Winchester "Triple Se7en" Muzzleloading 209 Primers

By Randy Wakeman

Winchester T7 primers
Illustration courtesy of Winchester/Olin Corp.

Is has been a long, long time since 209 shotshell primers were first used in muzzleloaders. The distinction of being the "first," I believe, goes back to the Michigan-developed Wolverine that, while innovative, was well ahead of the true need for 209 ignition systems. Alternatives to percussion cap ignition have been around for some time as well; notable being the large rifle primers used in Knight's Magnum Elite "Posi-Fire" ignition system of a decade ago.

Pellets changed the dynamic quite a bit. Once Pyrodex pellets caught on, the inadequacy of #11 caps became well known. Even though Pyrodex pellets have an "igniter pad" of good old black powder on one side, they don't always get loaded down the muzzle in the right direction. Many folks have gotten weary of misfires, and equally disgusted with flaming scopes from open-action frontloaders.

When Triple Se7en loose powder came on the scene around 2002 promising (and delivering) better than black powder velocities, T7 pellets soon followed. With the rise in popularity of Triple Se7en in general, and Triple Se7en pellets in particular, 209 shotshell primer use became close to mandatory. Triple Se7en pellets have always been recommended for use with 209 primers only, though musket caps usually light them off with little problem. Musket caps in inline rifles unfortunately light off scopes with equal ability.

Triple Se7en powder from Hodgdon is here, and it is here to stay. The beef against T7 has been the nasty, hard, slag-like fouling crud (the 'crud ring') that forms in front of some, but not all 209-fired breechplugs. The longer, cooler nippled breechplugs (Knight Rifles' bolt actions) have given markedly less hard taffy-apple crud formation for me than some of the others. The T/C Contender G2 in .45 caliber has been the worst of them all for me.

To attempt to address this fouling crud issue, a variety of attempts have been made, most of them fairly clumsy in practice, or less than satisfying. I used Remington .410 shotshell primers which helped with T7 loose powder, but were not reliable with T7 pellets. Winchester marketed 209 "muzzleloading primers," but all they were was standard W209 primers in more expensive packaging. Remington tried to make a quick buck with their "Kleenbore Muzzleloading primers," but that failed just as quickly. It was apparent, at least to me, that Remington did inadequate testing. The "Kleenbore primers" were far worse than the Rem. 209-4 shotshell primers that at least partially helped the crud situation, if only with loose T7 powder. Remington's dedicated "Kleenbore" muzzleloading primers just plain did not work.

Finally, progress has been made. It didn't happen in a good weekend; it happened over a period of two years with a huge amount of development by Olin-Winchester. Though the 209 battery cup anvil primer external dimensions were not changed, the primer compound was developed from scratch. "Everything on the inside is a brand new mixture," say my friends at Olin Corporation. That certainly seems to be the case.

There were multiple goals in the development of the Triple Se7en primer: eliminate or at least dramatically reduce the crud ring from Triple Se7en (as well as Pyrodex) in the majority of 209 primed muzzleloaders. While they were at it, they sought to maintain complete reliability when used with Triple Se7en pellets. Shotshell primers have been a known quantity for a long time (in shotshells), but Olin-Winchester wanted to go farther than the previous generations of 209 primers.

They took inline muzzleloaders, loaded them with Triple Se7en pellets, projectiles, and their experimental primers and froze the entire unit to minus 50 degrees F. Then, it had to fire T7 pellets without fail. The also experimented with flame temperature, gas generation, and other variables controllable by the primer energetic to get the clean ignition yet reliable extreme performance they wanted.

Accuracy was also important. As a matter of fact, sources report that H. P. Gregory set records just this year at the NMLRA Spring Shoot using these new Triple Se7en primers and Triple Se7en loose powder.

How do they rate in "strength"? As this is a new chemical formulation, it don't believe it is possible to directly compare these primers to older generation primer mixtures. Based on noise and flame output, they seem a bit softer than W209 shotshell primers, yet clearly stronger than the .410 shotshell primers I compared them against. I found no issue with these primers setting off pellets.

Are they cleaner? Without a doubt, they are radically cleaner than standard 209 primers. To give myself something visual to easily compare, I fired a number of standard 209 shotshell primers in Knight red Full Plastic Jackets. Inside the spent jackets, without exception, was greasy, black, scummy material that eventually forms hard carbon crud inside your breechplug, or perhaps in your action.

I then fired the new Triple Se7en primers the same way. Visual inspection of the inside of the red plastic jackets showed them bright red and clean, looking as through a primer had never been fired through them at all. Obviously, these new primers are not laying down anywhere near the scummy residue that standard 209 shotshell primers do.

With the initial testing I've done so far, I can say that the Winchester T7 primers do significantly reduce fouling build-up in muzzleloaders that have that issue, and further reduce carbon build-up inside breech plugs. It reduced the small, but manageable T7 "stuff" in a Knight rifle to practically nothing, and significantly reduces internal carbon build up in the Savage 10ML-II as well. Individual results will vary by make of rifle, breechplug design, and specific powder charge. Try them yourself, and you'll soon be a believer.

The Triple Se7en 209 muzzleloading primer is the most significant advance in inline muzzleloading ignition since the 209 primer itself first gained prominence. It is easily distinguishable from regular 209's with its black primer face so there can be no confusion. It is, to my knowledge, the first new priming compound designed specifically for muzzleloading and it is a winner. The outside dimensions are virtually identical to standard W209 primers, so it can be used in place of a standard Winchester 209 in any muzzleloader designed for 209 primers.


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Copyright 2006, 2016 by Randy Wakeman. All rights reserved.