I bought two used Bolen basepads from someone on BrianEnos’ forum recently, thinking that it would fit on my 170mm and be legal (fit in a magazine gauge). After showing it to John from JPL Precision, he checked with his USPSA Mag gauge and it didn’t fit! It was just very so slightly longer.
Coming home, I checked both basepads and lo-and behold, they’re not the same! All this while I thought they were the same basepads. One was just a hair taller.
Reading up online, Bolen has three types of basepads, 3mm, 4mm and 7mm. so I guess the one on the right is 3mm and left is 4mm. What a n00b I am.
Anyway, installed the 3mm on my 170mm mag tube now, and I’m sure it’ll be legal now. Here’s how they recommend we use it in an Open Gun.
- 3mm for 170mm mag tube should yield 28-29rnds of 38 SuperComp
- 4mm for a “tuned” 170mm mag tube should yield 29-30 of 38 SuperComp
- 7mm for a 140mm mag tube for 22-23 of 38 SuperComp