Bumping this thread with today’s 3x600 result. Well, more like observations. I shot my 12FV .223 as an FTR but with a rear squeeze bag and a Magpul bipod. As a reminder, this rifle has a 26” 7tw CBI with .090 freebore.
I loaded up some 88ELDs and 80ELDs at charges and OALs that preliminary testing suggested would be decent. I committed to shooting at least a whole relay with each.
88s went 190-5x (mr1-fc)
80s went 188-2x
3rd relay was experimenting with other loads and the 182-x was notably worse than either 15.5 load.
So I broke 190 for the first time thanks to 88/15.5 combination. 188 was my 2nd highest score with this rifle, also thanks to 15.5.
Now the interesting part: the SMT e-targets were showing trap speeds in the 1920-1930fps range. Comparing notes with
@jrh84 he was pushing Berger 90s to similar speeds. But from a 30” tube with pressures in higher ranges popping primers and destroying LC brass with his n135 charges.
In other words, 15.5 is giving comparable speeds at what appear to be significantly lower pressures despite my rifle have a 4” shorter barrel and .020” shorter freebore. And doing so with only 24.3gr.
While I’m not ready to anoint 15.5 as some kind of miracle, I will suggest that I consider the naysayers who pishposh at this powder for .223 to be grossly mistaken in the premature rush to judgment on 15.5 for .223.
Temperature stability, decopper additive, competitive velocity and LOW PRESSURES with what appears to be respectable accuracy potential.
What’s not to like about that?