Front sight post issues

[Blues]

Howdy everyone,

TL;DR:
Uninstalled scope, installed tech sights. I had to drift my front sight post significantly left. Any ideas as to why? Relevant images: http://imgur.com/a/YBZXh

Full story:
I received my Ruger 10/22 from an older family member some years ago. It came in what I believe was good condition and was a stock 10/22 except for a scope.

Somewhere in the past year or two a friend introduced me to Project Appleseed. I have been quite enjoying attending the events and learning a thing or two. At the last Appleseed shoot I attended I learned that my scope was not in good condition. I decided to do away with the scope and pick up a set of tech sights. I ended up purchasing the TSR200 sights, the Insert Ready Aperture System, and the sight tool.

While they were shipping, I did some research as to how to install the irons. I read some horror stores of people having issues removing the old front sight post. Some people had to dremel them practically in half before they would come off, others had to use a torch to liquefy some loctite that kept the sight post in place.

The sights arrived and I begun the install. I unfortunately did not have immediate access to a vise to use while drifting out the old front sight post, but was able to brace the rifle and barrel for this process. I decided that if I met with any resistance during this process I would stop and hold off on the install until I could bring my rifle to a friends house, but ended up having no issue getting the front sight post out and putting the new one in. I installed the two side screws, but not the set screw. I wanted to shoot the rifle and make any needed adjustments to the centering of the front sight before installing the set screw. I removed the scope and dovetail and mounted the rear sight. One of the two screws begun to cross-thread, but I backed out and got it re-aligned. Both screws were installed with blue loctite. Installing the new aperture was a bit annoying, but I was successful.

I went to a range with a buddy to test this new setup. I set my rifle up on sandbags on a bench and shot a group. The group ended up being 2.5 inches to the left and 1.5 inches high. Thanks to the Appleseed instructions I knew how to appropriately calculate and make the adjustments and did so, however my rear aperture ended up being set all the way to the right. Thankfully I brought my punches and hammer just in case. I removed the button head side screws from the front post, braced the barrel, and gave the front sight post a light tap. I left the side screws uninstalled and shot another string. I adjusted my rear aperture to the left, but it was not enough to bring the aperture to the center. I repeated this process a couple times and was able to more-or-less center the rear aperture, however  my front sight post ended up needing to be drifted a significant distance. Here are some pictures I took after returning home: http://imgur.com/a/YBZXh

This is where I appeal to those who have more experience than myself. Is there something I am missing? Something I have done wrong? An issue with my rifle? Nothing appears, at least to my novice eyes, to be noticeably wrong. When shooting at the range I even had my buddy (who is a better shot than myself and had been putting in some impressive work with his rifle while I was testing mine) take some shots in case my trigger hand was doing something utterly terrible to the rifle but his shots landed in the same place. Any input would be quite appreciated, and I will happily answer any followup questions to the best of my ability. I tried to include images I thought would be relevant, but if more would be helpful I will gladly take them.

Thank you in advance!

[FiremanBob]

Here's one test you can do: Remove the stock. Set the barreled action on its side on a perfectly flat table or bench top. You will probably need to clamp it lightly to hold it in place. Use a caliper or other precision tool to measure from the table surface to the nearest edge of the muzzle. Then turn the action over and measure the other side. The two should be the same. Any difference equals twice the deviation of the barrel from the centerline of the receiver.

A question: Was the scope windage at mechanical zero when it was zeroed? Scopes have a lot more adjustment than irons because of their short sight radius. So you may be doing the same compensation for the TS as the scope, but it's more noticeable.

[stoneknives]

1st All the screws must be installed. All screws need Blue thread locker.

2nd After you get the Ft sight in order. You can loosen the barrel and adjust it to the  by turning left or right to compensate. This will let you move your sight back to the center of adjustment. it does not take much twist to move the sight a lot. And make sure the extractor fits in the slot in the barrel, without touching the barrel. Finally remember RSS-FSO when making your adjustment.

[crobjones2]

I had a similar issue with Tech sights the first time I used them. I was dancing all around the target with every elevation change. Having a very competent instructor helped. I was instructed to take the sights to bottom and come back up 11 clicks, then start from there.
The culprit- front sight was high and as I changed elevation it would lean to one side or the other. I think I took it down somewhere in the neighborhood of 30 clicks

the other point that was made was about the sun angle and the highlight/ shadow on the front post and how it causes a natural shift. - sight black or a piece of charred wood works to alleviate that issue

[maxwell]

Use a caliper or other precision tool to measure from the table surface to the nearest edge of the muzzle. Then turn the action over and measure the other side. The two should be the same. Any difference equals twice the deviation of the barrel from the centerline of the receiver.

I sent my wife's 10/22 back to Ruger last year after doing this, since her rail-mount Tech Sights almost ran out of windage (aperture fully to the right) even with the barrel canted slightly. Ruger replaced the barrel and rebuilt the receiver, and the aperture now zeros just a few clicks off-center.

[Kennebago]

The slip-fit barrel/receiver setup does this sometimes if it's not straight or within spec.

Ruger used to build the 77/22  in a similar fashion (not interchangeable) and had a few small bad runs in the 1980s where receivers were drilled off-center or drilled wider than spec. I had one of the latter years ago, tons of fun.

[Blues]

You all are wonderful! I appreciate the responses. It looks like what I'll be doing is drifting my front sight post back to center and installing/loctite-ing the screws, then potentially trying to rotate my barrel. I'll be keeping tabs on this thread, and hopefully posting progress as I get time/tools to work on it. I've responded to everyone individually below.


FiremanBob:
I've been looking for an excuse to get some digital calipers, I'll try and get some this week. That, or see if I can't borrow a buddies workshop in the near future. I am unsure as to if the scope was at mechanical zero, but it is certainly possible that it wasn't and that it was already compensating.

stoneknives:
I'll drift the front sight back to center and install/lock the screws and hopefully combine FiremanBob's and your recommendations to re-center the barrel.

crobjones2:
I didn't consider making sure my rear aperture elevation was centered, I just kind of winged it. I'll drop the rear elevation down to the bottom and bring it back up 11 clicks (which I imagine is the center of its travel).

maxwell:
Out of curiosity, how old was your wife's Ruger when you sent it back? Judging by the serial number my rifle is about ~40 years old.

Kennebago:
Do you know of any location where information on bad manufacturing runs is compiled? I'm curious if I can look up my serial number and see if it may have been victim of flawed manufacturing. Now that I think about it, I guess the best people to ask that question of would be Ruger themselves.

[FiremanBob]

Your rifle is old enough that an off-axis barrel hole in the receiver is not likely. That's been a major issue on some 10/22s since 2014. More likely the front sight is a little canted.

You can use sight levels to help install the barrel. Installing the barrel with the receiver upside-down, one level across the bottom of the receiver and the other across the flat part of the dovetail slot for the barrel retainer block.

[Guntuckian]

On one of my 10-22 Rifles, I installed the TSR-100 Tech Sights.  Over two appleseeds, I found that the windage would walk all over the place with no rhyme or reason.  Eventually, the rear windage adjustment had to be cranked way over to the left.

Ultimately, I determined that the spring underneath the front post was too short!  That is, the compression force was too little to hold the front post in a stable orientation.  The front post would wander around left to right as a function of recoil.

Ultimately, I had to replace the small compression spring under the front post with a compression spring from an AR-15, and the transformation was remarkable.  The front post now was stable, and the wandering zero on this 10-22 went away!  And, the windage adjustment on the rear sight went back to the center where it should be!

Since then, I have seen this a couple more times on 10-22 rifles on the line with Tech Sights.  The key to diagnosing the problem is to take one's finger and see if the front post "wobbles" with very little pressure left to right.  When this is the case, then a replacement compression spring is needed.

The front post on the TSR-100 is a standard AR-15 front post.  The compression spring on the TSR-100 has a few less turns than an AR-15 front post compression spring.  So much less that the front post on some 10-22 rifles, especially older ones, is permitted to wobble!  I suspect that the  manufacturing tolerances on the older 10-22 rifles is different than on the new rifles, and the TSR-100 sight was developed using a much newer 10-22 Rifle than I had!

Anyway, check out if the front post wobbles with very little finger pressure.  If it does, then you need a stronger spring under the front post!

As for my old 10-22 with Tech Sights, I bought a youth stock off Ebay for it, and it has now become my standard loaner at many Appleseeds when 8, 9, 10, and 11 year olds need a loaner!

-- gb