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No. 108064 ID: b27d97
  I know it's very scaleable but how scaleable is it? Can you make a rolling block rifle for African game calibers or .50 BMG? What about .950 JDJ?
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>> No. 108065 ID: 3b0c56
File 154589460523.jpg - (347.68KB , 1400x795 , bullets, 12_7x44R Swedish rolling block 1.jpg )
12.7x99mm requires very strong breeches and chambers to keep them from blowing apart upon firing. Using an obsolete design from 1867, designed to fire much lower pressure black powder loads in 12.17x42mmRF would be... inadvisable.
>> No. 108066 ID: b27d97
Well, I mean how does it scale tho? You can beef up the parts on the gun but will the design still work if you do that?
Also http://www.accurateshooter.com/guns-of-week/amazing-breech-block-50-bmg-rifle/
>> No. 108067 ID: 07e942
File 154598417135.jpg - (31.52KB , 400x300 , original-remington-rolling-block_1_0953bc98759f0e5.jpg )
Possibly, but it's probably a worse choice than a bolt action. Since the action isn't straight inline, I could imagine the pivot pins and receiver bending away over time. Same reason they got away from asymmetrical locking lugs on bolt action rifles. (Like the early Mauser rifles.)

The rolling block was essentially a black powder action, though it did work with a couple of smokeless cartridges like .303 british and 8mm lebel, I think it would be impractical for anything larger.
>> No. 108068 ID: 61e76a
You could, however you'd need to beef everything up to such a level it would be neigh on unusible.
>> No. 108069 ID: f5c3ed
>.50 BMG
What sort of muzzle device would you put on such a monstrosity?
>> No. 108070 ID: 3b0c56
File 154611872179.jpg - (1.22MB , 2564x3000 , US Barrett M82A1 2.jpg )
This kind.
A "tank-style" muzzle brake with thick steel plates that direct the blast backwards. Don't ever stand along side to a Barrett gunner.
>> No. 108071 ID: 3b0c56
File 154611885491.jpg - (297.73KB , 2048x1036 , US Barrett XM109 25mm Payload rifle 2.jpg )
US Barrett XM109 25mm Payload rifle has an even beefier brake.
>> No. 108072 ID: 3b0c56
  SNIPER 101 Part 56 - Muzzle Brakes for Long Range Rifles https://youtu.be/_k6t-zq6qeU
>> No. 108073 ID: 3b0c56
  One of the heftiest muzzle brakes is this 18-pound monster on the .950 Fat Mac rifle. Yeah, the brake alone weighs nearly as much as three unloaded M16s.

"Fat Mac" - SSK Industries' .950 JDJ Rifle https://youtu.be/qg0RdhFnTd0
JD Jones’ .950 JDJ cartridge is a generally described as the largest sporting rifle cartridge ever produced, producing more energy than even the 4-bore cartridges that match it in bore diameter. Only three of these rifles were made, and the original loading was a 2600 grain (168g) cast bullet moving at 2200 fps (670m/s), for a whopping 28,000 foot-pounds of muzzle energy (38kJ). There are some antitank rifles that produce more, but nothing comparable in both energy and bore diameter in the sporting realm.

The rifle is built on a McMillan stock and action, and was originally produced on special order for a customer who wanted a really (really) big rifle that could use cast bullets. The cartridge cases were originally made from 20mm Vulcan cases trimmer down to a (mere) 70mm case length, with custom made lathe-turned cases replacing them when brass Vulcan cases became too difficult to source. The gun itself weighs a bit over 60 pounds, with nearly a third of that in the muzzle brake alone. This example is being sold with a whole bunch of ammunition components, which is a good thing since Jones/SSK stopped making the ammunition several years ago…
>> No. 108075 ID: efd69d
  I want me a rolling block air gun.
>> No. 108080 ID: b27d97
But you still have to beef the bolt up for hotter/larger calibers, no? Looking at 8mm Lebel rolling block vs. bolt action the former seems slightly less bulky.
>> No. 108082 ID: 61e76a
Well yes, but as I understand it the breech block is held in battery at the moment of firing by the hammer block/hammer spring.

If you were talking higher pressure ammunition surely the act of cocking the rifle would become more difficult. I'm sure it could be overcome with ratchets etc, the question is why? The bonus of a bolt action is ease of use combined with the possibility of a magazine feed.

That said, I'm sure the action could take it.

7 x 57 Mauser:
Maximum pressure (C.I.P.)390.00 MPa (56,565 psi)
Maximum pressure (SAAMI)351.63 MPa (51,000 psi)

7.62 x 54 R:
Maximum pressure 390.00 MPa (56,565 psi)

.375 H&H:
Maximum pressure 62,000 psi (430 MPa)

.50 BMG:
Maximum pressure (TM43-0001-27)54,923 psi (378.68 MPa)
Maximum pressure (EPVAT)60,481 psi (417.00 MPa)
Maximum pressure (C.I.P.) 53,664 psi (370.00 MPa)

The 7 x 57 mauser and it's Russian contemporary were rounds used in service issued falling blocks.
>> No. 108083 ID: b27d97
>Well yes, but as I understand it the breech block is held in battery at the moment of firing by the hammer block/hammer spring.

Not the spring https://youtu.be/GadzX6vPl8Y?t=241
>> No. 108087 ID: 61e76a
Ah I see, It has been some time since I looked at a rolling block.

The point still stands though, you'll need a beefy set up internally/in the chamber and recoil would be nasty.
>> No. 108089 ID: bbee29
>you'll need a beefy set up internally/in the chamber
Correct. I think a rolling block would be a bit more complicated to "beef up" properly because there's the "wedge-shape" breech block, the pivot, then the locking "wedge" part of the hammer and it's pivot. All four components would need to be made strong enough not only for the increased pressure seen here >>108082 but also the proportional increased bolt thrust. After all these parts are beefed up, you'd then need to make sure the receiver itself is beefed up to handle the various forces acting in tension and compression across the receiver. All those tens of thousands of PSI really start to become problematic as the "I" part of "PSI" gets bigger on, for example, a .50 BMG's case head.

It's doable but at some point the "WHY" factor just becomes too big to ignore. Falling block or simple "vault" falling block single shots kinda starts looking like good options.

>and recoil would be nasty.
About as much as any other manually operated/single shot .50 BMG rifle of the same weight with a similar muzzle device. Make it 30lbs or more with a big muzzle brake and it'll be comfy to shoot aside from kicking up a cloud of dust and clearing sinuses.

Seeing as how much thicker everything would need to be to handle a large case diameter relatively high pressure round, getting to 30lbs wouldn't be too hard. I'd probably use 1" diameter pivot pins with the breech and hammer "wedge" probably nigh fist-sized. Action might weigh 10 to 15lbs (or more) by itself depending how it's laid out exactly but I'm just guesstimating at this point. We have some 50BMG single shot rifles in the shop right now, there's a target barrel that weighs ~20lbs alone but action isn't too bad, single shot 2-lug (IIRC, looked at it two weeks ago) so the whole action isn't even 5 inches long, really standard stuff that's simple and that works. You can go with a lighter weight barrel too, I've seen some 50s tipping the scale with a scope on in the 20lbs range where a good portion of that was muzzle brake, still not terribly unfriendly to fire.
>> No. 108090 ID: b27d97

Because it's pretty cool.
>> No. 108091 ID: bbee29
I'm not saying it isn't, but how much money are you prepared for this "why" factor? Don't think I'm trying to dissuade you from this project, I for one own many many "why" guns that are starting to cost a shitton of money just because why (cool, I just like it).

All I'm trying to do is convey the complications and costs associated with such an endeavor.


This is probably what I'd use for the pivot pins. Mill the receiver from 4140, same for the "wedges". You might need to buy an old and completely fuckered rolling block, measure what you can, replicate it in a CAD program, and size it up. To ensure your face isn't repurposed as modern art, bring the oversized design CAD files to a mechanical engineer and see if you can coax a ballpart safety margin out of him. If everything gets milled out properly, send it to a professional heat treat place and be sure to request testing for hardness and such. All this will get expensive a lot very quick, but the cheaper you go, the more your "gambling with explosions" factor increases.
>> No. 108095 ID: b27d97
>Don't think I'm trying to dissuade you from this project

Haha, bless your soul man. I'm from a no guns country and have no machinist skills, just a blue collar office guy. Just thought maybe somebody maybe already tried something similar or knows about it.
>> No. 108108 ID: 61e76a
If it were me doing a big bore rolling block, I'd be tempted by building a 10 or 12ga mag/supermag with slugs.

Comparatively much lower pressure and you've still got a big bang with a monster piece of lead going down range. Would be handy for stopping a charging waterbuffalo too.
>> No. 108109 ID: b27d97
It would be cool to do what this dude is describing https://www.youtube.com/watch?v=-sWnqIspa9o but in rolling block action.
>> No. 108113 ID: 61e76a
I mean, yeah, but effort.

.244 H&H is a thing.

>> No. 108116 ID: b27d97
That´s a rifle round though, no? Smooth-bores are interesting in that, as the guy said, they don´t swage the bullet and don´t heat up as much and the length of the bullet not being an issue since you don´t have to figure out the twist rate. You can theoretically go crazy with hard exotic alloys since you don´t have to machine the rifling.
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