I've got a BRNO 22HP/12 gauge. It shoots well, but I don't shoot it well with it's course iron sights. So, I ordered a Weaver style scope base and a Weaver red dot type shorter base for it. I've decided to try some different options for making this a little more usable by giving me something other than the course irons to work with.

Does anyone have any thoughts on what might work to increase the effectiveness of this BRNO, and why? Figured the are some here who experimented a bit with same. FWIW, I shoot my handloads with obsolete 70 grain Sisk bullets. If I get serious about it, I'd like to try the Hammer mono bullets for this cartridge. Thanks.

A Valmet 300 series in 12/22HP I sold to a friend and good member here shot these very well. I found that .224 bullets of moderate weight worked as well or better than the longer 70gr .227 bullets.

Practice more with the iron sights, and make sure you shoot with Both eyes open when you use the red dot.

BTW...my wife just walked in and wants your chair. She's to chairs like I am to drillings.

https://www.nosler.com/22-cal-60gr-partition-50ct.html

These shot best:
https://www.shootersproshop.com/22-caliber-64gr-bonded-solid-base-100ct-blem.html

I've been fascinated with auxillary chambers and barrels. I've used chamber inserts in both shotgun and rifle chambers, and insert barrels. Insert barrels in the shotgun get kind of expensive but can be really accurate. Hammond Gamegetters can give you 22 short performance. There is a fellow in Alaska that makes inserts to fire 22LR and 22 mag in some calibers. I've not used them, but I use the Hammond's for small game.
I use cast ullets with Trailboss powder in my 5.6x50R to make a nice 22 mag load. I use that on squirrels to good effect.
Bfly

I'm not as experienced as some of the posters on this topic,but in my two trigger Valmet lower hi power 12 ga I have found the 55gr bullets to be more in alignment with the point of aim of the shotgun

I ordered a scope base and a red dot base from Optics Talk in Slovenia. When they arrived I mounted a Leupold 1.5-5 on it and went to check accuracy. Bullets touching accuracy was a real shock. Remington and Winchester were two shots touching, my handloads with 70 grain Sisk were close to that, S&B were 3/4, Norma about 1/2", the worst group being Dominion, but still useable at 1 1/2". All at 50 yards. Any of them will work but if someone needs Dominion that shoots well in their rifle I'd trade it for one that shoots a little better for me. I have about 5 boxes of Dominion.