Can I safely use high pressure .45-70 data in .45-90?

[Naphtali]

Hodgdon, and probably all publishers of reloading data, classifies .45-70 reloads by the platform that shoots it: Trapdoor Springfield is the weakest; Winchester and Marlin lever actions being intermediate; and Siamese bolt actions and Ruger #1s being strongest. Can I safely use loading data intended for Ruger #1s in a US Repeating Arms M1886 .45-70 that has been converted to .45-90? What I'm asking is whether the additional capacity of the .45-90 cartridge compensates for the higher pressure shown by the data.

[claybob86]

Doesn't sound like a good idea to me.

[Jeff Quinn]

Hodgdon, and probably all publishers of reloading data, classifies .45-70 reloads by the platform that shoots it: Trapdoor Springfield is the weakest; Winchester and Marlin lever actions being intermediate; and Siamese bolt actions and Ruger #1s being strongest. Can I safely use loading data intended for Ruger #1s in a US Repeating Arms M1886 .45-70 that has been converted to .45-90? What I'm asking is whether the additional capacity of the .45-90 cartridge compensates for the higher pressure shown by the data.

The main clincher in this inquiry is that the gun has been converted, and thus you have a custom rifle, and the chamber dimensions may or may not be standard. There is no shortcut. Start with Marlin-level loads, and work up for YOUR rifle. H322 and RL7 will probably work out nicely for you. When you reach the top for your rifle, you will likely be pushing heavy Ruger-level loads, and maybe even better, but there is no quick, safe way to get you there. Also remember, a 405 grain and heavier bullet of proper construction doesn't have to be pushing 2500 fps to do the job. They will completely penetrate any mammal when started at around 1800 fps.

[CowboyTutt]

Naphtali, I would listen to Jeff's recommendations. I've met Jeff, and a few other Shootists, and they really, REALLY know their stuff. NONE of these guys are ordinary shooters. Just my humble opinion, but I've met enough of them now, and even have a few I could call friends. I would listen to what he has to say.

-Tutt

[1886]

I have worked up a look for my modern 86 .45-90 that pushes a Mt Baldy 405gr flat nose 2200fps out of a 26" barrel adjusted to the muzzle. I do not use the load. I do not have a strain gauge and no real reliable way of measuring pressure except velocity. The load manuals do not show a load that is even close to this level of performance. The cases extracted easily, primer pockets remained tight and case life was good. The load is punishing, read steel butt plate and probably unnecessary. I took the approach that Jeff describes by starting with max .45-70 loads for the Marlin 1895. A 405gr hard cast at 2000fps will/would in all likely hood penetrate well just about any animal that has walked for the past 30,000 years. Just a side note, I think it is well documented that the .458 Win. loaded with 500gr projectiles will not break 2000fps at the muzzle despite published data and it has become an African standard if I am not mistaken. Regards. 1886.

[Lefty Dude]

Do as Jeff suggests, All Rifles digest loads differently. This encludes pressure, velocity & accuracy. Loads worked up for Ruger# 1's & 3's may be off the chart for your 1886. I have a Ruger #3 custom barreled for 30-40 krag. The loads I shoot are above .308 and very close to 30-06 Max loads.

Be very careful loading top-max loads, approach them carefully & slowly.

Then make sure that load is defined & marked as such.

[Montanan]

Use ONLY published data

[Naphtali]

Okay, I have the M1886. It is a USRA/Winchester in .45-70. A friend of mine has the same rifle, but his has been converted [slightly] to .45-90.

I understand completely that were I to do this, working up loading data for this specific rifle, and [each] specific load must subsequently be done.

For about $60.00 conversion fee the M1886 action is capable of furnishing more than .200-inch additional case capacity in overall length when using Starline .45-90 brass. I do not know to what this translate in terms of additional powder or water capacity. Were I to convert and handload 400-410-grain hard cast LFN gas check bullets, what would be a reasonable estimate of improvement in safe muzzle velocity compared with what I can obtain from this rifle as it is -- in .45-70?

[1886]

I have a B 86 SRC that was converted to, rechambered to, .45-90. I do not know what if any other work was done to the rifle to allow it to accept the longer round. The rifle will not allow me to load 2.80" rounds into the mag. tube from the loading gate. They are too long. 2.70" is the longest she will accept. These length cartridges will feed from the mag. tube into the chamber freely if the rifle is held horizontally but if for some reason one holds the rifle vertically she will hiccup. I have sent the rifle to Mic McPherson for massaging. Does the $60.00 cover a simple rechamber job or does it cover additional work? I would like to know. Thanks. 1886.

[crs]

Naph - That is a small amount of $ if you like the rifle and what you want is a modern steel Winchester 1886 .45-90, which is what I purchased a couple years ago.


With the strong action and added case length, you can handload somewhat faster 300 - 400 grain loads than in the .45-70. Theoretically, you can get up into the .458 Win mag range with the 300-350 gr bullets, however, these may be a handful shooting off the benchrest. There are some VERY experienced big bore handloaders on this forum who can chime in with relevant information, but I suggest that you start by reading this article by Paco
http://www.leverguns.com/articles/paco/ ... erguns.htm

and then work down to or up to what whatever loads please you and your rifle.
All big bore handloaders will be interested in your results.
Best of luck.

[Don McDowell]

Okay, I have the M1886. It is a USRA/Winchester in .45-70. A friend of mine has the same rifle, but his has been converted [slightly] to .45-90.

I understand completely that were I to do this, working up loading data for this specific rifle, and [each] specific load must subsequently be done.

For about $60.00 conversion fee the M1886 action is capable of furnishing more than .200-inch additional case capacity in overall length when using Starline .45-90 brass. I do not know to what this translate in terms of additional powder or water capacity. Were I to convert and handload 400-410-grain hard cast LFN gas check bullets, what would be a reasonable estimate of improvement in safe muzzle velocity compared with what I can obtain from this rifle as it is -- in .45-70?

Unless you're planning to load black powder and settle for using 300-350 gr bullets so the c.o.l will stay with in the length limitations of that action, its a waste of time, and will require the use of much more expensive brass.
Pick up a good reloading manual or 2 (lyman 48 is a good place to start) and just load the 45-70 up to the potential of the rifle. Your shoulder will give out soon enough.
Staying with the 45-70 in that rifle should allow you to use 500 gr bullets and its not any big deal to pop those out of the barrel pushing 1400+ fps, and there's precious little on this or any other continent that will need to be hit by any more than one of those when placed well.

[Naphtali]

. . . Does the $60.00 cover a simple rechamber job or does it cover additional work? I would like to know. Thanks. 1886.

This is an excellent question. I am unsure. I assumed the conversion included rendering feeding of 2.88-inch cartridges (LNF bulleted cartridges being shorter). Your reply makes me pleased I continued this thread.

I believe the gunsmith is in Dillon, Montana, but don't hold me to that until I discuss this with my friend. I should have an answer within the week.

[Elkhunter1]

It's called a 45/90 for a reason, 90 grains of powder in a .45 caliber bullet. Just shoot Black and forget about it. i can load about 82 grains compressed beneath a 405 FP and hang with anyone shooting smokeless.

Clean up is easy...simple green on a cotton patch. Bore Butter to store and call it good.

"Smokeless powder is a passing fad"

[Leverluver]

$60 bucks is the going rate for a rechamber job and nothing more. Work on the action and loading port to accept a longer cartridge will run a heck of a lot more than that. And that is just to get to 2.8". If you want more than that, you better get a second mortgage. If you are not going to "stretch" out the useable OAL, you will gain nothing. The bullet or powder cares not how long the brass is; only the powder room beneath the bullet base. If the 45-70 and 45-90 are limited to the same OAL you gain zero powder room.

I have fired over a thousand pressure shots with the 45-70. I have to ask if you have really ever tested what the 45-70 can do. Most folks haven't and would be stunned (literally) at the recoil it will generate. I have also tested the 45-70 to Ruger type pressures and you would be shocked at just how little extra velocity you gain; generally less than 100 fps.

Set up properly, in a strong action that accepts the full 2.8" cartridge, the 45-90 can essentially match the 450 AK, but again, that isn't that much over what a top load in a 45-70 can do. Unless you have a legitimate use for that extra 100 fps (and can withstand it), it really isn't worth the cost.

[1886]

I agree with leverluver, $60.00 will get you a rechamber job and nothing else. To modify the rifle to properly feed the 2.80" cartridge is a big, expensive job. I would experiment with the rifle to see just how long a cartridge you can easily load into the mag. tube through the load gate. I will guess it will be 2.70". If this is the case it will almost certainly require additional modification in order to smoothly feed the longer cartridge into the chamber. Try holding the rifle vertically and see how she feeds. What I have written is what I have experienced. To have the rifle feed the 2.70" length cartridge from the mag. tube into the chamber smoothly will require some work but is probably not a huge job. If you stay tuned and patient I will post what Mic finds with my rifle. I further agree with Leverluver that the .45-70 loaded properly in the modern 1886 platform is a beast and fully capable against just about anything you care to shoot. You will probably give out long before the rifle/cartridge combo reach their fullest potential. Regards. 1886.

[Hobie]

The real question is, "Why?" as the benefits are so small as to render the exercise fruitless for most of us. Most can load the .45-70 to the point that they don't want to shoot the rifle. That is beyond what is needed. But Jeff's methodology is entirely correct, of course, as he answered the question you asked.