Material, HT on Rem BP rolling block

[bufflernickl]

I have a question about strength of the black powder Remington Rolling block actions. I'd appreciate getting answers *only* from folks who actually know details, as I can speculate sufficiently all by myself :-)

This action has been rebareled with a modern .45-70 barrel, and has been shot with loads somewhat above BP pressures. Probably due to this, the pins, hammer, and block have become loose, and I am reworking it now.

Presently, I am lapping out the holes and will make larger pins when that is done. Additional work includes turning the firing pin and bushing the hole, plus lightening the hammer.

I'd like to know if there is a record concerning the differences in material and heat treat between the BP actions and smokeless actions, or rather, what the differences *are*. I can be satisfied with BP pressures in smokeless loads, but would like the ability to go higher, maybe to the SAAMI spec of 28KCUP. If the materials are the same over both types of actions, and it is only the heat treatment that is different, then I'd have this action re-heat treated. However, if there are significant material differences that would make it still unsafe at SAAMI pressures, then I'd likely not go to the expense and bother of re-HT.

Anyone actually *know* the answers??

Cheers/buffler

[Double D]

The problem isn't  the weaker older steels and heat treat, it  is the design of the action.  The Action has a tendency to "spring".  The top of the block springs away from the top of the rear of the barrel.  The bottom of the block held in place by the pins.  This causes the brass to stretch on the top side.  Not a big problem with straight walled cases, as long as you index, but still a problem.  

Why would you want to exceed pressure specs. If you are looking for increased velocity you'll get it at the expense of greater spring and greater stress on the action.  Accuracy will suffer. Eventually the action will fail.  Mine did. The Block will shear off the bearing surface of the hammer.

I haven't seen anything written on the specific difference in Steels and Heat treat from the BP to Smokeless actions.  But from all the ones I worked on in the past I can tell you there is a difference in steel.  There doesn't seem to be a difference in heat treat.  They are case hardened.  Once you cut through that hard surface they are soft underneath.

I tried to do what you are trying to do and it didn't work. I was warned by the old timers it wouldn't work. They were right.  Now you have an advantage that I didn't have. Access to modern made actions.  Forget trying to hotrod the old ones, get a modern made new action and go for  it.

[bufflernickl]

Double D,

thanks for the reply. I appreciate your insights, but you've got some things just wrong, and these are among the questions I am hoping to dope out. I'm not scolding you; AAMOF, I am really appreciative of your willingness to share your experiences. It is just that there are some well-entrenched, but mistaken notions about how firearms were designed a century and more ago :-) F'rinstance:

"The problem isn't the weaker older steels and heat treat, it is the design of the action. The Action has a tendency to "spring". The top of the block springs away from the top of the rear of the barrel. The bottom of the block held in place by the pins. This causes the brass to stretch on the top side. Not a big problem with straight walled cases, as long as you index, but still a problem. "

Well, there's no difference in the mechanical design, as far as I can tell, between a BP action and one designed for 7X57, which is *way* above the SAAMI pressure for the .45/70 and other BP cartridges. If it were only a matter of design, not mat'l or HT, then those 7mm RBs wouldn't have lasted a month in military service. So, we appear to have established that the *design* will hold up under say, 45KCUP, maybe more as I haven''t looked up the pressure rating lately for the 7mm Mauser.

"Why would you want to exceed pressure specs. If you are looking for increased velocity you'll get it at the expense of greater spring and greater stress on the action. Accuracy will suffer. Eventually the action will fail. Mine did. The Block will shear off the bearing surface of the hammer."

Have *no* desire to exceed "the pressure specs". First, there is *no* pressure spec for these actions, nor, for that matter, for any of the older actions that we use, including the great VZ24 BRNO Mauser actions, for that matter. You can't find a single bit of documentation in the historical record of any of these actions that says that *the action* was designed to withstand any specific pressure. They designed an action (and rifle) to the best (or appropriate) standards of "the engineering art and science" and then tested it with the desired cartridge in proof loads to see if it would withstand that pressure. That is not at all the same as *designing to a specific pressure spec*.

No, rather than wanting to exceed a pressure spec, I want to know if I can increase the pressure tolerance of this specific action up toward that of a *similar or maybe identical * action made for a high pressure smokeless cartridge and produced (later) on the same machinery and at the same plant!!!!

"I haven't seen anything written on the specific difference in Steels and Heat treat from the BP to Smokeless actions. But from all the ones I worked on in the past I can tell you there is a difference in steel. There doesn't seem to be a difference in heat treat. They are case hardened. Once you cut through that hard surface they are soft underneath. "

Here is one of the jewels that you've given me. You say you have direct experience working with these and you have noted the difference in steels between the different actions. It is also interesting that you find that they are only case hardened. Certainly heat treating of carbon steels was fairly advanced at that time, so it is easy to see that when making BP actions, they could choose not to use a more expensive HT when case would suffice for the pressures used. Then, when developing the action for smokeless, they might have opted for a more expensive steel to get toughness, but still chosen the cheaper case hardening over full HT. Can you tell me what differences you found between the two styles? Was it in harder cutting after the case is broken? Do you have any feel for the carbon content of the BP actions? I'd like this one *not* to shoot loose again, as it apparently has done since the rebarrel, and if there is enough carbon for a HT, then I'd happily send it off for that work, even intending to keep to BP pressures.

"I tried to do what you are trying to do and it didn't work. I was warned by the old timers it wouldn't work. They were right. Now you have an advantage that I didn't have. Access to modern made actions. Forget trying to hotrod the old ones, get a modern made new action and go for it."

Would you please tell me if there was any failure in addition to shearing off the locking faces. Or, if there was any indication of deterioration before the failure, like increasing headspace? This action shows .016" at the top of the breech and .009" at the bottom. That is substantial HS, and certainly more than I'm willing to tolerate. I can't believe that the gunsmith who rebarreled this action would have given it that much, or rather, allowed it out the door like that, so it *must have* been shot into that condition. I don't have any idea how hot the loads used in it were, nor how many were shot, but I'm going to try to find out. Anyway, did yours show notably increasing HS before it failed?

Finally, I have modern actions, and will continue to use those for high pressure cartridges. Next up is a full-bore .38/56 for smokeless loads on a Ruger #3 action. It will be my "long-range Western rifle" :-)

Again, I really appreciate your reply and thank you for giving me the benefit of your experience with the very action I'm reworking right now.

Cheers/buffler

BTW, DD, when were you doing this? You say you didn't have access to modern actions, so that indicates that it was before the Ruger #1 action was available.[/i]

[gunnut69]

Casehardening a mild steel is an excellant process and mausers were made this way for many years after different techniqes were developed.  Please note also that you compare apples and oranges with the 45-70 and the 7mm Mauser.  The amount of thrust applied to the block by the casehead area of a mauser is considerably less for the same pressures as would be applied by a 45-70.  The 7mm RB's had a tendency to develope headspace with use, as did they all to a degree.,  The great numbers of RB's built were more a testimony to the price and the simplicity of use and maintenance.  The RBs tendancy to shoot loose is well known and even the uneven nature of the headspace problem in you rifle should give you a clue..  They are great rifles.  They don't hold pressure as well as a Sharps or an 1885 Winchester.  There are modern versions of the RB that have been produced using modern materials.  I have no direct knowledge of them but have seen several of the Navy Arms RB's loosen quickly.  I would bet they were used with higher pressure loads as they are modern steel, so they should be able to take it.  The design remains the same..  Restore the rifle and use it at the pressures it will stand the longest...
Be safe..

[bufflernickl]

Gunnut,

thanks for the reply.

Yes, I've done block thrust caculations on both cartridges. After deducting the area of the rims, the thrust force is much closer than I'd guessed, but still around twice as high for the .45/70. It was that fact that made me think that better HT might make the .45/70 usable at SAAMI 28KCUP.

Your information that they *all* tend to shoot loose convinces me to keep pressures to 18K or less. As I said above, I can be satisfied with that performance for the use this rifle will get. I plan to buy a Marlin 1895 in .45/70 for times when I want more grunt :-)

I still hope to hear more information about this action's strength and usability, as that might lead to my doing a better job during this rework and to the rifle being much more long-lived than it was after the last one. Sure do wish he'd made it a .38/55 :-)

Cheers/buffler

[bufflernickl]

One More Question:

I'm now considering having the action re-heat treated. Does anyone have any recommendations as to whom I should send it and how much it might cost? I'm not looking for fancy color work, just competent plain work.

[gunnut69]

Well, doubling the effective thrust on an action is a considerable increase!  Still the Roller is a great action.  I have a No.4 early action with the screwed in barrel that I have plans to rebuild. someday..  Also I should note that since these were casehardened actions the steel(actually low carbon steel) used probably can't be hardened in the normal heat treating facility.  There simply isn't enough carbon for the metal to harden and we would have little real idea on the amount of case left on the action, if indeed any remains.  I suppose there are other shops performing this tasl but if it were my face behind that action, I'd call Doug Turnbull(sp.)  He advertises in GunList and I probably have an address around here somewhere but it's very late just now, and I'm beat.  If you want it, post back and I'll see if I can find it...  I have a highwall in the shop right now.  It was in a fire and the owners thoughtfully let it rust for several years.before deciding to see if it can be restored.  Normally I would say it's a lost cause but I'm experimenting with a new rust removal technique.. We shall see..  I've been waiting 'til the weather got a bit nicer as I don't want this mess in the house.  Good luck with the project.  If your interested I'll see if I can find an address.

[bufflernickl]

gunnut,

I am thinking about trying my hand at color CH. I've done quite a bit of HT on carbon and tool steels, but never any CH. I have a coal (coke) forge and can make char-bone-and-leather pretty easily, and in the same container that I'd later use for the parts.

Setting up a bubbler quench tank is no big deal, so that part is easily taken care of. The only variables I can think of are temp maintenance (try to borrow or rent a pyrometer) and how much coal I need to keep it at 1600F for 4 hours.

As for rust removal, I've been an old-tool nut for some time and you can't beat electrolytic rust removal. It will get the rust off and not touch solid metal. All you need is a battery charger, some clip leads, an old piece of rion or steel, and a plastic bucket. I can insert instructions into a post here if you need it. The only thing you *must* watch is that you get the polarity correct, or you'll ruin your workpiece(s). But, that is easy to get right.

lemmekno.

Cheers/buffler

[gunnut69]

That's amazing!  I've been mucking about with weapons of all types for too many years and I just heard of this electrolitic rust removal process.  It seems as if everyone else has known of it for years..  I have a set of directions but would appreciate your input..  I'm afraid I'm not proficient at color hardening steel.  I've cased a few frizens and such, even an old falling block rimfire action but never a color hardening..  I'd experiment with some scrap or see if there's anything on the internet.  Try a GoogleSearch...

[Double D]

Sorry for not getting back to you sooner. I think GunNut69 answered you sufficiently.  But I still think you deserve a response.

Double D,

thanks for the reply. I appreciate your insights, but you've got some things just wrong, and these are among the questions I am hoping to dope out. I'm not scolding you; AAMOF, I am really appreciative of your willingness to share your experiences. It is just that there are some well-entrenched, but mistaken notions about how firearms were designed a century and more ago :-) F'rinstance:

"The problem isn't the weaker older steels and heat treat, it is the design of the action. The Action has a tendency to "spring". The top of the block springs away from the top of the rear of the barrel. The bottom of the block held in place by the pins. This causes the brass to stretch on the top side. Not a big problem with straight walled cases, as long as you index, but still a problem. "

Well, there's no difference in the mechanical design, as far as I can tell, between a BP action and one designed for 7X57, which is *way* above the SAAMI pressure for the .45/70 and other BP cartridges. If it were only a matter of design, not mat'l or HT, then those 7mm RBs wouldn't have lasted a month in military service. So, we appear to have established that the *design* will hold up under say, 45KCUP, maybe more as I haven''t looked up the pressure rating lately for the 7mm Mauser.

I don't think I got anything wrong.  The Rolling block actions have weaknesses based on design, all of them, Military, Commercial and Smokeless. If you recognize the weakness and learn to work with them the Rolling Block will serve you well.

Have *no* desire to exceed "the pressure specs". First, there is *no* pressure spec for these actions, nor, for that matter, for any of the older actions that we use, including the great VZ24 BRNO Mauser actions, for that matter. You can't find a single bit of documentation in the historical record of any of these actions that says that *the action* was designed to withstand any specific pressure. They designed an action (and rifle) to the best (or appropriate) standards of "the engineering art and science" and then tested it with the desired cartridge in proof loads to see if it would withstand that pressure. That is not at all the same as *designing to a specific pressure spec*

.

I suppose you're sematically correct, I accept the lesson in semantics. I am just a lowly gunsmith and not a Scientist

I haven't seen anything written on the specific difference in Steels and Heat treat from the BP to Smokeless actions. But from all the ones I worked on in the past I can tell you there is a difference in steel. There doesn't seem to be a difference in heat treat. They are case hardened. Once you cut through that hard surface they are soft underneath.

I said that and I stand by that.

Here is one of the jewels that you've given me. You say you have direct experience working with these and you have noted the difference in steels between the different actions. It is also interesting that you find that they are only case hardened. Certainly heat treating of carbon steels was fairly advanced at that time, so it is easy to see that when making BP actions, they could choose not to use a more expensive HT when case would suffice for the pressures used. Then, when developing the action for smokeless, they might have opted for a more expensive steel to get toughness, but still chosen the cheaper case hardening over full HT. Can you tell me what differences you found between the two styles? Was it in harder cutting after the case is broken? Do you have any feel for the carbon content of the BP actions? I'd like this one *not* to shoot loose again, as it apparently has done since the rebarrel, and if there is enough carbon for a HT, then I'd happily send it off for that work, even intending to keep to BP pressures.

Sorry my experience is limited to the use of a hand files, lathe and milling machine to make only about 15 to 20 RB's.   I only have the unscientific data from my observations that the metal cut different and machined different in my experience.

Gunnut69 set you on the right course on this one already.

Would you please tell me if there was any failure in addition to shearing off the locking faces. Or, if there was any indication of deterioration before the failure, like increasing headspace? This action shows .016" at the top of the breech and .009" at the bottom. That is substantial HS, and certainly more than I'm willing to tolerate. I can't believe that the gunsmith who rebarreled this action would have given it that much, or rather, allowed it out the door like that, so it *must have* been shot into that condition. I don't have any idea how hot the loads used in it were, nor how many were shot, but I'm going to try to find out. Anyway, did yours show notably increasing HS before it failed?

Lets see if I can remember back that far it was back in the late 1980's early 90's.   Loose hammer and block pins. Springing like you describe, where the gap increases more at the top of the block than at the bottom.  (The hammer is rotating on an arc) Case separations of reloads.  Headspace was not always affected.  The 7x57 suffered the most from true headspace problems.

The block that sheared was  on a rifle that I bought from a gunshow that was marked 30 GOVT.  I thought it was 30-40 Krag.  I should have paid more attention or I would have noticed it didn't have a rim seat.  When I got it home and dropped a Krag round in it I knew something was wrong.  A 30-06 fit perfect.   The guy I bought it from said he shoot it but it kicked to much.   Later after the rifle was rebarrelled in 7x57 is when it let go.  The back of the hammer was slighty mushroomed and  cracked.   I never did find that case head and get the shivers just thinking about.

If you assemble only the block and hammer into a stripped action you can also sometimes feel a dent in the hammer body where the block is blown back into the top of the hammer during firing. Rotate the block closed and hammer forward.  Pull back on the block, keep pressure rearward on the block and with other hand slowly rotate the hammer back. You will feel the block get pushed forward as the hammer goes back.  All comes from that block get slammed back from firing.

Finally, I have modern actions, and will continue to use those for high pressure cartridges. Next up is a full-bore .38/56 for smokeless loads on a Ruger #3 action. It will be my "long-range Western rifle" :-)

Good rifle the Ruger, but not what I had in mind when I said modern made rifle actions.  I was thinking more along the line of an modern made Rolling Block action from Lone Star rifle Company. http://www.lonestarrifle.com/

You've got me fired up now.  I have a Rolling block I started on just for me back in the 80's.   All that needs done is the stock work and the metal finish.  I need to set the Martini's aside for a while and get this rifle done.

[gunnut69]

Well now you've gone and done it DoubleD!  I've got roller in the shop just now. It is a LoneStar with a Badger Barrel(I believe)  It belongs to a good friend of mine and it's been in line for a while..  It's a 45-70 though..  All I have to do is the stock work..  I've at least 3 rifles in the works 'just for me' and some have set for years!!!  Of course I can't pay myself much and so 'paying customers' get the first go!!  While I agree with your assements I also believe the design is OK for what it was designed to do.  If that is surpassed there will be problems...  Of course better materials will have a very positive impact...  Good luck to all the Rollers out there!!!