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View Full Version : Lyman Alaskan guts vs Weaver K2.5 guts



Rootsy
03-22-2014, 08:13 PM
These are two of the most commonly available commercial scopes legal for CMP Vintage Sniper competition on the 1903A4, M1C and M1D guns. Most have been well used and may need internal cleaning, lens work or reticle repair. These are not sealed scopes with inert atmospheres as the vertical Redfield split rings require partial disassembly. I flush with nitrogen or argon at least when re-assembling.

So with that said most people are too afraid to disassemble these old optics as I guess there is black magic or voodoo inside. The few professional options available have about a year turn around for what amounts to an hour or to of work in most cases. It is getting parts that is the hard part.

As you can see below there really is nothing earth shattering or NASA related to these.


First the Alaskan. This Alaskan has a simple tapered post. This post is 3 MOA wide (really blows). Therefore she is getting fine cross wires.


http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2980.JPG


http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2981.JPG


http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2982.JPG


http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2983.JPG


Next is a Weaver K2.5. This is a non-suffix scope (no 60B or C or whatever). This scope is much more simplistic than the Alaskan.


http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2985.JPG


http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2984.JPG


http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2979.JPG

red442joe
03-22-2014, 09:03 PM
tagged

Rootsy
03-25-2014, 08:17 AM
So onto the cross wires for the Lyman Alaskan. The post, according to the M82 (Mil version of the Lyman Alaskan) measures .0035 at the tip. On a target @ 100 yds that post covers 3 - 3.5 MOA. It is difficult to level and with the low magnification it is difficult to align it with the target, especially if the aim point is smaller than the post width. This becomes a pain really at medium range distances such as shot in CMP Vintage Sniper. At 600 yards that post covers 18 inches +/- of the 36 inch target. I find I like cross hairs better but many are too thick as is.

I've replaced cross wires on a few old optics, mainly Weaver K2.5 scopes. Not much to it other than making sure everything is oriented correctly. The Lyman is easier yet since the reticle ring is a .020 thick ring of brass that attaches to a larger body within the scope. The bad part is that there are no witness marks on it to align wires.

Disassembling the Lyman takes a bit of study and some small tools. There are very small screws (a few set screws that are 1/16 - 50). Keeping the stack up and part orientation correct as it comes apart eases re-assembly. I used a wooden dowel to push the guts out the ocular end from the objective end. Father time and sealant as well as the springs that put pressure on the reticle housing make things come out with some difficulty. Before re-assembling, everything will be cleaned and lenses polished. Inside of the tube will receive the slightest of grease to aid re-assembly and surfaces that have grease presently (the slide for the reticle) also.

The first thing to do is make a drawing of the reticle ring so you can make a drawing of it to transfer to a transparency (you younguns probably don't know what that is). I measured the ring with simple calipers but have since acquired the M82 blueprint book and my measurements were pretty close. Then I created the ring in CAD (Solidworks in this case) and printed it out on the transparency.

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2994.JPG

To prepare the reticle itself you need to remove the post which is soldered on and clean the ring. Using my granite surface plate and double sided tape I stuck it down and plugged in the soldering iron. A quick touch and the post is unsoldered and set aside for safe keeping. Using a razor blade scrape all of the solder until you have a flat surface.

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2987.JPG

Remove the ring from the tape and clean it with some alcohol or brake parts cleaner, etc. I switched to permanent double sided tape for a better hold and a larger area at this time too. Stick the reticle ring back down. Then cut out one of the printed templates. Align it and stick it to the tape over the reticle ring (see why I used a larger tape field). In this case I am using the mounting holes for alignment as well as the OD and ID of the ring.

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2996.JPG

Now it is time to make witness marks. I use a razor blade and a small hammer. Place the razor blade over the marks and give it a tap or two (not too hard). This will cut through the template and create a valley in the reticle ring for the wire to lay in. Don't get too aggressive or you'll have a two piece reticle ring. This is half hard brass. Cut witness marks in both directions. Pay attention that the reticle ring and template stay aligned. Once done remove the template.

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_2998.JPG

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_3003.JPG

Now it's time to play with the "fine as frog's hair" wire. This wire is supposed to be Ø 0.0005 inches in diameter. But with my mics it is more like Ø 0.0003 or roughly 1/10th the thickness of the post. Even at .0005 this reticle should cover roughly 0.5 MOA or somewhere around 3 inches @ 600 yds. Big difference from the 18 - 21 inches of the post.

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_3004.JPG

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_3006.JPG

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_3007.JPG

To stretch and hold the tungsten wire I use some regular old masking tape. Once you pull a length off the spool and cut with scissors it is easier to manipulate if you stick both ends of the wire to the tape. The stuff is so fine you cannot feel it between your fingers and you cannot easily see it without bright light against a contrasting background. With the grooves in the ring it is easy to align the wire. The stuff is pretty tough so you can apply some axial pressure to it without it snapping.

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_3009.JPG

Once the wire is in place, in the grooves, and taunt I use my tweezers to pick up just a tiny bit of mixed 5 minute epoxy. Dab it on and lift the tweezers away and let the surface tension break the strand itself so you don't end up with a big wispy strand of epoxy across your work. Once done I go back and spread it out a bit so I don't have a big lump of epoxy that may interfere with other parts when assembled. I let it sit over night to cure. I will cut the wire with toenail cutters or scissors (if they will do it at the tip) and then lift the ring off and trim the wire flush with the ring OD.

http://jarootfarms.com/photogallery/albums/userpics/10001/normal_IMG_3011.JPG

Re-assembly sometime this week.

langenc
04-05-2014, 10:10 PM
So how long is your lead time??

Rootsy
04-06-2014, 08:49 AM
Never really gave it much thought as I do not regularly take on work. I guess it depends on what needs to be done. Not very long though.

bachmanw
10-27-2018, 04:27 PM
Hi - New to your forum but saw this old post. I have an M82 scope which is (as you know) a modified Lyman Alaskan. On the inside of the front lens there is what looks like dried water marks. Like there was condensation in there at one time; like the spots you see on glasses from the dishwasher.

I would like to be able to get at that and clean it up. All the professional sites I have seen listed like Iron Sights and Parsons seem to have alike a year turn around time.

I am not afraid to try this and can see from the pictures some things; but I also don't want to destroy an all original M82. This came off one of my M1C's

Not sure if these were sealed or not; but if there is condensation in there it isn't sealed anymore.

Also don't want to screw up the tapered post.

Can you help with some more detailed instructions?

You were saying you push out the guts with a dowel?

Thanks,
Bill

Rootsy
10-27-2018, 06:54 PM
Remove the locking ring on the front end of the scope then make a tool that fits inside the tube to engage the slots. Turn CCW to screw the objective lens out. Count the turns precisely to return parallax to where it is set now. You can turn it in or out a turn or so to set parallax differently. I put a drop of blue locite in there when in place to keep it from moving.

bachmanw
10-27-2018, 08:26 PM
Rootsy
Many Thanks - I am not sure my M82 is exactly the same. The locking ring in mine is what held the sunshade on. It is part number A7575050. That is off. Below that is another ring with two slots in it (which already looks partially buggered. That is part number Screw A7575166. Below that is Objective according to the drawing.

Sorry but I am unable to post a link to another site yet. By the drawing I am referring to is from nicolausassociates(dot)com/images/M82%20Telescope%20Cover.jpg

I am pretty good at using tools - making tools not so much. Would need a little more direction there.

red442joe
10-27-2018, 10:18 PM
Holy necrothread!
Four and half years!
That's gotta be some kinda record!

I'm still in. Oh, I have a K2....

Joe

Rootsy
10-28-2018, 09:38 AM
4th photo down. The two pieces above tube all the way to the right are the objective lens and the retainer.