BSA 2x20, adjusting parallax

[WhiteHot]

Just mounted the BSA 2x20 on my 1377. I wanted to adjust the parallax down to something more reasonable for this gun. From what I have read, you take the retaining ring off the front, turn the objective CCW around 3/4 to 1 turn, and screw the retaining ring back on. This doesnt seem to work for the BSA scope.

I wrapped the retaining ring in electrical tape and turned it with some pliers. The retaining ring and the objective both rotated together. I was able to turn the retaining ring and objective out to adjust the parallax and that works. Now I want to tighten up the retaining ring. Problem is that the I cant seem to break the objective loose from the retaining ring. I have tried to take a screwdriver, insert it into one of the square notches that are 180 degrees apart and move it but it wont budge and I am starting to deform the notches. Seems like BSA used threadlocker between the objective and retaining ring.

Any tips from someone else that has done this on the BSA scope?

[gdm620]

I have adjusted the parallax on my 2x20 BSA and had no problem at all on the front ring sticking to the lense.  I don't know why yours is like that.  I just unscrew the retaining ring off and then adjusted the lense part until I had no movment of crosshairs at 10 yard that I wanted it set at.  Put the retainer back on and used it.  Don't know what to tell you.  If you screw it out to far you will lose the gas in the scope.

[WhiteHot]

Please take a look at the way mine is built and let me know if yours is the same. The stuff around the outside of the retaining ring is black electrical tape so I didn't mar the finish. When I turn the retaining ring, the inner part (the part with the notches) turns too. I think it is threaded into the retaining ring. This is the part that I would ideally hold in place while I thread the retainer back on, right? Or am I missing something?

It should be noted that when I unthreaded the retaining ring and inner piece around 1 full turn, I had almost no parallax at around 7 yards.

[WhiteHot]

I just unscrew the retaining ring off and then adjusted the lense part until I had no movment of crosshairs at 10 yard that I wanted it set at.  Put the retainer back on and used it.

So this is the part I dont understand. When you say you take the retaining ring off, do you remove it completely? If I take the retaining ring off, the objective will come with it and I am assuming I will lose the gas purge.  I am beginning to think that our BSA 2x20 scopes were made differently.

[gdm620]

Yes that is what mine looked liked.  You are right the retaining ring should come loose from the objective lense part with the notches.  It must be really stuck on there.  Mine came right loose. I take the retaining ring clear off of mine.  Then adjust the objective.   I don't know how you would get it unstuck with out the right tools.  I was lucky I guess on mine.  You are right don't unscrew the lense clear out because you would lose the gas in there.  So you have to figure out how to get the retaining ring lose from the abjective and you would have it.  It is so easy to damage that stuff.  Sorry I can't be of anymore help. 

PS:  Later today I will take a pic of mine with the retainer off so you can see what mine looks like.  I have to go to work for 4 hrs then I can do that.

[gdm620]

Here is what mine looks like.  The pics aren't that good but it is like yours.




Your objective must really be stuck to your retainer ring.  I don't know how you can get it loose.  Mine came right loose from the beginning the first time I did mine.  It was really easy.

I had a Simmons scope like that.  I couldn't get the ring loose from the lense.  I gave up on that scope trying to get it loose so I just use it not locked to the frame.  Kinda like you did on you BSA.

[hogrider04]

If you can adjust it the way you want it, just put a wrap of electrical tape around it to keep it in place. Won't be purty, but would save you trashing it out. 

[WhiteHot]

gdm620, thank you so much for the pics. Seeing it disassembled gave me the info I needed to keep disassembling mine.

hogrider04, I would rather break it than not have it right

So I heated the tips of some long nose needle nose, bent them outward, then filed them to fit the slots in the objective piece. I held the objective in place while I turned the retaining ring in to lock it in place. When I was turning the locking ring, there was quite a bit of resistance the entire time. There is definitely some sort of thread binding agent on the threads. It didnt feel like threadlocker because it didn't "pop" loose. I know that there is some sort of gummy adhesive that never dries that is sometimes used in the optics field to keep lenses from moving once they are focused. My guess is that is what was used here. Anyway, here are some pics of the tool I made.

[gdm620]

Good idea with the pliers.  Mine didn't have any type of sealer on it.  I bought it new.  Anyway glad you got it figured out.    I'm selling mine because I don't need it any more.  They are a great scope.

[hogrider04]

I was gonna suggest making something like that, but it's hard to tell what skills the person has when you just see him type. 
You obviously have the skills. Nice job!!! 

[bgmcgee]

I like your spanner pliers. 

[targettgii]

Nice job on the pliers.