Is there any specific load recipes that are optimized for shorter barrels? I'm looking to develop some loads for an AR pistol with a 10.5 barrel which will be used for home defense. My initial thought was 60-65 grain frangibles loaded on the hotter end of the spectrum but I'm new to shorter barrels so educate me.

Faster burning powder for shorter barrels.

Someone i don't remember who did a test recently using quickload and chronographing some test loads.

There was a minimal~ optimization with some powders iirc but it was extremely minimal.

I load as hot / fast as i can while still obtaining acceptable to me accuracy. We have quite a few 10.5" and a couple 11.5" guns.

55 grain loads produce plenty acceptable velocity to get bullet performance for anything i want to shoot with a bullet in that weight range.

77 grain loads you can expect around 125~ yrds to be the max for dependable bullet expansion while still producing 1~1.25 moa groups with something like a nosler cc out of a 10.5" gun (hopefully gold dot's too i haven't tested this)

That's loading at 5.56 velocities ~

I had the same thought when I got into an AR pistol in 223. Faster powders to reduce flash and blast. Problem with the faster powders is reliable function.

If your in a state that allows suppressors, that would be more rewarding than experimenting to optimize a 223 round in a short barrel. The end result will be a minimal payback on your expenditure of time.

Might think about a 300blk since the design intent was to function with a shorter barrel. Just a thought. I went that direction and found the heavier bullet allows lots of load variation is possible if you open up the gas port and use an adjustable gas block as you dial in the load.

For instance, I was able to get reliable function with a 110gr bullet at subsonic velocities from a 7.5" barrel. Recoil was like a bb gun. Fun stuff.

On the frangible bullets... I'd use those for practice on steel plates at close quarters, but not for a defensive round. Better options are available.

I fiddled around with it a bit using faster powders.

2230 gave exceptional velocity at the expense of terrible accuracy.

8208 gave exceptional accuracy at the expense of velocity.

TAC, as always, provided a good middle ground.

Whatever the optimal / highest velocity load in a regular length barrel is will almost always be the highest velocity load in a short barrel as well.

10.5 gives up a lot of velocity in 223. You may as well throw the heaviest piece of lead you can. I’d look at 77gr OTM or 75gr Gold Dot, or similar.