45-70, 45-90, 45-100, 45-110, 45-120 Compare

[GrampaMike]

Because of all the “talk” about these cartridges lately, and the conversation getting me to thinking about converting one of my BCs.   But not knowing which one is maybe better in some way, I decided to do a comparison.  Loaded all loads found in all of my load manuals into a spreadsheet.  First I deleted all powders where each cartridge did not have loads to represent it.  True, this did not leave many loads, but enough for my purposes.

Averages              Muzzle     Recoil      Energy lbs per
                          Energy                        Recoil lbs

45-70 Govt           2250           25                  90
45-90 Win             2569          33                  78
45-100 Sharps       2553          34                  75
45-110 Sharps       2803          39                  72
45-120 Sharps       2967          41                  72

My only conclusion is the 45-70 has the edge in cartridge efficiency, but the best reason seems to be is to have something different.  So I am back where I started.  It is good to have choices…

[Westbound]

Wow, it's suprising that the 45-90 outperforms the 45-100 on energy, and does it it with slightly less recoil

I've entertained the thought of rechambering, but I've decided to wait until I get a second BC.  I was pondering the 45-100, but the numbers just changed my mind.

[GrampaMike]

I am not sure but maybe "45-90 Winchester" case itself is probably different than the "Sharps" cases, that may account for the different loads I found.  I am sure someone here must know...

[quickdtoo]

Here's a tidbit to chew on..... The Lee 2nd lists a 45-70 500gr bullet with 52gr H4895 at 1679fps with a COL of 2.7"(another 45-70 H&R gotcha) in their modern rifle data which they use a max pressure of 50kpsi for most of their loads, but no pressure listed for that particular load, Hodgdon lists 60gr H4895 and a 500gr bullet in the 45-120 at 1809fps, but at less than 30kpsi. I've included some smokeless 45-90 data below.

Tim

http://data.hodgdon.com/cartridge_load.asp

[Jimbo47]

That's the kind of chart that can get you into a whole lot of trouble with the wifey.

If she would see that and knowing how practical women are with their thinking, you would have a hard time explaining why the old 45-70 although being such a great cartridge, just wasn't as good as that 45-120 will be, and the need to buy that other rifle.

[tykempster]

Low pressure loads can only do so much.  They are really inefficient in the bigger cartridges.  If you want a true comparison look at loads with the same pressures...

[LONGTOM]

I want to pursue this in another direction.
The 300gr seems to do all I need as far as bullet weight at this time.
Having two BCs I too want something different.
It seems that the average velocity for a 300 is around 1800 give or take with out hot roding it.
What kind of velocity would one get in a BC with a full case of BP in each of the five 45s length's? (70,90,100,110,120)
Just curious.


LONGTOM

[tykempster]

Blackpowder can only get bullets so fast I believe, so in the 45-120 it might push a 600 and 300 grain bullet pretty close to the same speed!

[Smokin Joe]

Wow, it's suprising that the 45-90 outperforms the 45-100 on energy, and does it it with slightly less recoil

The difference is case capacity. The drawn .45-100 cases are made from .348 Winchester. The .45-90 is a stretched .45-70. The internal capacity isn't much different until you get to the .45-110

[GrampaMike]

LongTom, you have a good idea, will try and break it down by bullet weight...

[Swampman]

The .45-70 with a 405 grain bullet at Trapdoor velocities will do everything I need.  I might consider the .45-90, but I don't want to fool with the weight and awkwardness of the B&C barrel.  I love the Handi because it's handi.

[TopperT]

Re: Black Powder Loadings:  I am using numbers found in "SPG Lubricants B.P. Cartridge Reloading Primer", by Mike Venturino and Steve Garbe.  (these guys really know Black Powder Cartridge shooting).

The only bullet that all cartridges shared in the listing for each was the 520 Grain Lyman #457125 in #2 Alloy.  The results are as published:
45-70     61 grains FF     1180 fps.
45-90     75 grains FF     1275 fps.
45-100    85 grains FF     1312 fps.
45-110    95 grains F      1365 fps.
45-120   115 grains F      1405 fps.

The 45 Caliber Lyman # 457125 weighing in at 520 grains were credited by the authors as having:
(muzzle) Energy (ft/lb)
@1200 fps  1663
@1300 fps   1952
@ 1400 fps  2264

Some comparison can be made from this I think.  Interesting indeed.  Jim.                       

[GrampaMike]

Found these numbers     Case Length     Case Capacity

45-70 Government             2.105"             79.0 gr
45-90 Winchester              2.400"             88.0 gr
45-100 Sharps 2.6"            2.600"             87.1 gr
45-110 Sharps 2 7/8"         2.875"            104.2 gr
45-120 Sharps 3 1/4"         3.250"            113.0 gr

45-90 case has more capacity than 45-100... curious...

[TopperT]

"tykempster".....I forgot to add that while there were no 'published' figures in my "SPG" book for the 45-120 re: BOTH a 600 and 300 grain bullet, its my understanding that performance "limits" would 'set' by the amount of powder that could be placed in the cartridge.  

The 300 grain head being smaller would leave more room so to speak and thus produce greater velocity from more powder.

The book I use lists for the 45-70 the following for a 330 and 520 grain bullet respectively:  
330 grain 75 grains FF 1445 fps.
520 grain 61 grains FF 1180 fps.

Depending on the 'type' of powder, my research to date, indicates that some powders  do NOT like 'compression' and can even loose effectiveness.  Swiss Powder for example is cited as one that does not like compression.  Shooters who use this have (so far as I have discovered) relied on lower 'innitial' case amounts for the trade-off of still higher performance.  or in short, more with a tiny bit less.  The is especially true of the 38-55.  Hope this helps.  Jim.

[bajabill]

what fuels my reservations about reaming my 45-70 is the lack of high power data for the larger, obsolete cartridges.

I can find all the data I want to load the 45-70 up to roughly 3300-3500 flb muzzle energy.  I know I can exceed this with equal pressure loads in the larger cases, but never really find a lot of documentation for it.  If I thought it was worth the risk, I could make my own with a load program but I like to keep it safer than safe and utilize published data.

[tykempster]

baja, those "high pressure" loads that are giving 3000 ft lbs in the 45-70 are giving me 6000 ft lbs in the 45-120.  Quickload is your friend...

[GrampaMike]

3 Different cast bullet weights all using Accurate 5744 powder and all at 28K CUP.
And all using 32" barrel and 8 lbs for rifle weight to calculate Recoil.


Accurate 5744                            Muzzle     Muzzle    Recoil     Energy/
325 grain bullet                              Velocity   Energy                 Recoil

45-70 Government                 38.6 gr   1947       2735      26.3        104
45-90 Winchester                 45.4 gr   2049       3029      30.7         99
45-100 Sharps 2.6"    41.1 gr   1996       2875      28.1        102
45-110 Sharps 2.875"    53.0 gr   2112       3218      34.7         93
45-120 Sharps 3.25"    55.1 gr   2071       3095      34.4         90



Accurate 5744                            Muzzle     Muzzle    Recoil     Energy/
425 grain bullet                              Velocity   Energy                 Recoil

45-70 Government               35.3 gr   1751        2893        32.8        88
45-90 Winchester                44.7 gr   1900        3406        41.1        83
45-100 Sharps 2.6"              41.3 gr   1862        3271        38.5        85
45-110 Sharps 2.875"           51.0 gr   1970        3662        46.0        80
45-120 Sharps 3.25"            51.8 gr   1994        3752         47.2        80



Accurate 5744                            Muzzle     Muzzle    Recoil     Energy/
525 grain bullet                              Velocity   Energy                 Recoil

45-70 Government              31.9 gr   1554        2815       37.0        76
45-90 Winchester               44.0 gr   1752        3578       50.3        71
45-100 Sharps 2.6"             41.4 gr   1732        3496       48.3        72
45-110 Sharps 2.875"         49.0 gr    1836        3929       56.5        69
45-120 Sharps 3.25"           48.5 gr   1964        4496       62.8         72


I also calculated the same chart for 32K, 36K and 40K CUP.