An interesting use for wool

New Zealand is well known for its sheep. Apparently Kiwis even use sheep products in their ammunition!

Beaver Grease manufactures wool wads for use in reduced loads, such as subsonic loaded .308 Win, to prevent the detonation phenomenon, otherwise known as the Secondary Explosion Effect where a chain reaction causes power to detonate, rather than burn slowly …

If you shoot reduced loads you will know they rattle around the cartridge case. This is especially noticeable in large cartridge cases. The danger of small charges in large cases has been recognised for many years and the mystery “detonation effect” responsible for blowing many pistols and rifle apart has been linked to this. By using ‘TCBK’ Wool Wads on top of a reduced load of powder the charge remains packed against the flash hole guaranteeing that the powder will not lie on the bottom of the case once chambered allowing the primer flash to burst over top of it causing inconsistent pressures or WORSE. ‘TCBK’ Wool Wads burn cleanly within the barrel of the firearm and leave no harmful residue in barrels or suppressor units.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • cashel111

    you dont need to publish this comment but i think there is a typo in the last line, powder not power? just letting you know 🙂

  • seeker_two

    Not anything new….many reloaders use Dacron as a filler when making reduced rifle & pistol loads….this is just “green-er”….

  • Matt G.

    Interesting. I was unaware of the detonation problem. Good to know.

  • DaveR

    got me to look further into this detonation phenomena. turns out that a)it is rare and b) it is not understood.

    still not convinced that there is any consensus as to the cause. would suppose that if it were a real problem, that a powder company would have investigated further.

    no matter what, the filler would be beneficial just from an accuracy standpoint.

  • James W

    Matt G: no one has been able to duplicate the “detonation problem” in a lab. The American Rifleman had an article about it over 20 years ago. They essentially said it sounded good in theory but had not been proven. Typically, a reloader blames a blown-up gun on on “detonation” of a reduced load of powder. In reality, it was caused by double charge.

    • dan citizen

      I do agree that detonation is too often the go-to explanation for an unknown failure.

      I have seen a gun come in, pretty much wrecked by a detonation, there was not enough room in the case for a double load. I have read of it occurring where a double load could have been handled by the firearm.

      Though detonation has not been duplicated in a lab, it has not been a focus in research to any significant degree, mostly because it does not coincide with conditions manufacturers are pursuing.

      The one I was able to examine had a very atypical appearance and was not similar to an overcharge failure. Internal ballistics are not my area of expertise, but it to others it appeared that it was a much faster pressure spike than with an overcharge.

      I’m guessing Nathaniel F. might be able to shed some light on this phenomena.

  • Regardless of the detonation issue, keeping all of the power near the primer has other tangible benefits.

    Consistent velocity, for one.

    Check the August 2011 issue of Guns & Ammo; article about the ridiculous variances in velocity that can happen when Cowboy Action Shooters load ammo below the reloading guide’s minimums.

  • armed_partisan

    I tend to agree with James W on this issue, and I do sub-powered, “Cat Sneeze” loads all the time. I prefer to use black powder substitutes like Trail Boss, which have the bulk to fill most of the case (to prevent double charges) while still providing very low muzzle pressure (muzzle blast) and reduced velocities. One of my favorite loads is a 120 grn round nosed cast bullet and 20.0 grains of Trail Boss in a .30-06 case. I still use it with hearing protection, but my friends who don’t say is “sounds like a .22”. It has no kick and is great fun for plinking, and short range varmint popping. I have introduced several new shooters to full powered rifle loads by breaking them of the fear of how big the case is with this load, too.

  • Yes! New Zealand … Where men are men… and sheep get nervous.