Since last Wednesday's work with the 9mm AR-15 carbine, I've been thinking about reloading for it.
The Rock River Arms upper is built with a 16-inch, 1-10" twist Wilson Arms barrel. It performed well with the handful of reloads using 147-grain Hornady XTPs, 4.2 grains of Unique and Winchester once-fired brass I fed through it. I still have some left, which I'll put to more extensive testing. I'll run some across the chronograph when the wind settles down. If I had to guess, they will probably clock around 1,000 feet per second.
I also have some 125-grain, .355-in. bullets on the shelf, Remington Golden Sabers and Speer Gold Dots, left over from when I reloaded for a Glock 32 .357 Sig.
The handloads with 88 and 115 grain JHPs were charged with Winchester 231 powder. It left much debris inside the fire-control assembly and throughout the upper receiver. I have had the same problems with it in 9mm pistols but thought it might burn better in the longer barrel. I finally gave up trying to brush and swab it out. Compressed air did the trick.
I have two pounds of Alliant Power Pistol and most of an 8-pound keg of Unique left. Both powders will produce higher velocities than the faster-burning Winchester 231.
Most shops don't stock Alliant Power Pistol here. One store about 50 miles usually has some, but they want more than $25 a pound for it. Power Pistol is one of the best powders I've used in .40 S&W and .357 Sig. I also use it in the .38 Special for 125-140 grain jacketed bullets.
Now that gasoline is down to $1.85 per gallon, I'm thinking about driving down to Winfield, Kansas, to Powder Valley, Inc., and stocking up on powder and bullets. It also stocks Zero jacketed bullets, an attractive alternative now that some 9mm bullets are selling for nearly $20 per 100.