Twist Question

[moodyholler]

In 32-20 I have a Marlin 1889, Winchester 92, and a Hopkins and Allen Single shot. The load I have shoots well in the Winnie but sucks in the other two. I also have a Remington #2 Rollingblock in 25-20 SS, Stevens 44 in 25-20 SS, Marlin 1894 in 25-20WCF, and Savage 23B in 25-20 WCF. The Marlin doesn't shoot worth a hoot. The other three will digest the same load with close results. All except Marlin like 86 grain bullets. Is the Marlin twisted different? Is the a 60 grain mold available? I am getting better groups with Hornady 60 FN bullets. Oh yes, shooting 113 grainer in 32-20. Should I look for a 90 grain or so mold for the Marlin. Thanks for your help, moodyholler

[KCSO]

First check the muzzle crown, a lot of the old ones I see are ovaled from improper cleaning or have visible dents or nicks. This can really play hob with your accuracy.

Aside from slugging the bores I would measure the twist in each gun. This is easy enough to do...
Get a cheap aluminum cleaning rod and lock tight the joints in the rod and then lock tight in a 45 caliber nylon cleaning brush. Put the brush about 6" down the muzzle and mark the top of the cleaning rod with a dot from a magic marker say 20" from the muzzle. Push the rod in until the rod makes one complete turn and then measure how much rod is left. Say the mark is 20" from the muzzle and one turn puts in 10" further in= twist 1-10, One turn for every 10" I would also slug the bores or do a chamber cast to see just what you are dealing with. I would also run a tight oiled patch down the bore and check for loose spots where the bore might be worn or bulged.
I am real leary of using published twist rates for the old guns as sometimes the info is not right and it is so easy to measure and know for sure.