Underhammer bore keeps getting larger!

[Sekiar]

About a month ago there were 10 nos engraved underhammer rifles sold on Gunbrokers, and I was luck to get the last one, numbered ten of ten. The adv. caliber was .50. Took it out to shoot today and when I started to load the .50 caliber round ball and patch just fell down the barrel. Since I had not measured the bore and didn't have any larger round balls handy, Ozark57 gave me a .54 caliber ball and it too almost dropped down the barrel. Well I though could it be a .58 caliber? I did notice when the rifle arrived that the hole in the barrel sure looked big...should have been a clue, but heck fifty caliber was engraved right there on top of the barrel for all to see. The only .58 caliber bullet availble was a .58 mini ball and it did seem to fit the bore. Did not load the mini but was almost sure I had a big bore .58 caliber underhammer with about 1:60 twist. Got home and found a box of .570 round balls and yep they seemed just right. Miked the barrel and it agreed that it should be shooting a .570 or similar diameter ball. All ten guns sold in less than three days. The others ranged in size from .36 to .58(listed as .50)and all built in the mid 80's. The all sold for less than $300.00 each. Will take some photos later and share.

 

[paulvallandigham]

If you bought a .58 Hawken, you have a very useful gun, for hunting large game. You can use it with fairly light loads for shooting deer, and load it up for Elk, Moose, & Caribou. Its a dandy caliber for hunting bear, too. Just don't beat yourself to death with it by using a steady diet of heavy powder charges. The cost of those large lead balls is enough to make you use it as a special gun, rather than use it for hunting small game, or plinking with it.

As one man shooting targets at 25 yds, using a very small charge of powder behind a PRB told my brother, all I need is for the ball to pierce the paper and backer board to score, right?

 

Paul,
I agree that a .58 Hawken can be a very useful rifle but Sekiar said it was an underhammer. Sounds like a modified H&A to me.
Mark

 

[Sekiar]

I have copies of the GUN DIGEST going back to the early 70's, and they show an H&A in 58 caliber which is very similar to mine. I believe that the ten guns were probably purchased from H&A without their markings in place and then engraved. That is the only difference between H&A guns of that time period and the gun I have.

 

Sekiar,
I also had a .58 H&A at one time but it was marked as such by the factory.
Mark

 

[Sekiar]

It was such a pretty day I took the rifle out for a test drive with .57 balls. After about twelve shots with 70 and 90gr of double F it printed about 2-inches to the left and down about the same amount.
Looks like I'll have to move the rear sight to the right and file the front sight and try again and see where it hits. That's really where the fun begins. These shots were taken at about 30yds.

 

[ozark57]

So,a .58 it is! That is interestin' gun. The engraving must have taken some time. Sure glad it shoots good.