I am considering a 1874 sharps in .45-120 and would like to know if the barrel length become surperflous at some stage.
Will a 34" barrel generate much more velocity than 28" or 30"?

If I get this rifle, I would most likely come out after wood bison in Canada this winter. So the next question;
Are there any problems that black powder experiences at extremely low temperatures?

I'm pretty much thinking that Geo nailed it for you, especially regarding the "lessor" 45's. For like weight bullets you gain perhaps 200 fps in muzzle velocity over the .45-70. Lot of grief for little gain. Only advantage to really long barrels is for offhand shooting as their weight steadies the sight picture, at least as long as you can hold it up, -10 seconds. Again, Geo has a point regarding leading insofar as cast lead bullets are concerned. Not sure that would apply to Paper Patched bullets, never tried them in a 34" barrel.

I have 7 BPCR rifles, so have a "little" experience with these...

If you're looking to be "authentic" at all, the .45-120 was never chambered in Sharps rifles (at least not by the factory).

From what I hear, the .45-3.25" isn't the easiest to either shoot or to extract a great deal of accuracy out of.

Sharps' longest "Sporting" cartridge was the .45-2-7/8" (.45-110).

Most 1874 Sharps rifles were chambered .45 cal. were either .45-70, .45-2.4" (called ".45-90" by Winchester) a small number in .45-2.6" (.45-100SS), or .25-2-7/8 (.45-110SS).

Most modern day shooters describe having fouling problems with the long cases and barrels in excess of 30".

Dan, I would not call 200 fps little gain. If Ray A. catches you bragging about a .458 WM at 1900 fps with a 500 gr bullet he has a coniption but the same bullet at 2100 is a real killer.

More realistically, a 200 fps increase over 1200 fps to 1400 fps is almost a 17% increase and enough that you might make a better call with respect to trajectory or even penetration.

200 fps in a .30-06 vs 300 WM type of cartridge probably doesn't matter much over most hunting differences. Scale is everything here.

Personally, I like a .45-2.6" case or a .45-2.4" case. Had both, love both.

Brent

Exactly right Brent!

It DOES depend on the bullet weight whether 200fps is relative or not!

Hi Brent, now I guess I have to "defend" my big yap... Aw, okay. In terms of muzzle velocity increase it is a large percentage, no argument there. In terms of what you gain for what you pay, maybe not so large. The velocity spread I quoted came from Cartridges of the World IIRC, and represent the factory numbers for like weight bullets betwixt .45-70 and .45-120-3 1/4, and I think were for bullets in the 470 grain range. Where the difference counts of course is on target, and I assume that would be some ways down range. You can define "some ways" however you like. In terms of the heavy bullets, well, up close there ain't but one degree of dead, and both cartridges will accomplish that. My perspective is that further down range the velocity spread will not be all that great because the faster bullet is operating at in a higher drag environment and will shed velocity faster. I know the BC's of but a few bullets of that nature but as an example, Lyman's data for the 457132 490 gr mould gives a BC of .384. Given 1200 fps and 1400 fps(muzzle) the 600 yard numbers are 860 fps and 916 fps respectively. The energy spread is about 100 fpe. TOF is 1.82634 sec vs. 1.6608 sec. Here's a funny one for you BTW, 10 mph deflection at that range is 66.02 inches for the fast one, 57.44 for the slower of the two.(.22 Match ammo vs. Hi-Vel will do the same thing)



The crosswind deflection is not a typo BTW and is symptomatic of the reason that 200 fps advantage evaporates over longer ranges. The highest drag environment a bullet faces is in the Mach .7 to Mach 1.3 velocity range. Wind deflection is mostly a matter of drag and the higher your get into that realm the more drag you generate. So, Speedy Gonzalez spots the Turtle a 9" advantage in drift, while the Turtle gives up an extra 92" of drop if both are sighted at 100 yards(this in context of -406" for the 1400 fps round). I only sez what I seez on this one...I find the 3-1/4" cases awe inspiring to look at, but still think it's a lot of thunder for little gain. BTW, those velocities are for the sake of comparison and not representative of the referenced cartridges. It was convenient.



Still, I'll probably succumb some day and buy one from somebody that got hypnotized...

Well, I guess we agree although our perspectives are from a different origin. All's well on the Western Front.



Thanks for the link. I nearly fell out of my chair when I saw your design! I "designed" a bullet a few years back with the collusion of Russ at Montana Precision Swaging, who in turn worked with somebody at Corbin to cook up something so similar in profile it is bizarre. My "delaminator ring", also at the ogive, was spec'd at <.005" step, this on a .422" diameter and .20+/-" meplat. Otherwise I doubt you could tell them apart visually. Funny part is that my purpose had nothing to do with aerodynamics. It's purpose was nothing more than a convenient reference for patching. I load them in .44 Mag, weight ranges from 250-350 grains are available, cup or flat base. I fiddled briefly with some 250 gr. bullets, but for the last 2000 rounds of so it's been 300 gr flat base at 1535 fps average. If I do my part they are good for MOA and have shot in the 8's with some regularity. Best I can figure the BC is in the neighborhood of .24 based on drop, not certain about that though. I haven't a clue if the "ring" accomplishes anything or not beyond my original intent. Shank drag is very small, but maybe you're on to something. I never did get a set of prints for the bullet, the designing was VERY informal.



If you know somebody that wants to make a Jurrasic .444 tell 'em to call Russ.



Catch you later.