What pressure limits should be applied to RB in 45-70?

Trap Door 18,000?

Contender 28,000?

I have never seen a written comment "opinion" on this.

I don't know what the maximum safe load would be in a 45/70 Contender but Hodgdon Powder lists loads of 28,000 CUP as being safe in the Trapdoor.

WC

Please be more specific ! Lone Star Rolling blocks ? old originals ? Swedish ? Imports ? what ones are you asking about ?

Thr RB is original Smokeless action.

I AIN'T trying to make it into a 458 Mag, but am wondering why one never sees "pressure limits" for this action.

It will be cast 325-380 grain boolits only.

The smokless was chambered for several calibers 8mm 7mm 30-60 30-30 and so on look at their pressures in a reloading book and you have your answer !

Lyman recommends keeping all the old BP guns to well under 20,000 CUP, including the Sharps and the large frame rolling blocks. Hodgdon says to just use the SAAMI 28,000 CUP spec, but even the factories load to under 20,000 CUP for fear of the effects on the old guns. There is some debate among RB shooters as to whether it is suitable for even the 40,000 CUP .30-40. The owner of Lone Star had an original 7mm disintegrate on him with modern factory ammo. I have a No.5 on order from him, but I will load mine down to under 35,000 CUP.

Asdf Did you order the 4140 steel receiver or the case hardened one ?

"On order" was the wrong way to put it. I have a deposit on one, but I'm wavering on the chambering (and have been for some time). As for the steel, I'm not aware of any options. I believe all his castings are the same, and suitable for case hardening. I don't know which alloy he uses, but it's probably in the 8000 series. The colors are nice, but I've read all case hardening colors are pretty fragile, so I'm thinking of having mine just blued.

Beware assuming that cartridges loaded 100 years ago were at the same pressures in modern standards. Phil Sharpe's big book on reloading states the 7mm cartridges used in the original military RBs were loaded to lower pressures. Whelen's early book hints the .30-40 was slightly lower pressure as well. Also, what modern shooters expect are not what militaries manned by conscripts expect. There are some reports that smokeless RBs are hell on case life, an issue which doesn't concern an army.

The most promising field report of RB strength is the 7.62 Russian models made in WW-I. One of these was captured in Viet-Nam, so it had probably served many years shooting mid-20th century military ammo -- impressive.

For what it is worth -- and I am a rolling block fan -- I have heard of and seen the remains of more No. 5 smokeless military RB actions blown up with 7X57 ammo than all other rolling blocks combined.I think they are a great action for use with BP cartridges and pressures, and possibly with small-head smokeless pistol and schuetzen-class cartridges. Otherwise, I personally am circumspect about them.

quote:

I personally am circumspect about them

When I first learned of the modern reproductions, I enthusiastically placed an order for a .30-40. I then began to wonder just how safe a proposition this was and began to look around for information on the strength of these actions. After several years, I'm still not sure what they can take. I suspect I'll end up backing off to .25-35, which has both lower pressure and a smaller case head. Call me chicken if you want.

The Danes rechambered the 45 cal R B's to the 8mm with a re-heat treat. I do think these will handle the 30/40 quite well. I am re-barreling one of these to 40/65 or maybe a 40/82
Mike

It never fails to amaze me how guys want to take an outdated /obsolete action and "load it up " to performance levels it was never intended for. then wonder why it blew up !

if you want performance get a modern action that you can stoke to your hearts content with no fear the modern design and steels will take it.

ruger #1 is one choice - for guys that want a classier and more sturdy action the wickliffe 76 is a good option. looks like a big stevens 44 1/2 . the factory chambered them in 338 win mag & 458. you would never have to worry about using your 30-40,or 7mm and larger in them.

anyone interested i can email a brochure & info

crownpress@alltel.net tom 814 774 5739

Mike: Rebarrelling one of the Swedish re-heat-treated Swedish actions to .30-40 sounds right. From 1889 to the early 90s, the Swedes took M1867 actions, replaced the breech blocks, hammers and extractors and re-treated the receivers themselves to handle the 8X58R. Their metallurgical skills had to be among the finest in the world at that time, and I would trust one of those actions before I would trust a later No. 5 smokeless Remington any day of the week. Still, as Tomo points out, these actions were obsolete then and much moreso now. But great choices for what you have in mind.

I hav 5 of these actions , M1867 Husquvarna , I barreled 40/65 on the sporter version , 45/90 & 50/110 on the heavier actions one is a 12.7X44R it is so nice I left it as original ,Got Brass from Buffalo Arms with 350 grain bullets , These actions R.C. in the low 40's! a Ruger #1 R.C's in the low 40's as for the internal parts they are case hardened , I would not trust loading over 30,000 PSI , I only use Hodgton Triple 7/3/F and crush .100 with .030 spacer or gas check ? which ever you like to call them ? I have a rolling breack block that was blown completely out of the action here if you would like to see it? use my personal e-Mail for picture ! It came out of a Remington Rolling Block 45/70 not a #5 action using IMR 4064 , The man was lucky that he did not have it hit his forehead ! It did however take his hat off ! I have it Here for fitting a new breach block ! It's measurements are .775 wide and hole is for .454 pin anyone know where I might find one please advise , Not Lone Star ! Or VTI

quote:

Originally posted by asdf:
Lyman recommends keeping all the old BP guns to well under 20,000 CUP, including the Sharps and the large frame rolling blocks. Hodgdon says to just use the SAAMI 28,000 CUP spec, but even the factories load to under 20,000 CUP for fear of the effects on the old guns. There is some debate among RB shooters as to whether it is suitable for even the 40,000 CUP .30-40. The owner of Lone Star had an original 7mm disintegrate on him with modern factory ammo. I have a No.5 on order from him, but I will load mine down to under 35,000 CUP.

I believe that the old smokeless RB actions were once considered capable of using military ammo generating up to around 40K PSI. BUT they have aged alot since they were made, and this fact is bound to have made them weaker than they once were. In addition, there is some difference in headspace dimensions for the 7X57mm round as chambered in the rolling blocks and as chambered in modern 7X57mm rifles- the RB has a "more generous" head-to-shoulder length than modern chambers. I don't know if this is because Remington wanted the rifles to function under dirty battlefield conditions, so they made the chambers big, or if the specifications for the round have actually changed since the RB's were made.

The main issue when using the older, "BP" actions is that the firing pins should be turned down and bushed if smokeless loads of any significant pressures are going to be used..... (20 K or more.....)