Falling Block 338 Norma Single Shot Rifle

[Bubba Boomstick]

I have a dilemna. I love falling block rifles. I also love modern big bore cartridges such as 338 Lapua, 338 Norma, 300 Norma, etc.

I want to combine the two. I think I could find a 416 Rigby Ruger No.1 and have a gunsmith put a new barrel on. Those Ruger actions seem certainly strong enough. Or I could find a cheap Ruger No. 3 and have my smith fabricate a new 0.585 ejector and add a recoil pad.

But my heart is set on a Winchester 1885 / Browning B-78 action. Are those actions strong enough? Would they work for a 0.585 bolt face cartridge? I see the high walls weren't chambered for anything more than 325 WSM. There's also a bunch of Pedersoli, Uberti, 1885 clones. I don't know if they're for modern cartridges.

Maybe I do 338 Edge or 33 Nosler for the 0.535 face if I can't get the 0.585 bolt faces to work?

Thank you for your input.

 

[Sniperhandle]

I have a dilemna. I love falling block rifles. I also love modern big bore cartridges such as 338 Lapua, 338 Norma, 300 Norma, etc.

I want to combine the two. I think I could find a 416 Rigby Ruger No.1 and have a gunsmith put a new barrel on. Those Ruger actions seem certainly strong enough. Or I could find a cheap Ruger No. 3 and have my smith fabricate a new 0.585 ejector and add a recoil pad.

But my heart is set on a Winchester 1885 / Browning B-78 action. Are those actions strong enough? Would they work for a 0.585 bolt face cartridge? I see the high walls weren't chambered for anything more than 325 WSM. There's also a bunch of Pedersoli, Uberti, 1885 clones. I don't know if they're for modern cartridges.

Maybe I do 338 Edge or 33 Nosler for the 0.535 face if I can't get the 0.585 bolt faces to work?

Thank you for your input.

416 Rigby pressure is 52,000

338 Norma is over 63,000

338 Lapua is almost 61,000

I don't think I would do that, The head is larger also, So more force against the breechface.

 

[Bubba Boomstick]

Ah, so you say the Ruger No. 1 actions aren't strong enough for the 65,000 PSI cartridges made today?

 

[Sniperhandle]

Ah, so you say the Ruger No. 1 actions aren't strong enough for the 65,000 PSI cartridges made today?

I'm saying for cartridges as large and high pressure as the Lapua and the Norma. I think you would be pushing it. I know other magnums have been done.

 

[AlNyhus]

Barrel tenon diameter is also a consideration As much as I loathe #1's compared to B78's/1885's, they do have about .065 more tenon diameter.

 

[DaveTooley]

For the .585" class rounds if everything is perfect you can get by with a 1-1/16" diameter tenon. That works most of the time. Sometimes it doesn't. It also doesn't provide much of a safety margin. I prefer 1-1/8" diameter tenons.
Bolt thrust is a separate category. Cartridge case head surface area X pressure.

 

[Bubba Boomstick]

For the .585" class rounds if everything is perfect you can get by with a 1-1/16" diameter tenon. That works most of the time. Sometimes it doesn't. It also doesn't provide much of a safety margin. I prefer 1-1/8" diameter tenons.
Bolt thrust is a separate category. Cartridge case head surface area X pressure.

I think I understand. So you’re saying when the barrel threads are 1-1/16” diameter, there will usually be enough steel between the chamber and the threads to be safe. But you prefer if there’s a little more meat between the chamber and the threads?


I have a Weatherby Mark V 9 Lug that was a 338 Lapua I rechambered to 300 Norma and now to 338 Norma. I didn’t notice anything strange regarding pressure once I rebarreled it by my gunsmith. I think they use Remington 700 threads if I recall correctly?

 

[Bubba Boomstick]

I wonder if I am better off going with a 0.535 bolt face 338 caliber if these actions are sketchy. They make a 338 Win Mag Ruger No. 1. Maybe I can do 338 Edge, 338 RCM, 33 Nosler or a 338 RPM.

Can the B78/1885 or Ruger No.1 eject a rebated rim like the 338 RPM?

 

[DaveTooley]

I think I understand. So you’re saying when the barrel threads are 1-1/16” diameter, there will usually be enough steel between the chamber and the threads to be safe. But you prefer if there’s a little more meat between the chamber and the threads?


I have a Weatherby Mark V 9 Lug that was a 338 Lapua I rechambered to 300 Norma and now to 338 Norma. I didn’t notice anything strange regarding pressure once I rebarreled it by my gunsmith. I think they use Remington 700 threads if I recall correctly?

You're correct. 1-1/16 works most of the time. The issue that occasionally shows up is when chamber pressure gets high the barrel tenon and to some degree the receiver ring expand beyond the yield point of the brass. That means the steel parts expanded and returned to their original size. However the brass expanded to a point that it does not snap back far enough to clear the chamber side walls. The result is hard extraction.

 

[Bubba Boomstick]

You're correct. 1-1/16 works most of the time. The issue that occasionally shows up is when chamber pressure gets high the barrel tenon and to some degree the receiver ring expand beyond the yield point of the brass. That means the steel parts expanded and returned to their original size. However the brass expanded to a point that it does not snap back far enough to clear the chamber side walls. The result is hard extraction.

This makes sense. And if I have difficult extraction on a falling block, is it harder to remove than a bolt action? Usually on a bolt action there is a cam that provides leverage on extraction. I’m not sure if there’s a similar system on falling blocks.

 

[Bubba Boomstick]

I also don’t know what the tenons are on the 1885 or Ruger No.1. If they’re way under 1-1/16” then I should just go to a narrower cartridge chamber.

 

[butchlambert]

How about about a 17 Hornet Ackley improved?

 

[Alex Wheeler]

The edge will help a little but not as much as you think because its a rebated rim. It will have more bolt thrust that a non rebated rim magnum and the hoop strength of the barrel will be less that a non rebated rim like what Dave is talking about. If you keep pressures down you would be fine, but you never know who will get their hands on it one day. Im not an expert of these actions by any means but those wide cases are hard on actions.

 

[AlNyhus]

I also don’t know what the tenons are on the 1885 or Ruger No.1. If they’re way under 1-1/16” then I should just go to a narrower cartridge chamber.

The B78/1885 (modern) are .935. The #1's are 1.00". And while the actions are strong enough, I'd never do one with a real wide back end case.

The 375 Ruger (.535 back end) necked to .338 would be worth a thunk.

 

[Bubba Boomstick]

The edge will help a little but not as much as you think because its a rebated rim. It will have more bolt thrust that a non rebated rim magnum and the hoop strength of the barrel will be less that a non rebated rim like what Dave is talking about. If you keep pressures down you would be fine, but you never know who will get their hands on it one day. Im not an expert of these actions by any means but those wide cases are hard on actions.

I forgot that it was a rebated rim on the 338 Edge, thank you for reminding me. Because the edge is a necked up 300 RUM which has a rebated rim, correct?

 

[Bubba Boomstick]

The B78/1885 (modern) are .935. The #1's are 1.00". And while the actions are strong enough, I'd never do one with a real wide back end case.

The 375 Ruger (.535 back end) necked to .338 would be worth a thunk.

Thank you for that information on the thread diameter. Yeah, now that you mention it, there wouldn't be a lot of room there. The base of the 338 Norma case is 0.585 and subtract thread diameter of 0.935 and I am left with 0.350 of steel wall versus the 0.478 of steel wall from a 1-1/16" (1.063) tenon. That's a 0.100" difference!

Sounds like the consensus is that the action strength of the falling block isn't the issue but the thickness of steel around the chamber after being cut for the threads.

Okay I am persuaded. I think if I am to pursue a 0.338 non-rebated, non-rimmed, cartridge I will go with a 0.535 or 0.473 sized case head. I want this rifle to be safe and reliable.

Let's see my options:
338-375 Ruger
338-06 Ackley Improved
33 Nosler
338 Ruger Compact Magnum
338-300 Winchester Short Magnum

I'll take more suggestions on cartridge options. I would like to get as close to 338 Lapua/Norma ballistics as possible. I love their ability to push the 225-250 grain bullets fast. Good thing about a single shot is I don't have to worry about magazine length and feeding. So I can probably get a long and skinny cartridge close with a long throat.

 

[DaveTooley]

Thank you for that information on the thread diameter. Yeah, now that you mention it, there wouldn't be a lot of room there. The base of the 338 Norma case is 0.585 and subtract thread diameter of 0.935 and I am left with 0.350 of steel wall versus the 0.478 of steel wall from a 1-1/16" (1.063) tenon. That's a 0.100" difference!

Sounds like the consensus is that the action strength of the falling block isn't the issue but the thickness of steel around the chamber after being cut for the threads.

Okay I am persuaded. I think if I am to pursue a 0.338 non-rebated, non-rimmed, cartridge I will go with a 0.535 or 0.473 sized case head. I want this rifle to be safe and reliable.

Let's see my options:
338-375 Ruger
338-06 Ackley Improved
33 Nosler
338 Ruger Compact Magnum
338-300 Winchester Short Magnum

I'll take more suggestions on cartridge options. I would like to get as close to 338 Lapua/Norma ballistics as possible. I love their ability to push the 225-250 grain bullets fast. Good thing about a single shot is I don't have to worry about magazine length and feeding. So I can probably get a long and skinny cartridge close with a long throat.

I worked with the 338-300PRC when Hornady and Accuracy International submitted it to the military. It doesn't have the capacity to launch 300's but for 250's it would be fine.
I have reamers and dies.

 

[Jonnyofalltrades]

There are falling block single shot actions out there that are built to handle that size of cartridge. The only one I can think of off the top is the Hagn action in the biggest size. Beautiful, but crazy expensive. Martin Hagn also just passed away recently, so availability might be an issue.

 

[dellet]

If you really want to do this, a serious sit down with numbers and metallurgy would be worth while.

Original Highwalls were chambered in many 50 caliber cartridges and a couple .577’s. Of course black powder. But consider the modern Miroku built Low Walls easily handle 60,000 PSI when the originals are questionable with smokeless pistol loads.

Some of the Winchester black powder cartridge rifle barrels were 1”-32 threads, whether you could re-thread an existing action to a 1 1/16th tenon could be worth looking into. I thinknthe action width is 1 5/16

Last thought would be, consider that the Browning B-78 was sold chambered in 7mm magnum. Base above the belt is .510”(?)

 

[Bubba Boomstick]

There are falling block single shot actions out there that are built to handle that size of cartridge. The only one I can think of off the top is the Hagn action in the biggest size. Beautiful, but crazy expensive. Martin Hagn also just passed away recently, so availability might be an issue.

I see all these companies doing lever actions in a modern way. They have picatinny rails and m-lok handguards, and threaded for a suppressors. I wish someone would make a modern falling block for some of the new amazing cartridges we have available today that have off the shelf ammo and use modern accessories. That’s what I’m trying to build for myself.