Estimated Internal Diameters of MEC Shotgun Bushings

[Liberty1776]

I need a #21 or #22 Mec bushing to throw some AA Super Handicap powder into an AA hull, but the bushings aren't available locally.

Smaller used bushings I can find. So I thought I'd drill one out until it throws the powder weight I want.

Glories of the Internet: I found a guy who estimated the internal diameters of MEC bushing based on a couple he had. Not sure how accurate it is, but it's a start.

299002

299001

[M-Tecs]

More info on the process

https://www.shotgunworld.com/threads/mec-bushings.204955/

[Shanghai Jack]

In the interim try some of the 3d printed bushings available on Ebay - I've even had the guy make me some custom bushings in "a" or "1/2" sizes.

[AndyC]

I can add the measurement of a 09 MEC bushing to that list - 0.261"

Others I've measured using a hole-gauge and calipers:

10 = .265"
11 = .272"
12 = .283"

[Liberty1776]

Here's another chart a fellow found and posted.

299195

[jmorris]

Gotta love arbitrary numbering systems, why call it a .5, when you can call it a 38…

Same people must have come up with “grains volume” vs the actual weight of the charge in grains.