.40-65 Winchester.; this old thumper is equally at home in lever actions and single-shots.
This renaissance has been a boon in some ways, a curse in others. The single-shot version of the cartridge is distinctly different than the original; bullets cast for this purpose are generally not usable in the 1886, nor is the reloading data. On the positive side, top-quality brass is readily available from Starline.
Here we will deal only with the challenge of getting ammunition that shoots in an 1886. First, what are the problems?
The major one is the requirements of lever actions with tubular magazines. Cartridges must be a certain length, and no longer or shorter, in order to feed and eject properly. The bullets must have Hat or round noses to ensure they do not ignite the primer in front under recoil. And bullets must be firmly crimped, which means the length requirement makes cannelure location critical.
The factory load for the .40-65 Winchester (also known as the .40-60 Marlin but not to be confused with die .40-60 Winchester which is a distinctly different cartridge) used a 260-grain bullet, and reloaders for 1886s should stick with that weight, at least to begin with.
The first problem you are likely to encounter is a difference between bore diameter and chamber dimensions.
Because the .40-65 began life as a black-powder cartridge firing soft lead bullets, the rifle depended on the "bumping" action of black-powder ignition to expand the diameter of the bullet before it entered the bullet, to engage the rifling. So a smaller-diameter bullet was loaded and the chamber so fitted.
If the bullet does not engage the rifling, you will get poor accuracy at best, keyholing at worst.
Smokeless powder does not bump a bullet, lead or otherwise. The obvious answer would be to use a larger-diameter bullet, but this is not always possible because the chamber may not accept it.
There are various solutions to the problem. One is to stick with loads of Unique and soft bullets. Unique does emulate the effect of black powder sufficiently to bump a bullet if it does not require too much expansion. Another solution is to find some,406-diameter bullets with a hollow base, similar to a modified Minieball. These will expand ahead of any powder to engage the rifling.
LOADS FOR THE .40-65 WINCHESTER Bullet Bullet Powder Starting Max. Source Weight Load (gr.) Velocity (gr.) (fps) Lead 260 Trail Boss 11.0 1,122 Wieland (Hayley) Lead 260 IMR 4198 23.0 1.113 *COTW Lead 260 Accurate 24.0 1,353 Accurate 5744 Arms Lead 260 Unique 14.0 1,464 Wieland Lead 260 Hodgdon 40.0 1,624 Wieland 4895 Lead 260 IMR 3031 44.0 1,959 COTW *Cartridges of the World by Frank C. Barnes
Although it is very popular with the long-range black-powder target crowd, their rendition of the .40-65 is radically different than Winchester's original. Bore diameter is .408-.410 inch rather than .406 inch, rifling twist is much faster, and bullets weigh from 330 to 400 grains rather than 260. The bullets often have a sharper nose than I would like to have resting against a primer, and the crimping groove is in the wrong place. Loading data (where available for smokeless powders) is simply not adaptable to the above-listed demands of a lever action.
It may be possible to find cast bullets with gas checks to allow higher velocities for hunting, but I have not seen any. Nor have I seen molds and gas checks available that would allow you to cast your own.
Something else to keep in mind: If you decided to embark on an odyssey of load development with custom molds and the like, factory sights on an 1886 are adjustable only so far. Increase velocity by too much and you quickly run out of adjustment room, necessitating a sight revamp. Stray very far from Winchester's original specifications for this rifle and cartridge and the obstacles mount up quickly.
For a 260-grain cast bullet, die best powders I have found are Unique, Accurate's 5744, IMR Trail Boss, IMR 4198 and 3031, and H4895. Each fills a unique niche with this cartridge.
Unique, as mentioned above, can (within limits) bump a soft bullet, and it provides velocity in the 1,200 to 1,500 fps range.
Accurate 5744 is an all-arounder, easy to use and ignite, requiring no filler and giving midrange velocities.
IMR's Trail Boss is a bulky powder intended for high-volume production of Cowboy Action loads. It fills the case, delivers moderate velocities and provides a lot of fun shooting.
IMR 4198 has been recommended for decades and is still worth experimenting with as you look for the right load for your rifle. It begins with very low velocities.
And speaking of velocity, there is great variation in measured velocities in individual rifles, with velocity delivered from my 1886 varying by as much as 500 fps from published data. Loading for an 1886 in .40-65 gives you a taste of what life was like for handloaders in the early days of smokeless powder. It's an adventure.
Finally, H4895 and IMR 3031 are extruded powders that will give the .40-65 as much velocity as it can take, if you want to load it for big game. With open sights and its looping trajectory, the .40-65 is a 150-yard deer cartridge at best, but that big, soft 260-grain bullet is a very reliable killer.
WARNING: The loads shown here are safe only in the guns for which they were developed. Neither the author nor InterMedia Outdoors Inc. assumes any liability for accidents or injury resulting from the use or misuse of this data.