Factory Ammo Consistency

[jlorensen]

I have a Savage Model 10 in .308 Win. This is a deer hunting rifle, and I've not had the time to work up handloads.....thus far, I've only shot 150gr SST Superformance ammo. At the range yesterday, I noticed the bolt would close on some rounds with very little effort, and others with a moderate effort. The "easy" rounds and "moderate" rounds ended up creating 2 different groups at 100yds, with the "moderate" being about 1.5" higher in elevation.

I used a headspace comparator and everything was very consistent....using an ogive comparator showed a difference of about +/- .03". Would that variability be enough to cause the bolt to close differently and produce 2 different groups? The rounds are well short of mag length, so just weird....it actually ended up that I could call the shot based on how the bolt closed....and ended up with 2 groups, about 1" in size, but stacked on top of each other.

Any thoughts???

 

[celltech]

Would have a hard time believing that a 150gr would be hitting the lands...unless that throat was cut stupid short. Bump one of the long rounds back 30 thou and see if goes in easy...

 

[jlorensen]

Would have a hard time believing that a 150gr would be hitting the lands...unless that throat was cut stupid short. Bump one of the long rounds back 30 thou and see if goes in easy...

I was thinking the same thing regarding the bullets....they definitely don't look long at all. I'll try to bump one back and see what happens. Now that I'm thinking about it, I think I have a couple partial boxes of different ammo, might try those as well.