I did some accuracy testing yesterday using WCC cases, 2.240" OAL, CCI #41 primers (I think - may have been standard CCI SR), and Hornady 55gr FMJ. Rifle used was a Stag 3 16" 1/9" w/ 5.56 NATO chamber, carbine buffer, AR carrier, and Aimpoint ML3. I was limited to the 25yd range as the deer hunters were sighting in. My intent with this load was to find something usable with the 55gr bullets I use for 3-gun, drills, and plinking.
Of the H335 loads I tested, 24.7gr grouped the best. Of the RL-7 loads I tested, 20.5gr grouped the best, albeit slightly worse than the H335 but not substantially worse. Considering I was shooting off a rest and that during a match, I won't be afforded such a luxury, I'd consider the accuracy to be practically a wash.
However, recoil with the RL-7 loads was noticeably less than the H335. Between the recoil and lower charge weight (i.e., less expensive to produce), I'm inclined to use RL-7. The 4.2gr difference is 17% less powder, a substantial savings in a volume application (a savings which might be used for better bullets, maybe?).
For the 3-gunners out there, how has powder choice and recoil impulse affected your reloading? What have your experiences shown you?