First: You have a real good rifle. The NEF Huntsman and Sidekick are great rifles. The Huntsman frame will accept a shotgun barrel and the Sidekick is a muzzleloading rifle only. Other than that they are identical. The breechplug you want is made by Metrics Unlimited. Call 1-800-638-7986 and ask for Nick. He can tell you what you need for your rifle. The "MU" plug will eliminate the plastic carrier, and is BH209 compatible. It uses an "O" ring below the 209 primer and eliminates the blowback into the action. You also will probably want to order the Hubbard ramrod that replaces the stock one (right now I do not have the Hubbard contact info available). The Hubbard rod is considerably stronger than the stock rod and extends two inches longer than the stock rod when extended. It also is relieved for pointed bullets and has the correct threads for accessories which the stock rod does not. You should be able to handle up to 150gr. of Black Powder or the equivalent charge of substitute powders but be aware the substitutes are sometimes more powerful than real black powder and should be reduced in charge accordingly. Actually any charges over 100gr. of powder are usually less accurate and unnecessary for any hunting use. If your rifle has the longer barrel (which I think it does) you can burn a little more powder than the shorter barrel versions. If I remember the Heritage is a slightly fancied up version of the NEF but can't remember if it was the Huntsman or Sidekick. Any more information you can email me at
klewisinc@msn.com. Keith Lewis (I have a Huntsman and have the .25ACP breechplug as well as the MU plug). The MU plug is better than the .25ACP one and a lot less work.
Just found the information: Hubbard Outdoor Products
7926 HWY 155
Montevallo, Al 35115
1-800-236-7486 or 205-665-0444