FWIW:
Saturday last I went to the local gunshow -- as usual just to buy "stuff" from a parts & supplies point of view (since my wife say I already have a the "guns" I need).
Anyways,... I'd been searching for years for a `94 Marlin in 38/357 and -- of course -- none to be had. THIS time I ran into a 2000-ish slicked up CowboyCompetion/octogon/case-hardened/runs-like-water NIB`94 in 38 Special. Obscene price.
I walked away three times... You know the rest.
SoI grabbed it, a 24" Dewey rod, and 50 rounds of just-for-the-heck-it reloaded Georgia Arms 158gr_38Special Cowboy and headed out to the range.
At 50 yards I couldn't keep more than 3 shots out of ten even on a 3x3' NRA pistol target.
All over the frigging place....
Whiskey/Tango/Foxtrot, Over.
Went home and slugged the barrel.... you guessed it.
TIGHT barrel constriction (I mean tight) just ahead of the chamber where it screws into the receiver. (a few other places too, like the rear sight dove tail... gee thanks folks.) Lead bullet gets squeezed down for the first inch and rest of the barrel looks like a sewer pipe for all intents and purposes.
Now what...
OKAYyyyy.. Go with a
soft (30:1) SAECO 158gr TC bullet and a [U
]fast[/U] powder (W231) to smack things out into the grooves/keep a grip on things out of the starting gate (and beyond). Result ? 3½" group w/ some vertical stringing at 50 yards.
OKAYyyyy Go with a somewhat slower powder (N340)/kick the charge way up to both initially smack the soft bullet and keep it smacked pretty good as it travels. Result ? 1" x 2½" vertical group.
Hmmmmm..... Go w/ somewhat (but
not too hard) bullet and keep it near maxed out w/ that slower powder:
Result?
postscript:
1. Just changing from 30:1 to Lyman#2 alloy increased the velocity by 50fps
2. I'll get around to lapping the tight spot out -- sooner or later.