Marlin internal barrel dimension

[Marlin Junky]

Can anyone provide the internal barrel dimensions for Marlin 45-70's? Can I assume that all Marlin models chambered for the 45-70 cartridge have barrels that differ only in length and outside contour?

Thanks,
MJ

[454PB]

I don't know what all you want, but I slugged my new Marlin GS 45/70 with Ballard rifling, and it was .457".

I size to .4585".

[Marlin Junky]

I don't know what all you want, but I slugged my new Marlin GS 45/70 with Ballard rifling, and it was .457".

I size to .4585".

.457" makes the grade.

Thank you,
MJ

[45r]

When I looked at 2 GG's,one blue and the other SS the grooves looked shallow especially the SS one.Does anybody know how deep the rifling is.They were both 2007 model year mfg.The rifling didn't look as deep as my 2001 45 colt CB.

[BABore]

I've slugged a few 450 Marlins and 45/70's of recent manufacturer. All had the new "Ballard" rifling. All of them ran 0.4582 to 0.4587. A slug pounded completely through the bbl will commonly be smaller than one pounded flush with the muzzle, then back out. I do both slugs on purpose. Marlins are notorious for bbl constrictions at the dovetails, rollmarking, and bbl threads. Marlin ka-chunks the dovetails in with a punch press....after they are rifled. All my guns have been firelapped to remove the constrictions and leave a tapered bore. All of the so called "Ballard" rifled bbls I've measure have had 0.0030 to 0.0035 deep grooves. This is the same as the older Microgroove bbls. In all cases the chambers have allowed up to 0.462 diameter boolits. For a Marlin, I personally wouldn't touch a mold that wouldn't drop a boolit of at leat 0.460+.

[StarMetal]

Babore hit the nail on the head. He and I talked about this exact issue before and I said I'll bet it's not cut rifling, I'll bet you they button rifle it. Here's what it says on their ad:
The Classic Model 1895

The tried and true configuration of this famous 45/70 rifle. It features a 22" barrel with deep-cut Ballard-type rifling and an American black walnut pistol grip stock with cut checkering and swivel studs.




Deep huh???


Joe

[NHlever]

There was a period quite a number of years ago when Marlin microgroove was only .0015 deep. I've measured Marlin 30-30's that had a bore of .305, and a groove depth of .308. The most recent microgroove I measured had a bore of .3017, and a groove dia. of .309. I had an older 336A in 30-30 that would shoot 170 gr. j word bullets very well indeed, but would tumble Speer 100 gr plinkers, and other short bullets so badly that I couldn't hit a 25 yard target. That confused me for a bit until I recovered a few bullets in the melting snow. They miked .305! Hmm, so I slugged the bore, and got my answer. The slug tapped in evenly for about 4", and then dropped of it's own accord about 10", and then was tapped the rest of the way through the barrel. There was a bulge in that barrel just large enough that the long bearing surface bullets would maintain marginal contact with the rifling, but short bullets would not, and when they re-engaged the rifling they were "out of time". It was pretty interesting chasing that one down. Marlin rebarreled the rifle for me though it was old at the time, and it shot well after that.

[felix]

My 41 Maggie Marlin has 0.003 lands, so what you say could be common. Finally, cast shooters have been noticed. ... felix

Also, that kink was what I mentioned in the other thread about the honesty of the cutter/forger/former. BR barrels shoot, or they don't for this reason: a rifling hiccup, however small and from whatever reason. ... felix

[Marlin Junky]

For a Marlin, I personally wouldn't touch a mold that wouldn't drop a boolit of at leat 0.460+.

I've never casted for anything in 45 caliber. Is it realistic to assume current RCBS, SAECO and Lyman molds will drop bullets this fat?

I'm starting to wonder whether I should be checking into M92 clones from Cimarron in .44 Magnum. Do they really have .006" deep grooves (.417"/.429")? Assuming quality barrels and close tolerances, I suppose the chance of getting 300+ grain PB's to shoot acurately to 200 yards or so should be within the realm of reality.

MJ

[pdawg_shooter]

I have 7 45cal moulds. If you want .460 you better figure on lapping or Begaling them

[45 2.1]

I have 7 45cal moulds. If you want .460 you better figure on lapping or Begaling them

The situation of being able to obtain correct size molds for the Marlins and other 45 caliber rifles will end shortly.

[JesterGrin_1]

Okay 45 2.1 you threw that out there lol. Now what???????????

[45 2.1]

Okay 45 2.1 you threw that out there lol. Now what???????????

The fellow will announce himself within a few weeks I suspect.

[Tom Myers]

Can anyone provide the internal barrel dimensions for Marlin 45-70's? Can I assume that all Marlin models chambered for the 45-70 cartridge have barrels that differ only in length and outside contour?

Thanks,
MJ


These are values from a chamber cast that I evaluated from a Marlin 1895 MR and stored in my chamber database.

I only have this one sample so it does not indicate that all marlin chambers are the same.

Hope this helps.

Tom Myers

http://www.tmtpages.com/LinkSkyImages/ranch_dog/ranch_dog_45-70_Govt/45-70_Govt._RD_1895_MR~Barrel-40%25.gif

http://www.tmtpages.com/LinkSkyImages/ranch_dog/ranch_dog_45-70_Govt/45-70_Govt._RD_1895_MR~Barrel-40%25_45-70_Govt._R-P_Rot_Cutaway_Crimp-35%25_RANCH_DOG'S_TLC460-425-RF_Rot.gif

[ghh3rd]

The fellow will announce himself within a few weeks I suspect.
What ever transpired? Who is the mystery person?

[JesterGrin_1]

What ever transpired? Who is the mystery person?

What it means is that Ranch Dog Outdoors is now back open. :)

[arcticbreeze]

What ever transpired? Who is the mystery person?


What it means is that Ranch Dog Outdoors is now back open. :)

I don't know if you guys realize this thread is over a year old. I betting he was referring to NOE.

[leftiye]

Probably BaBore.

[JesterGrin_1]

All three good places to get a mold. But I know the NOE molds for the Marlin are patterned after the Ranch Dog designs. The only difference is that Ranch Dog designs are Micro Groove and NOE is not.

BaBore has his own designs. :)

[jh45gun]

I've never casted for anything in 45 caliber. Is it realistic to assume current RCBS, SAECO and Lyman molds will drop bullets this fat?

I'm starting to wonder whether I should be checking into M92 clones from Cimarron in .44 Magnum. Do they really have .006" deep grooves (.417"/.429")? Assuming quality barrels and close tolerances, I suppose the chance of getting 300+ grain PB's to shoot acurately to 200 yards or so should be within the realm of reality.

MJ

Get the Lee .459 Hollow Base 405 grain bullet it shoots great out of my Marlin Guide gun in 4570 and I size it to .459.

[Jon K]

All three good places to get a mold. But I know the NOE molds for the Marlin are patterned after the Ranch Dog designs. The only difference is that Ranch Dog designs are Micro Groove and NOE is not.

BaBore has his own designs. :)

??? Care to expand on this?

Jon

[Indio]

I recently slugged my Marlin 45-70 micro groove barrel and it a .459. I'm in the process of making up a load of test rounds, .461 cast bullets loaded into new remington cases easily drop into the chamber.

[9.3X62AL]

FWIW, my Ruger #1 in 45-70 has a .459" groove diameter and 8-groove form. Lands will fit a .449" pin gauge, .450" is a no-go. I take this to equate to grooves being .005" deep. The leade in my rifle is quite short and very abrupt.

Most of the mass-produced 45 caliber rifle moulds drop boolits at .457" or thereabouts. That might have been all right 100+ years ago using binary alloys and black powder, but THESE DAYS the hobbyists use tri-metal alloys--smokeless powders--and rifles are cut wide. GET WITH THE PROGRAM, LYMAN AND RCBS!

On the other hand, the RCBS 300 FNGC does shoot well in my 45 Colt BisHawk--and the Lee 405 grainer opened nicely to .460" via lapping. There won't be another mass-produced 45 caliber rifle mould crossing my doorstep.