OK Guys, this has been my experience with the Huntsman over the last 4 years, your mileage may vary. Hopefully this will help someone else too.
ken,
You might not like what I am going to tell you, but the Huntsman breech plug was not designed for pellets, especially 777 Pellets. 777 pellets are not reliable in my Huntsman, I get slight hangfires and of course accuracy suffers greatly. The breech plug was designed for loose powder, however it will shoot Pyrodex pellet fine due to the real Black Powder that is bonded to one end for ignition. 777 Pellets do not have the Black Powder bonded to them and are harder to get ignited.
Are you getting these slight hanfires or hesitations at ignition?
I am betting if you switched to 777 loose powder or Pyrodex Pellets, your groups would tighten up substantially.
I know this is probably not what you wanted to hear, but until H&R/NEF redesigns the breech plug 777 pellets will not be 100% reliable in the Huntsman/Sidekicks. I know there are other who claim to use 777 pellets, but I cant hit the broadside of the barn with them. With 777 loose powder, my Huntsman shoots as good (actually better) as my Whites, Knights, and T/C.
I shoot everything from 200 grain saboted bullets to 460 grain pure lead conicals in mine. I took that little 5x5 elk in Colorado with 80 grains 777 FFFG, fiber gasket wad and a 430 grain White Super Slug (obsolete). I use 777 FFG for saboted bullets.
Unless your lockup is loose, I really dont think it is the gun. You can put a 3/8" O-Ring over the forend lug to basically float the forend as best as can be expected. Directions for this are in the FAQ's in the NEF/H&R Center Fire Rifle Forum.
Verticle stringing can usually be contributed to inconsistant measuring, and yes, pellets can be inconsistant due to several factors. If you have a powder scale, weigh 10 or 20 of those pellets and record the weights, you will soon see they are not equal. One load could have two pellets on the light side, the next load could have two pellets on the heavy side. 777 pellets are packaged in a box that is not sealed air-tight, this allows the pellets to absorb humidity like a sponge. Breech plug design is another factor.
Before you blame the rifle, I would start with some 777 FFG loose powder. Just remember 777 FFG is 15% more energentic than other loose powders and all pellets. 85 grains of 777 FFG is equal to 100 grains Black Powder, Pyrodex, 777 Pellets, Pyrodex Pellets.
My Huntsman loves the 300 grain SST/Shockwaves (85 grains 777 FFG) better than the 250 grain SST/Shockwaves. So you may also want to try the 300 grain XTP's if you prefer that bullet.
Sorry I wrote a book, but that has been my experience (4 years) with the Huntsman and 777 pellets and powder. I went to the .25 ACP ignition last year, and wont be going back to 209's and plastic primer carriers.
