Home Forums Hunting & Shooting Custom Rifles & Wildcats Marlin 336 30-30 Ackley Improved...

Recently aquired a nice used Marlin 336 in 30-30 and decided to rechamber it to 30-30 Ackley Improved. I'd done this previously on a Win 94 that I was rebarreling and it worked out quite well for that, so I decided to do one more since I already had the reamer.

Here's the rifle:



I had to fabricate a shop expedient reamer extension as the 3/8" extender that I had wouldn't fit into the rear of the Marlin's receiver. Used a section of 1/2" copper tubing for this and it worked just fine.

The nice thing about the Marlins is that you can leave the barrel on the receiver when rechambering.

The whole operation was a success and I've already had it to the range for initial tests.

However, I had to cut that short as I discovered that the loads that were just fine in my Winchester were a bit too hot in the Marlin... since I used the same reamer, I can only figure the difference lies between the microgroove rifling and the ballard style of the replacement barrel that I used for the Winchester.

So, loaded up some more test rounds at reduced levels to try again. I am aiming for 2500 fps from the 20" Marlin. The 26" Winchester easily hits 2600 fps with 150 grain Speer bullets.

I'll post the range report after I get that done - hopefully this weekend.

After the rechamber, I decided to refinish the stock - removing the white line spacers and using spirit stain and BLO to finish. Finished up by installing a Leupold one piece base and rings to hold the 2x7 Nikon Prostaff in low mount. Just about perfect for this rifle/cartridge I figure.

ETA - if the pic of the rifle isn't showing - ist because the board where its posted is going through maintenence - so please be patient, it'll show up later. Thanks.

I've heard that the 30-30AI is a fairly impressive improvement in velocity, sounds cool! Hadn't thought about the fact that you can pull the bolt out of the back and leave the barrel on for rechambering.

Yep, you get an honest 250 fps improvement over standard 30-30 rounds.

Basically, a 307 Winchester.

This and the 25-35 Win AI are the two very best AI's as far as actual improvement IMHO.

I have been wanting to do a 30/30 AI for a long time. If you are ever of a mind to trade off one of yours let me know. It would be a great compliment to my model 71 Deluxe in 348AI. Thanks for the report, keep us updated!

wouldnt mind adding those AI's to my cartridge collection. if ya got some spare dummy rounds...

Safariman - trust me when I tell you that the chamber reaming work is very simple, straight forward and uncomplicated. The finishing reamers are $100 and under (Midway) and are almost foolproof to use. I used the "standard" 40 degree shoulder reamer and then got Lee's die set to match.

You just remove the bolt, put the rifle in a padded vice vertically and insert the reamer down through the back of the reciever - use lots of cutting oil, stop frequently and flush with brake cleaner (what I use) and take it down until the lip of the reamer hits the back of the chamber - you're done. The reamer has a pilot that guides you, so very easy.

This is a home gunsmithing job that just about anybody can do.

Just like your 348, you fireform cases by shooting standard 30-30 rounds, which gives your cases a perfect fit to the chamber - I then neck size mine.

Ironeagle - PM sent. Oh - and my cases are just standard 30-30 cases that I've fireformed, so the heads will just say 30-30...

One more thing - for anybody wanting a 308 Marlin, you can save a lot of $$ by going this route ($300 for used 336 and $100 for reamer) and you can sell the reamer when you're done with it - they last for quite a few jobs. And now you can get the gummy bullets if that's your thing and just about match the 308 Marlin's perormance with the 30-30AI. Plus you can still shoot 30-30 Win in a pinch.

OK, managed to get to the range today. The star of the test loads was 38 grains of W748 under a 150 grain Speer fn. Gave 1.5" and 2" groups at 100 yards. I didn't bring the chronograph so I don't know what the speed is, but I'll check that next range session. 40 grains gave almost 2600 fps and showed pressure signs - so, I'm hopeful that the 38 grain load is hovering around 2500. Based on past tests, that would make sense.

Well gunsnet is back up - that's where I keep my pics - thought I might show what the rifle looks like now - replaced the buttstock as it sanded too much off of the original when I refinished it...



I think it looks much better and I like the clean pistol grip too.

And here's the tooling needed to rechamber (finishing reamer, die handle and my homemade extender...):

OSOK,

Is your replaced stock an original Marlin stock or an afermarket? It looks good. Thanks...

Thanks, it's an aftermarket purchased from Brownells - unfinished buttstock. Fit was good - just had to tweek the inletting a little bit.

OSOK,

Just acquired a Marlin 336 in 30-30 last fall. It's the carbine model. The idea of a 30-30 AI chamber for my rifle is tugging at my strings...

Have a Winchester 94 Trapper .30/30 I got nearly 10 years ago and shortened for my oldest son. He wound up never getting a deer with it before moving to a Ruger .260.

So it's just sitting in the safe.

Is the barrel too short to make going the AI route terribly inefficient or would it be like adding 6-10 inches to a regular .30/30?

How much worse is the muzzleblast from an AI?

Have been pondering just making up some "turkey loads" for ultralite woodscruising, but curious if AI loads could turn this snubby levergun into a formidable truck gun and sometimes doe popper.

I have three 30-30AI rifles: two Winchesters and a Marlin, all 20�. This wasn�t planned, just turned out that way.
I have a 16� Winchester Trapper which shoots the 130-grain Speer bullet very well. I would try this bullet before I gave any serious consideration to Improving it. The 130-grain Speer bullet is an excellent deer bullet from the 16� barrel. Also try the new Hornady LeveRevolution in the Trapper. The new Hornady ammunition is at its best in the short barrel. The pointy bullet provides the best improvement in trajectory when fired from the short barrel. I have a 26� barrel rifle and have compared the ammo in the three barrel lengths at 200-yards. If you compare the new Hornady ammunition side by side with any other 150- or 170-grain factory ammunition at 200-yards you will see the difference clearly. When firing your groups sight in your rifle using the 170-grain bullets and shoot the other two bullet weights using the same sight setting.

I don�t intend to discourage you from playing with the 30-30AI as I enjoy shooting and hunting with the cartridge. There are many 14� and 16� Contenders chambered for the 30-30AI and their owners are quite pleased with the performance from the short barrels.

Well, I would suggest that you would get about 2400 fps with a 16" barrel - maybe 2350 with 150 grain bullets. You'd basically beat a standard 20" 30-30 by about 100 to 150 fps.

Muzzle blast seems about the same as a standard 30-30 in the 20" barrel but I'm sure you'd get a bit more with the 16" - especially with the slower burning powders.

Keep in mind that you'll need to unscrew the barrel on your 94 - which entails getting or making a good barrel clamp to avoid buggering the barrel shank.

Why must you unscrew the barrel?

I don't think there's enough clearance - room for the reamer with just the bolt removed. I may be wrong. I reamed my 94's barrel before I mated it to the receiver.

I've read several times that the barrel needs to be removed.

Do you know this to be wrong?

I have reamed three Winchester Model 94�s to Improved. I found it easier than the Marlin 336. I used a home made reamer extension, it would have been easier with a commercial extension. Here is a link to a thread on hand reaming chambers for the lever actions. Not very well written but it gets the point across.

http://shootersforum.com/showthread.htm?t=8472&highlight=hand+reaming

Here are a few more links on loading the cartridge, you have probably seen some of these before. There are many more threads on the Beartooth forum as there are several active 30-30AI shooters on the board.

http://shootersforum.com/showthread.htm?t=12144&highlight=30-30ai

http://shootersforum.com/showthread.htm?t=9924&highlight=30-30ai

http://shootersforum.com/showthread.htm?t=6794&highlight=30-30ai

http://shootersforum.com/showthread.htm?t=9669&highlight=30-30ai

http://shootersforum.com/showthread.htm?t=5813&highlight=30-30ai

http://shootersforum.com/showthread.htm?t=11363&highlight=30-30ai

http://shootersforum.com/showthread.htm?t=15167&highlight=30-30ai

http://shootersforum.com/showthread.htm?t=12629&highlight=30-30ai

Well that answers that! I didn't pursue it any futher because I was doing a rebarrel already with mine, so the old barrel had to come off anyway.

That's exactly the way I did my Marlin. Only my shop-made extension was copper

Thanks for those links!

I've settled on W748 as I have a good quantity of it and it meters through my powder thrower really well. Varget is an excellent choice too IMHO.

There are a number of threads on the 30-30AI on the forum. Lots of active shooters.

Winchester 748 met all of my velocity goals for the 150- and 170-grain bullets.
For high velocity with best accuracy it is hard to beat Hodgdon Varget.
For highest velocity with accuracy just a bit behind Varget Alliant Relodr 15 is the way to go.
To be honest for best use with all bullet weights Hodgdon 4895 or Hodgdon 335 may be considered a do-it-all propellent in the 30-30AI.

I'm presently trying to get back the .30-30 AI I sold in a moment of foolishness. 336A Marlin, 24" barrel. Dead accurate.
I had great luck with Reloder 15 in this cartridge, with 170 or 150 grain bullets. No chrony, so no idea how quick, but 1.5" groups at 100 yards were easy to get.