Front sight ramp reattaching

[LeftHandGuy]

Hi all.

Looking for any suggestions before I take this to a gunsmith.

I fitted a new sight to my Zastava M70, and as part of that process went to centre the blade of the front sight (the front blade as fitted at the factory was definitely off-centre).

Anyway, a couple of taps in, and the whole ramp came off, which was a bit of a shock! It also revealed an attachment system I hadn't seen before with a threaded carrier intended to sit in a shallow dovetail.

The underside of the ramp strongly suggested it had been glued on at the factory (the rear sight base had been, and I needed to apply heat to remove it).

I can reassemble the components, but the whole thing just won't stay in place when I try to reinsert the blade, a few taps and the ramp is off.

I have tried peening the dovetail, peening the dovetail onto the carrier, and setting it up with a small bead of 2 part epoxy. So far nothing I have tried has held up to my trying to reinsert the front blade.

Anyone else with this arrangement and what did you do?

 

[webley701]

Whilst you can try to ‘tap’ the front sight insert to adjust it (with the attendant issues you’ve found), normally a tool is used which holds itself on the ramp & has a threaded ram which pushes against the base of the insert. It applies no load to the ramp / barrel fixing. Brownells should have a variety of these tools.

 

[Heym SR20]

If you are bonding it, you need to make sure it is very clean in the joint. Also roughen the surfaces up. Use a slow setting epoxy - 24 hr araldite is very good, ditto JB Weld. But make sure its fresh and in date.

 

[LeftHandGuy]

Whilst you can try to ‘tap’ the front sight insert to adjust it (with the attendant issues you’ve found), normally a tool is used which holds itself on the ramp & has a threaded ram which pushes against the base of the insert. It applies no load to the ramp / barrel fixing. Brownells should have a variety of these tools.

Thanks, yes I thought about one of those:

https://www.brownells.com/tools-cleaning/gun-tools/gun-sight-tools/front-sight-pusher/

But the overall weakness of assembly is what is giving me pause here, is this a very common way for a front ramp to be installed? I was expecting to find it screwed into the barrel, and TBH I was surprised that both front and rear had been glued...

 

[Heym SR20]

Thanks, yes I thought about one of those:

https://www.brownells.com/tools-cleaning/gun-tools/gun-sight-tools/front-sight-pusher/

But the overall weakness of assembly is what is giving me pause here, is this a very common way for a front ramp to be installed? I was expecting to find it screwed into the barrel, and TBH I was surprised that both front and rear had been glued...

Traditional way was solder, but modern epoxies are just as strong.

Best way is to have a barrel band made integral to the ramp.

 

[HonestJohn]

This is a classic of what I call ‘what lies beneath’!! Reg. used guns.

You will find the front sight ramp is likely not original, and the original sight was dovetailed into the slot, so some Joe glued a random ramp on.

Or, someone removed the ramp, dovetailed the barrel for xyz reason, and when re-selling they glued the original back on, but the screw hole was of course gone.

Or, this is not a zastava barrel, but a random fitted after, and whose original rifle wore dovetailed sights.

Or, very likely, zastava procured a barrel with a dovetail front sight and glued the ramp on. The two rear sight holes lend themselves to this idea, the stock inletting also looks original, so likelihood is either this, or someone tried to fit a different front sight at one point.. given the drift marks, could well be the case too, but why.

Either way, low heat solder is your friend, and easy to get in the US

 

[webley701]

Thanks, yes I thought about one of those:

https://www.brownells.com/tools-cleaning/gun-tools/gun-sight-tools/front-sight-pusher/

But the overall weakness of assembly is what is giving me pause here, is this a very common way for a front ramp to be installed? I was expecting to find it screwed into the barrel, and TBH I was surprised that both front and rear had been glued...

It’s not an uncommon way to hold a ramp on & it works well enough (assuming a suitable tool is used for adjustment ) - but it’s difficult to beat a soldered on version - unless a ramp is made of a non-ferrous metal of course.

 

[LeftHandGuy]

This is a classic of what I call ‘what lies beneath’!! Reg. used guns.

You will find the front sight ramp is likely not original, and the original sight was dovetailed into the slot, so some Joe glued a random ramp on.

Or, someone removed the ramp, dovetailed the barrel for xyz reason, and when re-selling they glued the original back on, but the screw hole was of course gone.

Or, this is not a zastava barrel, but a random fitted after, and whose original rifle wore dovetailed sights.

Or, very likely, zastava procured a barrel with a dovetail front sight and glued the ramp on. The two rear sight holes lend themselves to this idea, the stock inletting also looks original, so likelihood is either this, or someone tried to fit a different front sight at one point.. given the drift marks, could well be the case too, but why.

Either way, low heat solder is your friend, and easy to get in the US

Ta! As it happens this was not actually a used gun, so I am pretty confident it's true OEM.

The rear sight holes are 4-48 threaded and I was quite surprised that after removing the screws, that the base stayed very firmly in place! I had to use a blowtorch to loosen it. I was however able to clean up the glue residue better than at the muzzle end.

WRT to solder, would the surface prep be the same as for epoxy?

 

[Klenchblaize]

Or, the Op has 'opened' the dovetailed barrel channel when whacking the assembly with a hammer?

K

 

[LeftHandGuy]

Or, the Op has 'opened' the dovetailed barrel channel when whacking the assembly with a hammer?

K

Indeed I might have, in fact probably did, and was the assumption I made when re-peening the dovetail.

I still don't know what the best coarse is to re-mount it though....

 

[HonestJohn]

Ok, please accept my apologies, I can now see there is a dovetail base to the front sight ramp. What is likely the case is that the dovetail is oversize and the insert slides out.

If this is the case, you only really need to cement the dovetail base firmly in the slot, with either a very good two part epoxy or low heat solder. Clean the metal with acetone several times first, and if using solder, read up on how to do it - it’s not as easy as put a bit on and heat it, but it will hold very well if done correctly. Then the ramp should be able to be tightened down with the screw and held in place with either a small amount of solder under it, or epoxy. Verney Carron uses a 3m two part epoxy to hold their double rifle barrels together, so if you pick the right product, you might find it easier to use, and to avoid damaging the bluing via heat application (which is also not great for certain barrels as it can induce heat stress - although not for low heat solder).

 

[LeftHandGuy]

Ok, please accept my apologies,

Absolutely no apology needed, all interesting observations!

I can now see there is a dovetail base to the front sight ramp. What is likely the case is that the dovetail is oversize and the insert slides out.

Yes it, the carrier, is loose in the dovetail

If this is the case, you only really need to cement the dovetail base firmly in the slot, with either a very good two part epoxy or low heat solder. Clean the metal with acetone several times first, and if using solder, read up on how to do it - it’s not as easy as put a bit on and heat it, but it will hold very well if done correctly. Then the ramp should be able to be tightened down with the screw and held in place with either a small amount of solder under it, or epoxy. Verney Carron uses a 3m two part epoxy to hold their double rifle barrels together, so if you pick the right product, you might find it easier to use, and to avoid damaging the bluing via heat application (which is also not great for certain barrels as it can induce heat stress - although not for low heat solder).

I shall have to see if I can find some acetone! I'm using regular JB Weld at the moment which I would have guessed is comparable to standard Araldite etc, but they do have "steel infused" version which might work better perhaps.

 

[HonestJohn]

Absolutely no apology needed, all interesting observations!

Yes it, the carrier, is loose in the dovetail

I shall have to see if I can find some acetone! I'm using regular JB Weld at the moment which I would have guessed is comparable to standard Araldite etc, but they do have "steel infused" version which might work better perhaps.

JB weld is excellent if applied to clean surfaces and will hold well. I have used JB weld to cement scope bases where holes were so unaligned only welding and re drilling were an option - and they have never moved nor been able to be knocked off by a hammer tap. I would not use the quick steel version, but only the one that sets in 12-18hrs personally. Usually comes in red and black tubes I think. It’s also easier to clean up residue and to align the sights perfectly square after applying than solder. But, do get those surfaces clean, and give the JB a little warming up so it flows

 

[Klenchblaize]

If it were mine I'd enlarge (better define) the barrel undercut with a suitable
and enlarge the base of the captive nut

by either heat & hammer or braze some additional material to it, then file to an interference fit that will allow the ramp to be screwed tight to barrel.

K

 

[VSS]

Watching with interest...
One of my P-H rifles had had the foresight removed before I got it, but I've subsequently acquired the right foresight for the rifle. It would be nice to attach it, purely for aesthetic reasons.
I was wondering if there was some sticky alternative to solder, and it looks like this thread will give me the answer.

 

[HonestJohn]

If it were mine I'd enlarge (better define) the barrel undercut with a suitable View attachment 401449
and enlarge the base of the captive nut
View attachment 401450
by either heat & hammer or braze some additional material to it, then file to an interference fit that will allow the ramp to be screwed tight to barrel.

K

But if the slot is not cut perfectly square, the sight will always sit slanted, which might be the case here

 

[Klenchblaize]

Watching with interest...
One of my P-H rifles had had the foresight removed before I got it, but I've subsequently acquired the right foresight for the rifle. It would be nice to attach it, purely for aesthetic reasons.

Interesting, as this is exactly what I'm hoping to do with my Anschutz 22 Hornet. Fortunately I plugged the two attachment holes with wax some 30-years ago so hopefully the threads are still in good shape. Waiting to hear if parts are still available from the new UK Anschutz Importer.

K

 

[HonestJohn]

Watching with interest...
One of my P-H rifles had had the foresight removed before I got it, but I've subsequently acquired the right foresight for the rifle. It would be nice to attach it, purely for aesthetic reasons.
I was wondering if there was some sticky alternative to solder, and it looks like this thread will give me the answer.

If you do use JB weld, clean the squeeze out before it sets or you will scratch the bluing getting residue off. I recommend first removing majority of excess, then using a very sharp plastic (not metal) tool, remove the final residue squeezing out under the edges after 1-2hrs when it’s holding the item in place, but still soft enough to remove, and whilst unset, wipe off more with acetone soaked rags. Note, if you don’t push the sight firmly down, or you apply too much, you will have a small grey epoxy line showing

 

[Klenchblaize]

But if the slot is not cut perfectly square, the sight will always sit slanted, which might be the case here

The profile of the ramp's underside will ensure it snugs down flush.

If uncomfortable with attacking the barrel with file etc, take to a competent Gunsmith- not a Plumber.

K

 

[HonestJohn]

The profile of the ramp's underside will ensure it snugs down flush.

If uncomfortable with attacking the barrel with file etc, take to a competent Gunsmith- not a Plumber.

K

Agreed, but if the barrel dovetail female slot isn’t sitting square to the top of the receiver, the screw hole will follow, esp if the bottom is flush. Unless you change the angle on the bottom of the dovetail insert for correct for any misalignment in the dovetail cut. Since the OP noted it was not aligned, this might well be the case - zastava aren’t known for, let’s say, world leading tolerances machining wise