Experience with down-sleeved chambers?

[keavin nelson]

I am considering having a 20ga sleeved down to a 28 (chambers only) due to a bulge at the end of one chamber.

My question is how well will it perform, will there be a velocity loss, how might it pattern.

Does anyone have experience with a similar situation and resulting performance.

Thanks

Keavin

[Mills Morrison]

We've talked about this but 16 to 28 performs surprisingly well

[Brian Dudley]

It would be no different than using gauge-mates. Which I always wondered how performance is on that too.

[Bill Murphy]

Performance from 28 to 20 should be no problem at all.

[CraigThompson]

I’ve used the Briley shorty tubes in 12 gauge skeet guns for the 20-28 and 410 with very good results . The most noticeable thing I found was how much louder the report was with 410’s . But on the skeet field they performed adequately. My thought is if a 12 gauge barrel shoots 410’s okay with the shorty tubes (they’re maybe 6 inches long) , then anything else should be a piece of cake .

[Arthur Shaffer]

I have tried gauge mates in several variations and they seem to work very well. The little data I have seen has not shown much velocity decrease, usually along the lines of a reduced shot charge in an overbored barrel.

The problem is that tehy will not, as a general rule, fit in a 2-1/2 inch gun. They are not generally as useful as they would seem. I have a couple of older inexpensive guns with pits that I have lengthened the chamber in to 2-3/4" and then used the gauge mates.

If there was a commercial source for the chamber sleeves, they would be simple to install for anyone with the equipment. They would go in like the headspace repair rings that Brownell's has/had. The same piloted tool would bore for them.