Anyone else ever deal with this problem?

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denster

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I finally got the weather and time off to coincide and made it to the range to sight in the Kibler SMR I built over the winter. It is a .32 flinter and my first load produced good groups at 25yds. The problem is with the sights centered on the swamped barrel my groups were 3in low and 4.3in left of point of aim. That means a correction of .110 in elevation and .157 in windage. The front sight as provided is only 3/16 tall that would only leave a .077 nub. Not really a problem just use a taller rear sight and that is where the problem lies. The barrel flat at the rear sight is about .325. That means if I made all of the windage correction on the rear sight it would have the notch right over the right edge of the top flat. If I divide up the correction it makes both sights look whopperjawed.
My first thought as to solution is a taller and wider leafed rear sight where the notch can be offset but the body of the sight still be mostly centered.
Anyone else ever deal with this problem? If so I would be interested to hear your solution.
 

Kansas Kid

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If it’s the first time shooting in a new barrel get a hundred or better rounds through it before getting too radical. I just shot in my new .36 TOTW barrel and the first time out I had the rear sight moved way right but ended up about center after a couple times out. Just a thought.
 

Grimord

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I would shoot some more groups to lead lap the bore. You may find that the groups come back towards the center.
 

Larry (Omaha)

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I finally got the weather and time off to coincide and made it to the range to sight in the Kibler SMR I built over the winter. It is a .32 flinter and my first load produced good groups at 25yds. The problem is with the sights centered on the swamped barrel my groups were 3in low and 4.3in left of point of aim. That means a correction of .110 in elevation and .157 in windage. The front sight as provided is only 3/16 tall that would only leave a .077 nub. Not really a problem just use a taller rear sight and that is where the problem lies. The barrel flat at the rear sight is about .325. That means if I made all of the windage correction on the rear sight it would have the notch right over the right edge of the top flat. If I divide up the correction it makes both sights look whopperjawed.
My first thought as to solution is a taller and wider leafed rear sight where the notch can be offset but the body of the sight still be mostly centered.
Anyone else ever deal with this problem? If so I would be interested to hear your solution.
Good description of your SMR sight issue! I personally do not like low sights even though they are more period correct because of mirage. I think your "first thought" would make you the happiest, but my reply is based on what we know now. You need to shoot it at 50 and 100 yards to get more info. I would then consider taking a smidge of windage adjustment on the front to help, but not so much that it stands out. Some guys may chime in and tell you to tweak the barrel a tad. I have never bent a barrel, but others here can and will help if you just ask.
Good luck!
 

EC121

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My Kibler Colonial also had a low back sight. I JB Welded a higher thin blade on the back of the rear sight. Then, after centering the front sight, I cut a notch off center in the rear sight. Nothing done that can't be removed. You can order a higher back sight after test firing. Bending the barrel is an option. A bench, 2 pieces of wood and a C-clamp. Bend it in the middle.
 

denster

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Thanks for all of the replies. Gives me some ideas.
 

rafterob

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Don't go with your first load just because it grouped well. You will be better off shooting multiple groups of 5 with increasing powder charges. I start at caliber=grains and then increase 5 grains for each group. My goal is to get the best group at the highest point of impact on the target. Once I have achieved and confirmed that load by shooting at least 3, 5 shot groups, I then work on adjusting the sights. Yes, you can do the calculation and come out with a number to file your sight down to, But I also would not go that route. As is commonly said here, you can always take more off, but you can't add it back on. So file the front sight a little at a time until you reach the right spot. Use the back sight for lateral windage only, unless there is no other option than to adjust its height.
 

Grenadier1758

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I would shoot some more groups to lead lap the bore. You may find that the groups come back towards the center.
How does that lead lap a bore?
Now shooting more groups doesn't really lead lap the bore unless you use some JB Bore paste on the patch with the fine grit. Shooting more can take some of the sharp edges down on the lands, but it will take several hundred shots for a normally patched ball to start having an effect on the tool marks in the bore. Using the Bore Paste as a patch lube, the lapping can be done with as few as ten to twenty shots. Be sure to do a thorough cleaning to remove all the polishing paste from the bore.
 
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"The barrel flat at the rear sight is about .325."

That is way too much. Drifting both sights puts each 5/32" off center. That will look bad and mess up the cheek weld.

Call Jim Kibler and get advice. He and Katherine are there to help.

Bending barrels is fine for experts with the knowledge. IT will likely end in disaster for a casual builder.
 

Grimord

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Now shooting more groups doesn't really lead lap the bore unless you use some JB Bore paste on the patch with the fine grit. Shooting more can take some of the sharp edges down on the lands, but it will take several hundred shots for a normally patched ball to start having an effect on the tool marks in the bore. Using the Bore Paste as a patch lube, the lapping can be done with as few as ten to twenty shots. Be sure to do a thorough cleaning to remove all the polishing paste from the bore.
A patched ball does do some lapping of the barrel. Several folks on this forum have stated that it took several rounds to smooth out the bore of the Lyman Great Plains rifles. This is what i was referring to.
 

M. De Land

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See if you have an even crown on your barrel.
I've seen this quite often and is the reason one wants to orientate a new barrel vertically. The other thing I though of is the barrel may actually have been bored straight and was bent while being swamped in the mill vice. I have never liked bending barrels although it is/was common practice with barrel manufactures. It usually does not cause trouble in a muzzle loader as they do not get hot enough to" walk" with the slow rate of fire but it can happen with modern cartridge barrels when they heat up.
I'd try to correct it with sight movement (front and back) and load development first as has been mentioned. If bending is required than it should be done on a jig between V blocks and in a controlled manor. I did one barrel on my vertical mill using the quill screw which has a lot of leverage and a mic to check the progress. It corrected the sight alignment and has stayed put. If I had it to do over I would use an arbor press as I had to re-calibrate the mill treble from the pressure applied by the quill screw.
 

denster

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I used a laser boresighter in the barrel the type that contacts circumference of bore 6" in and at the muzzle. Deviation was in the same direction but less than 1/3 of what the target indicated. Looking like it may be a crown problem. The crown looks good but it only has to be off a little. I have a crowning tool just have to turn a .32 arbor for it. I think I will touch up the crown and give it another try.
 

hanshi

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My experience has been that most American manufactured barrels shoot just fine from the very first shot and need no "shooting in". Of course there are exceptions, but I've just never run across one. Factory rifles, especially imported ones, do often benefit from bore polishing or a fair amount of rounds being fired. Imported barrels are normally excellent and very accurate; just sometimes rough.
 

Griz44Mag

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I finally got the weather and time off to coincide and made it to the range to sight in the Kibler SMR I built over the winter. It is a .32 flinter and my first load produced good groups at 25yds. The problem is with the sights centered on the swamped barrel my groups were 3in low and 4.3in left of point of aim. That means a correction of .110 in elevation and .157 in windage. The front sight as provided is only 3/16 tall that would only leave a .077 nub. Not really a problem just use a taller rear sight and that is where the problem lies. The barrel flat at the rear sight is about .325. That means if I made all of the windage correction on the rear sight it would have the notch right over the right edge of the top flat. If I divide up the correction it makes both sights look whopperjawed.
My first thought as to solution is a taller and wider leafed rear sight where the notch can be offset but the body of the sight still be mostly centered.
Anyone else ever deal with this problem? If so I would be interested to hear your solution.
I have a very nice old Chris Jackson rifle with an early WM LARGE barrel that the sights are modified exactly as you stated above.
It is a viable solution.
 

GregCSarver

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I finally got the weather and time off to coincide and made it to the range to sight in the Kibler SMR I built over the winter. It is a .32 flinter and my first load produced good groups at 25yds. The problem is with the sights centered on the swamped barrel my groups were 3in low and 4.3in left of point of aim. That means a correction of .110 in elevation and .157 in windage. The front sight as provided is only 3/16 tall that would only leave a .077 nub. Not really a problem just use a taller rear sight and that is where the problem lies. The barrel flat at the rear sight is about .325. That means if I made all of the windage correction on the rear sight it would have the notch right over the right edge of the top flat. If I divide up the correction it makes both sights look whopperjawed.
My first thought as to solution is a taller and wider leafed rear sight where the notch can be offset but the body of the sight still be mostly centered.
Anyone else ever deal with this problem? If so I would be interested to hear your solution.
Try more powde
 

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