Smart move by JPAT

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Bill Calfee

Gun Fool

• Jan 6, 2021

• #1

Smart move by JPAT


CYA accuracy fool friends:


JPAT just fit and tested the new Muller Mini 4-MI barrel on one of my iconic RFBR guns, HOT STICKS.





Since this Muller Mini 4-MI rifling pattern is new, and the proper leade engraving length unknown, JPAT did a clever thing and set the initial leade engraving length at .125"....


And tested it at this length.....and was not satisfied with the accuracy, although excellent...


He then changed the engraving length by moving the barrel shoulder and breech face of the barrel........


And now is well pleased....


Now.................


What is the proper engraving length for this new Muller Mini 4-MI?


My gut tells me JPAT isn't about to reveal that, just yet.........

And why should he......he did all the work?


Your cited, Muller Mini 4-MI fool friend, Bill Calfee



_____________________


PS:


Oh I'd love to show you CYA folks these test targets......but it ain't my call to do so....bc

 

B

Bill Calfee

Gun Fool

• Jan 7, 2021

• #2

Leade engraving length of the new Muller Mini 4-MI

Leade engraving length of the new Muller Mini 4-MI


CYA accuracy fool friends:


Since this Muller Mini 4-MI is new, the proper leade engraving length was unknown...


JPAT, when he fit this new Muller to Hot Sticks, set the engraving length short, at .125"


And when he tested Hot Sticks at this .125" engraving length, it shot great....


So most RFBR schmidts would have stopped at this engraving length...


But JPAT was not totally satisfied....


So he lengthened the engraving length......


I wish I could show you CYA folks the test targets....


But that's JPAT's decision.....


Your pistol friend, BC

 

B

Bill Calfee

Gun Fool

• Jan 21, 2021

• #3

What is the best leade engraving length.....?

What is the best leade engraving length.....?


CYA accuracy fool friends:


What is the best leade engraving length for the new Muller Mini 4-Mi rifling pattern.....?


A chamber reamed with the Calfee, .2250" diameter, straight walled reamer, with 2 degree leade...

And using Eley black 6034 for the gauge....


The proper leade engraving length, for both Lapua and Eley, is between .142" and .150", depending on the groove diameter of the Muller Mini 4-MI barrel you're working with....


Your pistol fool friend, BC