Marlin 1895 GG bore measurements

[brstevns]

Getting ready to slug the barrel on my marlin 1895GG 45/70 and was wondering what others have found to be their bore measurements.

[Boondocker]

My GBL slugged out to .459, I have read alot of people came out with .459.

[Keyston44]

My Guide Gun slugged at 457.

Key

[Greg B.]

My standard rifle slugged .457 measured with a dial caliper.

Greg B.

[Dutch4122]

My ported 1895GS slugged .457"

[btroj]

Slugged my 1895 at .457. I was a bit amazed it was that tight. I size to .460 and will continue to do so. It certainly shoots well for me.

[jh45gun]

I never slugged my GG but I shoot my Lee 405 HB sized at .459 and it shoots great.

[brstevns]

Mine slugged .4575, my bullet is dropping .4585 . so will give it a try as is. Bullet is Lyman 462560

[TXGunNut]

.459 w/ a dial caliper. A bit of constriction under the rear sight dovetail.

[brstevns]

At what FPS you guys shooting?

[btroj]

I soot anywhere from 1300 to 1800. I have pushed it harder but don't see much reason to.

[MtGun44]

Measuring with a dial caliper is +/-.001" so your .457 might be .456 or .458, and you cannot
tell. You really need a .0001" rated micrometer to do bore slugging that will have any
accuracy.

Bill

[dubber123]

I think mine slugged either .458" or .459". I however size to .462" to help center the boolit better in the gigantic chamber mine has. A round loaded with a .462" boolit will still drop right to the rim with a thud if loaded through the port.

[brstevns]

Measuring with a dial caliper is +/-.001" so your .457 might be .456 or .458, and you cannot
tell. You really need a .0001" rated micrometer to do bore slugging that will have any
accuracy.

Bill

You are right, I did use a micrometer capable of going to .0000 That gave me the .4575 reading.

[monge]

we are measuring the grooves not the lands right?

[brstevns]

we are measuring the grooves not the lands right?

That is right (the Grooves)

[monge]

Just cast 100 lee340 from a mold I got from midway boolits are 461+-1/2 the lee sizer is 460 advertized at 457 they were backorder for a month I wonder if :killingpcthey changed the size?:holysheep

[brstevns]

Just cast 100 lee340 from a mold I got from midway boolits are 461+-1/2 the lee sizer is 460 advertized at 457 they were backorder for a month I wonder if :killingpcthey changed the size?:holysheep

I think you are lucky if you are getting 461 or better from the mold and also have a .460 sizer from them.
The lee mould I have drops a .457 and my sizer does size at .457. Both a little small for my 45/70. Had to beagle the mould and use a 459 H&I die for sizing.

[monge]

Just sized a couple today and they sized at .457 going to try to hone it out to .459?

[ebner glocken]

.458" on mine.

Ebner

[brstevns]

Just sized a couple today and they sized at .457 going to try to hone it out to .459?

Let easier to beagle it a few .000 and not have the worry of ruining the mould.
Did this (beagle) to a few of my moulds and this worked out great.