I recently tried out the 18.1 grain H&N Sniper Magnums in a BSA Scorpion and a Theoben MFR. The BSA shot them at 860 fps and the MFR at 915 fps. I shot them at 20 yards, with no wind, and didn't have good results. The BSA shot barely under 1/2" groups, and the MFR was over 1/2". Both guns shoot JSBs 15.89s, 18.13s and H&N Barracuda's under .150" at 20 yards for 5 shots. There was some vertical stringing with the Sniper Magnums.
The package says the Sniper Magnums are 5.50mm, which if were Barracudas or JSBs, would not shoot that well in my guns. However, the heads measured .220" average, almost 5.59mm, which must be too tight. Also, the skirts on these fit rather tightly in both guns chambers.
Perhaps you will have better luck with them.
The package says the Sniper Magnums are 5.50mm, which if were Barracudas or JSBs, would not shoot that well in my guns. However, the heads measured .220" average, almost 5.59mm, which must be too tight. Also, the skirts on these fit rather tightly in both guns chambers.
Perhaps you will have better luck with them.