Got my BAMM load thanks to Grouchy

[lostvaquero]

Well I too have been playing with TB in Swiss K31.  Our range probably will let us do BAMM with loads running less than 1600fps.

 

The Norm bullets are nice but I also had some 160g hitec poly bullets.  Just chronograph them very consistent at 1559 fps with 15g TB.

 

I also had a few 210g poly bullets but had to back off the amount of TB as 15g a bit too much.  Max amount there I could get was around 14g and result was a ho hum 1250 fps.

 

Have not put the 160s on target but pretty sure going to do fine.

 

Hats off to Grouchy Spike for all his load development it sure cut a bunch of time off development.

[Grouchy Spike]

LV, good to hear that you and your K-31 are doing well! 

 

Overall length is critical.  I gauge every round by running it through the chamber. (observing safety practices)  If the bolt doesn't close easily and fully, as evidenced by the position of the end of the operating rod in the bolt, the firing pin can be released but won't contact the primer.  Continued hits like that may eventually damage the internals of the bolt.  This problem of a cartridge not fully chambering is caused by incomplete sizing all the way to the base or Overall Length.  I resorted to a Redding sizing die to solve the problem of sizing.  Until I gained confidence in the sizing die, I ran every recised case through the chamber.  Occasionally a case will be difficult to resize, indicating a need for some annealing. 

 

L.E. Wilson made a run of cartridge gauges to check headspace and overall length of the case, but last time I checked, the supplier (Grafs.com) was sold out.  Once used cases are determined to be at correct dimensions, the cases don't usually need further trimming.

[lostvaquero]

I got one the Wilson checks off evil bay.  I check rounds in there but remember your advice to chamber check.

 

Thanks again for getting me there.