate and try to only use bullets that your twist can stabilize adequately.  I would try to run a Hornady Interlock 180 grain if applicable/possible.  It is a soft point, boat tail bullet with a cannelure.  Easy to load, can probably be stabilized with a 1:12 twist, definitely with a 1:11 twist.  Bullet length is 1.275", SD is 0.271, G1 BC is 0.452 according to Hornady.  The charge of Trail Boss I use in a 308 case is 10.6 grains - YMMV!  Best of luck...

- R -

10.3 gr of 2400 will work with a 208 gr bullet, but it drops 8" at 100 yards

Will it cycle an AK or AR?

What's the energy at that distance?
A 175 i bet would work good.

Is it possible to pull bullets on steel cased stuff and lower the charge?

So best option is to get an adjustable bolt?

Sweet Jesus this is more complex than i thought. I guess ill move this to the sbr suppressor section.

Thanks