New Here but need some help with a marlin 336 in 30-30 for cast

[slips73]

I recently aquired a 1980's i believe, marlin 336 in 30-30. I am Looking for info about casting for micro-groove rifling this was something i didn't think about before but makes complete sense I have heard that using about .002 larger makes for some very accurate rounds. I have used huntersupply bullets from midwayusa for .357 and saw they have 30 cal 165 grain flat points @.311 diameter. Would this work for a marlin 336 with microgroove rifling? Is there any aftermarket barrel makers for ballard/deep cut rifling because i mainly shoot just lead bullets. Can anyone point me to a mold that would cast this the lee ones seem to cast @ .309 which is good for normal ballard type rifling but would be too small I assume for the shallower rifling of the 336 microgroove. Anyone have any tips for me aside from selling it?

thanks, Adam


edit: I have heard I need to slug the bore to figure out the diameter, is this done easily or does it require a gunsmith?


edit: http://www.midwayusa.com/product/204...lead-flat-nose

these are the .311 diameter bullets ^^^^

[Keyston44]

I couldn't get .311 to chamber in my 336. I size to .310. You don't need a new barrel, Microgroove shoots lead just fine. Slug your bore with lead slip sinkers from a fishing store if you need to slug your barrel.

Key

[Pb2au]

First off, welcome to the forum.
I also have the same rifle and have enjoyed good success in shooting cast through it.
1) You can absolutely slug it yourself. A gunsmith is not needed to do so. You will need a pure lead slug to drive through the barrel. In my case, I have some 32 caliber round ball that fit the bill. I lubed the barrel with a patch that was coated with Lee's case sizing lube, but even a light coat of gun lube will work. Also I lubed the ball.
2) Starting at the muzzle, I place the ball on it, then tapped it into the bore to start it using a hard rubber faced mallet. I used the mallet to avoid damaging the muzzle.
3) I have some 1/4 brass rod I bought at the hardware store that cut into 4" sections. Using the same mallet, I used the first piece of rod and started tapping it down the bore. When you run out of rod, grab the next section and use it to start tapping on the previous rod which is still in the bore. In effect, you are just stacking the rods up. What I feel that is important to avoid is using wood dowels. There is a risk of breaking one in the bore and wedging it against the ball. At that point you will have a real project on your hands.
4) Once you have the ball all the way through the bore, retrieve it, wipe it down and get your micrometer out and measure away.

In my case, the bore slugged at 0.3075". I ended up sizing the bullet to 0.309" and gave it a shot. In my case, it proved to be a good fit with good accuracy and no leading. From what I have read here, going at least 0.001" over is a place to start, with some folks here reporting that they arrived to 0.002"-0.003" over bore size to achieve acceptable results. Be sure to search the forums here for more info!!!
I ended up using Lee's 170 grain flat point mold with good results. It drops the boolit with my alloy at just at 0.0310".
I hope this helps!

[slips73]

Awesome, thanks guys, was recommended over here by BCUSA and looks like it worked.


Also if anyone can answer this, do you know if 38-55 conversions (my favorite round to reload for) entitle any other changes to the rifle? Will 38-55 cycle through the tube, lifter, carrier dog etc?

[Hyphenated]

You can ship your Marlin to Jes Rebore for the conversion. No alterations have to be done to it other than a rebore. Money well spent. He has done (2) 38-55's for me and a 35/30-30.

[Iowa Fox]

Don't listen to the rumors about micro groove Marlins. Size them as fat as will chamber, good lube, the right powder, and they will out perform Ballard rifling.

[slips73]

Ok thanks, yah Jes was the one I was looking at. Does he do Ballard type rifling that's cut? Or is it button rifled?

[slips73]

Don't listen to the rumors about micro groove Marlins. Size them as fat as will chamber, good lube, the right powder, and they will out perform Ballard rifling.

What about with soft lead? I have heard of the bullet ''stripping?"

[RickinTN]

Many folks on this forum recommend "fat and hard" for bullets for microgroove. This approach has proven correct for my several 30-30 rifles. Mine will take a bullet of .311. I tried the Hunters' Supply bullet you mention and my results were OK, not spectacular, but OK. Achieving good accuracy with a plain based bullet seems to be an art and a science to me. A gas checked bullet will usually give quicker satisfaction.
Good Luck,
Rick

[Hyphenated]

Ok thanks, yah Jes was the one I was looking at. Does he do Ballard type rifling that's cut? Or is it button rifled?

That's a good question...I never asked I just assumed Ballard. Either way they shoot fine with cast boolits and the price is very reasonable.

[Gunnut 45/454]

My Marlin 336 30-30 shoots the Lee 113, 150 and 170 gr GC's just fine sized .309" ! Just as accurate with cast as Jwods! I shot them as fast as the Jwods too! Water cooled, WW alloy.

[wrench man]

JES does cut BALLARD rifling, you can get 3, 4 or 5 grove, I do believe?, I had him do my 30A into a 356 Winchester, it's more $ for the 5 grove, I did opt for the 5 grove on mine.

[slips73]

I have heard some stuff over on marlin owners about the JES rebored in 38-55 not being a true 38-55 in the sense it is really chambered/reamed for .375-.377 diameter and .375 win and long brass will not fit. While the .38-55 is a true .379-.380. Diameter, does anyone have any info on this?

[btroj]

Tighter is better. Some of the chambers on the rifles don't allow a big enough bullet.
As for "not a real 38-55" I say what? So a Marlin 44 may rifle with a .432 bore isn't a real 44 mag? Ruger might use Sam barrel on 44 mag and 44-40 revolvers yet they traditionally used different bore diameters, which one is "fake"?

The CHAMBER determines the cartridge, not the bore size. That has to be the dumbest thing I have ever heard.

[slips73]

Tighter is better. Some of the chambers on the rifles don't allow a big enough bullet.
As for "not a real 38-55" I say what? So a Marlin 44 may rifle with a .432 bore isn't a real 44 mag? Ruger might use Sam barrel on 44 mag and 44-40 revolvers yet they traditionally used different bore diameters, which one is "fake"?

The CHAMBER determines the cartridge, not the bore size. That has to be the dumbest thing I have ever heard.


I meant it in the fact that it is actually reamed for a .375 win and that in a true sense it is more of a hybrid of the two as i have also read that the longer 38-55 brass does not fit


And as for tighter being better I understand that but if it is TOO small than bullets cast at .380 diameter would be too big and cause a pressure spike or not even chamber at all which would be the case for some factory 38-55 with cast bullets. that is my concern

[TXGunNut]

Welcome to the forum, slips73. Seem to recall some threads about the thinking behind how JES bores for the 38-55. I believe Ranch Dog had a Rossi done several months back. There's nothing wrong with the .375W, could have some advantages over the 38-55. Could also visit the JES site, great source of info.

[btroj]

I think it would be afar easier to find suitable moulds to cast a .378 bullet than one goin.382.

As for the 30-30, I find that a big enough bullet makes the difference. i use a .311 in mine and it doesn't lead and shoots very well.

[slips73]

Ok cool thanks guys after a bit of research I found many offerings in .378-.379 bullets as well as a lyman mold. Apparently the original 38-55 in lever actions was a .375-.377 bullet and there were many variances so it seems I stand corrected.

[slips73]

And I think I will try some .311 bullets in my rifle before I decide to rebore and see how accurate they are

[TXGunNut]

I'm looking for a similar rifle, actually. If it doesn't work out as a 30-30 I may go the JES rebore route. Traded a 336 off recently that I couldn't get to shoot, just realized it would have been a good candidate for a trip to JES. Oh, well. I think I'd rather have a good 30-30.

[GREENCOUNTYPETE]

strait clip on wheel weight with 2% tin sized .310 or .311 add a gas check to a fat heavy boolit and don't try for max speed you should find where you get accuracy

i went with a .311 push thru sizer , it crimps on the gas checks but barely touches the boolit that drops from the mold at .310

I went cheap with the Lee c309-170rf it works , haven't tried it on game yet but some day

i have a load with pistol powder that gets an un gas checked boolit to around 1300fps and i can ring the steel plate with that at 100 yards all day long

I think it is all about filling the bore and not trying to push to fast and compensate for that with heavy boolits that will comfortably go a reasonable speed

size does matter