I looked at a older marlin lever action in .45-70 on the 2nd hand rack at our local gun shop. The guy told me it was about 10+ old and it didn't have the new "micro bore"? It's in excellent condition and the price is reasonable.

In the real world, how important is this?

Thank you.

I think when they first came out they had cut rifling, then they went to the Micro-groove rifling and then back to what they now call "Ballard" rifling. I don't think it makes any difference at all if you're using jacketed bullets. If you want to shoot cast it might make a difference, but you can do certain things to mitigate the problems that supposedly accrue to the Micro-groove barrels. Also, based on my experience, those problems are grossly overstated and most might be traced to other errors on the part of the operator such as undersized bullets...

Short answer, get the rifle.

[ 10-19-2003, 03:37: Message edited by: Hobie ]

There is nothing wrong with the Micro-groove barrel as long as you use jacketed bullets. My old one preferred 405 gr bullets with 1-hole 5-shot groups at 100 yds. With the 350 gr bullets all I could get was 2-2 1/2 " at 100 yds. If you are after accurate cast bullet groups, it's a 50-50 proposition. The only cast load that was somewhat accurate was a gas checked 550 gr at 1530 f/s which only gave 2 1/2" to 3 1/2" five shot groups at 100 yds. This is obviously a hot load as this will kick like hell. This has since been converted to 475 JDJ and is still shooting OK.

I must have lucked out because my Micro Grooved 45-70 shoots both jacketed and cast bullets very well. In fact the dam thing shoots both the downloaded cast bullets and the full power jacketed bullets to the same POI at 25 and 100 yards. I still can't quite figure out why but I'm more than happy about it. The cast bullets are.459.
Take care,
Dave

Hobie - THANK YOU!

100yrd 1 hole groups??? Heck boys I'm a tradional bowhunter, I don't even nock an arrow when game is that far out. At a 100yrds I'm still calling or rattling.

Well, Dude, you don't have to crawl that far anymore as the 45-70 with proper loads will be effective up to 250 yds if you know your drop and hold over accordingly. But, the point of the exercise is to get as close as you can, isn't it.

I have both a marlin GG and a Marlin 1895SS,,,,,I took the SS out and had it shorten too 18.5" and recrowned and this is what I shoot my 350 grain jacketed bullets in , I save my GG for the 350 hardcast with the same load of reloader 7.

The idea that a micro groove bbl will not shoot cast bullets is a myth. Yes micro groove barrels might be a little more picky about what they like they you can obtain good cast bullet accuracy from one. You just might have to experiment a little to find a load it likes.

A new 45-70 can be purchased in my neck of the woods for $410. If the price is less than $350 I would get it in a heart beat. If not I might pass - Some people are guilty of red lining their 45-70's. Gun is probably ok - but I will take a new one over a used on for close to the same price.

As far as the rifling - Sounds like the 45-70 you are talking about may not have the micro groove. I would rather have the cut rifling for 45-70, but I have marlins with both and get good accuracy from both.

Keep us posted

David

A microgroove barrel should say so on the barrel. The ballard rifling will have two asterisk on either side of the description of the firearm on one side of the barrel. Not sure which side. Accuracy out of my new Marlin with the ballard rifling is incredible. It shames a couple of my Varmint guns. Also shoots many types of bullets accurately.

The first 2000 or so 45-70 Marlin 1895s in 1972 had conventional rifling. They then switched to Micro Groove, and has been noted, recently they switched back again mainly because of complaints from cast fullet shooters. The so-called Ballard rifling is conventional rifling, nothing special about it.

There is a Marlin firearms forum on which you can probably get serial numbers and all that detail stuff.