260 load confusion

[quillow]

I'm in the process of loading up some Nosler 140CC bullets. Hogden shows a range of 39 to 42 with H4350. Yet a 142MK at 41.5 to 44.5. OAL the same. Unfortunatelly Hogden only shows a partition bullet. When I go to Noslers site it just shows a spitzer in that weight and no H4350 powder. Why would the heavier longer bullet have a max of 2.5 grains more powder being loaded to the same length? Anyway I loaded up 5 each from 41 to 42.5 in .3ths incriments. Anyone ever load these and what was your experience with them?

 

[arizonajake]

Probably due to the fact that boat-tailed match bullets, such as the Sierra 142s have a smaller bearing surface than the Noslers you describe. Another reason may be test barrels used, since some tend to be a little tighter than others and may run up pressures higher with less powder than others. If one bullet manufacturer uses a tighter or rougher barrel than the others, for testing, results will be different. Your approach to load development appears to be sound. Best of luck!

 

[Erik Cortina]

Start at 39.0 and work up! Load one of each .5 gr. apart and stop when you see or feel pressure signs. When that happens you have found the absolute max load for your rifle.

 

[louielouie]

I've had some good luck with these bullets BUT it required a lot of sorting to achieve it - weight variations weren't so out of the ordinary (for a 'regular' bullet) but the bearing surface length varied quite a bit of the 500 that I sorted using a pair of comparators.

0.015" jump definitely showed tighter groups (less vertical) than 0.010" and 0.020" might be better.

 

[Ringostar]

Ive used many of the nosler comps in a 260. I loaded them up to 44.5 gr of 4350 with no problems. I did have one box with some problems, but nosler replaced the box, and i havent had any problems since then.