Home Forums Lever Action Central Big Bore Levers mod 71 bolt peep ... how to adjust

My recent mod 71 came with a broken screw head on the right side, assuming this is for windage adjustment. I don't want to break any others, so I ask, what are all these screws for.

1. I get the vertical adj knob that has UP on it.

2. I assume the screw with the broken head is the windage adj, but which way to turn to move the rear sight right, left.

3. A little headless screw that looks like one to lock something in place ???

4. the second screw on top, with slotted head, that sits between #1 and #3 (above).

5. On the left side, the other side of the windage screw #2, But how do you adjust it.

thanks for your help. Just trying to do no damage.

Charlie

This is what I was told years ago. The double headed screw right below the peep (which on your rifle looks like the right side is broken) obviously adjusts windage. The little screw just in front of the peep is a set screw that locks the elevation spring in place. The screw closest to the big elevation knob is the elevation zero set screw used to keep elevation from going below 100. On the left side of the sight base you will see lines for 100 200 300. I have never removed any of the screws completely.

If you're thinking of repairing your windage screw, this place make reproduction 98A bolt peep sights and has parts that interchange with originals. http://oldgunsights.com/About.html
It appears your broken side is the screw (4-40 IIRC) and the other side is a slotted head nut. The tip of the screw is dimpled and peened to lock it to the nut. I have an M65 with a bolt peep and the nut side is broken. I have a replacement but haven't got 'round to fixing it yet.

Charlie, go over to accurate reloading forums and PM my old buddy Bob Nisbet, he'll make you a new screw.

Gunner

That's who made the one for me. Unless he's found a new source for screws, the heads are a bit smaller (.050") than the originals so get both the screw and nut so they match.

thanks guys. I wanted to make sure I didn't make things worse by trial and error, especially with the broken screw head. And this gives me a source for the a new screw. Great info.

Charlie

You guys still around?

Pics on this thread seem to suggest the two smaller in-line screws -- between aperture and thumbscrew -- are opposite from what you've described above.

https://www.24hourcampfire.com/ubbt...8-bolt-peep-sight-questions#Post15256268

Looks to me like the spring is captured by the forward-most screw -- i.e., the one closest to the thumbscrew. Which would make the rearmost screw the elevation zero set.

???

-Chris

Thanks, but I sold the rifle last year. It was too nice to hunt with and too expensive to sit.

Still here, I have my 71 sighted in so do not want to mess with the sights. It looks from the pictures that you are right about the screws and what they do. There was a guy named Bob Nisbel who was an expert on all this. His contact info which he posted was

Robert.Nisbet1US.Army.MiL
or
RANisbetYahoo.Com
If anyone just has a question about the sight or its parts, call me.
256-876-1939

Bob Nisbet

He will know. If you find out please post the answer. THX

Thanks. And I'll see if he's still available...

-Chris

Looking at these pictures I think you are correct.

https://www.ebay.com/itm/EARLY-PREWAR-ORIGINAL-WINCHESTER-COMPLETE-BOLT-PEEP-SIGHT-FOR-MODEL-64-OR-71/224166859596?hash=item343162d34c:g:M-cAAOSwvUdfaoZ1

I've made some progress, and I've actually adjusted my sight for elevation -- relatively easily as it turns out. I've been emailing with Bob Nisbet, too, and he's been very helpful!

My going-in situation was that the elevation knob wouldn't turn. In order to make it turn, I had to back off the little screw closest to the aperture, then depress the rear of the sight base (aperture end) and rotate the thumbwheel while still holding the sight base down. Afterwards, release downward pressure on the sight base, tighten that little screw, done.

I had actually "pre-treated" that little screw with a drop of Kroil first -- assuming 80+ years of non-use might have caused things to be a bit recalcitrant -- but as it turned out I'm not sure the Kroil was at all necessary.

In your first note, you said that "set screw locks the elevation spring in place." I think it locks the sight in that it prevents further downward sight movement once the thumbwheel is properly adjusted.... but it's apparently not the screw that controls the spring itself. The small screw closest to the thumbwheel holds the spring... which Bob says also passes through a hole in the bolt (for lateral stabilization) and actually rides on the firing pin. (???)

Bob's labels for those two screws are:
- El Zero Set (Optional) -- the screw closest to the thumbwheel (the screw that holds the spring)
- El Spring Screw -- the screw closest to the aperture holder (the screw that doesn't hold the spring, does lock the setting, and prevents elevation below 100)

-Chris

Great info, thanks

In retrospect... adjusting elevation was so easy, given a clue, I'm surprised a whole boatload of M71 owners here on the Fire didn't just chime in with simple directions:

- back off the little screw closest to the aperture holder
- depress sight base
- rotate thumbscrew as desired
- tighten the little screw

-Chris

Seems that way. A bunch of us used these old 71s with bolt peep for years in our northwoods camp but we never spent any time adjusting the sights. The camp elders always said of you can hit a plate at 50 yards you are good. So that's all we did and, because our shots were always less than 100 yards, we took a lot of deer! Maybe if we missed we would have spent more time on the sights. Glad to have this information though, now I'll probably use up a few boxes of expensive ammo making sure I am right on. It will be fun though and well worth it. Thanks all for the information.