I am considering adding an open sight to a little CZ 17HMR rifle.

The barrel thickness at the muzzle is about .200. Is this enough meat to drill and tap a hole for a #8-40TPI screw? How deep should the hole be? I'm thinking 3-4 thread pitches so about .100in.

Can this effect accuracy??

Brett

Curious as to why the 8X40, does it recoil that much? On that caliber, I wouldn't want to get much closer to the "groove" than .075 with a flat bottomed hole.

My Parker Hale 300WM barrel came with the front sight screw holes all the way through to the bore, and it shoots ok [2.4 moa 5 shot group average]

That's what the sight comes with.

As it's a fine pitch thread it's still a fairly shallow hole, although fat...

Brett

quote:

Originally posted by tnekkcc:
My Parker Hale 300WM barrel came with the front sight screw holes all the way through to the bore, and it shoots ok [2.4 moa 5 shot group average]

You know, if you were to put some longer screws in the sight, you might be able to use the word "pattern" rather than "group".

quote:

Originally posted by Westpac:

quote:

Originally posted by tnekkcc:
My Parker Hale 300WM barrel came with the front sight screw holes all the way through to the bore, and it shoots ok [2.4 moa 5 shot group average]

You know, if you were to put some longer screws in the sight, you might be able to use the word "pattern" rather than "group".

There is no front sight or screw on the muzzle, so the two holes act as recoil compensators.

Brett --

Do you have a product number or pic of the sight you're using?

-- ale

quote:

Originally posted by tnekkcc:
There is no front sight or screw on the muzzle, so the two holes act as recoil compensators.

It would tend to do that for sure. How did it shoot when there was a sight?

aleaddict,

This is what I had in mind.

[IMG:left] [/IMG]

Thanks for the help.

Brett

Have you considered acraglass or solder? I'd be tempted to do those first, and then you could always D&T a tiny hole if you were really concerned about the epoxy bond. I would also see no reason to go with a #8, or #6 for that matter.

Brett --

Don't underestimate the power of loctite. There are several types available, one of which should do the trick. Since you're dealing with a rimfire, I doubt recoil would be an issue. It would also save you from having to re-blue your barrel. Just a thought...

-- ale

Mark & aleaddict,

Thanks for the suggestiions. I do have some low temp solder, In-Sn, and some Black Max Loc Tight. I may just try that first.

As always I'm probably trying to over do things.

Best regards;
Brett

If you use the low-T* solder you'll need to strip the bluing on your barrel first. Otherwise, the flux will do it for you. I've never used it before but that's what I've read. The Black Max loctite is extremely strong but dries very quickly so there's very little wiggle room for getting everything square.

I would suggest using the Red loctite and hitting it with a little MAPP gas to help it cure (a trick I picked up from Westpac). I used this method with a banded front sight I have attached to a mandrel, applying just the Blue loctite during the fabrication process, and I could barely get it off!

quote:

As always I'm probably trying to over do things.

That's my problem, too. Just so long as you're happy with the results. There's no wrong way to do things, just "different ways" of doing the same thing. Good luck.

-- ale

Blaser, Mauser, Sauer, Heym and others does this drill and tap also with their fabric made barrels, so why should it not work...?!

If You drill and tap, why not taking an LED-powered front sight like this here:


LED-powered Front Sight

Thanks again everyone,

Ale, do you recall what number the "red" loctight is??

Brett

Brett --

I bought the #271 loctite from Brownells, but if you do a search on http://www.mcmaster.com you'll come up with 746 listed items. Perhaps someone with more knowledge than I can recommend a couple different product numbers for your application.

All I know is #242 Blue loctite + MAPP gas = a VERY STRONG bond. I had to use a lot of heat and pound like crazy to remove the banded sight base from the mandrel. I can only imagine how strong the #271 Red loctite bond would be using this same method.

-- ale

quote:

Originally posted by aleaddict:
I can only imagine how strong the #271 Red loctite bond would be using this same method.

-- ale

You would have destroyed the sight had you used the 271. Another good one for "banded" stuff is 609. Actually, it's probably the most permanent of the two.

Thanks again, guys.

Westpac, would you recommend 609? What is the "pot life" or how long do I have before it sets up?

Also, will I need to remove the barrel blue?

Brett

quote:

Originally posted by Brett:
I am considering adding an open sight to a little CZ 17HMR rifle.

The barrel thickness at the muzzle is about .200. Is this enough meat to drill and tap a hole for a #8-40TPI screw? How deep should the hole be? I'm thinking 3-4 thread pitches so about .100in.

Can this effect accuracy??

Brett

Sweat the ramp on that barrel, or use a barrel-band type ramp that has a set-screw throught the sight blade dovetail to hold the ramp in place. You have to use a "sight pusher" with these ramps........

quote:

You would have destroyed the sight had you used the 271. Another good one for "banded" stuff is 609. Actually, it's probably the most permanent of the two.

Westpac --

What is the issue with #271? I don't want to recommend something that might ruin a barrel, mine or someone else's. Please enlighten us "over-engineering" DIY'ers Many thanks!

== ale

quote:

Originally posted by aleaddict:
Westpac --

What is the issue with #271? I don't want to recommend something that might ruin a barrel, mine or someone else's. Please enlighten us "over-engineering" DIY'ers Many thanks!

== ale

Here are the companies material data sheets for the 271 and 609.

http://tds.loctite.com/tds5/docs/271-EN.PDF

http://tds.loctite.com/tds5/docs/609-EN.PDF

You will probably have to get an engineer to explain the data. My area of expertise is in the area of trying to remove pieces that have been glued with the stuff.

You won't damage barrels using either product provided you get the parts on and aligned before it begins to set. 271 and 609 allow a fair amount of work time before you have to worry about it setting up on it's own. Once I have the item where I need it, I apply a little heat which as you've seen, quickly sets up the stuff. Under the right conditions, the right Loctite can be very useful.

All this talk about loctite and MDS forms has been too much for my pea-sized brain to process. Here's an email I sent to Henkel Loctite this morning, along with their reply that follows:

quote:

Description: I have a round metal sleeve (front sight base) that I would like to attach to a barrel. Other gunsmiths have recommended either #271 or #609. The sleeve is made from 12L14 and the barrel CM steel. Both will be blued before attaching. It is essentially a slip-fit mating surface. Any recommendations? Many thanks.

Date of inquiry: 3/4/2008

Use 609 if its 360 wrapped sleeve. If not use Product 325, Item number 32530 with Product 7387, Item number 18861 rated to 350F

Great on all metal bonding. Available at your local industrial distributor.

Jim Adams
Henkel Industrial Products Division
Technical Information Services
1001 Trout Brook Crossing
Rocky Hill, CT 06067

I forgot to add, here is an image that was attached to the reply from Henkel Loctite:

I'm sure the gunsmiths over at Henkel Loctite know what they are talking about, but, their prior recommendation for the use of #325 for retaining those items that are not 360 is a bit confusing in light of the comment at the bottom of the image they sent you. I would think that items with a minimum wrap of 180, as pictured in their image, would clearly benefit from a little retaining compound. Probably one of their "plastic" retaining products.

I have only tested the strength of their 271 and 609 products on banded items, but if time allows, someday, well into the future, I might try some tests on some 180 degree stuff. I can see where the limited use of a retaining compound, when used in conjunction with another form of fastener, can be an advantage when refinishing a weapon isn't an option. Until then it's comet flux and exhaust fans for this kid. And thanks for posting their reply to your inquiry.

So I guess I'm back to screws and solder or loctite on the screws...

Brett

quote:

Originally posted by Brett:
So I guess I'm back to screws and solder or loctite on the screws...

Brett

A screw should be just fine.