Lighter 45-70 Gov't Loads For Deer and Black Bear

The Remington Core-Lokt, besides being spelled funny, seems to work well in everything from trapdoor Springfields to spiffly loaded Ruger No. 1 rifles. They expand quickly and retain weight at the velocity levels reflected in the load table. Is that “in” or “on” a table?  The Sierra Pro-Hunter has a little tougher jacket, but still fits this application. Hornady lists the FTX not only for strong lever action rifles, but also for modest velocity Trapdoor Springfield loads. They expand quickly but stay intact. The Hawk Precision is a pure copper jacketed bullet. The core is soft lead and the jacket on this particular bullet is 0.025″ and suitable for thin skilled game. It is another bullet that gets big quickly, but holds together.

The handloading exercise was relatively straight forward, with just a few twists driven by unique aspects of the various bullets

Notes

IMR Trail Boss is a terrific powder for assembling reduced loads for big bore cartridges. Unlike some powders that  do not respond well to low density use and pressure spike, Cheerio looking Trail Boss is low density and case filling. Pictured left, 19.5 grains of Trail Boss in a case that holds 79 grains of material with the density of H2O. Approximately 50 grains of Re10x would occupy the same space as the Trail Boss.

A subject case is marked at the depth the specific bullet is to be seated; the depth rod of a caliper is a good tool for the job, Trail Boss is filled to that mark and then that charge is weighed. That weight represents the maximum load for that cartridge and bullet combination. The starting load is determined by multiply the maximum charge weight by 0.7. I’ve used this for the largest big and dangerous cartridges and it makes for a lot of fun with a rifle that will otherwise see limited use. Tough to put a 100 full tilt rounds through a 500 Jeffery from a shooting bench and live to tell about it.

In the case of the 45-70, Trail Boss loads can be shot from the bench all day without ill effects and, while the velocity is low, the accuracy is high, offering the basis for useful target practice.

Cases were trimmed to 2.100″ with the exception of the cases used for Hornady FTX loads, which Hornady indicates must be trimmed down to 2.040″. As you can see, I spare no expense on case prep equipment… yes I am being sarcastic. 90% of my case trimming is done with an old RCBS manual trimmer. It is easy to set up by setting the outside jaws of a caliper to trim length, placing one side against the shell holder base and then sliding in the cutter until it touches the other caliper jaw, before locking the adjustment collar.

I bored some holes in a 2×4 to tightly match the trimmer base. This allows me to mount it on a flat surface anywhere in the shop, held in place with a C Clamp. Minus the 2×4, I mount the power trimmer the same way, held to the bench with a C clamp.

Another piece of high tech gear. Hand primer for CCI strip mounted primers with universal jaws. This one is about twenty years old and is as purchased with the exception of a new jaw spring. I use this during load development because it is fast, handy and it provides a good feel for seating primers. I have a bench model version and press priming tools but, like the case trimmer, it is used 90% of the time.

The material case wall thickness spec is only 0.011″, 0.010″ actual, and there is no spiffy neck or shoulder to add rigidity. For some reason, the Sierra bullet kept catching the case mouth until I added a Hornady expander to the die set. The bullet’s heel radius was generous and the diameter was fine, so I think the problem was the way the seater engaged the bullet’s ogive, causing it to lose axial alignment; the bullet entered at an angle and the heel caught on the case mouth.

Ultimately, an RCBS full length sizer, Hornady expander, Redding Competition seater, and Lee Precision crimp die were used with the exception of the FTX loads as the short case required for the FTX would not align with the Lee tool. I also could not use the RCBS expander as it opened the case too far even before a light flare was formed… meaning the bullet fell into the case without urging.

For my purposes, the Hornady FTX would probably be set aside, but only because I am lazy and have a problem committing. I don’t like spending the time trimming cases down 0.060″ to a nonstandard 2.040″ and then having brass that is then only useful with FTX bullets. But then they are very accurate, they retain velocity longer and they have good terminal ballistics. Let’s look closer…

Following a slippery slope

From the Real Guns exterior Ballistic Calculator and samples from the load data on this page.