the 45/120 and the 450 Ne are VERY simular, so here's the WHY on people poohpoohing the 45/70 but saying the 450 NE is enough...

and why I am building a 45/120 double, not 45/70..

a picture is worth 1000 words

Jeffe
Ive always wondered one thing. Maybe you can answer? 45/70s can be loaded to some high pressures. IE ruger #1 loads. On the shotgun/ double rifle how much more can you go before you hit the pres limit?
I am an old fashion soot lord (blackpowder guy). The 45/120 was made to get more holy black in there because the sharps and such could take the pres. Seems like you are going to have alot of space left in your case.
Dean

Thats why I'm planning on a 45-90. Still room enough for 2000+fps with a 400+ gr, but close enough to shoot factory 45-70 in a pinch. Damn, though, that 120 case IS IMPRESSIVE. Hey, I can run in a 120 reamer, if I get bored.

It's norma brass. I guess I need to section a 45/70 and 45/120 to show clearly the cases.

Much like loading a 458win mag to HIGH pressure, and a lott to low pressure, to get 2150 with a 500gr bullet, except MORE so.. it's nearly 1.25" longer than a 45/70, not "just" .80

I would like to see a side by side photo if you would be inclined to indulge me.....

i'll do that tonight

Jeffe
Maybe I am starting to understand. I always thought the winmag was high pres because the limited case volume forced one to use a hotter powder to reach the speeds you could get with a 458lott using and more "normal powder" But I guess what you are saying it has to do with the "taper" of the case?
Not doubting anyone just trying get an understanding.
Dean

The theory is that a larger chamber area can work at a lower pressure and get the same job done as a smaller one at higher pressures. Less efficient but more fun and interesting. R.

Dean..
it's about capacity .. and velocity, assuming you apply the same reloading practices...

i think the winmag is about 92gr, and the lott is about 108 gr...

and if your target velocity is 2150 with the same bullet, and you are trying to load to the lowest possible pressure to GET there ...

well, the winmag is a 63K psi load at 2150 .. and the lott is the same at 2300 ..

BUT, if you load the lott to 2150FPS (even with its top powder) pressures will be VERY much lower than the winmag.

IF you can load a 400gr .458 in a 45/70 to 2050fps, if you use the same reloading practice, loading that same bullet, in the same length barrel, loading a 45/120 to the SAME velocity will result in MUCH lower pressure....

of course, you could jack a 45/120 to MORe pressure and drive a bullet faster, but not for me!
jeffe

450 NE 3 1/4?

okay.. i'll post a picture of a 45/70 case, and 450 NE 3.25, and 45/120 ...

it will be crystal clear as to why the 45/70 aint enough gun

quote:

Originally posted by jeffeosso:
Dean..
it's about capacity .. and velocity, assuming you apply the same reloading practices...

i think the winmag is about 92gr, and the lott is about 108 gr...

and if your target velocity is 2150 with the same bullet, and you are trying to load to the lowest possible pressure to GET there ...

well, the winmag is a 63K psi load at 2150 .. and the lott is the same at 2300 ..

BUT, if you load the lott to 2150FPS (even with its top powder) pressures will be VERY much lower than the winmag.

IF you can load a 400gr .458 in a 45/70 to 2050fps, if you use the same reloading practice, loading that same bullet, in the same length barrel, loading a 45/120 to the SAME velocity will result in MUCH lower pressure....

of course, you could jack a 45/120 to MORe pressure and drive a bullet faster, but not for me!
jeffe

The capacity of the cases in question are as follows:

45-70 case holds 75.51 grs water

45-120 case holds 113.04 grs water

450NE 3 1/4" holds 136.04 grs water

Most 45-70 doubles are regulated with a 350 gr bullet @ 1800 fps

The 450NE 3 1/4" doubles are regulated with a 480 gr bullet @ 2150 fps

The 45-120 regulated with a 400 gr bullet, @ 2050 fps would be 100 fps slower, and with an 80 gr lighter bullet. The 450NE will have as low, or lower chamber pressure than the 45-120 loaded with a 80 gr lighter bullet, @ 100 fps lower speed. This defecit is caused by a 23 grs of water less powder capacity in the 45-120 case, resulting in haveing to use an 80 gr lighter bullet to get up to within 100 fps of the 450NE, so the comparison to the 450NE is not that close!

Still, I think if a guy were building a double rifle from scratch on a shotgun action, and would regulate the rife to 2050 fps with quality 400 gr bullets in the first place, instead of simply re-chambering a 45-70 double the resulting rifle would be much more favorable!

A rifle set up the way I mentioned above chambered for 45-120 coming in at around 10 lbs, with good express sights, and a low powered scope in QD mounts, would be a real tool in the moose canoe, and wild Boar, and black bear, wouldn't have a chance!

Mac,
I think you are mixing 450 #2 and 450 NE case capacities.. no matter, I will weigh them both when I get home..

I want an AS LIGHT AS POSSIBLE 45-120 regulated at 2000fps with a 400gr bullet for practical purposes to shoot deer and pigs and remington 405s... its goign to be sortish barreled, and not intended to get big pressure.

and if a 45-70 can do that with high pressure loads, just think how a 45-120 can do it with less

I agree very much with Jeffeosso on the idea of 45-70 is not enough. It's not about higher pressures but about getting a chambering thats freindly to the action and design at hand. The 45-70 is good cartridge in itself but not as flexible or versitle as another with a larger capicity. R.

First request.. Show the 45/70 and 45/120 .. I added the 450 NE (kynock brass) for further comparison

Note that the 450 NE and 45/120 are EXACTLY the same length

Next, direct compare of the 450NE to the 45/120..
450 NE has the thinner rim, greater body diameter (do NOT jump to conclusions)

Sectioned cases - Calibers marked
I have been asked if I was worried about "weak" 45/120 brass.. pictures are hard to lie with ...

the 45/120 NORMA appears to be of heavier construction than the 45/70 RP .. and was somewhat harder (or just more resistant to cutting) than the 450NE kynock

Oh, note the 375 RUM case, just for grins to compare to.

Long and short of it, the web is .01 thicker on the RUM than the 45/120 or 45/70... the 45/120 and 70 are the same.. the 450NE kynock is .008 thicker than 45/70 or 45/120.

This should put to rest any fears that the 45/120 is "just" low pressure, as it is the heavier CONSTRUCTION as the "super dooper" 45/70

Last but not least.. Case Capacity...

45/120 Norma NEW -- unfired, unsized, stuck old primer in

450 NE berdan primed Kynock cases RESIZED.. seemed to be denser and walls UP by the neck thicker

45/70 RP cases, fired, not resized...

so go 5 grains +/- if you like

empty case weight then filled case weight.. as close to the same as possible, average of 3 weighings

450NE case 325.1e 447.3 f.. net 122.2gr h20

45/120 241.2 e (no typo 241.2) 366.5 f 125.3gr H20 (yes, it weighed MORE water than the 450 NE.. i measured each 3 times

45/70 168.2e 251.5 f, or 83,3gr

The 45/120 norma has a TINY ammount more space than the 450 NE, as measured on my digital scale. duplicate cases (i sectioned the originals) can be made available at the march 9th shoot.


Long and short of it, I can't think of one practical reason to build **MY** pig/deer/water jug doublerifle-from-a-shotgun on 450NE..

I think the light came on for me. What is lowering the pressure is the increase of the surface area of the shell / chamber. Giving a large area for the force to be spread over. thus lowering the pounds per square inch. The increase of volume causes the increase of surface area.(can be done by increasing diameter or length)
Thanks I am a bit slow.
Dean

well, sorta... bigger case means more capacity.. using the same load techniques, you can get more velocity with less pressure, by increasing volume

big enough case (to a point) means you can load the pressure way down (area under curve) and get the same results, though not as effeceint.

you can load a 30-378 down to 30-30 levels,,, if you wanted, and it could be (depending on powder choice) VERY low pressure

quote:

Originally posted by jeffeosso:
Mac,
I think you are mixing 450 #2 and 450 NE case capacities.. no matter, I will weigh them both when I get home..

When you get home check pages 598, 612, and 621 of "The Handloader's Manual Of Cartridge Conversions" by John J. Donnelly

The 450NE#2 has even more capacity, but I don't have the numbers for that one at hand, and it is not listed in the book by Donnelly! The 450NE 3 1/4" is definently 136.04 grs water, as opposed to the 45-120's 113.04 grs water.

Mac
i weighed em myself, on the same scale... typos happen

quote:

Originally posted by jeffeosso:
Mac
i weighed em myself, on the same scale... typos happen

Was the 450NE 3 1/4" case you weighed against the 45-120 from Norma like the one sectioned in your picture? if so, the Berdan primed case will always have less powder capacity than a Boxer primed case of even the same cartridge! Nobody uses Berdan primed cases today, and the Donnelly book is all Boxer primed cases. Maybe that is why they seem so close to you!

But surely with black powder the pressure, regardless of the case size, is always the same regardless of the being .30-30, .32-40. .40-65, or Etc.

I was always led to believe that the pressure was lower but for the full length of the barrel. Thus, in shotguns in Britain for many years the first or "provisional" proof of the unfitted barrel was always done with black powder to show any flaws up the ENTIRE LENGTH of the barrel.

So, with black powder, there is no differnce in pressure between a .45-70 or a .45-120 surely?

And would those early .45-70 cases be balloon headed? So more capacity?

be that as it may.. I can get the 400/405gr bullet, with short barrels, in the 45/120 to go 2050 and be UNDER 30K psi...

which fits exactly what I want it to do, which aint to compete with eithe rthe "REal" 450 NE or super duper hot 45/70 loads ..

or, it suits me

quote:

Originally posted by jeffeosso:
be that as it may.. I can get the 400/405gr bullet, with short barrels, in the 45/120 to go 2050 and be UNDER 30K psi...

which fits exactly what I want it to do, which aint to compete with eithe rthe "REal" 450 NE or super duper hot 45/70 loads ..
or, it suits me

Now that's a real reason to build any rifle, because it suits you!

Jeffe,

What's the wall thickness of the cases before the radius?