elevation on oct to round rifle barrel

[rich pierce]

My new .54 rifle built using RCA 19 as inspiration has an octagon to round barrel. Initial sighting in on the Getz barrel was done with .530 ball, 85 grains GOEX FFG, 0.018 ticking.  Patches look perfect.  The rifle is shooting about 2" high at 25 yards after I've filed the rear sight down about as much as I can.  The front sight which is silver is staked in, not dovetailed, and is about the height of some originals, maybe 4-5/32" tall.   Now I have to decide to either yank the front sight out of there and replace it with a taller one or bend the barrel.  Which would you recommend?

And for a .54, where would you want it shooting relative to point of aim at 25 yards to be dead on at 75 yards with a modest load like 85 grains of FFG?

[Dr. Tim-Boone]

aim 2" lower!!     I'll let the experts make the recommendations, but personally I would not bend the barrel...cause if I did it would probably shoot around corners after I did it!!  Staking a taller piece of silver and hen filing down to make POI the same as POA  seems like the easiest thing to do well....

[smylee grouch]

Because the front sight is staked in would it be posible to solder an extension to the top of it?      Smylee

[hanshi]

My smoothbore has a rear sight and shot around 7" high.  I filed down the rear to bring it to bear and it is fine with elevation.  I considered bending the barrel as a last resort.

[smokinbuck]

Rich,
Unless you are going to shoot exclusivly at 25 yards, I would try it out at least 50 yards and then decide what to do to the sight.
Mark

[frenchman]

I would do another one or lead solder an extension it won't take has much heat, it comes with the learning curve, i  hope the gun is not blued, reality of gun building
C'est la vie mon ami

[rich pierce]

Oh it's blued all right.  But the Mike's Express Blue is so easy to use I'm not worried.  I think I will have to craft another front sight, rip this one out and install a taller one.  But first I'd better find out how it's shooting at 75 and 100 yards!

[frenchman]

Rich,
i was i bit luckier than you, i could take mine off and i welded a piece of brass.
I shot the rifle got the height right and made a new one. Keep me posted i am very interested on the height of that sight front and back what's your hold, bull or 6 o'clock.

 I am getting interested in this 200 yards with round ball and with the underhammer it's very very interesting that would be my first try , than work with my flint. Something to try for this yardage i am wondering if i should go peep sight or the challenge is open sight
Good luck
 

[bob in the woods]

Not sure what style of rear sight you have. I made my own and the " notch " is very very close to the barrel
flat.  Might try making anew rear sight instead of messing with the staked front sight?

[SCLoyalist]

I wouldn't bend the barrel as long as there were options to be explored for changing front/rear sight height.   


As to your point of aim question:  85 gr 2F ought to be giving you somewhere around 1600 fps of muzzle velocity.  If you adjust your sights to be dead on at 75 yds (i.e. the bullet path = zero), then at 25 yds you would be hitting about 1.2" above point of aim,  at 50 yds 1.3" above point of aim, and at 100 yds would hit 3.1"  below point of aim. 

     

[rich pierce]

Guys, thanks.  Bob, my rear sight "front leg" is pretty much flat to the barrel so there's no going closer to the barrel.  I'd say it is as low as what's seen on many early originals.  Off to the range this weekend to see where it's hitting at 75 and 100 yards, then we'll see if I need to replace the front blade.  I've put aside the idea of bending the barrel.

[Daryl]

2" at 25yards should be about 2 1/2" high at 75yards, Rich.

That's an estimate using .75" height for top of the front sight above the centre of the bore, along with .8 for the BC and 1,400fps for the 85gr. 2F powder charge. Higher velocity or higher sights will, of course increase the impact's height.

As-is, it should be zero'd for 100yards. Holding 1/2 sight height in the rear notch instead of level, ie: "holding a fine sight (or bead)" should give a 25/50yard zero.  This is normal 'holding' for iron hunting sights - even as described in Forsyth's book when he spoke of the Kentucky rifle and how it was aimed.  Holding a fine sight for close in shooting and a full (level) sight for 100yard shooting, showing they had a long point blank range with one set of sights.

 He compared these to the English conical ball shooting and fast twist round ball hunting rifles of the period needed sights for both 50 and 100yards to be able to hit with due to their excessive elevation requirements.