45/70 barrels

[larry1945]

Couple years ago I bought 45/70. It has hx serial number, h&r and made in Gardner.  I thought all the barrels were made by marlin and were micro groove.  This one has 9 grooves and shoots cast extremely well. Are all 45/70's 9 groove?

[quickdtoo]

Depends when the barrel was made, they have made MG 45-70 and others in the past, Marlin MG barrels have changed too, I have a three late model H&R 8-groove 45-70s that appear to match their early specs, I also have a couple older H&R 45-70s that are 6-groove.

Tim

http://www.leverguns.com/articles/fryxell/microgrove-barrels.htm

In 1972, Marlin introduced the Model 1895 chambered in .45-70. Initially, these rifles were made with 8-groove Microgroove barrels, with grooves that were .060" wide and .003" deep. The next year this was changed to a 12-groove barrel, with the other specs remaining the same. Again, groove diameter is spec-ed out at .4587", so oversized cast bullets are called for in these guns. All of these .45-70 Microgroove barrels had a 1 in 20-" twist.

[larry1945]

Thank you for the info on 45/70 barrel.  I either can't count or can't type.  I went back and looked at it again and it is an 8 groove.  I had loaded case w/o any powder and cast bullet just moved about half out of case and thats when I saw the grooves.

[gcrank1]

Yeah Larry, the number of lands/grooves will increase depending on how many times you keep going around the circle  , its that spiral that'll get ya.
If you want to shoot cast bullets it sounds like you have the easy one; its hard to make a load that doesnt work in one of those.