Basically, there are three pressure levels for the 45-70: low (26,000 psi?), for old trap door Springfilds and old lever actions; medium (44,000 psi?), for new lever actions; and high, for Ruger #1s and modern bolt actions.

There is a huge difference in the cartridge's potential, according to what the different pressures one's rifle is able to safely fire. It seems to me that in order for the Spartan to be of interest to most of us, it would, at least, have to be able to fire the middle pressued rounds.

Just wondering.

Remington had put out the 26,000 PSI number but I had calculated the bolt face thrust for the 30.06 and the 30.06 will have more thrust. If you compare it to the 45.70 you should be able to load the 45-70 to 36,000+psi to get the same thrust as the 30.06 on the breechface.


45-70 (.608 Rim) .302*.302*3.14159*28,000psi = 8,022 Lbs force of thrust

30.06 (.473 Rim) .2365*.2365*3.14159*60,000psi = 10,542 Lbs force of thrust

But that's assuming that the chamber sidewalls are thick enough to handle that load.

Well, that takes care of that brilliant idea!

I wouldnt worry about it to much, pretty sure Donkey's will be flying and my exwives will be sending me money before they hit the market

Thrust is caculated on base size.
Actually inside tht case size,
but you have to section case.
Base of 45-70- is .505. So thrust for that
based on above formula at 28k is 5700 lbs.
Of course thrust is less on both 06 and
45-70 due to part of the thrust that case takes and inside diameter smaller than base.Which
is a factor of about 2/3 that I use.
So 45-70 could be loaded 44,000 in Spartan.Ed.

Remington just said late fall ...
moved again

jeffe

ed and jeffeosso...

what is the biggest cart you can rechamber this to with the 458???

45-100???



and what velocities do you think it could be pushed to within reason???

or leave it alone and use it as a hog gun?

BS,

I have heard of guys rechambering all the way up to 450 Nitro Express on some of the other 45-70 doubles.

I wouldn't think it impossible to rechamber to a 45-100 so long as the cases doesn't get significantly wider and the pressures don't climb too high.

The crux of the matter is however...the damn rifles may never show up! I would like to have one, in 45/70, just for the hell of it and I may never get the change to buy one.

quote:

or leave it alone and use it as a hog gun?

There's a reason Remington isn't selling these yet.....I have no clue what it is but the fact that it's being continuously delayed smells bad and frankly I'd be very reluctant to consider any rechambering until there was sound engineering information that anything above factory loads was safe.

There's just too much here that has a bad odor and safety just might be the hangup.....again I'm purely speculating......but it's not the worst guess to assume.

I am going to lengthen the throat to shoot 400gr/450gr barnes bullets. No other changes, it'll stay 45/70

jeffe

Actually, you should be able to chamber for 45-120-3-1/4", if there is no monoblock problem. I had a guy (20 years ago) borrow my reamer from a gunsmith to rechamber a Pedersoli 45/70, and he reported no problems. The whole concept of chambering past the monoblock line always bothered me though.

As to the comments on backthrust, they are generally the limit on breakaction guns. I have always used the above method for estimating. However, it doesn't take into account the effect of the wall grip of the cartridge. This would seem to help (which it does) but you have to be careful of apples and oranges. If you are trying to scale from a small, relatively nontapered cartridge, to a large very tapered, it can come out way to high.

Frank DeHaas on his book on constructing single shot rifles has a really detailed writeup on a method for calculating thrust and breechblock bearing size. It is well worth reading. I believe it looks to be technically accurate, the only fly in the ointment always being that you have to assume a coefficient of friction based on how oily the cartridge is. This is one reason to always degrease/deoil your cartridges after loading.

I should have mentioned that the reamer I had was for the 45 Basic. The 45/120 correctly has a bore of .451. Apparently Pedersoli thought so at that time too, since their 45/70 barrels were too small to take the reamer pilot. The smith ended up buying the reamer for the guy so they could grind down the pilot. I doubt it is the case now, but if you have an older Kodiak and shoot .458 bullets, pressures could be going higher than expected.

quote:

Originally posted by hubel458:
Thrust is caculated on base size.
Actually inside tht case size,
but you have to section case.
Base of 45-70- is .505. So thrust for that
based on above formula at 28k is 5700 lbs.
Of course thrust is less on both 06 and
45-70 due to part of the thrust that case takes and inside diameter smaller than base.Which
is a factor of about 2/3 that I use.
So 45-70 could be loaded 44,000 in Spartan.Ed.

With .505 for the 45-70 internal diameter and .440 (closest number I could find) for the 30.06

At 60K in the '06 case it should allow you to load the 45-70 to 47,000 PSI to get equivalent thrust.

But, I'll also agree that these continued delays are cooling me off on the idea of buying one. I would like to see someone shoot one with the 28K loads for awhile to see how they do.

First: I realize that this is on the Big Bore forum and most folks here are a little "strange" to begin with but how many of you can really take the recoil of a 458 Magnum in a 7 pound rifle. I sure as hell can't (won't). Rechambering the Pedersoli, which is a near 10 # rifle is a whole different thing than the Remington.

Second: You'd be very surprised at how little difference between a 40KCUP and a 28KCUP load. That last 12KCUP gets you very little. In the case of a 350gr bullet, the difference is barely over 100fps; ~2200fps compared to ~2090fps. Yes, I know that factory is not nearly that hot but they don't load anywhere near 28K in the first place; more like 20K.

Like Jeffe said, throat it to your favorite bullet, load it right up to 28K and grit your teeth, because it is going to hurt, real bad.

Mike

Mike,
this link is to movies on how you handle 116# of recoil. Warning, it's a couplep meg DL
http://weaponsmith.com/mov-550-exp.html

I shoot my "crackhead" big bore all the time.. a HR 45/70, weigh 6.25, loaded up prety hot...

kicks a BUNCH but not bad

jeffe

Well I did preface my statement by saying "strange". Maybe I should have added "a little tetched in the head"

I'll have to pass on the video. Out in the boonies with 28K dial-up isn't the place to down load moving pictures.

Hello,
Some two weeks ago, called Remington factory, spoke with Cust. Svc. rep. and explained to her that seen some owners in Canada talking about their "Remington" doulbe rifles made in Russia and she said that those could not be Remington for none, repeat none, marked Remington had ever been imported to North America. The ones in Canada were brought in under EAA heading and there were barrel ruptures and a recall had been issued but as usual, end users and some distributors had not returned them.

As for the units coming in under the Remington banner, she said that date was unknown, but did recognize that a serviceable double rifle under the 1000.00 level would certainly be popular and they looked forward to having all the troubles worked out and shipping them. This info not from distributor, dealer, but from home office of Remington Arms Co. Did note that a new presentation on their web site, but no date certain offered. They will be here when the get here is the true skinny I believe.

In the posts above, I didn't mention the reason I had the 45-120 reamer. BELL had not been making the brass long, and I wasn't aware of anyone who had chambered a modern rifle. I took a Ruger No 3, added a set of No 1 wood, and rechambered it from 45-70 to 45-120. Loads were worked up based on the Ruger action. The rifle weighed about 7.5# and the loads were in the 460 Weatherby range. Mike is correct, the recoil was atrocious. When developing loads, I used a PAST recoil shield and 25 # bags of shot between the buttstock and my shoulder. Fired offhand, it was brutal. It is the only rifle I have ever owned which I wouldn't let an inexperienced shooter try. I really believe it could have caused severe physical damage to the uninitiated. I personally don't believe rechambering one of the Remington's to a high cap case would have much merit. I suspect recoil of a heavy bullet 45-70 is all most people would want.

Art,
we need to form a club. I did the same thing, we call them Rugger #2's here in Idaho. Mine has a 30" 1 1/8-1" tapered octagon barrel and Laser-Cast 500gr 2200fps loads are not bad. A 24Bhn cast bullet will take a lot of speed. Of course mine weighs an even eleven pounds and the forend is 1/4" wider (fuller?) and the buttstock is 1" longer as well.

I plan to run the 120 reamer in mine as soon as I get some data accumulated from the 45-70 loads. An extra 1 1/8" of case has to be worth something at equal pressures. Picatinny Arsenals' 1997-2002 testing shows an actual velocity increase of one-fourth the case capacity increase as a percentage. IE: add 20% case capacity, see 5% velocity increase if pressure levels are maintained as a constant. You guys made me curious. I just filled both cases (once fired to show real capacity)with ReLoder-7 as a powder check. 45-70WW case 71.5gr. Bell 45-120 118.2gr. Average of five cases full weight. The 120 holds 1.65 times the amount of powder the 70 case does. If that is a 65% increase in powder capacity, then the 120 ream job should add 1/4 of that, +16.25% in the form of a velocity increase...right? I shoot my 45-70 Sharps with the 500gr Laser-Cast at 1500fps on elk, deer, and to date two buffalo (bison). All one-shot fast kills. IF, THEN...is the computer model; and it positions us to gain 16.25% over that stout but moderate pressure load and end up with a 500gr bullet at or near 1750fps. I WOULD point those two barrels at a Cape Buffalo and squeeze the triggers one at a time.

Rich

Rich

I can't speak to cast bullet loads, my experiment was with jacketed heavy bullets. I started with 45/70 Ruger loads at top pressure as a base and worked up from there. The case capacity is well above a Lott and very nearly equal to the 460 Weatherby. You can imagine the performance with Jacketed bullets and No 1 pressures. I wrote an extensive article on it which was tentatively accepted by Rifle several years ago, but the editor later declined.

My dealer was recently told by three different distributors that the 30-06 double rifles would becoming this summer all in one batch and will need to be "proofed" prior to being sold.

They all indicated that the .45-70's would not be coming - ever.

Les

quote:

Originally posted by Art S.:
I should have mentioned that the reamer I had was for the 45 Basic. The 45/120 correctly has a bore of .451. Apparently Pedersoli thought so at that time too, since their 45/70 barrels were too small to take the reamer pilot. The smith ended up buying the reamer for the guy so they could grind down the pilot. I doubt it is the case now, but if you have an older Kodiak and shoot .458 bullets, pressures could be going higher than expected.

I have the 134th Pedersoli double rifle off the bench, and the grouve dia is .458, and the bore dia is .450. This rifle has been re-chambered to 458 RCBS, and shoots fine with full loads.

There is a big difference between the Biakal, double and a Pedersoli. The Pedersoli is as solid as a bank vault. However, I think everyone has the wrong idea where re-chambering either of these rifle to a longer case. The fact is a 45-70 case/load that will push a 400 gr bullet to 2000 FPS will develope a lot more chamber pressure than the same bullet pushed to the same speed from the larger 45-120 (3 1/4") case. If the bullet is kept at the same speed, the pressures go down as the case volume goes up! The formula to determine thrust is OK, but it isn't a decideing factor in the re-chambering to a longer case. Double rifles do not,very often, or almost never, fail by thrust on the breach face, but blow the sides of the chamber from over pressure. The chamber pressure is far more likely to bulge the chamber walls, than to push the barrels off face, from high pressure. The thing one needs to think on is, the 30-06 has far more chamber wall thinkness than the same outside diameter barrel butt, with a 45-70 chamber. It is a dangerous practice to say simply because the same rifle that will stand 60,000 lbs chamber pressure chambered for 60-06, will automaticlly stand 60,ooo lbs after chambering to 45-70, or any place close to it.

The barrel butts, at the breach end on the Pedersoli, are 1 1/8" in dia, leaveing the wall thickness at close to 3/8". Addtionally, the Pedersoli isn't a Mono-block barrel set, but a shoe-lump, giveing a full 3/8" of uninterupted wall thickness.

The thrust formula is fine, but is not as simple as some want to make it. The actual thrust applied to the breach face is effected by the shape of the case, the length of the case, and the surface of the chamber. With the same pressure, a straight walled case will cause less pressure on the breach face than a heavily tapered case. The pollished chamber will apply more pressure on the breach face, than will the same cartridge in a rough chamber. The 45-120 chamber is not as hard on the rifle as the same bullet speed in a 45-70. The larger the case is, the lower the chamber pressure if the bullet is pushed at the same speed, with the same powder.
In fact, one would be better off to re-barrel the 45-70, to a 9.3 barrel, and chamber ot 9.3X74R which actually developes more chamber pressure, but give you thicker walls in the chamber. The 9.3X74R will push a 286 gr soft or solid at 2286 fps , and get 3400 fpe at muzzle. That is a far more versetile cartridge than the 45-70!

OK, I bought one of the Baikal 30-06 so I can give a good opinion of what hopping up a 45-70 could do.

First of all mine would not handle 30-06 pressure. The bbls would be pushed off face and the lever was realy hard to open. I shot mid-range handloads and they worked good, but get near max loads (or with factory loads) and it was just too much for the gun. Hopping up a 45-70 to higher levels may give pressure problems.

Second the jack screw system wich lets you regulate the bbls will need to be adjusted to compensate for the hopped up 45-70. Mine happened to have lots of adjustement room left to bring the bbls closer together (needed for heavyer loads and bullets). Yours may not have much room left as it comes from the factory and you may run out of adjustement before you can get the bbls to shoot together.

Third is that with the jack screw system the floater bbl must "chase" the fixed bbl when regulating. So with heavy loads that shoot wide the floater bbl must be adjusted over to where the fixed bbl is hitting. This causes the point of impact to be off to the left requiring you to move the rear sight to the right. It is quite possible you will run out of adjustement room for the rear sight before you can get the sights pointing where the bullets are hitting. This happened to me when I re-regulated from 165g to 180g bullets I had to move the rear sight all the way to the right, almost running out of adjustement room.

quote:

Originally posted by Republic of Alberta:
OK, I bought one of the Baikal 30-06 so I can give a good opinion of what hopping up a 45-70 could do.

First of all mine would not handle 30-06 pressure. The bbls would be pushed off face and the lever was realy hard to open. I shot mid-range handloads and they worked good, but get near max loads (or with factory loads) and it was just too much for the gun. Hopping up a 45-70 to higher levels may give pressure problems.

Second the jack screw system wich lets you regulate the bbls will need to be adjusted to compensate for the hopped up 45-70. Mine happened to have lots of adjustement room left to bring the bbls closer together (needed for heavyer loads and bullets). Yours may not have much room left as it comes from the factory and you may run out of adjustement before you can get the bbls to shoot together.

Third is that with the jack screw system the floater bbl must "chase" the fixed bbl when regulating. So with heavy loads that shoot wide the floater bbl must be adjusted over to where the fixed bbl is hitting. This causes the point of impact to be off to the left requiring you to move the rear sight to the right. It is quite possible you will run out of adjustement room for the rear sight before you can get the sights pointing where the bullets are hitting. This happened to me when I re-regulated from 165g to 180g bullets I had to move the rear sight all the way to the right, almost running out of adjustement room.

NOW! Gentlemen, here it is, from the horse's mouth, a man who owns one! The action being so loosly fitted that it binds with factory ammo in the caliber it was factory chambered for should shed some light on why "CHEAP", and "DOUBLE RIFLE" should never be used in the same post!

When you first look at it the action actualy appears to fit up nice and tight.... just that when you shoot it is not strong enough to hold the bbls on face. Problably wants to hinge open a little bit as well as a bit of stretching.

Mine may be one of the very first made or possibly one of the ones that were recalled and not returned. I have some hope (however faint) that I will recieve a new rifle that works a bit better.

Time will tell.