12 Bore Schrifle project

[ChrisG]

So I was at my local gun shop the other day and he had a Marlin 512 on the rack for a steal. Iron sights and a fully rifled 12 gauge barrel. So I bought it. Originally... it looked like this. This is not my picture but it is the same gun. And it is controlled round feed. It just doesn't have the big Mauser extractor... it is a piece of sheet metal instead. A Mauser extractor on this thing would have added another pound to the weight probably

Being that I can never leave well enough alone... I wanted to use it as a basis for a true short range bear hammer. I know in the "slugs for bear" thread that I said I don't like foster slugs... and that is true. But this isn't going to fire foster slugs....

So last night I cut the barrel back to 18.5" and re-crowned it.

I ordered a mass of Magtech 12 Gauge brass hulls and all the correct 11 gauge fiber wads and nitro cards:

and a 775 grain .732" Accurate Molds Bullet mold that looks like this:

I am looking to load shells like these:

Only they will be huge flat noses with a .55" meplat.

Then the real work begins. The stock will be reshaped to be more of a European rounded forend, a more tapered pistol grip and a new darker finish, then cut new checkering.

In the end what I will have is an 18.5" CRF 12 bore rifle capable of slinging a 775 grain wadcutter to around 1,200 fps for close in Adirondack bear hunting. I think it will be lots of fun! It is sort of a "making a silk purse from a sow's ear" but I thought it would be a fun project nonetheless. Is there anything else I should do while I am at it?

 

[AZDAVE]

The only thing left to do is go shoot and hunt with it

 

[Shootist43]

Are you going to reinstall a front sight of some sort? What scopes are you considering? Have you been thinking about this project for a while? I wouldn't think 12 Ga. crowning tools are very common.

 

[ChrisG]

Are you going to reinstall a front sight of some sort? What scopes are you considering? Have you been thinking about this project for a while? I wouldn't think 12 Ga. crowning tools are very common.

The front sight is going to be soldered on. I don't feel comfortable drilling into a barrel that is only 1/8" thick and then tapping a hole that shallow. I may leave this as an open sights only proposition right now. It came with a scope mount but it is a side saddle (apparently the only type of mount made for this rifle due to the bolt channel being cut into the top of the receiver like a Mannlicher Schoenauer.) I am not a big fan of the way it looks. I have been dreaming of doing a large bore rifle slinging a super heavy slug, but light enough for short range thick cover maneuverability. Velocity has to be kept low (<1,300 fps) to keep recoil down. I considered both a 20 gauge and 12 gauge but a 12 gauge came up first. I don't have my mold yet but I have boat loads of lead ready to go for this thing. Brownells sells a 12 Gauge pilot for the cutter I already have but a friend of mine has a metal lathe so I asked him if I could come over and chuck it up. I just cut a basic crown on it with that. It isn't a 400 yard gun so the crown isn't going to be as crucial as it would be on a long distance rifle.

I am also going to make a barrel band sling swivel for it by TIG welding a sling swivel stud to a piece of 1" ID thin-walled steel pipe, then soldering it on and bluing it.

I may ultimately put a low power scope on it but we'll see how it shoots with irons for now.

 

[Shootist43]

Our thoughts are pretty much the same. For up close and personal, irons are the better way to go. Any possibility of NECG sights?

 

[ChrisG]

Our thoughts are pretty much the same. For up close and personal, irons are the better way to go. Any possibility of NECG sights?

I wish I could put an aperture rear sight on it but that stinking slot in the reciever gives me nothing to attach it to. I could put express sights on it but I really like the low profile of the existing sights. Mine actually has the adjustable rear like a Ruger 10/22. not the wedge elevated sight like the one in the picture that you would find on a BB gun. The only other option... and it would be a ton of work, would be to attach a peep to the rear of the bolt shroud since it is made of fairly heavy gauge metal. If I decide to go that route, I will likely employ the TIG welder again to attach a base for the peep to attach somewhere there.

 

[Bullthrower338]

Cool project! Maybe AO ghost ring somehow

 

[DonT]

Any thought about using one of the modern red dot sights. No need for a front sight, quick acquisition, Adjustable and excellent in low light or when the game is dark in color. Sounds like you have a side saddle mount on the gun already so it shouldn't be to much work adding a scope rail too it that the red dot could mount too or make a mount that goes in place of the rear sight with a short piece of rail...

I did this on an H&R topper I had that I re barreled to 44/40 and it works very well.

 

[ChrisG]

Any thought about using one of the modern red dot sights. No need for a front sight, quick acquisition, Adjustable and excellent in low light or when the game is dark in color. Sounds like you have a side saddle mount on the gun already so it shouldn't be to much work adding a scope rail too it that the red dot could mount too or make a mount that goes in place of the rear sight with a short piece of rail...

I did this on an H&R topper I had that I re barreled to 44/40 and it works very well.

I wish it was that simple. The side saddle mount is a propriety Weaver with a "half dovetail" and the scope mount is all one piece with rings already attached. I wish it were a usable rail but apparently when this gun was made, they didn't think people would be any more imaginative than "I want a scope with a 1" tube on it." My TIG is DC only. If it could do AC and could weld aluminum, I would cut the rings off and weld a picatinny rail low mounted onto the base to make a usable rail that I could mount anything to.

It looks like this:

And is two pieces. One that mounts to the gun and the rings are attached to and mounts to:

base

rings

 

[DonT]

Cut the rings off but leave a slight "trough", get a piece of 1" round aluminum, cut it in half lengh wise and mount into the trough with screws up thru the bottom. Mount your rail to that or if you have access to a mill cut the dovetail into the aluminum rod you just attached to the mount.

Just a thought....DonT

 

[IvW]

I will be watching this with interest...great project.

I am still kicking myself for not buying a 12 ga 3" Marlin bolt action goose gun many moons ago...

 

[ChrisG]

I will be watching this with interest...great project.

I am still kicking myself for not buying a 12 ga 3" Marlin bolt action goose gun many moons ago...

I was amazed when I took it out to shoot it with just some cheap foster slugs I had laying around... It functions so smoothly and it fed that blunt straight walled shell right into the chamber slick as could be. I was thinking about etching the barrel in a fancy scrolling antique font that just said ...

 

[ChrisG]

Here it is cut down but without the front sight reinstalled yet. 18.5 inch barrel

 

[BeeMaa]

Red dot that may work for you.
https://www.midwayusa.com/product/1...t-1-tube-1x-3-moa-dot-with-weaver-style-rings

 

[ChrisG]

Red dot that may work for you.
https://www.midwayusa.com/product/1...t-1-tube-1x-3-moa-dot-with-weaver-style-rings

Unfortunately it's discontinued... right now I have that 1.5-5 Leupold vx-2 on there... not what I had intended to use it for but it works...

 

[ChrisG]

So I got around to TIG welding up a barrel band sling swivel. It's not done yet but it is made from a 1" steel bushing and a piece of 3/8" key stock. I originally tried it with a wedge key but it was too narrow and got crooked when I welded it so i went back to 3/8" square key stock.

I welded them together and then cut out the piece in the middle so the ends of my welds won't be part of the finished product. Here are some pics:

And here is the roughed out piece that the sling swivel will be made from

I would have just bought one but it turns out no one makes a reasonable prices barrel band that is 1"+.... go figure

 

[ChrisG]

Bullet mold came in today.

775 grains .732" diameter

It's gonna be fun to start throwing these downrange

 

[ChrisG]

One of the hard cast 775 grain wadcutters that mold throws next to a 9mm round for comparison. I think at 1,200 fps it should take care of a black bear...

 

[ChrisG]

I haven't gotten my brass shells yet so I decided to load some of these up with some plastic hulls I had laying around to see how they shoot.

Trying 30 grains of Alliant 300MP

 

[CAustin]

Chris would love to see what kind of hole this will put through some plywood....then maybe a 2x10