I was trying to develop a 223 subsonic load for my ar-15 using surplus WC820 (like H110) powder last year because they are much better powerwise than 22lr.
60 grain Aguilla SSS at 700 fps is 65 ft-lbs
40 grain std vel at 1050 fps is 98 ft-lbs.
55 grain 223rem at 1050 fps is 134 ft-lbs
69 grain 223rem at 1050 fps is 168 ft-lbs
80 grain 223rem at 1050 fps is 195 ft-lbs
The difference is clear. It is wimpy, but lets see a raise of hands for those willing to take one in the gut.
I'm not sure how well a 22 conversion kit shooting rimfire bullets in a centerfire barrel works, but I hear they do not do as well as a dedicated 22lr ar-15 upper. My limited load development gave me about 2 moa. I was able to stablize the speer 70 grain round nose and the 55 grain FMJ, but not the 69 grain and higher match grade bullets in my 1-9 twist ar-15 when shooting subsonic. None of them cycled the action enough to pick up the next round either.
I am thinking that if I were to get a ar-15 pistol, attach a stock and 16 1/4" barrel, remove any buffer weights and chop the spring, I may be able to make something that works semi-auto, but that is not in my budget now.
I could care less about warranties on my guns. The only ones that ever see factory ammo are the rimfire and 7.62x36 or 7.62x54R guns.
Ranb
Edited to add; I do not have a warranty on my silencers as they are homemade on form 1's (< $50 + tax).
If a load does not keyhole at 100 yards, then I consider it safe to use suppressed. I can fix small stuff, but if I really shred the internals, then I will just chop up the can and make another one on a new form 1.
