Thread: Scope Mounting 101

I've had a look at a few past threads re this topic here and have seen advice given that is not good IMO, hence I will give ya'll some of mine. I notice MANY used scopes for sale on TM that have been seriously marked/ruined by people who clearly don't know what they are doing.
So starting with the scope base/s or rail : this needs to be attached securely to the receiver. Do u glue it on ? Yes ? Is Loctite a good glue for this job ? NO !!!! Loctite is fantastic stuff but it does not have the kind of gap-filling properties that may well be required here. Use a hard two pot epoxy. NOT araldite. I have something in my pants harder than Araldite and as my wife will tell you, that aint hard !
So rough up the mating surfaces a little first, then DEGREASE thoroughly with a solvent like brakeclean, acetone etc. Then apply some poo and screw the bases/s rail down. Use High Tensile steel screws, not stainless ones. The stainless ones will likely break !
Keep the poo out of the screw heads so u can disassemble later if you need to. Just heat the epoxy with a low flame/iron or whatever when you want to remove it and the epoxy will turn to a soft gummy form.
Once the bottom part is set then attach the rings onto it. Do they need lapping ? Maybe if it's a one piece rail and the rings are a top level matched set then you could miss the lapping step. I still wouldn't trust them to be properly true so would lap them in a little first to check.
Lapping is another story and I won't go into that, as it's not rocket science BUT make sure to remove any sharp edges from the rings top and bottom halves when done !!!!! If the rings are ally then you can scrape those sharp edges off with a knife. A good knife will scrape the sharp edges off steel rings too. But REMOVE THE SHARP EDGES or your scope will end up looking like all the other scopes people have ruined.
Obviously age and/or experience adds to the basics outlines above. Cheers.

I'd add to the above that you should do yourself (and your scope and rings) a favour by using a torque wrench to do up the cross bolts/screws etc to the correct torque.

I've always used hi-strength araldite for bases (after a de-grease). Also just used what ever screws came with the bases and rings with locktite.... Not good enough you reckon?

Originally Posted by Dama dama

I've always used hi-strength araldite for bases (after a de-grease). Also just used what ever screws came with the bases and rings with locktite.... Not good enough you reckon?

Just gotta be hard mate. Araldite is not normally right. A good one available in small tubes is "Devcon Plastic Steel" or "J B Weld", both hard and strong and grey in colour.
I just mentioned the screws as a side note really, as the supplied ones are normally the right ones.

I have usually always used 2 part epoxy under bases but my last rail on a Barnard I tried Loctite 660 Quick Metal. I have just had reason to replace that rail with another and when I removed it the fill looked vg. Have found JB Weld vg also. The Yanks love that stuff.

I usually put the bog on and then just nip the base screws down, just. Once bog/filler has cured I remove the screws one at a time, small dab of Loctite 243, and then torque to desired torque.

I torque the cross bolts but not the ring caps. I only use bushed rings if possible (Sako or Burris) and do them up by "feel". Never had any issues.
All non bushed rings I lap. Have found somereal horror stories with some rings even the so called better quality ones. Ring alignment before lapping sometimes improved by swapping front to back or even rotating 180 degrees.

I use an adjustable wrench and a Warne breakaway t bar.

Many years ago I was in a party up the Rangatata and a guy in the team had one of his bases come loose with total loss of zero and some disappointing misses. Disaster in that situation and also criminal that he let it happen.

When fitting scopes I will "zero" the scope. That is, set windage and elevation in the middle of their adjustment, this has the crosshair optically centred with least chance of abberation or parrallax. (And if you're inclined to twiddle turrets, gives you max avail adjustment)
If rings aren't good I will clean them up with a file to 90%+ contact, achieves same as lapping, just without using lapping tool. (I'm not opposed to lapping tools, but if I can get away without grinding paste near a gun, I will)
I fit the bottom half of rings to the gun and lay the tube in it and "boresight", if it's too far left or right I will swap the rings front to back, or 180 degrees (one screw left and one right, ie) to get it as close as possible. Then put the top halves on and nip them up (this has NAF perfect contact between rings-scope body), slack the mounts and torque the top, then torque the mounts, boresight again then zero by shooting.

How important is it to torque the top caps on? Or loctite and nipping them up good enough?

Its such a pricey peice of kit to buy if you're not doing this regularly or only have a few firearms to set up. Alignment bars, lapping bars, levels, torque driver.

There isn't a forum communal kit floating around at all? I'd contribute to this. I'd like to do it properly. Do it once, do it right.

Originally Posted by Projects

How important is it to torque the top caps on? Or loctite and nipping them up good enough?

Its such a pricey peice of kit to buy if you're not doing this regularly or only have a few firearms to set up. Alignment bars, lapping bars, levels, torque driver.

There isn't a forum communal kit floating around at all? I'd contribute to this. I'd like to do it properly. Do it once, do it right.

Truth is mate there are LOTS of pitfalls for the unwary or inexperienced to fall into. Lots of guys do not get it right. And if you take your rifle to your local store then they could very well not do it properly either. Two things are most important : the scope does not get damaged and it gets locked down properly and tight. Maybe stick to rings with plastic inserts unless you know what you are doing ?

Great topic LRP, good follow on info for alot of folk, @Mauser308, I had a Nightforce rail that did exactly that, weirdly it was,t the BDL receiver that was out it was the Expensive Rail that had to be skimmed and repainted .

Mark at Waitaki Engineering sorted the N/F rail for me
I also have three of his rails one 223, one on Sako 6.5 that he drilled and tapped at my request and another on the 6.5 06 Remmy all are perfect.

I always thought that you'd have a hard time moving a rifle on if you had loctite or steel epoxy on the receiver. So I have never done it. is it easily removed?

I have just put the bases and rings on as is. screwed together. never had any issues with zero hold.

What torque screw drivers are people using? I had a huge POI shift when my rings got properly torqued at the range.

I use the fat wrench , it seems to work fine
Bought it off one of our advertisers on here.

Originally Posted by jakewire

Mark at Waitaki Engineering sorted the N/F rail for me
I also have three of his rails one 223, one on Sako 6.5 that he drilled and tapped at my request and another on the 6.5 06 Remmy all are perfect.

Marks rails will be perfect, as with the NF one. The Remmy BDL receiver very likely won't be because they are machined then heat treated after, so they warp. The likes of a Barnard receiver is heat treated first then machined after. They are perfect.

@LRP
Read what I said.

Originally Posted by jakewire

@LRP
Read what I said.

Yes I see now. Sorry. BTW I just started this thread through having seen many scopes on TM , some bloody expensive ones, that people are ruining just because they don't understand the basics.