I have an 80's 1B in .223 with a supposed 1:10 twist. I've tried to verify the twist and get about 1:11. It is a bit persnikity but sometimes I get accurate with it.
I have removed a bit of metal from the barrel rib and that was real helpful.
I installed a Wolfe hammer spring and that helped some speeding the lock time.
Some of my loads can hover around .8 to 1.25 if I work really hard and conditions are good - I can't do it consistently. I can even get a rare group at maybe .75 but that's about it.
Such a pretty gun, sure wish it would make .5 to .75 groups.
I have not done the forearm hanger fix.
Also, I have a leather cheek pad to get my head up to the scope level. I have an older 6-18 Burris AO on it but usually shoot it best at about 12x.
liberal Justice Hugo Black said, and I quote: "There are 'absolutes' in our Bill of Rights, and they were put there on purpose by men who knew what words meant and meant their prohibitions to be 'absolutes.'" End quote. From a recent article by Wayne LaPierre NRA