The .45-90 vs. the .45-70 - is there a tangible difference?

[Quick Draw McGraw]

Just curious.

[bigbrowndog]

My 4590 in a Win 1886 will push a 405gr bullet at 2300fps easily with no pressure signs, I typically run it at 2200fps just to be extra careful. My 4570 in a Marlin 1895 will push a 405gr at 1850fps, granted the Marlin is an 18” barrel and the Winchester is a 26”. Essentially I see the 4590 as a 4570 from a Ruger 1 but as a repeater.

Trapr

[bradshaw]

"My 4590 in a Win 1886 will push a 405gr bullet at 2300fps easily with no pressure signs.... Winchester is a 26”.
----Trapr

*****

Trapr..... Whether this is an original Model 1886, or a new one, 2,300 fps from a 405 is .458 Winchester velocity. May we assume the 405 grain .458 Bullet is a jacketed soft point made for the .45-70? If so, it will flatten a large whitetail buck at the old-time 1,300 fps velocity. I loaded these bullets warm in a Ruger Number 3, loads which, after I saw how they demolish 5 gallon tins of water, I would not use on a deer.

What powder & charge gets you 2,300 fps in the .45-90 at mild pressure? And is it more accurate than the same bullet from a .45-70?

My limited shooting with cast 500 grain bullets over black powder in .45-90 indicate greater load sensitivity than with the same bullet in .45-70. By load sensitivity I mean more difficult to reign in extreme spread with the .45-90, which ES translates as vertical dispersion at target.
David Bradshaw

[bigbrowndog]

It is a PC’d 405gr, I’m at a hunting camp right now so can’t check powder charge to be positive but it is RL7. I’ll get back to you on exact charge this weekend when I’m back in town. I started low and worked up, and when I got to 2300 FPS stopped and went with 2200 FPS.

Merry Christmas, Trapr

[taffin]

Nov 27, 2018 19:52:58 GMT -5 bigbrowndog said:

My 4590 in a Win 1886 will push a 405gr bullet at 2300fps easily with no pressure signs, I typically run it at 2200fps just to be extra careful. My 4570 in a Marlin 1895 will push a 405gr at 1850fps, granted the Marlin is an 18” barrel and the Winchester is a 26”. Essentially I see the 4590 as a 4570 from a Ruger 1 but as a repeater.

Trapr

NO PRESSURE SIGNS? EVERY FIRED CASE SHOWS PRESSURE SIGNS.

[Quick Draw McGraw]

Interesting. I am curious because you can get a BFR cylinder in .45-90, but I don't know that it would be worth the trouble. I am guessing it's probably not going to give a noticeable difference in performance from a BFR.

[bigbrowndog]

Mr. Taffin,  there were no pressure signs!!!...........kidding I tend to write as a speak, so no high or excessive pressure signs.
I realize that straight cases show pressure in different ways than bottleneck cases do so I tried to be diligent and cautious by utilizing what I had on hand to help me in determining what was maximum and what was not. As I recall since 4590 data is mostly all old guns and blackpowder loads, I searched LoadData and found some loads for the nickel steel barreled 1886, and also took one of my 4570 loads for my Marlin, fired it in the Winchester chamber and measured case head expansion also took a fired case from my Marlin and measured its case head after firing. Also took maximum chamber dimensions (don’t recall where I found them) and used those measurements to determine maximum case head expansion that I would accept. memory says case head expansion on the 1886 was the same as the 4570 case from the Marlin.

385 Lyman #457124 Alliant RL-7 57.0 2,117
Remarks: max load; 24,900 cup    This load is from Lyman 48th edition.
I used a 405 gr bullet instead of the the 385gr listed. The load provided me 2300fps, as previously stated, I settled on 56gr. as it provided 2200fps.  The information I was able to find out on the 1886, was that it was easily capable of handling the listed CUP. So increasing bullet weight 20gr would not be a detriment.

www.riflemagazine.com/magazine/article.cfm?tocid=416&magid=30,....good article on the modern 1886.

Trapr

[bigbrowndog]

A mind is a terrible thing to waste and a memory is a terrible thing. I went back and looked at my notes and discovered I have no mention of reaching g 2300fps, I swear I did but unless I tossed those loads since I wasn’t going to use them I can’t find them.
However,......57gr of R7 provided these chrono readings with a PC’d 405gr bullet, 2218, 2211, 2196, 2185, 2200. The notes with the load show easy shooting and no pressure signs (no abnormal pressure signs)
I had started at 54gr and it provided 1975fps average, 56gr of R7 provided, 2140, 2175, 2178, 2157, 2178, again no pressure signs and easy shooting.

In my previous post I stated I currently use 56gr of R7, that is incorrect I do shoot the gun at 2200fps but with the 57gr load, and I alternate between it and a load using a 425gr Beartooth bullet at 2050fps using 54gr of R7.

Hornady shows .504 measurement at the case head or just above, my 45-90 fired loads measured .505 - .510 at the same point. I had some old factory PMC ammo that I shot and measured as well, it too measured .505 - .508. Primers are slightly flat as would be expected but still exhibit rounded shoulders and no cratering or flow back into firing pin hole.

These load appear safe in my gun, and I do not recommend anyone using them without starting at least 10% lower and working up from there. My rifle is a new Winchester 1886TD, not an older vintage gun from the turn of the 19th and 20th century.

Trapr

[mooshoo]

recoil

[bigbrowndog]

Mooshoo,....YES!!! But the rifle is 26” full octagon so it’s heavy, and I had the buttstock replaced with a more full piece and replaced the steel buttplate with a 1” kickeez pad.
Essentially it is a 450 Alaskan.

I had a 50 Alaskan built shortly after finding the load I wanted to use, and it was more fun and easier to carry so the 1886 has sat in the safe with less than 100 rounds thru it by me.

Trapr