.260 bullet set back
- Thread starter GRIZ1911
- Start date
- Status
Sunray
Member
There is no formula or set distance off the lands that applies to all rifles. Every rifle has its own preference. Even two identical Tikka's will have slightly different chambers. One could be 20 thou the other 10 thou. Entirely by trial and error.
After all that, you can forget the off the lands stuff altogether until you've worked up the load. The whole off the lands thing is a load tweaking technique that's usually not necessary. Max OAL for .260 Rem is 2.800" from the pointy end to the flat end. No ogives involved.
After all that, you can forget the off the lands stuff altogether until you've worked up the load. The whole off the lands thing is a load tweaking technique that's usually not necessary. Max OAL for .260 Rem is 2.800" from the pointy end to the flat end. No ogives involved.
GooseGestapo
Member
- Joined
- Jan 6, 2003
- Messages
- 6,167
Essentially what Sunray said.
My Rem M7 .260 wants ogive touching the lands. However, I started at the Speer manual published seating depth to start load trials. I then started tweaking from the most accurate load (typically 1-1.5gr under maximum published). To determine "touching" I sized the first 1/16" of the case mouth and inserted a bullet, chambered the "dummy" and extracted the round and measured oal.
I the placed bullet in normally sized case and sated .01" longer and checked by "feel" seating bullet deeper until I could only barely perceptibly feel the tension from the round chambering. I use this in lieu of "hard chambering" as I'm a hunter, first, and my M7 is a HUNTING rifle, so I want easy chambering.
If so loaded you see flattened or cratered primers, back off another 1-1.5gr on charge weight. My loaded rounds with Speer 120 & 140 are at 2.830" and fit magazine.
I've started shooting a lot of service rifles (SMLE. 03/A3, Garands, M1carbine) and as such, I want effortless chambering and extraction and case longevity. My 03/A3 is an UGLY Remington with nearly new barrel. It shoots better than a human can aim it with my "Garand" loads of 47.0gr H4895 and a Hornady 150gr FMJ. My first group after centering group on target had four shots touching at 12o'clock and a "called" flyer at 1" left. Bullets seated to 3.260", nearly a quarter inch off the lands. Go figure!
My Rem M7 .260 wants ogive touching the lands. However, I started at the Speer manual published seating depth to start load trials. I then started tweaking from the most accurate load (typically 1-1.5gr under maximum published). To determine "touching" I sized the first 1/16" of the case mouth and inserted a bullet, chambered the "dummy" and extracted the round and measured oal.
I the placed bullet in normally sized case and sated .01" longer and checked by "feel" seating bullet deeper until I could only barely perceptibly feel the tension from the round chambering. I use this in lieu of "hard chambering" as I'm a hunter, first, and my M7 is a HUNTING rifle, so I want easy chambering.
If so loaded you see flattened or cratered primers, back off another 1-1.5gr on charge weight. My loaded rounds with Speer 120 & 140 are at 2.830" and fit magazine.
I've started shooting a lot of service rifles (SMLE. 03/A3, Garands, M1carbine) and as such, I want effortless chambering and extraction and case longevity. My 03/A3 is an UGLY Remington with nearly new barrel. It shoots better than a human can aim it with my "Garand" loads of 47.0gr H4895 and a Hornady 150gr FMJ. My first group after centering group on target had four shots touching at 12o'clock and a "called" flyer at 1" left. Bullets seated to 3.260", nearly a quarter inch off the lands. Go figure!
- Status
Similar threads
- Locked
