I seen a thread in the archives about a Huntertown Arms Fusion T22 integrated barrel suppressor (Ruger 10/22) and was wondering about the porting? Hole diameter and how far the holes are from the chamber. I was wanting to see if the poster had anymore info, but he is lost in the archives.

I have a 16" barrel (ported for the suppressor) basically leaving the original barrel intact about 10" long. I was trying to figure out porting to decrease velocity to keep high velocity .22s from going supersonic. In the process I learned cheap 22 ammo velocity is all over the board.

Anyone run down this road? and want to pass some info.

I know the don't do it, you will ruin your barrel, poke out your eye and the mailman will never deliver to you again. I wear glasses and the mailman never talks to me anyway....

I don't have any info about porting to keep the rounds subsonic, but why couldn't you use a shorter barrel to keep them subsonic?

My integral 22/45 only has about 2 1/2 inches of regular barrel and the rest is ported out to the standard pistol length.

https://apps.dtic.mil/sti/pdfs/AD0847383.pdf

I have no experience, but this may help as a starting point.

IIRC, the Hi-Standard pistol of OSS & Powers/U2 incident is in this Frankfort Arsenal 1968 study.   Page 35 as you scroll, but the original document is pg 19 (typical .gov)

Money shot:
Silencing of the Hi-Standard barrel has been accomplished essentially by drilling the barrel and enclosing it in a silencing tube. The barrel has four longitudinal rows of "bleed" holes, 0. 125 inch
in diameter and spaced 0. 250 inch apart. The primary function of the holes, is reduction of the ballistic pressure which, in turn, also reduces the velocity of a supersonic Long Rifle cartridge below the speed of sound.

This design used bronze mesh as a heat sink & gas flow disruption & needed servicing/replacing.

Disregard if you already know: the 60gr Aguila subsonic are too long to be stabilized by standard .22 barrels & need 1/8 or tighter.  I’ve known 2 guys—one just last week— who had problems with this round; I’m not sure if it’s still made.