Gunsmithing Stuck Screw Unertl external mount scope

[pmclaine]

I recently bought a nice Unertl 10X external mount scope. Its in real good shape but sitting in a closet for the last 40 odd years froze up a bunch of stuff.

Im intending on using this scope in building a fake USMC 1903 with telescopic glass, M1941. The Marines did not use the recoil spring assembly and I need to remove it in order to get the look.



There are two screws that hold the erector in the scope body just behind the pope rib. They are oval head and protrude just ever so slightly that they prevent sliding the spring collars off the pope rib, down the tube toward the ocular and off the scope body. In my case I cant get one of the erector screws out in order to do what I want to do. Ive been told usually removing just one screw will allow the collar to pass. The screw that is frozen in place is somewhat chewed up and the collar wont pass over it.

I spoke with a gentleman that is well versed in working on Unertl scopes. Unfortunately he is not taking work right now. He told me to fit a screw driver blade to what remains of the screw, unplug a drill press, mount the blade end in a drill press, use firm pressure from the press on the screw and turn the chuck by hand to remove the screw.

Sounds legit but takes more balls than I have. Heat is not an option.

Is removing a stuck screw from a scope gunsmith work? Can a smith repair/replace just about any screw of American manufacture?

 

[LRI]

He's right.

The trick is getting the screw driver edge ground/machined just right so that you have an almost interference fit with what's left of the slot. You can't just go blazing away on the screw driver otherwise you'll cook the heat treat right out of it. When I'm faced with this stuff I make the screw driver blade to where I have to tap it into the slot.

Heat can be an option. You just don't cook the screw with a torch. Use one of the little butane "crack torches" and tap your screw driver insert into the screw to where it stands alone. Then apply heat directly to the insert. It'll travel down into the screw and heat soak the immediate area without scorching the surrounding area. We use this technique almost daily with the group buy as actions often arrive with base screws in less than pristine condition.

The best bet is a tip out of the Brownells super set. The steel is better and you'll notice right away that the blade geometry on the inserts are radically different than what you'll find on a Snap On truck or Sears.

If your terrified, box it up. I'll do it. I too have a pet affection for these optics and own several.


Happy to help.

C.

 

[pmclaine]

I was just on the Brownells site looking at manga tips and than decided to come here first before emptying my cart to see what advise had come through.

Using calipers it looks like my driver tip should be .15 diameter by .024 thickness. Brownells has some that are close I would have to file to fit.

I appreciate your offer to work on the screws and get them removed. I'm waiting to hear back from Aaron Davis to see if he had any NOS screws so I can replace the old with new. If I get the chewed up one out I don't want it going back in.

Let me get back to you.

 

[29aholic]

I got a better idea. Why don't you trade me that Unertl for my Lyman 5A???

 

[LRI]

If I had to, I could probably make you a new screw. I've done little bastages like this before. They're kinda fun to do every once in awhile. (I'd play with a rusty razor in a busy street before doing it all day though....)

 

[pmclaine]

If I had to, I could probably make you a new screw. I've done little bastages like this before. They're kinda fun to do every once in awhile. (I'd play with a rusty razor in a busy street before doing it all day though....)

Based on the work I've seen you post this probably falls into the easy category but than again it's the "easy" ones that destroy an excellent reputation.

One thing I have heard is any heat on a Unertl is a no go but your method of using the screw driver tip as the heat sink is probably safe. Once the old goo is loose I can't imagine it takes much to break it free. I was originally told just remove one screw and the spring collar would slide off without risking the erector moving. I don't know enough about the interior of a Unertl to know if removing two screws is safe. I can get one screw out but the chewed up condition if the other interfere with the passage if the collar.

Just heard from my gunsmith that the rifle will have Steve Earle blocks mounted and ship back to me next week. As noted waiting to hear from Aaron Davis, former Unertl employee that has a bunch of NOS stuff, to see if he has any screws in his inventory.

All I really need to be ready for the rifle is to have the recoil spring removed. I'd really like to get the mounts anodized black to more closely resemble a WWII USMC sniper. If I go the sending out route is anodizing something I your bag of tricks?

Thank you for taking the time to respond and share your knowledge. I hope I'm not being a pain in the nuts.

Phil M

 

[LRI]

I would guess that original bases were made from steel. Not AL.

Steel is either blued or Parked. AL is anodized. You can do anodizing yourself at home. There's a dozen or so You Tube vids on it. Basically some acid, a battery charger, some dye, and one of the misses pots in the kitchen. Not hard at all. Just be sure it's not a good pot. . .

C.

 

[29aholic]

So I guess that's a no on a trade hunh?

On another note, do you think the Unertl guy has any lenses? I have a 2 1/2" that was in a fire.

 

[pmclaine]

So I guess that's a no on a trade hunh?

On another note, do you think the Unertl guy has any lenses? I have a 2 1/2" that was in a fire.

I'm all full up on my quota of Lyman's, sorry.

Contact for Mr Davis......

[email protected]

937-631-2854

I hope it's helpful, sounds like he wants to do more Unertl stuff. I bought a spring stop off him last week. Shipped quickly. Hope he has something for you.

 

[pmclaine]

I would guess that original bases were made from steel. Not AL.

Steel is either blued or Parked. AL is anodized. You can do anodizing yourself at home. There's a dozen or so You Tube vids on it. Basically some acid, a battery charger, some dye, and one of the misses pots in the kitchen. Not hard at all. Just be sure it's not a good pot. . .

C.

The Steve Earle bases are color case hardened steel.

The Unertl target mounts, external type, are aluminum. The USMC mounts seem to have an odd black, bronze, green color from age. Tokiwartooth, making the green Redfields, may give it a try.

 

[29aholic]

I'm all full up on my quota of Lyman's, sorry.

Contact for Mr Davis......

[email protected]

937-631-2854

I hope it's helpful, sounds like he wants to do more Unertl stuff. I bought a spring stop off him last week. Shipped quickly. Hope he has something for you.

Thanks Phil
Do you have any Lymans up for trade? I have a Junior TS in a 6x but I need something 10x or better.

 

[pmclaine]

Thanks Phil
Do you have any Lymans up for trade? I have a Junior TS in a 6x but I need something 10x or better.

i was jesting about owning any Lymans. The only other vintage scope I have is a 4X tasco that has been on my 10/22 since bought new in 1986. It sweet, slight ring marks, typical wear on the plastic turret caps. Its cherry make me an offer!

I have a honey hole of sorts for old rifles and scopes. The proprietor buys and sells estates. He doesnt take requests to look for anything and he does not fall in love with what he sells. Inventory comes in gets stacked unceremoniously in its spot, gets listed in an online ad and sold or someone like me walks in the door and sorts through the pile to find a gem.

The Unertl in the photo above was one of two he had. The other is a 14X I believe and was sitting on the shelf last time I was in Shangri-La. The 14X was priced at $600 but that was before I bought its lens caps for $25 to use on my 10X. He also has Lymans and some Winchester external adjusts. I have seen Fecker on occasion. The Northeast may now be anti gun but due to the fact Springfield Armory, Winchester, Colt and all the greats used to call New England home there really are some great pieces that come from the homes of guys no longer using them and with family that does not value their old possessions.

 

[29aholic]

i was jesting about owning any Lymans. The only other vintage scope I have is a 4X tasco that has been on my 10/22 since bought new in 1986. It sweet, slight ring marks, typical wear on the plastic turret caps. Its cherry make me an offer!

I have a honey hole of sorts for old rifles and scopes. The proprietor buys and sells estates. He doesnt take requests to look for anything and he does not fall in love with what he sells. Inventory comes in gets stacked unceremoniously in its spot, gets listed in an online ad and sold or someone like me walks in the door and sorts through the pile to find a gem.

The Unertl in the photo above was one of two he had. The other is a 14X I believe and was sitting on the shelf last time I was in Shangri-La. The 14X was priced at $600 but that was before I bought its lens caps for $25 to use on my 10X. He also has Lymans and some Winchester external adjusts. I have seen Fecker on occasion. The Northeast may now be anti gun but due to the fact Springfield Armory, Winchester, Colt and all the greats used to call New England home there really are some great pieces that come from the homes of guys no longer using them and with family that does not value their old possessions.

I think I have a Tasco on the 10/22 I bought new...in 1976

$600 for a 14x Unertl is pretty cheap. Keep me in mind next time you go over there.

 

[pmclaine]

I think I have a Tasco on the 10/22 I bought new...in 1976

$600 for a 14x Unertl is pretty cheap. Keep me in mind next time you go over there.

Update - forgot I had more bits in my Borka kit, took a look and the perfect bit was included by Kortik.

Got the buggered screw out and removed my recoil spring. I had visions of sending the external mounts out to be anodized like the USMC ones were but after dodging that bullet I just put the scope back together minus the recoil spring and will shoot it as is.

Now matter how close I get it to look like a USMC sniper it never will be and I only chance fucking the scope up if I screw with it any more.

29Aholic - I had no plans to hit that place soon as it is very bad for my wallet but if you have a particular interest in that scope Ill make a point of stopping by. I dont know much about the Unertls. My only interest in them was to build the clone I am working on. I know from looking through the 14 it was clear of debris and had fine crosshairs, no center dot. Its and exact twin to mine save the difference in magnification. Im pretty sure mine was marketed as a 1.25 inch target. More info on the scope here......

Unertl 10X - CMP Forums

Note looking over my CMP post I see I identified the other scope as a 16X. It may be a 16X than.

 

[pmclaine]

LongRifles,

Thank you for posting to help. I was able to get my issue taken care and your advise was part of the solution. Found a really tight fitting bit in my Borka kit and it was the answer.

Phil M