Home Forums Hunting & Shooting Custom Rifles & Wildcats Mod. 71 35-348 Improved?

Getting ready to send a Mirkoru Mod 71 to Jess the re bore guy and have it made into a 35-348 Ackley Improved. If any of you have any experience with this wildcat please share your thoughts, loads, etc.

Going with a 3 groove 1-12 twist for 220 to 250 grain Kodiak Bonded bullets for our moose, caribou and bears. Should be close to a .35 Whelen out to 250 yards, but I doubt I can reliably hit well at that distance with a peep sight, but time will tell.

I have no experience with this cartridge. I do have two 348's, one with a rough bore that I was tempted to rebore to a 35-348 or larger. It still shoots adequately for my eyes and distances that I hunt. The other I had a custom scout scope mount built for it because a previous owner drilled the receiver for a side scope mount.

Sorry for my confusion, but are you boring it out an additional .010"? If so, does that work?

Undecided as to what to do, go with a .348 Imp. or a 35-348 Imp. The .348 Imp. is a simpler and cheaper deal and there are a few decent bullets for Alaska's critters. Can I swag a .358 bonded bullet to .348 diameter? The .348 Imp case has a tad more capacity, but not enough to matter.

Any one got a .348 or 35-348 Imp. reamer for rent?

Time to get sound advice form those that know, my Campfire buddies!

I guess I don't see the practicality of a 35-348 wildcat. There are flat point bullets available from Kodiak, Hornady, Barnes, Hawk, Woodleigh and Swift for the 348. The variety of flat points available in 35 caliber is considerably limited compared to the 348. I have a 348 and would be inclined to leave it as is, put a good receiver sight and a patridge front sight blade like a Skinner or Redfield Sourdough and shoot some 250 grain bullets. I doubt you'd notice any difference in the field between a 348, 348 AI or 35-348 AI.

Well horse feathers, I am undecided from one day to the next. Seems like a simple reamer job to make it a .348 Ackley Improved is a smarter move for more power, better case life and easier to fireform and cheaper to do. After looking around there may be a better selection of Flat Point 220 to 250 grain bullets for the .348. Woodleigh and Alaska Bullet Works come to mind.

Why does a .348 Improved hold a very small bit more of room then a 35-348, seems backwards to me.

I'm sure I can find a gun smith in Alaska to drop rifle off with so I don't have to mail it to the states, so I would save even more money that way. Finding a reamer is the hard part so I may have to have the gunsmith or me rent one.

I really wanted access to the cheap 220 grain .35 caliber Speer Flat Points and need to find out if they can be swaged down to .348 and still shoot ok. I have never swaged any bullet down, but understand a special die can be ordered for that.

Appreciate everyone thoughts.

You can get bullet sizing dies from CH4D for a fairly reasonable price. You can also use Lee push through cast bullet sizing dies. I've sized .416 down to .411 with Lee dies. Drawn bullets (swaging increases bullet diameter, drawing reduces diameters) seem to shoot just as well as regular bullets. I'm all for a guy experimenting but Hornady has a 200 grain 348 if you want a less expensive practice bullet. I can tell you from personal experience drawing bullets is a pain in the butt. Ultimately you are going to spend more time than its worth. IMHO.

Brass life is not something I've ever heard as a complaint with the 348. I mean how much do you expect to shoot this rifle? If you had a couple hundred rounds of brass, set your dies correctly for proper resizing so as not to set the shoulder back too far, and loaded and fired each case 5 times, you would have shot your 348 more than most 348s have ever been shot in their existence.

The 348 is a great lever gun round as it is. I have a 348 but not a 348 AI, but I cannot imagine the AI doing enough better than the original to make the effort worthwhile. But we're all rifle looneys here so if doing it just to satisfy that something different urge, then by all means get after it. Pragmatically it doesn't work for me.

It will mainly be a moose and if need be bear rifle, but would like to get a caribou with it. Which is why I will be using 250 grain bullets and want to get over 2,500 fps mv with them and can't do that with a standard .348 case. n Scratching that itch and fulfilling a dream. If I can swag the cheap .35 caliber 220 grain Speers to .348 I could use them also a benefit.

Heck, I don't even need the rifle as I have a very good Mod. 94 Big Bore .356 Win. and Marlin 45-70.

Having both 348 WCF and 348 Ack Improved rifles, I would advise forgetting the 35/348-its not practical. The bull moose killed in 2007 with
the 348 AI with 270 gr Hawk bullet was flattened like struck by a diesel locomotive.
Winchester designed a serious rifle in the Model 71. A 348 or 348 AI will run circles around
a 356; if you have an extra un-needed safety on that Marlin-get rid of it.
The 450 Alaskan on an 1886 or Model 71 will seriously flatten anything
in Alaska from Point Barrow to Admiralty Island. I have a pre-war 71 in that caliber.
The Wyoming guide killed in 2017 by a grizzly could really have used that rifle.

I built one on a Siamese Mauser Action decades ago, from scratch with a custom barrel from a major maker no longer in business. It was also an idea to rebarrel a Browning M-71 from .348 Winchester to .35-348 (Winchester) Ackley Improved, but in the ways of life, never got around to it. The greatest difference is that a larger selection of .358" bullets are available, the downside was that California mandated lead free bullets for hunting, which thinned the number of suitable bullets to zero. So, I gave up for the lever action conversion. The bolt action rifle can use pointed bullets, so I worked up a fireforming load with old batch of bulk Remington Core-lokt .358 180 grain bullets, and went off to the range. Using load data from www.loaddata.com, my first load of IMR4064 was too light and collapsed the case shoulder walls, while a bit stiffer load formed them normally. Had I continued to work up loads I would have used Barnes TSX bullets, but moved on to other projects. In the end I didn't see it as much more than working with a novelty.

Below is, left to right, a Winchester factory Silvertip .348 WInchester load, a sized case with fireforming load, and a fireformed load with a .358 Sierra bullet.





Below is what happens with too light of a load, pressure is not high enough to blow out the shoulder area, so the gas flows back and ruins the case. The case on right is normal result of fireforming.



When I was working with the .348 Winchester and the wildcat .35-348 version, I had laid in a supply of .348 Winchester brass, as it was a seasonally produced item, but now that Starline and Hornady offers it although at a price, I picked up an additional 250 cases. If you go ahead, use the load data with caution, back off and risk cases rather than blow something up.

Not much to gain in the aforementioned wildcats over the classic 348. Have you considered the 450 Alaskan ?
Go big, or go home

I am undecided now between the regular .348 or the improved version. Nothing wrong with a couple hundred feet more velocity and fire forming should be fairly easy and I did not buy this as a collectors piece. I also only hunt in Alaska and if I did use it on our little deer I would be well armed for a big bear.

I have a very good Marlin 45-70 and the heavy jacketed 350 or 400 grain Kodiak's and a case full of H322 makes for good close range brownie medicine. So a 450 wildcat is not worth it to me.

A guy in the states is checking to see where he put his Ackley Improved reamer and head space gage.

One of my concerns is how the sharper less tapering improved version will function in the rifle. But, so far no one has said that is an issue.

Hard to tell exactly from the pics, but it appears the taper on the improved case is reduced somewhat, maybe a good bit. That taper serves to ease extraction, I believe, which leverguns don't have in abundance. Something to consider, or perhaps research before you commit.

The improved versions of the .348 Winchester and the .35-348 Ackley Improved were the result of a 1960's collaboration between P.O. Ackley and Bob Hutton, technical editor of Gun and Ammo Magazine. Hutton developed a line of wildcat cartridges he labeled, "Leverpower", with the .35-348 Ackley Improved designed to duplicate the .350 Remington Magnum in a Model 71. Here's a link to a book regarding P.O. Ackley's lifetime of gunsmithing: https://ackleyimproved.com/portfolio/ I had at one time corresponded with Ackley regarding conversion of Siamese Mauser actions and the necessity of hardness testing and reheat treating, before beginning.

In the case of the reduced taper .35-348 Ackley Improved there was no mention of extraction difficulties in the lever rifle. I had no trouble with the cartridge in the Siamese Mauser. I also have a Browning 1886 reproduction, that shoots my favorite .45-70 Government load used in the Siamese Mauser; a 350 grain .458" Hornady InterLock bullet over 53 grains of IMR 3031, for just under 2,000 fps velocity. That load will kill everything that needs killing, and surprised me by shooting through a 36" diameter dead oak tree on the ranch used as a target holder. Other than that, check out this article on the .405 Winchester in a better rifle, the Model 95 Winchester, which I also own in .30-06 Springfield chambering. https://en.wikipedia.org/wiki/.405_Winchester that article also lists some max power wildcats.

There are many alternatives, and some are just too hot for my old body these days, given they disassembled my cervical spine a few years ago to remove a spinal cord tumor. I should also note that I no longer build rifles for the Ackley Improved cartridges, as there are just so many standard cartridges available tha do the job. If you do go that way, I recommend checking into Hornady's Custom Shop, that made me a hydraulic case forming die for my last Ackley, a .22-250 Remington Ackley Improved. The die was made from two fired cases and a chamber reamer drawing, and form water filled brass with a single hammer blow. I had a set of reloading dies made at the same time. Just more stuff to experiment with, saving barrel wear, and passing time to stay out of trouble.

Why not bore it to .366 and AI it? Better selection than .348, and likely to be a better/easier bore and rifling job.

In the two 348 Ackley Imp rifles that I have owned, down to only 6 Model 71s now-no extraction difficulties
experienced and accuracy remained good after the re-chambering. I cannot recommend re-boring away from the
.348 to another diameter. It is not cost effective, and there are now more excellent 348 diam bullets than ever before. Brass
lasts longer in an improved case.(Anneal case mouths with a candle or torch).
W. John is correct on the history of the 348 AI, and Ackley's Vol 1 book will confirm that and Harold Johnson's
450 Alaskan first built in the 1950s at Cooper Landing, AK. Requires a re-barreling for the .450 series or 50 Alaskan.
The 348 cartridge was designed by Winchester for a purpose, and it definitely improved on
the performance of the 33WCF in the smokeless 1886 rifles. As issued, it will
kill anything that walks in Alaska, Canada and the lower -48.

If one is creeping around the willows and alders of Alaska as a sourdough,
a 450 Alaskan is just the ticket. A modern 45-70 or 45-90 will also do the business.
Bears have a lot of endurance, and they must be stopped before they sometimes
are killed to save a hunters hide. The 1886/Model 71 Winchesters are probably the
slickest lever actions ever made for fast repeat shots-when it counts.

Some 348 case option reading...

http://forums.accuratereloading.com/eve/forums/a/tpc/f/6521043/m/699105246

https://www.levergunscommunity.org/viewtopic.php?t=36305