Factors in seating a long range tang mounted peep sight?

[BCRider]

For a while now I've been dabbling infrequently with my two single shot rifles, a rolling block and a Uberti 1885. I'm running a Pedersoli rear sight on the rolling block and one that came with no name but which I suspect is also a Pedersoli on the 1885.

Now opinions on the Pedersoli sights aside I was never really taken with how they mounted to the tang. It all seemed a bit.... er, OK...... a LOT vague what with the irregular shape of the tangs and the nondescript lower side of the mount. I filed and shimmed as needed to get the staffs to sit vertical to the top face of the octagonal barrel but I wonder at how consistent the sights are between shots.

So is there a good method for mating the base of the sights up to the tang? I'm all eyes for replies!

I promised myself that this year is the year that I get serious about my long range single shot shooting. Everything is going to be inspected closely from this issue to my load testing and on to my positioning when shooting.

So far my initial loads and shooting method are producing roughly 3 inch groups at 100 yards. But I keep getting one "flier" out of about every 4 shots fired that opens the group up to somewhere between 6 to 8 inch size. And there's no rhyme or reason to it. I might get 3 wild shots and suddenly a half dozen good shots. And with the "massive" kick of the .38-55's I'm shooting I'm pretty confident that it's not a flinching issue.

[Tatume]

Your shooting is not displaying "flyers" (outliers), but inconsistent accuracy. You are right to inspect everything. I don't know how the rear sight is mounted on your rifles, but to see a correct mounting examine a CPA Stevens 44-1/2 or another gun of similar quality.

If you try to wiggle your sight with your fingers, is there any discernable movement in your rear sight? If so, then the mounting or the sight itself is suspect.

[ascast]

That the one with the tang as an after thought, right? If you suspect the sight is moving between shots, I think you could move it with your fingers. Lots of loc tight will help.

[Chill Wills]

but I wonder at how consistent the sights are between shots.

Maybe a little more info on this part would be helpful. Do you mean that the sights wiggle? Or do you mean the staff moves with in the sight base? Or something else?

Good target tang sights are highly repeatable so if you are wondering about the basic tang sight mechanical concept; if everything is tight and of good quality, the sights are great and very accurate.

If you are shimming stuff to get it stable or shimming to make the staff plum, something is not right. At most, stoning the sight base might be needed on good equipment.

Also, if you are truly shooting long range, a little out of plum to the 11 o'clock on your staff will keep you zeroed at LR. (you are not ready to do this to your staff yet - keep it straight)
Michael Rix

[rfd]

getting GOOD sights for bpcr and setting them up correctly is very important for top consistent accuracy. the pedersoli bodine roller i have came with pedi's sights that are serviceable but not capable of the adjustments and precision required for competition. they lack a barrel spirit level (either separate and on the barrel, or contained within the front globe), a soule micrometer on the tang (or front globe) for windage, a variable aperture hadley eye cup for the vernier, and a tang sight base that's adjustable so that it can be set to 90 degrees of the barrel. both of my bpcr rifles now sport lee shaver super grades - a world of positive difference worth the $500 expense.

when working up a load, many things need to be taken into consideration - the consistency of the rounds built, the shooting venue and weather, and how you shoot. i do all my load work ups off bench sticks, clamped to the bench, then drop down the x-sticks.

[country gent]

A real easy test for alighnment is to use a tall target backer. 6'-8' tall with the target on the bottom. At 100-200 yds shoot a good group on the bottom target. annd come up on the rear sight so that the group prints at top of backer aiming at the bull on the bottom. If the backer is square and true then the groups should be one right above the other. A chaulk line down the middle helps alot here. As to sight repeatability thread clearences and slide clearences affect this. Mounts and bases fit and fit of the detent spring in the staff and its tension also have an effect. Another is the vernieer graduations need to be clean and crisp to discern the readings easily sometimes ( most times for me ) a magnifying glass is a big help to read them accuratly.

[enfield]

Country Gent, that's a good idea to try, I'm going to do that next time at the range. Then I would have to decide if it's me or the sight that's crooked

[country gent]

A simple way to keep everything the same is to use one of the barrel blocks Randolph S. Wright talks about in his book Loading and Shooting the Paper Patched Bullet A beginneers Guide. This clamps around barrel and has a flat bottom to set on the rest. I made one for my half round pedersolis barrel. Set and clamped the level stays where it is very reliably. I made mine from hard maple 1" thick 4" tall and 6" long. Drilled the hole oversized for a 1/16" rubber sheet to grip cushion barrel. 2 1/4" screws clamp it in place. Hard wood, plastic, aluminum, or even a mould or form could be made and fiberglass poured to make one. We had 3 8' tall targets at the club they were great for checking this and also if you knew how high you needed to be at 200 yds to get rough zeros for longer ranges. They got used alot by NRA High Power shooters to get zeros for 300, 600, 800, 900, and 1000yds. For the BP rounds 10' tall would probably be better.

[Chev. William]

A small point: Inspect the Muzzle using a 10x or 20x magnifier to verify there is no asymmetrical wear or a "ding" or "burr" on the junction between Bore and Crown. Wear from The cleaning of the Bore via the Muzzle can wear one point of that junction more than another and any slight ding or burr will affect accuracy and repeatability of your shots.

Best Regards,
Chev. William

[BCRider]

Lots to consider and test for. Thanks for all the answers so far.

The joint between the base and tang isn't loose by any means. But I wonder about the seating not being solid and even enough which might be causing some slight shifting.

Leaning a tad towards the left, eh? That's to compensate for bullet spin and the bullet walking sideways a little? It's funny you posted that because I've already seen how there's a drift in windage as I go from 100 to 300 yards. I thought it was me tilting the gun or possibly there was more wind drift than I thought there was. Or that I hadn't gotten the sight dead on vertical and the difference was due to a slight leaning and how it moved as I raised the peep in the staff. I'll look at including a very slight angle to the staff at some point here soon. Great stuff there Chill Wills.

I've also been considering a clamp on low power scope mount to use with load development. It would involve removing the fore stock for the time being to make room for a clamp on mount that goes on the barrel up close to the receiver. Just one way to take my own eye balls out of the equation and to also test the rear sight to see if it's the rifle and ammo or the sights that are producing the issue.

The front Lyman globe style sight has a riser mount I made up that holds a bubble level. It's pretty good to use in the open but when I'm under a covered firing line the shadow hides the bubble. But it IS usable and I was using it during the test session earlier this week that caused me to post this question.

I'll likely modify the bubble mount to drill a hole or three through to the front side so that light from downrange can back light the vial.

[marlinman93]

When I install a tang sight on one of my single shot rifles, I use a straight edge on the side of the receiver, and visually check it to see how the staff compares to the straight edge. If it's not parallel, I will work the base, or shim under the base. I've never had any problems using copper or aluminum shim stock to get a staff vertical.
I also use the straight edge to check for play in the staff. If I can wiggle the staff and see movement as I view it beside the straight edge, it either goes away, or I find what is causing it. Determining if the issue is play in the staff, or the base, should not be hard to determine. I've got a few inexpensive tang sights I use for casual shooting that had play in the pivot point. I took them to my mill and opened up the staff hole and installed a brass bushing. Then reamed the bushing for a close fit with the pivot screw. They will never be competitive sights, but the accuracy was much improved!

[country gent]

Getting the play out of a sight can be tricky and there are so many areas to look at for it. Base to tennon, mount screw to hole in tennon, slider to staff, Eye piece base to its mount. Threads themselves, I have a budget hadley that the appeture holes arnt drilled evenly changing appeture size slightly changes Point of impact even. Drilling out the hole and fitting a bushing could go one step farther and also be used to fit the bases width to the bases slot closer quite easily. Everything has to be square and true for tight tolerence fits to move free.

[Doc Highwall]

BCRider, how much experience do you have shooting with iron sights?

I shoot a lot of small-bore and with the under 1100 fps velocity the long barrel time makes follow through important, also how well the stock fits you so that sight alignment can be repeated shot after shot.

Stock weld/cheek weld is VERY IMPORTANT in achieving good groups with a scope, and even more important with iron sights.

Single shot rifles like a rolling block, especially with a lot of elevation takes your cheek off the stock making you use your jaw as a anchor point, making sight alignment much more difficult.

All I can say is pay attention to your sight alignment and focus on the front sight when shooting, also have you done any tests with front sight apertures and a target size that duplicates the targets you are shooting at in minutes of angle. These can go a long way to improving your scores.

[BCRider]

Marlinman, I'll look into those factors. And I do know that I was not impressed with the staff to base fit. In fact I keep having to tighten the screw that tensions that joint. So that's a prime spot for an issue. I'll check it and report back. Thanks.

Doc, I hear you well on all those factors. And I'll be the first to admit that I'm still working out my stance and hold. Because the main goal of this setup is to shoot the long range "buffalo" side matches in SASS events I'm focusing on using crossed sticks and a small stool. I've come up with a way of seating on the stool that has my arms crossed and pressed together and my elbows solidly on my knees for the most possible bone to bone connections and that "X" of my arms to lock things as much as I'm able.

I've also got and thoroughly enjoy a couple of other peep sight rifles. A 1938'ish BSA Martini with the originally supplied peep sight setup and a CIL Anschutz with the Anschutz target peep sight and front globe sight. I can normally shoot these well enough that they make me look good and the guns have little to be ashamed about.... This is mostly from either prone on a padded bench or from elbows on the shooting table. I prefer that over rested simply because using a rest seems a little too much like cheating. So I tend to only use a rest for the longer distances or when testing ammo for matching to the barrel or load testing on center fire.

As a side note shooting those rimfire rifles at a 12 inch square gong out at 200 yards sure is a lot of fun. With the optimum ammo for each rifle a shooting buddy and I were not having too much trouble keeping all the hits within a 5 inch size group on a day with some lightly gusting wind. We were using a front rest for this distance. Elbows on the bench only goes out so far....

I've played with a couple of the front inserts but nothing highly technical. I'd welcome any suggestions on optimizing the choice of insert or some description of the factors I should be considering for picking an insert.

I also need to find a bigger target for out at 300. At 200 the 12 inch Shoot-N-C is a nice clear dot in the front sight. But at 300 it's a slightly darker grey blur than the rest of the cardboard I'm using as a backing board. On my way back from the last test session I realized that even giving the corrugated cardboard a flash coat of white would help a lot.

One thing I sure have learned is that any sighting system we are using has to include the target setup in terms of size and contrast in the considerations. We can't aim at what we can't see clearly.

Thanks to everyone so far for the suggestions. In some cases I'm nodding due to having those bases already covered. But it's still a good reminder. In others it's giving me a good reminder to go back and double check some things that I thought were a bit iffy. And some other things are totally new and need attention.

You're all proving once again how great this little online community is. Thanks.

[country gent]

Sometimes A simple wide post up front works better than any apetures. On odd shaped targets its hard to beat a simple 6 oclock hold with a post up front. A fairly wide post at 6 oclock allows you to see all of the target and dosnt block any of it, When the post just touches or a small line of light is held it is easy to duplicate the hold every shot. I use a post up front often. Look for a post .090 wide or so and try it with a simple 6 oclock hold on the targets. The post makes it easy to Favor a shot for windage or elevation also. Ideally with an appeture insert and round bull you want to see a "line" of white between appeture and bull you then watch the line of white and when its even fire the shot. A good set of inserts and simply Looking at a target thru the sights seeing them can accomplish alot. Buffalo arms, trac of the wolf, Lee Shaver, C Sharps, Montanna Vintage arms all have the insert cards with an assortment of inserts to fit most popular sights and they arent all that expensive cost wise. Look at thier web sites and see they have good pics of the cards and wat offered on them.

[marlinman93]

I've always liked a peep insert up front for up to 200 yds., but that depends on the target also. Some targets over fill a peep aperture, so it's hard to tell if the sight is centered or not. Most the time I prefer a post aperture front on a globe for longer range work. But the farther out the target is, the narrower the post needs to be, or I can't tell where it is on the target. A .10" post might work fine at 500 yards, if the target is wide enough. But it will be way too wide for almost any target at 600-1000 yds. I prefer a very narrow post most the time for longer distances, and .060" is as wide as I like. A .040" wide post is better for me, and I file the fat front posts down to make them very narrow, and useful for me.
On the 600 yd. dinger a .060" wide post is wider than the 24" dinger, so impossible to tell if I'm centered or slightly off. And if the wind is blowing, it's also too wide to hold some windage to the side, as no way to determine or guess how far I'm holding off. Hate to start adjusting windage, as it changes so often I'd be continually chasing the wind!

[Doc Highwall]

In highpower shooting the targets sizes for the aiming black are,
@ 200 yds. 13"
@ 300 yds. 19"
@ 600 yds. 36"
@ 800 yds. 44"
@ 900 yds. 44"
@1000 yds. 44"

[BCRider]

CG and marlinman, I've always preferred the circle front sight inserts. But you make a lot of sense on the post style. At some point when I'm down to the small things I'll give the post inserts a try.

Doc, so far when shooting at targets in the matches they tend to be a mixed bag. The SASS side matches as shot around this part of the country use whatever steel targets are available through the clubs. But your 19" ball circle at 300 would sure be a nice size for my practice and sighting in sessions. I'd see the target circle in the front sight instead of a grey blur that way. Thanks.

A quick check shows that I might be able to find some Birchwood Casey 17.25 inch Dirty Bird targets for out at 300 yards. I'm keen on these spatter targets despite the added cost simply because I can see the spatter rings through my spotting scope that way. Otherwise it's a black hole on a black background. And good luck with that! ! !

[EDG]

For me to shoot the best groups with a BPCR I have to use a front aperture insert made by Lyman and a 6" to 8" black bull at 100 yards. The Lyman insert has a very wide band around the aperture. I cannot use the various thin ring apertures mounted on what look like cross wires. The thin rings disappear when I use them. The Lyman 17 inserts fit the Browning front sights like they were made for them. The 3 circles are much easier to align for both windage and vertical.

[M-Tecs]

Also, if you are truly shooting long range, a little out of plum to the 11 o'clock on your staff will keep you zeroed at LR. (you are not ready to do this to your staff yet - keep it straight)
Michael Rix

Lot of folks have a hard time with this. While this is for Buffington sights on trapdoors it illustrates spin drift well http://www.trapdoorcollector.com/shooterstext.html

The Springfield 1903 sights are also angled to compensate for spin drift.