Large Flash Hole Test

[Farmer]

Tested differences between std flash holes and the larger NT type. 
45 ACP 200g Plated SWC, 4.3g e3 WLP primer WW brass, 1.240 oal XDM 3.8”, 30’ from target 10’ from chrono. 5 rounds ea. 
Large FH .148”   Std FH .076”

Av 821 fps           Av 832 fps

ES 21                    ES 25

SD 9                      SD 9

Lg flash

Std Flash

I need to test the accuracy on the large one again just to make sure my grip wasn’t off a bit. Was fairly surprised at the Loss of velocity although one was a fair amount lower (811) than the others and I do remember one round seating easier than the others. Basically it really didn’t make much difference but if you were on the line one could mess you up. I’m going to test some 9’s when I get a chance to see if it follows a trend. 

Brass with Lg FH is on top, Std on bottom. Large did seem to show a little less psi if you were reading primers. 

Edited March 18 by Farmer
Added pic

[Farmer]

I remember reading about not using enlarged flash holes for anything other than blanks or the Speer plastic target ammo. I guess the industry has changed their minds.