I got nothing that answers the questions, the Huntsman manual shows 100gr Max, nothing on pellets, magnum loads, or breech plug diameter. I've never shot my Huntsman barrel, our muzzleloader seasons suck here and the deer population in the area we've always hunted had a 99% winter kill 2yrs ago, so I don't expect there will be anything worth hunting for another 7-8yrs if it's like the last winter kill we had. FWIW the OP hasn't been online since the day he posted. Best recommendation is use the search for previous posts, both here and GBO Reloaded, I've been hoping Busta would chip in, his PB pics in the FAQs are busted like everyone else's. [IMG class=inlineimg]https://www.go2gbo.com/forums/images/GreyBeardOutdoors_toucan/smilies/tango_face_sad.png[/IMG]
I would chip in more, if l didn't have to jump through all the hoops to just post a simple reply. This new format sucks, bad!
Then you have a smart ass moderator and a few others that don't have a clue, promoting shooting smokeless powder out of Huntsman's and Sidekicks using the Metrics Unlimited Breech Plug. What could go wrong there??? Ask Dinny and Old School Ranger what loads are safe to shoot.
For the other guys in the thread, here is the old pics. Just make sure to read the red print. Disregard the .45 caliber information in the first pic, they never released the fast twist 1:20 NEF Huntsman .45 cal. Do not use that information for the old H&R .45 caliber Huntsman's from the 1970's.
The first pic is for the NEF Huntsman, 2002 revision.
The second pic is for my 2004 NEF Sidekick .50 caliber with 24" barrel with 7/8" breech plug. Same for my last model year 2008 H&R Sidekick .50 caliber with 26" barrel and 5/8" breech plug. They both use the same manual with the 2004 revision. Barrel length of 24" or 26", breech plug of 5/8" or 7/8" is all the same.
You can find the information that goes along with these pics in the stickies, I think.
This will probably be my last post here, one way or the other. Not the same place it used to be. Lots of good people here, but a few misguided one too.
Don't anyone ever shoot smokeless powder in a Huntsman or Sidekick with any breech plug including the Metrics Unlimited Breech Plug. The rifles and breech plugs were not designed for smokeless powder pressures, and were never condoned by H&R/NEF, Marlin, Remington, or Metrics Unlimited. PERIOD!