Slugged my 1894, now I'm confused as heck!

[Kirbot]

So, I've been browsing around the forum for about a week now...
I picked up a 1970s vintage Marlin 1894 with the micro-groove barrel a while back, and everything I've read says I'm probably going to need to cast .431 or larger bullets for it.

So, I just slugged the barrel to make sure, and... Something is screwy!

I used an aluminum shotgun cleaning rod and a brass hammer to tap a soft lead ball through. It pushed through the first 10"-12" on the muzzle end, rather stiffly, like I expected. But then it seemed to loosen way up and just knocked right through the rest of the way.

The big confusion came when I measured the ball with a pair of dial calipers.
.427 at the widest point.

Well that still doesn't sound right!
I though Marlins ran oversized?

Any input?
Should I just pick up a cheap .429 bullet mold and see what happens?

[Zim]

Was the tight spot under the rear sight? Some of these have restictions there. Might want to lap the tight spot.

[nagantguy]

Had a Rossi once did the same thing tight loose at chamber end slug fell.out with one tap. Marlins do have often times a constricted portion of barrel usually under front sight. Ruger single actions are also known fer this.

[Char-Gar]

Calipers do not give accurate readings for this purpose. Don't waste time slugging the barrel for it doesn't matter what size it is. Cast Bullets should fit the throat. Use a good gas check bullet sized .431 or larger and go shooting. Don't make this harder than it is. Disregard all the "slug the bore" stuff.

[Kirbot]

It felt like the whole front half of the barrel was the tight portion.
I double checked the slug with a mic, and it accurate was within about .001

I guess the tried and true .431 is still going to be the best option. I was just hoping I might be able to get away with a $20 Lee mold.
I can't find any .431 molds for less than about $100.

[fouronesix]

When slugging a bore, that relief felt after a few inches is common. After all, the slug has been completely sized by the bore and lands at that point. If on the other hand it gets tighter somewhere down the bore, assuming a clean and lubed bore, then that does indicate something like a true constriction. You might slug it again and re-measure both slugs, not that hard to do, to confirm the groove diameter, then go with it. No reason to doubt the measurements if due diligent in slugging and measuring. Developing an accurate and happy load is another question.

Or if you do suspect tighter at muzzle than at breech, remove the bolt (easy enough with the Marlin), then slug from the breech end toward the muzzle. You should be able to feel if it gets tighter toward the muzzle.

[Kirbot]

Or if you do suspect tighter at muzzle than at breech, remove the bolt (easy enough with the Marlin), then slug from the breech end toward the muzzle. You should be able to feel if it gets tighter toward the muzzle.

I'll try that in the morning.

I might just go ahead and try a cheap .429 mold. If it doesn't work out, I can always ebay it.
Holding out for a $100 .431 mold means waiting a lot longer until I can get some other expenses taken care of. Being unemployed has it's drawbacks....

[Nobade]

I have learned that whatever size boolit fits into a fired case is likely to give you the best results. Normally that's around .433" or so. If you have smaller boolits and want to see how bigger ones would shoot, paper patching works wonderfully in those rifles.

-Nobade

[facetious]

Get the Lee mould and if it casts to small thy are not that hard to lap to a bigger size.

[Pb2au]

Each rifle will dictate it's own needs.
In your case, the bore is coming in at .427". Char Gar, Nobade and many others are wise in their experience recommending a boolit to fit the throat. They have about a zillion boolits downrange to give them this conclusion.
The crux of the issue for you is to avoid buying a more expensive mold to try and fill up that throat. So, fire up the search function here on the forum and look for threads concerning 'beagling'. This is a technique in which you can try and enlarge the mold you have, this saving some dough.
Good luck, and welcome to the forum!

[salvadore]

I had a late eighties early nineties 94cl in 25/20 that refused to shoot with any kind of accuracy. I lapped the tight spots, front an rear sight sites, out of the barrel. Shiniest bore I've ever seen. Ended up with a shiny bore inaccurate rifle.

[fouronesix]

If I wanted to shoot a bullet with an elliptical cross section then I would "beagle" it and shoot it in a rifle that had an elliptical cross section bore.

There's no reason to not try and determine the groove and bore diameters of the bore of a rifle- any rifle. To say just "fill the throat" is an often parroted saying here. Throat dimensions vary greatly and does nothing to address the questions in the OP.

If I were slugging a 44 cal MG bore and came up with something like .427-.428" groove-- I would get a mold for an original style 44 cal bullet that hopefully dropped at .428-429" at about 180-200 gr and use a fairly soft alloy of BHN 9-12, lube with a fairly soft lube, load to low-moderate reasonable pressure and velocity and see how it worked. If it didn't work to my satisfaction, the most I'd be out would be maybe a $20 Lee mold.

Dang, that "fill the throat" cliché has had me bugged all these years- especially when trying to find the throat in a muzzleloader to get it to shoot well. :veryconfu

[fecmech]

I've read says I'm probably going to need to cast .431 or larger bullets for it.
Your rifle maybe illiterate or maybe just didn't get the memo on bullet size. I have been called "cheap" in the past (I prefer the term "value conscious") so I would buy the Lee mold and try it. As far as elliptical bullets and bores I have had excellent results in the past with "Beagled" bullets. Ya never know till you try.

[Kirbot]

Well I'm still a bit confused. :veryconfu
But maybe a bit less so.


I guess now my choice is... do I go with the 200 grain .429 round nose that will feed but MIGHT be a little small....
Or... The 240 grain .430 SWC that MIGHT not feed reliably.

[Nobade]

There's no reason to not try and determine the groove and bore diameters of the bore of a rifle- any rifle. To say just "fill the throat" is an often parroted saying here. Throat dimensions vary greatly and does nothing to address the questions in the OP.

If I were slugging a 44 cal MG bore and came up with something like .427-.428" groove-- I would get a mold for an original style 44 cal bullet that hopefully dropped at .428-429" at about 180-200 gr and use a fairly soft alloy of BHN 9-12, lube with a fairly soft lube, load to low-moderate reasonable pressure and velocity and see how it worked. If it didn't work to my satisfaction, the most I'd be out would be maybe a $20 Lee mold.

Dang, that "fill the throat" cliché has had me bugged all these years- especially when trying to find the throat in a muzzleloader to get it to shoot well. :veryconfu


Yep, I hear you. Those muzzleloader throats are pretty tough to measure! However, in this case it is appropriate because of the chamber design. The chamber has no step at the end of the cartridge, just a cone tapering to the bore. So no matter how big a boolit you put in a case, it is not going to be big enough to fill the throat. So you do the best you can, which is put one in that will just barely enter a fired case. The goal is to get that puppy launched straight into the bore without tipping or gas cutting, and the bigger it is the shorter distance it has to fly unsupported before it gets a seal. So, it's way bigger than the barrel's groove diameter. Normally you wouldn't want that, since normally it wouldn't fit in the throat. But these pistol caliber lever guns aren't normal. They have chambers in them that are perfect for shooting with black powder and soft lead, since the boolit will slug up and seal as it is leaving the case. And there's no step to catch fouling and make the next round hard to chamber. But if we want to be modern and shoot hard boolits and smokeless powder, we need to make some allowances for the chamber design. The main reason these rifles shoot poorly with cast but OK with jacketed is that brief moment when the boolit has been released by the case but isn't into the bore yet. It tips a bit, and at the same time gas blows past it and torches off some lead. Of course they won't shoot. Now I have proven it to myself time and again - if you must use smokeless powder, make the boolits as big as you can manage and it will shoot as well as it's going to with that particular combination. But if you load them with black powder and the correct boolit, they almost always outshoot smokeless loads. Unless you paper patch for it, which means you're going to have ammo that is far, far too long to work through the action. But the power and accuracy are simply astounding. My own Marlin 1894 44mag, made in about 1973, is a awful bore leading mess with any sort of .430" standard cast boolits. It will hold maybe 6 MOA on a good day. But when I load it with black powder, it holds 1.5 - 2 MOA at 100 yds, about the limit of what I can see with the factory barrel sights. It also never leads the bore, and doesn't throw wild fliers. When I paper patch for it, I can throw a RCBS 240gr. SIL boolit at 1950 fps using a full case of IMR4227 and hold that same 1.5 - 2 MOA out to 200 yds. (with about .100" of boolit in the case.) There is no way it is going to do that with normal cast boolit loads. And it has a .428" groove diameter, but I feed it .433" boolits since anything less just plain doesn't work.

-Nobade

[salvadore]

My second 94 CL is a 32/20 that I believe Marlin made in 2004 or so. Unlike the earlier 25/20 this shooter is a tack driver with everything I've fed it so far. All of my molds cast greater than .314 and because my 32/20 revolver chambers took a .314 cast bullet I sized to .314 for the rifle. My first range session using a GC cast bullets and a 1680 load suggested by Paco Kelly @100yds put ten rounds into 2.25" with seven going into 1.25". My jacketed loads are almost as accurate. I also worked up a PB load using 3.7grs of 231 that goes into 3" at the same distance. I'm guessing I'm getting this accuracy because my groove diameter is .312 or less as per the Duke City gunsmith above. I guess I'll have to cast the PB bullet softer and try it with BP. Egad, another project.

[Nobade]

Salvadore,
32-20 is different. It doesn't have a "funnel" throat like 357,41,44, and 45. In fact it doesn't have much throat at all. That's why if you seat a .314" boolit much outside the case it will be hard to close the action and you end up with rifling marks on the boolit. And as you have found, they shoot extremely well. I also have a 1894CL, probably the same vintage as yours. At least I think it's from that last run they did. It shoots great with smokeless and black, and any sane load seems to work just fine. Big difference from those pistol caliber chambers!

-Nobade

[salvadore]

http://i299.photobucket.com/albums/mm297/farcla/DSCN0694_zps129c3008.jpg (http://s299.photobucket.com/user/farcla/media/DSCN0694_zps129c3008.jpg.html)

So, I tried a lovern, a Lee 8mm and a ranch dog mold designed for the 32 wsp and all would engrave on the rifling making chambering difficult. They all shot OK, but when I got an accurate 32-160G that had a short front band with the nose tapering immediately in front allowing chambering without hitting the rifling. My powder charge was the same with all bullets, but the Accurate bullet was the most...accurate. Why wouldn't the engraved loads shoot as well as the one that had to make the jump. I know this is off topic, but enquiring minds.....

[Fergie]

You could always use a set of pin gauges down the bore to see what kind of restriction you have. Granted, you may be going down the rabbit hole, but it would give you the best explanation for the restriction(or lack there of).

[Wind]

Hey there Kirbot -- Bore slugging can actually reveal quite a bit of information about the inside of your barrel. From your description of the muzzle end interference, I'd be very inclined to think you have a very fouled bore. The previous owner may have run a combination of copper and cast projectiles and this can create quite a mess.

Look at your first slug. Is it kinda hazy and fuzzy like the one on the right in this picture?

115120

That would indicate a filthy bore. It would also indicate a damaged bore, but I think the location would suggest just dirty. I'm a big fan of Wipe-Out foaming bore cleaner for the copper fouling, and Kleen-Bore Lead-Away patches for lead and powder fouling. Both need to be run with extremely tight jags.

Then re-slug your bore. The slug should be looking more like the little guy on the left. A micrometer with provide more accurate dimensions than a dial indicator. Might consider investing in one.

Hope this helps. Best regards. Wind