.45-70 Marlin

Trail Boss in the .45-70 for light recoil

Q: I own a Marlin lever-action in .45-70 which kicks like a mule with full-power reloads. Since I intend taking up Western action shooting I’d like to make up some light-recoiling loads.

I’ve been told that Trail Boss is the best powder for this because it is bulky and doesn’t need fillers. Could you suggest a decent load using the 405gn LFP bullet?

Reg Ellis

A: You are right. Trail Boss is a high-density powder and this is the secret of its success.

The granules, which resemble miniature doughnuts, have a bulk density of 0.3 grams per cubic centimetre. Many of the pistol powders we previously used have a density of 1g/cc or more.

Don’t confuse this term with loading density, which is the amount of available space in the cartridge case, which is filled with powder.

Using ultra-fast pistol powders increased the amount of empty space, giving rise to problems due to powder position in the case unless you used a filler.

By my rule of thumb, loads closer to 100 percent or even lightly compressed tend to improve accuracy.

In the .45-70 with a 405gn cast bullet, the maximum load of 13gn (which is pretty much a case full) yields 1000fps.

My load development started with 11gn, which gave 940fps; 11.5gn got 965 and 12gn gave 1015fps, for an increase of roughly 15fps per 0.5gn increment.

Take your pick, but for Western action shooting 11.5gn seems just about ideal.




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Nick Harvey

The late Nick Harvey (1931-2024) was one of the world's most experienced and knowledgeable gun writers, a true legend of the business. He wrote about firearms and hunting for about 70 years, published many books and uncounted articles, and travelled the world to hunt and shoot. His reloading manuals are highly sought after, and his knowledge of the subject was unmatched. He was Sporting Shooter's Technical Editor for almost 50 years. His work lives on here as part of his legacy to us all.