Got my GM .54 smoothbore barrel in for TC Hawken

[TANSTAAFL]

Barrel was as near perfect fit as possible for a drop in factory offer. No Helicoil and bore was nicely polished, except for a very slight difference in bluing coloration, cannot even tell where the breechplug was fitted except on bottom three flats.

Why though the two drilled and tapped holes for rear sight (holes 13/16" center to center) when only one is utilized? Also, the small screw in top rear of breech plug, what purpose does this serve? (pulled to check, and it is a solid bottom hole)

For you guys that have one, do you leave the rifle sights on? As I will be using it for shot, considering blanking rear sight screw holes and changing out the bead front sight to a lower profile fowler type.

All in all, this looks like a very good barrel, certainly makes for a much more versatile dual purpose gun.

 

[roundball]

Why though the two drilled and tapped holes for rear sight (holes 13/16" center to center) when only one is utilized?

Noticed that on every GM barrel I've bought...I assume the hole drilling jig is the old style, and they're using the new style sight which does not align both holes...and they decided not to to buy a new drilling jig...I remove my single screws and reinstall them with blue loc-tite...never had one come loose yet.

Also, the small screw in top rear of breech plug, what purpose does this serve? (pulled to check, and it is a solid bottom hole)

That's the rear mounting hole for a weaver style scope base...same plug is used on a variety of 15/16" barrels.

For you guys that have one, do you leave the rifle sights on? As I will be using it for shot, considering blanking rear sight screw holes and changing out the bead front sight to a lower profile fowler type.

I've done a lot of that same experimenting, changing front sights, removing rear sights, nothing worked well. Then "articap" told me what he does which is to simply put a piece of tape over the rear sight and just set the front bead on top of it as if you were sighting down a shotgun rib...works perfectly.

certainly makes for a much more versatile dual purpose gun.

I love mine...extremely accurate with Hornady .520" balls and .018" pillow ticking, plus throws terrific shot patterns at 30 yards:

TIGHT PATTERN FOR SMALL GAME
70grns Goex 3F
1/2 Circle Fly lubed cushion wad (slice with razor blade)
1+3/8oz #5s/#6s/7.5s depending on use
Circle Fly OS card

MORE OPEN PATTERN FOR WINGSHOOTING
70grns Goex 3F
FULL Circle Fly lubed cushion wad
1+3/8oz #5s/#6s/7.5s depending on use ***
Circle Fly OS card

*** 1+1/8oz #8s/#9s for trap or skeet targets

 

[TANSTAAFL]

Thx Roundball, I will start with the rear sight taped. That sounds like a great idea from Articap, certainly no need to reinvent the wheel when you guys have come up with the answer.

Remove the tape and one is instantly ready to go for for RB shooting.

Tans

 

[spaethjm]

I have the same barrel for a Lyman 54 smooth bore I use a 535 with .10 patch accurate to 59 yds 4 inch group. I am in the process of making a shot load for turkey hunting.

 

[TANSTAAFL]

Tried out the GM .54 smoothbore barrel today, and I was impressed. 55 grains of Goex 3f, .535 RB and .010" spit patch, four 3 shot groups at 50 yards, ranging from 2.5" to 4" for each group, these fired from block of firm 4" foam rubber rest off vehicle hood. The rear sight was fully depressed and centered on the horizontal 0 mark. It shot to point of aim and I never even had to adjust.

For 1 oz of #6 shot, 55 grains of Goex 3f, (little powder, much shot, shoot far) 1/8" over powder card, lubed 1/2" fiber cushion wad, shot, and thin over shot card. Was very dense at 25 yards, and still a good killing pattern out to 35 yards. All of the thin over shot cards were found within 10 feet of muzzle, OP cards and wads, I have no idea where they went. Having no cards and wads for the .54, I used a 9/16" punch on some .62 ones to downsize them and that worked out fine. The cushion wads I had near saturated with Stumpy's Moose Juice, and this sure made for keeping a clean bore throughout the 10 shot string.

I used the black tape to blank off rear sight suggested by Roundball as per Articap's method, this worked terrific with front sight bead centered on top of tape just above line of sight.

All in all, could not be more pleased with the drop in GM smoothbore barrel.

And the new style TC flinter replacement lock, I am thinking of starting to call it "Old Never Fail," if I do my part, have never had a misfire with it yet, and goes off as fast as any other flintlock I have.

 

[roundball]

Tried out the GM .54 smoothbore barrel today, and I was impressed. 55 grains of Goex 3f, .535 RB and .010" spit patch, four 3 shot groups at 50 yards, ranging from 2.5" to 4" for each group, these fired from block of firm 4" foam rubber rest off vehicle hood. The rear sight was fully depressed and centered on the horizontal 0 mark. It shot to point of aim and I never even had to adjust.

For 1 oz of #6 shot, 55 grains of Goex 3f, (little powder, much shot, shoot far) 1/8" over powder card, lubed 1/2" fiber cushion wad, shot, and thin over shot card. Was very dense at 25 yards, and still a good killing pattern out to 35 yards. All of the thin over shot cards were found within 10 feet of muzzle, OP cards and wads, I have no idea where they went. Having no cards and wads for the .54, I used a 9/16" punch on some .62 ones to downsize them and that worked out fine. The cushion wads I had near saturated with Stumpy's Moose Juice, and this sure made for keeping a clean bore throughout the 10 shot string.

I used the black tape to blank off rear sight suggested by Roundball as per Articap's method, this worked terrific with front sight bead centered on top of tape just above line of sight.

All in all, could not be more pleased with the drop in GM smoothbore barrel.

And the new style TC flinter replacement lock, I am thinking of starting to call it "Old Never Fail," if I do my part, have never had a misfire with it yet, and goes off as fast as any other flintlock I have.

:thumbsup: :thumbsup: