To all of you fellers who told me so.......go ahead....say it.

Since my original post on how to reduce extreme spread, I've been doing a lot of shooting, chrono'ing and observing. I won't bore you with the details. But I will show you something interesting (I thought) from this morning's bench session.

Load #1: 250 gr. Sierra SBT Fed 210M 81.0 gr. IMR-4320 Wby. Brass

Avg. Velocity @ 10'...... 2945 fps
Ext spread............... 40.82 fps
Std dev.................. 17.77 fps
100 yd. 5-shot group..... 5.0"

Load #2: 250 gr. Sierra SBT Fed 210M 92.0 gr. H-414 Wby. Brass

Avg. velociy @ 10'....... 2965 fps
Ext spread............... 41.55 fps
Std dev.................. 16.52 fps
100 yd. 5-shot group..... 1.4"

Two loads with nearly the same physical statistics (and still a fairly large extreme spread) and majorly different results on paper.

I still think I should be able to tighten up the group a bit. But I will be able to sleep at night, now.

Strut, this is good work and a great observation on your part. One might think that barrel vibration has something to do with the accuracy issue. That being the case consider that all else being equal, 11 grains more are exiting the barrel for each shot! Even though it is in gas form, the weight of the powder charge affects recoil and I am confident barrel harmonics. Good luck and good shooting.

quote:

Originally posted by Strut10:

.......100 yd. 5-shot group..... 5.0".......

quote:

Originally posted by wildboar:

quote:

Originally posted by Strut10:

.......100 yd. 5-shot group..... 5.0".......

Yeah.......no crap. Looked like a decent shotgun buckshot pattern.