oversized chambers with Marlin 1894 45 colt barrels

[cvarcher]

Ok, Im hearing conflicting opinions on this and Id like to know the truth. Are the Marlin 1894 colt 45 barrel chambers oversized to todays modern 45 brass?

[kimwcook]

My cases show a little blowby, but they aren't loaded very hot either. I have no issues with excessive case expansion.

[J Miller]

The 1894 Cowboy I have is about average. The chamber is larger than it needs to be, but not to bad. The one in my Win 94AE Trapper is larger.

I don't have any trouble with excessive expansion and I don't get blow by either.

Joe

[adirondakjack]

The standards for .45 colt have not changed since the BP era. Sooooo, makers are pretty well stuck to cut a chamber so that any case that is within those sloppy BP standards will chamber. (BP guns had to have clearance or they'd need very frequent cleaning)

So long as the chamber is concentric to the bore (almost always is pretty good), this is not an issue. with leverguns the sloppy chamber actually HELPS ease feeding issues. The converse would be the fairly tight .44 mag tolerances, and the more frequent feeding issues leverguns chambered for .44 experience.

None of my .45s exhibit issues even at Ooh la la pressures. I do know that cases fired at the high end in the marlins end up needing a good full-length resizing, or they resist chambering in my ruger revolvers, so yeah, the Marlins are at the outside edges of tolerance.

[marlinman93]

Every .45 Colt gun I've ever owned showed blowby on the cases with light loads, so the 1894 showing this isn't from a loose chamber. I haven't heard of oversized chamberes in new 1894 Marlins.

[Griff]

Every .45 Colt gun I've ever owned showed blowby on the cases with light loads, so the 1894 showing this isn't from a loose chamber. I haven't heard of oversized chamberes in new 1894 Marlins.

Ditto.

[thornblom]

I have a Marlin 1894 Cowboy Limited in ,45 Colt. It has a 24" octagon barrel. If I use Remington or Winchester cases, I get a little smudging on the outside of the front of the cases. Using the same loads in Star-line cases, no smudging. The starline cases are heavier and so must be thicker. Less expansion.

It works for me.

Sincerely,
Dave (Bubba) Thornblom

[Lefty Dude]

Several CAS/SASS shooter using the Marlin 94/45 have used 44-40 case's blown out to 45 colt. The thinner rim of the 44-40 case seals and you have less blow-by.

I shoot 44-40's in my Uberti 73 Cimaroon, I have no problem. In my Colt SAA 44-40 with the 44 special cylinders I get some side dark stains on the case's.

You know when you have excessive blow-by and a large chamber when you feel the powder spit on your face.

[Cast Bullet Hunter]

Ok, Im hearing conflicting opinions on this and I'd like to know the truth. Are the Marlin 1894 colt 45 barrel chambers oversized to todays modern 45 brass?

Opinions don't mean anything, dimensions do. The SAAMI standard base dimension for .45 Colt is .486 +.004/ -.000. Go to this link: http://www.leverguns.com/dimensions/images/45colt.jpg Measure your fired cases, if the expanded case in no larger than .490 then your chamber is not oversize. It may be larger than you would like, but still within standard dimensions.

I would like to know why several got off on a "blowby" tangent, but that is typical of people not reading and understanding the question, or simply parroting that which they have "read somewhere"! This has absolutely nothing to do with chamber dimensions, but strictly developed load pressure. The only other factor that has an effect is case thickness/hardness. Certainly thinner/softer cases will expand sufficiently to obturate than harder/thicker.