Reloading .45-70 with Triple 7

  • AUTHOR: mike
  • March 20, 2020
Reloading .45-70 with Triple 7

            I prefer real black powder over any of the substitutes, but I realize that in some parts of the country the real thing can be hard to find. Black powder is an explosive and lots of communities have imposed stringent storage requirements on it. It isn’t unusual to have to build a free standing, cinderblock, steel lined powder magazine for black powder storage. That often makes carrying black powder more trouble than it’s worth for sporting goods stores. Because most black powder subs aren’t classified as explosives, shops can carry them without worrying about onerous storage requirements.

            The best way to buy real black powder is to order it by the case from a distributor, and have it shipped to you. You’ll save a lot of money on the per pound price of powder that way. That’s what I do. Admittedly I go through a lot of powder, but, even if your powder needs are more modest, this approach can still work for you if you split the case with three or four friends.

            If you need to shoot substitute black powder there are basically three families of propellants to chose from. First there is Pyrodex, made by Hodgdon. It is a charcoal based propellant that is essentially a modified form of black powder with the sulfur removed to reduce its ignition sensitivity. Pyrodex was the earliest successful black powder substitute.  It performs very much like real black powder, but it is aggressively corrosive, so a quick clean up is required.

            The next family of B-P substitutes are the powders formulated with ascorbic acid. The major benefit of ascorbic acid based powder is a very low level of fouling that is mostly water vapor. The down side is that the powder is extremely hydroscopic; which means it absorbs water from the atmosphere. All genuine black powder and B-P subs are hydroscopic to some degree, but I remember the first ascorbic acid powders on the market would actually get soupy if you left them in an open container in hot humid weather. Over the years the manufactures have mitigated this quite a bit, but they haven’t eliminated it. The other downside of ascorbic acid powders is that the fouling is wildly corrosive to brass. Because of that I’d never use them in an 1866 or Henry rifle. And cartridge cases need to be washed soon after a shooting session. These powders will turn an unwashed cartridge case into a green, lumpy monstrosity in a few days.

                        The third family of black powder substitutes are the sugar based powders. While Pyrodex is chemically very similar to black powder, Triple Seven, also made by Hodgdon, is quite different. It is based on sugar. It is a relatively low fouling powder, and, while it too must be cleaned up soon after shooting, it isn’t as nearly corrosive as Pyrodex.

            As you can see, each of the black powder substitutes has their strengths and weaknesses. There isn’t a single black powder substitute that I’d recommend for everything. For instance I prefer Pyrodex pellets for both cap and ball sixguns and large handgun cartridges. Ascorbic acid powders work well for .38 caliber pistol cartridges.

            Triple Seven is about 15 percent more powerful volume for volume than black powder. That’s why I like it for rifle cartridges. When you are pushing Volkswagen sized slugs you want a powder that will move then down range with authority. Though Triple 7 is a black powder substitute, it isn’t black powder. It has unique characteristics that have to be taken into account when you load with it. Like black powder it should be loaded volumetrically, rather than by weight. And you have to realize that with Triple 7  your bullet choice will absolutely dictate your powder charge.

            Hodgdon has an excellent reloading manual on line. If you have access to the internet I recommend that you go to their website and download a copy. You’ll find Triple 7 loads in the cowboy action shooting area of the manual. The most important part of that section are the general directions at the top. The specific load information you can take as a sort of general guideline, but you’ll need to work up a specific load for your components. Here’s why. As Hodgdon’s into to Triple 7 says, T-7 needs to fill the case to the base of the bullet, but it should not be compressed. This is important. You can get away with perhaps a tenth of an inch of compression, but, go beyond that, and you can see pressures skyrocket. And you’ll get very erratic performance.

            Trust me on this. I know. When Triple 7 first came out there wasn’t any cartridge loading data available for it, so I loaded it like 2F black powder, with up to a third of an inch of compression…Holy Smokes that stuff was wicked hot!! Hot but not very accurate. Velocity spreads were enormous. It almost turned me off on Triple 7 until I learned how to load it.

            There isn’t any voodoo to the process. You just have to know how deep your bullet sits in the case. The easiest way to do that is to take a wooden dowel and stand it along side of your bullet and mark the stick at the height of the crimp groove on the bullet. To determine your powder charge until you can put the dowel on top of it and your crimp line is even with the case mouth. However much powder that is, it will be your load for that particular bullet.

            I had decided to build .45-70 Triple 7 loads for three different bullets. I’d be using  405-grain and  500-grain flat-based bullets from Montana Precision Swaging. I picked up a few 50-round boxes at the local Cabela’s. I’d also loaded up for the 405-grain hollow-based slugs I cast myself from a Lee Precision mold. I measured the lengths of each bullet and determined that the 405-grain hollow-base bullet, with its long skirt, would only allow 50 grains of FF Triple 7. The 405 and 500 grain slugs each accommodated 55 grains of the powder. All the loads were set off by a standard, Federal Large Rifle primer.

            To test the ammo, I selected my Harrington and Richardson Handi-Rifle. This is a great little break top, single shot rifle that is simple, rugged and accurate. It is also light. At seven pounds it is 30 percent lighter than a similarly chambered Sharps rifle. That makes the Handi-Rifle handy indeed in the woods, but, from the bench, it can be punishing. I’m not particularly sensitive to recoil, but after firing 120 rounds of .45-70 ammo through the Handi-Rifle I’ve got a semi-permanent bruise on my shoulder.

            In addition to the Triple 7 loads, I also grabbed a few genuine black powder loads to use as a reference point for the T-7. That load consisted of a 405-grain hollow-based bullet over a full 70-grain charge of 2Fg Goex black powder. That’s my heaviest loaded black powder .45-70, so I thought it would provide the best black powder baseline to compare to the hotter Triple 7.

            At the range I fired all loads from both the 50 and the 100 yard range. I thought that would be a fair test of the rifle, but it turned out to be more of a test for my rapidly aging eyes. I started off with the 70 grain black powder charge pushing the 405 grain hollow based bullet. In that light rifle the recoil from this load was vicious. It clocked at 1,252 feet per second and at, 50 yards, it printed a lovely one and a half inch group from the bench rest. At one hundred yards my group opened up to six inches, which is good for me with iron sights.

            After firing 20 rounds of that heavy black powder ammo, my shoulder was already sending out S-O-S calls, but I pressed on. The next load I shot used the same 405 grain hollow based bullet, but this time it was over 50 grains of FFg Triple 7. This load moved along at 1,242 feet per second over the F1 Chrony. That was only 10 feet per second less than the 70-grain black powder load. Despite the comparative velocities and bullet weight, the Triple 7 load had less perceived recoil…maybe I was just getting numb. Groups with this particular load were pretty disappointing. At 50 yards the best I could do was three inches. At 100 yards my group opened up to nine inches. The Handi-Rifle just didn’t like that bullet and powder combination.

            After that I moved to the 55-grain load of Triple 7 with the flat based 405-grain bullet from Montana Precision Swaging. This was the most accurate load of the test. Velocity was slightly less at 1,191 feet per second, but the groups at 50 yards were inside an inch and a half. At 100 yards I shot a 10-shot group into a three-inch circle minus two fliers that were my fault. This load gets a gold star.

            Finally I broke out the real heavy stuff; a 500-grain bullet over 55-grains of FF Triple 7. By now I was 60 rounds into the test and my shoulder was well tenderized. So I wasn’t relishing the prospect of the recoil those 500-grain slugs would be dishing out. Those heavy slugs slowed velocity down to 1,055 feet per second. Accuracy at 50 yards was again excellent. One five shot group measured an inch and a half and the other measured just over two inches. From 100 yards my first five shot group measured three and three-quarter inches. The next group was four and a half inches. Triple 7 obviously liked the flat-based bullets better than it liked the hollow-based rounds.

            If you can’t get real black powder, Triple 7 is a good substitute.  It has the power and the accuracy for either hunting or long range target shooting. And, once you understand its unique rules, it is easy to load.


Harrington & Richardson Handi-rifle

Caliber: .45-70

Barrel:  22 inches

OA Length: 38 inches

Weight: 7 lbs

Capacity: 1 shot

Sights: Williams rear aperture, front Truglo fiber optic

Action: Break top single shot

Finish: Blue barrel, color case hardened receiver

Stocks: walnut butt stock, hardwood forearm

Points of contact:

H&R 1871, LLC
60 Industrial Rowe
Gardner, MA 01440

Lee Precision Inc.
4275 Highway U
Hartford, WI 53027

Hodgdon Powder Company
6231 Robinson
Shawnee Mission, KS 66202

Montana Precision Swaging
P.O. Box 4746
Butte, MT 59702


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