Originally Posted by Adam
Very interesting. I would be interested to hear of anybody with experience of a .177 ST barrel, that does
group at 50m, sub 12 ft.lbs. I can't say I've read any positive confirmation of this nature.
I've long believed that between 40 and 50 yards is a kind of critical range for 12 ft.lbs .177, where a lot of barrel/pellet combinations will group exceptionally well below that range and start to open out above that range. We read similar stories for the Defiants a few years ago. Great for closer ranges and FAC, by some accounts not so good for FT at 55 yards.
There must be a PhD research project or two in this somewhere.
Over 45yds and under 12fpe the average .177 pellet is starting to become unstable unless it's spun properly which doesn't seem to happen properly with the ST barrels at lower power levels. Maybe at higher power the smaller amount of twist is amplified which probably isn't the right word, but because the pellet is given more twist it stays stable further out? Who knows for sure.
I do know, is that my experiments with .223 rounds over 600yds have shown that generally faster is better and faster, with longer bullets is even better, so there must be an ideal shape pellet for the ST barrels over 45yds, it's just a question of finding it.
Just out of interest does anyone know roughly what the twist rate is on the ST barrels?
Edit: Did a bit of delving and some chap on a BR forum reckons that the ST barrels come in at 1:96" twist. Now considering that most .177 barrels are around 1:17 to 1:19" that does sort of suggest that only spinning a pellet for 1/5 of a rotation before unleashing it on the World doesn't work, which is borne out in real World tests.
Makes you wonder what they were on when they came up with the concept....