edwardware
Member
- Joined
- Feb 23, 2010
- Messages
- 4,426
I'm addressing an interesting issue with my Rem 700 SPS Tactical (16.5", 1:9" twist). I've loaded three bullets so far, with radically different results. All loads are in LC brass, FL sized, S&B SRPs, BL-C(2). Groups are always 5 shots, and repeatable on different days. Loading with a micrometer dead-length seater.
1) Sierra 1360, 55gr soft point with a tanget ogive. Tuned load yields 0.5 MOA repeatably.
Zoom
2) Hornady 22271, 55gr VMax, with a secant ogive. First time out (untuned) several different charges shot 0.75 MOA groups; the worst charges shot 2+ MOA. Tuning OAL and charge should improve this.
Zoom
3) Hornady 2266, 55gr soft point with cannelure, with an abrupt secant ogive. I have run the range of charge and OAL, and cannot make a group better than 2 MOA.
Zoom
So what is going on with the Hornady SP? I don't expect the cannelure is helping, but it can't be that bad; semi- rifles shoot sumMOA with cannelured and crimped ammo all the time.
I've read that secant ogive bullets are very sensitive to jump-to-lands; how sensitive? Should I recover the COAL range in increments less than 0.012"? How much jump should I start with? Jump from jam, or just touching the lands?
I called Hornady, and they blamed the BL-C(2); I called Hodgdon, and they blamed the bullet. . . go figure.
Any suggestions?
1) Sierra 1360, 55gr soft point with a tanget ogive. Tuned load yields 0.5 MOA repeatably.
Zoom
2) Hornady 22271, 55gr VMax, with a secant ogive. First time out (untuned) several different charges shot 0.75 MOA groups; the worst charges shot 2+ MOA. Tuning OAL and charge should improve this.
Zoom
3) Hornady 2266, 55gr soft point with cannelure, with an abrupt secant ogive. I have run the range of charge and OAL, and cannot make a group better than 2 MOA.
Zoom
So what is going on with the Hornady SP? I don't expect the cannelure is helping, but it can't be that bad; semi- rifles shoot sumMOA with cannelured and crimped ammo all the time.
I've read that secant ogive bullets are very sensitive to jump-to-lands; how sensitive? Should I recover the COAL range in increments less than 0.012"? How much jump should I start with? Jump from jam, or just touching the lands?
I called Hornady, and they blamed the BL-C(2); I called Hodgdon, and they blamed the bullet. . . go figure.
Any suggestions?