Can a Stevens 25 RF be converted to 25-20 WCF?

[rickster]

I still am unclear as to why it would be dangerous to shoot the same bullet, that is operating at the same pressure down a barrel by using a case that is larger.
... Why? This is Gunsmithing 101 and I am having fun learning!

Since I am an engineer, I thought I might be able to put together a post that would explain how all this works. But after typing for a half hour last night, I could see my post would raise more questions than answers, if it didn’t put everyone to sleep first. So I stopped.

Rereading your post today, I think I may see where the misunderstanding is, and will try to help there. If I miss, please excuse me. We can try again.

It appears that you are thinking of the cartridge as a rocket motor, where the thrust is determined by the opening (in this case, the bore size). Actually, a hydraulic ram, as Bret described, is a good analogy. In a rocket engine the thrust is developed by an imbalance of internal forces caused by reduced pressure at the outlet. In a firearm, the thrust is generated as the bolt prevents the case from expanding like a bladder. The forward case walls are (typically) locked to the chamber walls by friction while the rear case walls stretch backward toward the bolt head. The force on the bolt will be the pressure times the cross sectional area of the case at the widest point minus the strength (tension) of the case. If the pressure is low, and the case is strong, the bolt feels no thrust, and may not even be contacted. If the pressure is high, and the case reaches yield, the bolt thrust will be roughly equal to the force that would be generated if the case were a hydraulic piston.

And then there is the matter of hoop stress in the barrel……..

I typed this as fast as I could during my lunch break. I hope it makes some sense.

[Bret4207]

Is it possible for an engineer, an educated man I assume, to make a post without resorting to abbreviated foul language? The "F" word in it's many forms is a no-no on this site. Rather than just notifying a Moderator, I thought I'd make you aware so you could fix it yourself. I'm sure you didn't intend to be offensive, but we have women and kids reading these posts.

[rickster]

Fixed.

[gnoahhh]

Most women and kids I know use the "F" word more than most men I know.!

[Bret4207]

Most women and kids I know use the "F" word more than most men I know.!

Not here they don't. Why drag this place down to the same level as the rest of our crumbling society?

[Bret4207]

Fixed.

Thanks Rick!

[MNruss]

The snowshoe theory doesn't work because it's just your weight on the snow shoe, a finite fixed amount.
Sticking to the hydraulics analogy (it's a good one) :
Force applied over an area = pressure.
Pressure applied on an area = force on that area.
Chamber PSI applied over a larger area = more force on the breechblock.
More force on the breechblock = more force on
those itty-bitty screws acting as pins.
Think of a big hydraulic cylinder vs. a small one pushing on something
The larger diameter cylinder pushes harder, and if the pin on the end of the cylinder breaks, well in this case, KaBoom.
I wish I had better writing skills.

[Suo Gan]

But the force you can exert on a snowshoe could be different for each and every step you take. What would happen if you hopped on one foot with a snowshoe on, you would sink further in the snow than if you jumped and did this with two feet, right? A larger snowshoe would help us sink a lesser amount into the snow not more...but this is spread over a larger area. But if you could control this perfectly and apply the same amount of force (in our case gunpowder) to a single, and then a double set of snowshoes...They will equal each other out.

I understand that a larger cylinder pushes more but for a shorter distance, a smaller pushes less for a longer distance. The same amount of fluid (in our case gunpowder) will move them so that they will... equal each other out!!!

These are essentially the same principles IMO.

What has been said, and what I need explanation on is how the smaller a case head is helps an action to feel less force to the rear. My untested hypothesis is more force is being "felt" by the sides of the case the smaller in diameter a cartridge is. Therefore less energy exists to move the cartridge to the rear.

But there must be an equal and opposite, otherwise we will be set back scientifically a few hundred years.

What I am reading in the posts is that there is less equal and opposite the smaller a case head is? That makes no sense to me. Perhaps I need to blow the dust off the old physics book.

I think that for the sake of this friendly discussion we can STOP thinking in terms of the Favorite. I mean all of this is a large enough pill to swallow. Also I think that the Fav argument is biased one way or the other (mostly one way). And I think that some of you think you may need to beat it in my head that the Favorite is not a strong action. I know this.

[MNruss]

is that we're not moving anything, just applying presure.
If any thing moves, bad stuff can happen (KB)
So a big ram pushes harder than a small ram, and any movement = breakage.
Therefore a big ram is more likely to cause breakage in whatever fixed object (breechblock) is being pushed against.
Breech thrust is important in T/C contenders, also.
The snowshoe analogy applies (only kind of) if the same powder charge & bullet is loaded into a larger case the general result is less pressure.
(38 special load in a 357 case >> less pressure.)
(increasing C O A L will do this also)
Again, I wish I was a better writer.
Regards
Russ

[Suo Gan]

But we are on the same page. The same energy will equal the same energy however you slice the pie. We must limit the energy applied to the hydraulic ram because to do what you are saying would equal an infinite amount. A ram with infinite amount of fluid to move it will move its entire length or at least exert its complete force on an area. A charge of powder is finite. I think we are saying the same thing, but in a different language...of course You are the drunk Chinaman!

I think I am going to move to the logsplitter principle next! Can you split a log with a flat piece of 12"x12" steel? No? But you are saying it works better than the wedge. That is what you are saying!

Also, please do not take offense. I have gotten ribbed pretty well on this thread. I figure I can start doling it out too.

[Bret4207]

Suo Gan- Remember this is laymans terms- If you have a 38 Special case and load it to 20K PSI it exerts a certain amount of pressure to the rear. If you take a 44 Special and load it to the same 20K PSI and all else is equal to the 38 case (wall grip, etc.) you have a larger "hammer" pushing back on the breech block, bolt, whatever. Yes, it' sort of counter intuitive, kinda anyway. But the breech still has to deal with that 20K. The breech block remains the same size while the base get's larger pushing over a larger section of the breech block, so a larger section of the breech lock (whatever that happens to be) is affected and transfers that energy to the locking area.

[Chev. William]

This OLD Thread has some 'General Comments' that may or may not apply:
The Stevens Favorite came in Several Different Versions over the Years, and yes, as manufactured the Strengths of the Actions Varied with the Date and Version Manufactured.

As to Strength of the Actions:

An Early 'Favorite' with 3/16" diameter soft steel screws for pivots and a .450" wide Breech Block is NOT the same as a later one with Hardened and tempered pivot screws and a .480" wide Breech block or a "Favorite" with a .550" wide Breech Block and .213" heat treated Alloy Steel pivots (1915 type). I even have one that has a .600" wide Breech Block with larger "ears" for the pivot which has .250" pivot for the Breech Block and .213" pivot for the Lever.

As to the pressures of Cartridges:

The .22 Short, the .22 Long, and the .22 Long Rifle are ALL rated for the SAME maximum pressures. just the bullet weights seem to be the largest variable in their different velocities in MODERN loadings.

A .22 Hornet case FULLY Resized Down to the diameter of a .25 Stevens Case Body (.276") by pushing it in to a Sizing Die all the way to the Rim top face, will still have about the SAME case wall thicknesses,including just above the Web, and I have measured sectioned Hornet cases that indicate the wall just above the Web is .013" thick. This leaves a Web diameter of about .250" in the downsized Hornet. The RIM diameter of a .22LR Rim is .276" to .278". Comparing these, the .22LR Rimfire cartridge will have more area pressing on the Breech Block than the .25 Stevens Sized Hornet Centerfire Cartridge at the Same Chamber Pressure.

All Rifle Receivers not made from Aluminum Alloy, Brass, Bronze, or other NONE-Ferrous metal or Plastic are by definition made from Ferrous (IRON) alloy. Stevens appears to have used Cast Steel in their receivers, then heat treated them for wear resistance (Case Hardening). Grinding upon different Age Stevens receivers throw 'Low to medium Carbon' characteristic type Sparks.
While grinding upon Cast IRON (Ductile) throw 'high Carbon' characteristic type Sparks.

Has anyone actually done a thorough Laboratory Analysis on several Stevens Favorite Receivers from the full range of manufacturing Production?

Just my Comments on the General sense of the responses in this Thread. Yes I admit these are my own Observations and yours may Vary. But "Blanket" Condemnation of the FULL Range of Stevens 'Favorite' Actions as being 'Too Weak' is misleading verging on Blanket condemnation of a Whole Manufacturers product line based upon one know 'weak' product from early production.

Best Regards,
Chev. William

[Chev. William]

My question is about converting a Stevens Favorite chambered in 25 rimfire over to a 25 caliber centerfire preferably 25-20 Win. I have heard that some have done this using the .25 auto cartridge. So can this be done, what steps would I need to take, and would the action be strong enough for the 25-20 Win.?

I know, I know, I come up with some hum dingers don't I?

How do you weigh in? WAG's?

I am tired of the thing just sitting there with nothing to do! A gun without a job is a pure shame.

After reading the Roughly three pages of Posts on this Thread I feel No One is actually Reading the previous posts or even the Original Poster's Question completely.

There are Different Versions of the "Stevens Favorite" and the "Stevens 44" with different characteristic "Weaknesses and Strengths".
The Earliest Versions are Different from the Later Versions as parts are NOT directly interchangeable between the different eras of Production.
Example: A 1889 "Favorite" Breech block is too narrow, and has too small pivot holes, to fit in a 1915 "Favorite" Receiver.
And the 1915 Breech Block cannot even enter a 1894 Receiver, without major rework to either or both.

As to CF conversions of a RF version; that Does Entail Machine Work. But the ones who are saying ALL Favorite Type Receivers And Actions are "Too Weak" to withstand CF cartridges OF the SAME diameters are making Broad Stroke Condemning Comments without Fully Reading the Posts.

Why is it Unsafe to Convert a ".25 Stevens (Long) RF" Favorite to a ".25 Stevens (Long) CF" Design cartridge using the SAME Case Diameters and the SAME Bullet Diameter?

Each Reply to the proposal ONLY responded that the "parent Case" listed was too powerful for the 'Favorite' in general Without Reading the FULL posted comment that it was REDUCED to ".25 Stevens Sizes".

Later Era Stevens Favorite were made and sold chambered for the ".32 Long RF" cartridge, which is the SAME Size as the ".32 Long Colt CF" cartridge (which is NOT a .32 S&W Long CF Cartridge!!!).
The Stevens ".32 Long" barrels I have do NOT have the Same Bore/Groove diameters as the "S&W" version Specifications and will NOT Chamber a S&W size Cartridge.
My Barrels seem to have chamber diameters of around .320" or smaller to fit the .318" diameter of the .32 Long/.32 Long Colt Case, NOT the .337" to .339" of the 'S&W Family' Cases.

If you don't like the Idea of a Stevens 44 with .293" Diameter Pivot Pins for the Breech block and Lever and .187" Diameter pivot pins for the Link, with a Breech Block that is a Tight fit between the Pivot pin and the Receiver Shoulders when in Closed position being used for a .32 Extra Long Cartridge (converted to CF from RF) then you are avoiding Thinking of what this Action was built for and just where would you find "Modern High Power Factory Loaded Cartridges" for it?
For that matter, where are you finding "Modern High Power Factory Cartridges" for .32 Long Colt?
I have NOT seen ANY Factory Loaded ".32 Long Colt CF" in other than low power 'Cowboy' shooting Loads on the market, and those don't even come up to the .32 Long RF Specifications for performance.

.25 Stevens Long, either RF or CF versions, have NOT been Factory Loaded since about the 1970s by anyone, and not generally factory loaded since the beginning of WW2. Even then the Factories were not loading them to the Original Performance Specifications, down loading by about 150fps to 200fps of Muzzle Velocity. And the .25 Stevens Short was even further 'weakly loaded'.

For modern comparison, a .25ACP cartridge is about the same size as a .25 Stevens Short, but is loaded to perform about the Same as the Original .25 Stevens Long out of a Rifle Barrel.
Interestingly it is the SAME Case diameter and Bullet Diameter as the Stevens Cartridges.
It also has a 'Rim', that would let it be chambered, and extracted, in a .25 Stevens Barrel.
The .25 Stevens was loaded to around 23,000psi Maximum Chamber Pressures and the .25ACP is currently rated for 25,000psi Maximum Chamber Pressure, just slightly (about 8-1/2%) higher.

In a 1915 Favorite, with Modern Replacement alloy Steel Pivots Screws and Pins and a close fitting CF Breech Block, I think it would be reasonable to fire a .25ACP in a .25 Stevens (Long) chambered Barrel.
I would not try this in a 1886 Favorite however.

Further, Given the improved strength of a "Stevens 44" action due to it's increased size, I would try firing a .25ACP cartridge in a CF model fitted with a .25 Stevens (Long) chambered Barrel; either Side Extractor or Center Extractor Versions.

The later '44' action Versions shot 'loose' under 44-40 RIFLE Hunting Loads, but worked well with Target Loadings, so strength of the action is sufficient for .25 Stevens (Long) in either RF or CF Cartridges of the SAME dimensions. The .25-25, 25-21, and 25-20 SS also were fired in the later '44' actions for Target Shooting but not Hunting Loadings.

Yes You all have Experience and Knowledge that lends Stature to your thoughts but you dilute it by NOT Stating Which Version(s) you are Referring to.
And, Yes I have seen photos of Breech blocks of Early Versions Broken due to High pressure cartridges being discharged in the early Action(s).

That is why I do NOT Advocate reworking then to fit Modern, currently Factory Loaded Cartridges, such as the .32 S&W Long, .32 H&R Magnum or any similar Cartridges.

Just my 'Rant' on the 'Quick Draw' posts that miss the target questions.

Best Regards,
Chev. William

[35remington]

Given the cheaper cost and ready availability and suitability of the Contender action for the 25-20 cartridge, all this speculating is firmly in the category of "why bother?" A better, stronger, cheaper and equally handy rifle can be had without any worries about suitability. It will likely be more accurate as well.

This places the idea of converting a Stevens Favorite action in the "not even remotely practical compared to better alternatives" category. Why wonder or hedge when complete assurance of suitability can be had for less hassle and cost?

The point is as moot as moot gets.

[Chev. William]

35remington,
You are correct in your comments on the 'Practical' side of converting a "Stevens Favorite" in .25 Stevens (Short or Long) RF to '.25-20' (Either SS or WCF).

Best Regards,
Chev. William

[Chev. William]

Suo Gan,
You asked a General Question on converting a "Stevens Favorite" in ".25 Stevens RF" to ".25-20 Win." which is incomplete as it does not state the Era/Model of 'Favorite' you are asking about.

In general the 25-20 Winchester Center fire cartridge was designed and produced to fit Winchester Action 1892 of the Era, that could not handle the length of the '.25-20 Single Shot' straight walled cartridge that was then used for Target Shooting and occasionally for Hunting at the time.

Cartridge Name	Bullet Diameter	Shoulder Width	Body Width	Rim Width	Case Length	Case Capacity
.25-20 Single Shot	.257	.296	.315	.378	1.635	20.4
.25-20 Winchester	.257	.3332	.348	.408	1.330	19.4

As you can see from the table dimensions it is both larger in diameter and shorter in length.
The .25-20 S.S. nominally was loaded with 85 grain bullets at 1410fps; later from 60 to 90 grains and speeds from 2500fps (60 grain) down to 1200fps (90 grian).
The .25-20 Win. nominally was loaded with 85 grain bullets at 1440fps; later from 60 to 90 grains and speeds from 2249fps (60 grain) down to 1623fps (90 grain).
Diameter of the Cartridge bases (.315" for the 'S.S.' and roughly .347" for the Win.) and of course their Areas, are greater than the .25 Stevens diameter (.276") and Area.
Even if you load the proposed cartridges to Maximum Pressures of the .25 Stevens RF, both of them would exert more total Force on the Breech Block and its pivot Screw/Pin (Force = Pressure times Area) than the .25 Stevens Rf cartridges.

It is Generally not recommended to modify a Stevens Favorite of any era to take a Cartridge that is currently Factory Loaded and has larger base diameter than the Cartridge(s) originally offered by Stevens in the particular model.

Further; The .25 Stevens used a bullet of .250" to .252" diameter in Barrels with Bore/groove diameters of about .244"/.250" while the 25-20 Cartridges use bullets of .257" to .260" diameter in Barrels of about .250"/.257" bore/groove diameters.

Best Regards,
Chev. William

[cdupuy]

I have 42 rounds for that rifle if you are interested?

[Chev. William]

I have 42 rounds for that rifle if you are interested?

What rifle? Or more Exactly, what Cartridge designation?

Best Regards,
Chev. William

[Geezer in NH]

[Line it to 22lr. Favs are NOT strong! No centerfire 25-20 factory loads would be safe.]

+ 5,287

.

Agree no matter the shape of the action. Want to play CF in a Stevens get an Ideal 44 to start

[vh2q]

Well at the risk of being excoriated I am going to state the following:

1. The 22 mag is loaded to the same pressure (SAAMI) as the 22 lr. I have a Stevens 1915 that I fitted with a 22 mag barrel, and I have put hundreds of rounds through it. I believe I used a 224 groove barrel for the magnum but I don't remember exactly. The 22 mag bullet is .224" whereas the 22 lr is .223" so not a good idea to simply rechamber a 22LR.
2. I have converted the 1915 to CF in the following calibers: 218 Bee (40,000 psi), 256 Win Mag (43,000 psi), 357 Magnum (35,000 psi), 32-20 (16,000 psi)
3. I have converted an 1894 from 32RF to 32-20
4. I have fitted a ruger 10/22 barrel to a favorite.

In all cases I replaced the action pins with modern hard pins that were a hair oversized, calling for reaming prior to conversion for a tight fit. I have replaced the action screws with modern steel screws made from grade 8 bolts, or alternatively from drill rod that was hardened after turning. I usually make the lever screw (and this is the weak point as the screw is skinny) one letter size larger than original as the holes in the lever and the action are usually a little oval so I ream them round to take the new screw. If I cut threads I make them as shallow as I can. The action must be made tight and over center before setting up the headspace for any of these conversions.

In some cases I have threaded the action and barrel shank, but in most I have used the standard retaining screw.

I have casehardened some but not all of the actions. As someone stated these are cast steel not cast iron. But not as strong as forged steel. When you engrave one of these actions, you don't get nice curls, you get chips.

In all the CF conversions, I use mild handloads and I make sure there is adequate leade in the throat.

The only problem I have encountered is the lever screw bending, and that was using modern replacement screws that I bought from a vendor. After that I made my own oversized and hardened screws and had no further problems. I find it difficult to imagine that the breech block can fly out of the action as it is attached to the lever assy as well as the action itself. If it failed it would likely "gape" allowing hot gas to escape from the primer and/or cartridge head, most of which would be deflected upwards. I had this happen once with a 22lr that was a bit loose but unmodified. The case failed at the rim, there was a rather loud bang and some smoke but no harm done.

The breech block is buttressed by the action shoulders which I believe adds a degree of safety to the action. If the action starts to yield the play will be obvious, which is not true with other types of action where the lockup is not "tactile" and exposed.

I do recall reading in a book by P.O. Ackley where he did an experiment on a rifle that was chambered for 30-30. He successively and deliberately increased the headspace and was unable to detect any breech thrust at all due to the brass gripping the chamber walls. If the CF case is roughly straight-walled, it seems that theoretical breech thrust is not reached in practice. It should be relatively simple to calculate how much pressure a given brass case can withstand before it needs to rely on the breech block to prevent failure in tension. I suspect the ctg manufacturers dimension the case accordingly but I am not sure of that. No rimfire cartridge is going to display this behaviour as the cases are very thin indeed. That's why rimfire ctgs are loaded to low pressures. And sloping cases (like the hornet and the infamous 22 jet) are not going to grip the chamber as well as straighter cases like the 357 Mag.

I have also converted a 44 in 25RF to 5mm Rem Mag. The firing pin on a 25 Stevens does not need to be repositioned for this conversion. The 5mm has MUCH higher pressure (33,000) than the 22 lr or WRM (25,000) so you have to have a tight extractor fit to support the thin case rim. The Remington 592s had a very sophisticated two stage extractor to deal with this risk. I plan to do the same conversion on a 1915 but I would not try it on a 1894.

I would not do this type of conversion for a third party, for obvious reasons. And I should say "do not try this at home", if you do it's "AT YOUR OWN RISK".