Marlin .44 Microgroove Groove Diameter

[insanelupus]

Just out of curiosity. Those of you that have pre-safety 1894 Marlins, what is your groove diameter for the .44 Magnum?

I decided to try something. I've got one that came in that had been shot with some jacketed bullets. Before cleaning I slugged the barrel at .429". There was a little jacket fouling that cleaned out of the barrel, but not much. I'm guessing there won't be much difference in post cleaning in the measurement, but I could be wrong.

Also, what size of cast bullet do you run out of your Marlins. I'm tempted to try a .431" so I can size the Lyman 429640 (non HP) I have for both Marlins and Rugers.

[BABore]

Shoot them as big as the case/chamber will allow which will be the size that will slip fit into a a once fired case from a full powered load. Be sure to remove any vestige of a crimp when checking this. Marlin Micro's like big boolits. Most shoot 0.432+. Also be sure to check for any bbl constrictions. You can check for this by comparing a bore slug that was pushed through the full length verses one that was just pushed into the muzzle, then back out. Marshall Stanton (Beartooth Bullets) has several articles on the 444 at his site. It's his favorite levergun and a good read.