What is the proper depth adjustment for a stop pin ? (New Pics added)

[Lochlainn]

Hi Folks,

I have a new Leapers scope and a one piece mount coming from PA for my Crosman Storm XT. The stock scope that came with it is pretty bad and when the stop pin is screwed down into the hole the threads are showing and rough against the side of the hole. The recoil caused it to put a slight dent into the rear side of the hole in the receiver. What is the proper depth adjustment for the stop pin ? Should I stop right before the threads start showing ? At that point though it is just sticking out a little bit.. It seems that it would be better if it was farther down into the hole and not beveled so it would be more secure. Perhaps the new one piece mount will have a different type of stop pin. Was hoping you guys could give me some advice so I don't ruin the hole on the receiver or the new one piece mount. Thanks !

Regards,
Lochlainn

[Bentong]

If you screw the stop pin in too deep, it will be in the way of the piston when cocked. I never use my stop pin when setting my scope ring. Before I tuned my springer I used a single mount 4 screws to hold the scope in place. Metal need to be de-greased for friction to hold. On my Genesis, I torqued the mount really tight and it pinched the action to where the piston rubs and gouged it. With lube/deburr tune, I can use my leapers 2 screws dual mount with no problem.

[oldpink]

Bentong, your experience with being able to get by without using the stop pin is the exception, not the rule.
My own guns must use them, and no amount of clamping force can keep the mount in place if I don't, as is the case with nearly anyone else who has a magnum springer.
My little .177 Gamo Delta does fine without using the pin, but it's only a 500fps class gun, so recoil is nearly non-existent.
Also, I don't believe the Storm XT's stop pin hole exposes the piston in any way, at least if it's anything like that of the Gamo, which has some receiver steel still at the bottom of the hole.
Therefore, I would advise that you most definitely must use the stop pin.
First take the scope out of the rings, loosen the clamp, degrease all parts (you already did, right?), apply the blue Loc-Tite to the scope stop (you don't want it reversing out of the hole), position the Leapers mount, then slowly turn in the stop until you just barely touch the bottom of the stop recess in your receiver top, then back it up roughly a quarter turn.
Tighten down the clamps, then the scope, again Loc-Tite on all screws.
You should now be done.

[Lochlainn]

Bentong, your experience with being able to get by without using the stop pin is the exception, not the rule.
My own guns must use them, and no amount of clamping force can keep the mount in place if I don't, as is the case with nearly anyone else who has a magnum springer.
My little .177 Gamo Delta does fine without using the pin, but it's only a 500fps class gun, so recoil is nearly non-existent.
Also, I don't believe the Storm XT's stop pin hole exposes the piston in any way, at least if it's anything like that of the Gamo, which has some receiver steel still at the bottom of the hole.
Therefore, I would advise that you most definitely must use the stop pin.
First take the scope out of the rings, loosen the clamp, degrease all parts (you already did, right?), apply the blue Loc-Tite to the scope stop (you don't want it reversing out of the hole), position the Leapers mount, then slowly turn in the stop until you just barely touch the bottom of the stop recess in your receiver top, then back it up roughly a quarter turn.
Tighten down the clamps, then the scope, again Loc-Tite on all screws.
You should now be done.

Thanks for the replies Oldpink...when you say "then slowly turn in the stop until you just barely touch the bottom of the stop recess in your receiver top" I assume that means that some of the threads of stop pin will be exposed rather than just the beveled part of the bottom of the pin ? I have seen some youtube videos where they said the stop pin should just barely be coming out of the bottom of the mount and others seem to think that you should go down pretty deep. I wonder what the stop pin looks like on the mount I am getting...This is the one that is being shipped to me- https://www.pyramydair.com/product/leapers-accushot-1-pc-mount-w-1-rings-high-11mm-dovetail?a=636

And here is a picture of the stop pin hole on the receiver of my Storm XT. You can see where there is a little damage that happened due to the stock scope and rings being mounted... It's not that bad but annoys me and I want to avoid any further damage.





I had the scope pin protruding to the point where the threads just began, so there was not much sticking out. Here are a few pics to help explain what I am talking about..This is how I had it initially-



or is it supposed to be like this ? Seems like those threads would gouge up that hole ?



These are the stock rings that came with it not the Leapers one piece obviously. Just using them for illustration. Has anyone had an experience with the Leapers one piece that I linked ? Does the stop pin look like this ? Thanks

-Lochlainn

[oldpink]

Best to have as much of the pin inside the corresponding hole as possible because that gives you more surface area to distribute the recoil.
I wouldn't worry about the threads at all, but if it really bothers you, how about turning it in to where you want it, then taking a Dremel tool or other grinder, then gently grind away the threads that protrude?
That would make your mount hard to use on another rifle, but the mount only costs $18, so big deal.

[Perry]

Loose the stock stop pin and use the one that comes with the new rings. It should be much better with no threads.

[Lochlainn]

FedEx tracking number says the new mount and scope should be here tomorrow. Can't wait to put it on and try it out

[Davee1]

You'll find that the Leapers stop pins look different from the pics you showed.  Their stop pins have a flat end instead of a point.  I use Leapers mostly, and I've always installed my stop pins as far as they would go into the mating hole, but not enough to lift up the mount.  So when I hit bottom, I back off the engagement of the pin just by a small amount...probably somewhere around a sixteenth of a turn or so.
Sometimes the hole on the rcvr is much bigger than the OD of the stop pin itself.  In that case I engage the stop pin until it contacts bottom, back off slightly, and move the mount rearward as far as it can go, then tighten up the mount screws.  That way, the mount is already moved in the direction that recoil will take it, and the stop pin is already up against the rearward wall of the rcvr hole...and recoil cant take it anywhere(hopefully).  Never had one fail yet.

[oldpink]

Lochlainn, for what it's worth, I looked up the screw you are talking about, and the one you have with the point is called a cone point set screw.
The kind that your Leapers mount comes with should have the proper unthreaded protrusion for the stop hole.
That type of screw is called a "full dog point set screw."
Here is an example of that type of screw that I just ordered for my own scope mount: