The New Marlin's Tight Barrel

[ChristopherO]

I recently acquired a 1895 Cowboy Action in 45/70. After lapping the barrel to smooth it up I ran a slug down the barrel. My micrometer is packed away so I measured it with a friend's digital caliper and was surprised when it read .4575. Hmmm, I keep reading Marlin bores their rifles a bit over instead of under. I'm wonder if the new Marlins are being built with tighter bores than earlier guns. Anyone else experiencing this?
Been expecting to need a .459 or .460 mold but that may not be the case, now. Guess those Lee molds may not be too small after all.
Any experienced input is welcome.

[W.R.Buchanan]

I'd go back and check that number with a micrometer.

A digital caliper is not accurate enough to get repeatable measurements down to .0005 and especially from one you don't know the calibration of.

No matter what anyone says.

Randy

[runfiverun]

you bought the cowboy not the regular
they put decent barrels on the cowboy ones [with rifling] and charge you accordingly.

[dubber123]

The barrel on my 1895 Cowboy looked like a set of old railroad tracks. A good firelapping fixed that. I don't know what the bore runs actually, but I do know the huge chamber swallows rounds loaded with .462" boolits with ease, and shots them pretty well.

[scottfire1957]

Load something and shoot it. Report back, then get better answers. Shoot factory or handloads, then ask.

[ChristopherO]

The micrometer says the same thing as the calipers, .4575 runs average. The widest point did not reach .458.
Suppose this is not a sloppy bore. I may slug it once more to be sure but am pretty confident this is accurate.

Dubber123, I understand your railroad comment. Running the lap rod back and forth allowed me to feel how rough this new barrel was fresh from the factory. I have high hopes for this rifle now, though.

[scottfire1957]

Have you fired any rounds in this rifle, or are you worrying yourself over loading a round yet to be fired?

Shoot a factory standard load, see what it does, and go from there.

[ChristopherO]

Yep, waste of time replying to this thread.

[TXGunNut]

Yep, waste of time replying to this thread.

I disagree. Looking forward to the range report.

[Gtek]

New Haven, North Haven, Poo Haven (Remlin), vintage? You may very well have a .456" due to the bean counters told them not to replace button until .455".
On the upside, look at all the possible molds and if real may be a blessing after a little work.

[scottfire1957]

Yep, waste of time replying to this thread.

Far as I can tell, you've put nothing down the barrel. So, yeah.

DO SOMETHING. Tell us what is good and/or bad.

[waksupi]

Yep, waste of time replying to this thread.

Must be a post count builder.

[scottfire1957]

Yep, waste of time replying to this thread.

I HAVE to ask. You've been a member of this site since '06. What are you wanting to know?

[ChristopherO]

Now that I am on a keypad instead of a smart phone I'll give an answer. TxGunNut, thanks. When I choose to take the rifle to the farm and shoot I'll try to keep you in the loop.
As far as being a member since 2006, yes, that is about the time I took up traditional archery and not too long afterwards crafting Indian self and laminated recurve bows. A fantastic pursuit that eclipsed the rifles in that period. I'm not so immature as to need to up my post count. I've wasted enough time on the internet over the years for that nonsense.

Who here enjoys someone they don't know telling them what they ought to do in a condescending manner? Any raised hands out there? I didn't think so. I'll shoot my rifle when I am ready to shoot my rifle with out the need for a stranger insisting that I shoot my rifle. When I was a younger man without any patience I would instantly purchase ammo and shoot a new to me rifle as fast as I could. These days the getting there is much more satisfying than just wasting bullets or boolets to prove they will travel down the barrel. It's been many years since I've purchased a new rifle because the ones I had held my attention. Now that Ohio allows straight walled cartridges to be used for deer hunting an 45/70 sounded like a fun new acquisition to pursue. As I did with new rifles in the past the first task is/was to slick up the action, lap the barrel, give it a trigger job, fit the buttstock to fit, etc., before even chambering a round. I've got the time and inclination to wait. It allows me to get to know my rifle better and how it functions. Then, when I am ready, I'll go fire it at target for accuracy off the bench.
This being a cast boolit forum I expected those participating to have read the stickies posted that explain these procedures and how they assist in getting the best out of their firearm. Simply firing a bullet down range does nothing to interest me or any benefit the rifle, since I hand lap anyway. I'll stick to the proven steps for accuracy, of which one of those is slugging the bore to see what size mold would be the best fit. Again, a little research on this site shows that mold size to bore size is imperative to wringing out the most accuracy. Originally stated above having read that Marlin makes oversized bores I was intrigued to see this particular cowboy action barrel was not in that camp. With this said my comment above " I'm wondering if the new Marlins are being built with tighter bores than earlier guns." is also my question. I figured those educated in Marlin, mainly the Remlin rifles may have experienced this, as well. If not, fine. If my posts aren't to your liking then kindly pass them by. Live is too short to belittle and make snide comments. If you have productive comments I look forward to discussing them with you.
Cheers

[Yodogsandman]

+1 CriistopherO!

[murf205]

ChristopherO, it's amazing what somebody will type on a keyboard that they would never say to you FACE TO FACE. Good luck on your 45/70 Cowboy, I love mine.

[W.R.Buchanan]

I have one too,,, Marlin's tolerance on .45-70 barrels is .458 +/- .002,,, so your barrel is right in there.

Boolits with noses like the RCBS .45-300 and .45-405 and .45-500 will work and feed just fine. There are plenty of moulds out there that have nose profiles like this and pretty much all of them will deliver every bit of accuracy that is needed or possible from a gun like this.

Good luck on your quest.

Randy

[scottfire1957]

I had no intention to sound condescending.

I my humble opinion, you simply failed to set a baseline of accuracy for your rifle before you started changing things. From your original post, I took you lapped the bore before you fired the rifle, therefore, no baseline data to see followup improvements or lessening of improvements with each change.

As I, and I'm sure you've read here and other places, you change one thing at a time in the search for improvement. You're rifle may have been sub MOA before the bore lapping.

If I misinterperated your post, I apologize. But I always shoot first, and change AS NEEDED.

It would be a shame that you took a rifle that shot perfectly as wanted, and ended up with a rifle you couldn't wait to get rid of.

I'll leave it to you. Good luck.

[murf205]

I have one too,,, Marlin's tolerance on .45-70 barrels is .458 +/- .002,,, so your barrel is right in there.

Boolits with noses like the RCBS .45-300 and .45-405 and .45-500 will work and feed just fine. There are plenty of moulds out there that have nose profiles like this and pretty much all of them will deliver every bit of accuracy that is needed or possible from a gun like this.

Good luck on your quest.

Randy

ChristopherO, I have a 405C mold from Accurate Molds that shoots really well in my Marlin CB. Mine slugs right on at .458 and .459 boolits are just right for mine. Tom at Accurate does beautiful work and when you find your diameter, a custom mold is a really nice addition to your set up. I have never tried any boolits @ .460 because the rifle shoots so good with .459's. Again, good luck and remember, this site is full of good advise from some of the best people in the business. I would be hard pressed to find the kind of knowledge some of these guys have anywhere else.
Murf

[dondiego]

I had no intention to sound condescending.

I my humble opinion, you simply failed to set a baseline of accuracy for your rifle before you started changing things. From your original post, I took you lapped the bore before you fired the rifle, therefore, no baseline data to see followup improvements or lessening of improvements with each change.




As I, and I'm sure you've read here and other places, you change one thing at a time in the search for improvement. You're rifle may have been sub MOA before the bore lapping.

If I misinterperated your post, I apologize. But I always shoot first, and change AS NEEDED.

It would be a shame that you took a rifle that shot perfectly as wanted, and ended up with a rifle you couldn't wait to get rid of.

I'll leave it to you. Good luck.

I agree here. You need to shoot it to determine what it is going to do.