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offset scope mounts

18 posts · September 11, 2010 to November 7, 2010 · Archived from the original AirgunOne.com community forum

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Hi All,
I have a Leapers 3x9 Bug Buster. i bought an Accushot offset scope mount for it to add to my new TF-87. I even drilled a hole in the receiver to accommodate the scope-stop screw. This mount will not hold on the 87 without the scope stop screw in place (the mount has two stop screws, but the holes for the second screw stop do not align properly on the receiver - my fault). Anyway, what other offset scope mounts are you guys using out there? Anyone know of an offset mount that has more than two securing screws?
thanks,
Flyby out
Well the Bug Buster had to come off. The offset scope could not hold on to the TF-87. So the scope is now on my Beeman 1073, and doing fine. That rifle does not have the power of the -87 which now has the Center Point 4x16x40 mil dot on it. I took it off the Beeman. The TF has not thrown it off yet. It's being held in place with a Leapers Hi-mount unit that has three mounting screws plus one stop screw. Leapers appears to be a low-end producer of mounts. I've written to it about the poor performance of it's offset scope mount on powerful springers.
Flyby out
I'm missing something here. What happened to the scope stop that came with the gun. that should hold it whether you use rings or a rail. :confused:




USA43 :cheers:


http://www.compasseco.com/scope-mounts-tech-force-piece-mounts-c-13_14_84.html

http://www.compasseco.com/tech-force-contender-series-caliber-p-1690.html
hi 43,
Were I to use the scope stop which came with the rifle, I would give up an additional inch of eye relief. The Bug Buster has a three inch eye relief. Moving it further away from my eye is not an option. At this moment I have disassembled the scope mount and am cleaning it up prior to trying to mount it on the rifle again. It was bugging me that the scope-stop screw on the mount did not stay in place. I intend to not only use Loctite on it, but to use another screw to jam-lock against it. I'll use Loctite on that screw as well. I really want to make this work. Heck I even ordered another 3x9x32mm-AO Bug Buster for only $49.00 shipped.
If I can solve this problem I can be hopeful of having the new scope stay put on a refurbished RWS49 I hope to buy one day.

Meanwhile I have been in contact by email with Leapers about the lack of clamping force on it's offset scope mount. Today i was on the phone with Leapers and received a follow-up email. In it I was told Leapers will look into a re-design to improve the clamping force of the mount to the rifle'a scope rail. It is possible leapers will buy a TF-87 to use as a test bed.

I am not obsessing, but the idea of a lightweight compact variable power scope has it's appeal. The big thing is the parallax adjustment the scope has: 3ft to infinity. That means I could use it indoors and outdoors;very important to me. Plus, i don't want a heavier scope n an already heavy rifle. hence the Bug Buster fit the bill. Now to solve the riddle of that offset scope mount.
Flyby out
Yeah the bug buster has to be set back...

now in regard to the offset you have.

i'm using it on my tomahawk. thats magnum powered but smooth.
with NO pin just the 2 base allens....marked it and it does not move at all.


i've checked and rechecked and chrono 899 to 905. that base hold well.

You did clean the rail of all lubricants with alcohol and the mount as well?

doe that TF have a smooth firing cycle or is it a kicker. cause one stop pin should be sufficient...loctite the stop pin they have a way of backing out as well.
Hi 9Ring,
I am having no further problems with the Bug or the mount. I am using one stop pin in a new hole (gotta seal up the others one day). Plus I used Loctite on the stop pin, and even used the second stop pin to jam-lock the first one (after filing it down to flit relatively flush). Now I can master the TF-87. It still has a nice kick to it, but it is what it is. I'm sure I can make it's firing behavior smoother, but for now. I'll try to get better at it as it is. It's doing an average of 835fps in .22, which I think is a bit low for the rifle. I wonder how I can get it up to 900FPS?
Thanks for the reply!:thumb: much appreciated
Flyby out
Hey that a smart move using the other stop pin to jam in a single stop pin.

Thank you...

this place is great.

I'm gonna post up.

E Arther shooting..

has HAWK HD 3 x 9 40 for 59 bucks..

Hawks have a great reputation for holding powerful guns Zero.
Hi 9Ring,
I am having no further problems with the Bug or the mount. I am using one stop pin in a new hole (gotta seal up the others one day). Plus I used Loctite on the stop pin, and even used the second stop pin to jam-lock the first one (after filing it down to flit relatively flush). Now I can master the TF-87. It still has a nice kick to it, but it is what it is. I'm sure I can make it's firing behavior smoother, but for now. I'll try to get better at it as it is. It's doing an average of 835fps in .22, which I think is a bit low for the rifle. I wonder how I can get it up to 900FPS?
Thanks for the reply!:thumb: much appreciated
Flyby out

835 in .22

thats damn good. i know th 87 is the new High powered TF on the block.

My Walthers hit in the 950's + but since being tuned for smother actions....they have lost a bit and average 850...tuned though.

Youre getting great FPE. from a stock TF.

I have a Bug as well.... was hard to find a gun it would fit ...eye relief wise.

glad you got it nailed down( no pun)

9R

PS when you drill i assume your using a titanium drill bit....what size bit by hand or do you have a drill press.?
Hi 9Ring,
I have no drill press. I got away with just using a hand drill. Since I was planning to mount the Bug Buster I had bought the offset scope mount for it. I removed the stop pins then put the mount on the scope rail, and tightened it down in position. Then I selected a drill bit just under the diameter of the stop-pin hole closest the the rear of the receiver. Then I carefully inserted the drill bit (I was using a variable-speed drill), careful to try to stay away from the threads in the hole, and very carefully used this drill bit to make a centering mark on the receiver. Just enough to mark it, and no more than that. Then I selected a drill bit that was the same diameter as the bottom of the stop pin, the non-threaded portion. From there it was simple to drill the hole, stopping frequently to clear away the scrap away. I even held the rifle propped in position with one hand. Yes I went slowly, and with gentle, but increasing pressure. I used a new shard drill bit to do this. I used this same technique to drill into the receiver of my Browning 800 Mag pistol, but only to drill into, not through the receiver. I drilled that hole just deep enough to "capture" the stop pin without penetrating into the receive as was done on the -87. Works like a charm for me.;)

Oh, you'll no doubt need the offset scope mount for the Bug Buster. It has eye relief that's closer to two inches rather than the three inches stated by Leapers. Best place to buy if you don't have on is at Optics Planet. Let me know if you need the part number. It's $13.95 there.
Flyby out
9Ring That is the exact same method I used on my B3 but the stop pin stuck thru on the inside of the receiver, so I just used my dremal to grind off the protruding pin and polished it up with some fine sand paper no problem because the seal doesn't get back that far and it doesn't bother the piston. I'm thinking about trying to drill and tap screw hole in the top of a receiver to mount a weaver scope rail.
Oh, you'll no doubt need the offset scope mount for the Bug Buster. It has eye relief that's closer to two inches rather than the three inches stated by Leapers. Best place to buy if you don't have on is at Optics Planet. Let me know if you need the part number. It's $13.95 there.
Flyby out

Is this the mount you are referring to Flyby?
http://www.opticsplanet.net/leapers-airgun-22-1-bi-directional-offset-optimum-profile-mount-rgpmofs38-25h4.html (http://www.opticsplanet.net/leapers-airgun-22-1-bi-directional-offset-optimum-profile-mount-rgpmofs38-25h4.html)

I've been following this thread with growing interest, as I am the owner of 3 Bug Busters -- all slated to be installed on different rifles. (Airguns Daily had them on for $49 one day, limit 3 -- and I jumped on it) I was not expecting to need an offset mount though, until now.

They way you describe the stop pins on the mount make is sound like there are actually 2 of them? Or am I just wishfully thinking? I had a Tasco Red Dot on my Win. 1000X, definitely lighter than a scope & with a full length (one piece) mount, and it only took about 200 shots for the Red Dot to sheer off the screw that held the factory scope stop plate on the receiver. (Yes, the mount was firmly up against the stop and everything was as tight as possible and locktited [new word :)]) So now this thread has me concerned! The 1000X is a re-branded Hatsan 60 and there is nothing subtle about it's recoil, in either direction.

One of the other Bug Busters is destined for a B3 I'm working on. (The third is for a rifle to be acquired at a later date) So, in the combined experience of all 3 of you gentlemen, would you say with a degree of certainty that I will need offset mounts on both of these rifles?

Oh yeah Flyby, did I ask you if this was the offset mount you were talking about?
http://www.opticsplanet.net/leapers-airgun-22-1-bi-directional-offset-optimum-profile-mount-rgpmofs38-25h4.html (http://www.opticsplanet.net/leapers-airgun-22-1-bi-directional-offset-optimum-profile-mount-rgpmofs38-25h4.html)

(see what happens when you get old -- can you say dementia?) :D

Thanks,
wtfb
Well crud, Flyby. I went back to the begining of this thread, and I discovered you had posted this:
Hi All,
I have a Leapers 3x9 Bug Buster. i bought an Accushot offset scope mount for it to add to my new TF-87. I even drilled a hole in the receiver to accommodate the scope-stop screw. This mount will not hold on the 87 without the scope stop screw in place (the mount has two stop screws, but the holes for the second screw stop do not align properly on the receiver - my fault). Anyway, what other offset scope mounts are you guys using out there? Anyone know of an offset mount that has more than two securing screws?
thanks,
Flyby out

Have I ever mentioned anything about getting old and dementia?...

Anyway, I would appreciate input on my other questions... whatever they were. ;)
Is this the mount you are referring to Flyby?
http://www.opticsplanet.net/leapers-airgun-22-1-bi-directional-offset-optimum-profile-mount-rgpmofs38-25h4.html (http://www.opticsplanet.net/leapers-airgun-22-1-bi-directional-offset-optimum-profile-mount-rgpmofs38-25h4.html)
in the combined experience of all 3 of you gentlemen, would you say with a degree of certainty that I will need offset mounts on both of these rifles?
Thanks,
wtfb
The first thought that struck me when I got up this morning was: "Duh, :doh: why don't I just use the 2 piece mounts I have and mount one of the Bug Busters and see if the eye relief is OK, or if I need to order some offset mounts." It didn't take me long to find the answer myself! So, I'll be putting in an order for 3 of the mounts from the link above on payday!! Sure am glad you brought this issue up, Flyby! Thanks. :yo:
WestTexas, wait one. Update here. I have been successful in mounting the Bug Buster on the TF-87 using the offset scope mount in your link. It works perfectly now. What changed? I drilled a new hole in the receiver, but this time I used a larger drill bit to make a center mark in the receiver. In my past efforts I used a smaller drill to mark center (with the scope mount locked in position), but I was off center, and that may have been responsible for the failures and disappointments I had. This time I was successful because I went through the same set up, but used a drill bit that was nearly the diameter of the threaded hole used by the stop pin. I was very careful to keep the drill clear of the threads as best I could, and was successful in making a well-centered "punch" mark on the receiver. Then it was all good from there. I drilled the hole to the diameter of the bottom of the stop pin. I remounted the scope, had to shim the rear ring to compensate for droop, and got to shooting. The scope does not move, and holds center just as I wanted all along. The initial failures were all my fault.

But be aware of this. The Bug works just fine, as advertised, but the eye relief is a bit closer than three inches. If you can live with that, I say go for it. I have two Bugs, and they are successfully mounted using the offset scope mounts. I even put the same offset scope mount on my Browning 800_Mag pistol. I used the same hole-centering technique on it and was again successful.

The offset mount does have two two scope-stop pins, each in it's own location. What I did was to drill for the use of the rear location,to place the mount closer to the end of the receiver to avoid interfering with the rifle's action (inside). Then I used the second stop pin to jam-lock the inserted pin. I ground the "nipple" (I'll call it that for clarity) off the second stop pin so It would fit flush in the body of the scope mount. Of course I used blue Loctite #246 on all threads.

By the way, I found that I did not have to drill all the way through on the Browning's receiver. I was able to drill just deep enough for the pin to be able to "bite". I would suggest trying to find a similar depth. Oddly, it seems that the thickness of the receiver on the Browning pistol is greater than that of the receiver on the Tech Force-87. I was though the TF's receiver almost before I knew it, and I was being careful, stopping and checking, stopping and checking. I guess I learned something there, eh? ;) Oh, I drilled all holes while bracing the (two) rifles and the pistol with my left hand, and drilling with my right. I don't have a workshop, let alone a drill press. So I feel good at what I've done, though it was a crude way to do it.

I hope this helps clarify things. I say go for it. One final thing. You may save a few cents by ordering from PA, if you only want one scope mount: http://www.pyramydair.com/s/a/Leapers_Accushot_1_Pc_Bi_directional_Offset_Mount_ w_1_Rings_High_11mm_Dovetail/2409

But if you buy two mounts from Optics planet and you can get free shipping if the order is $29.95 or higher. If you go with Optics Planet, I suggest calling them and placing the order over the phone. Here's why. When you order two mounts, they will not by themselves add up to enough to qualify for the free shipping. But ask the customer service person for help with buying something just costly enough to put you at or over the minimum free-shipping amount. I ordered a cheap key ring (with a light) for less than two bucks, and that did the trick. I live in Ohio so ordering from PA means I incur shipping plus taxes on the order. I saved a few bucks! :)
Flyby out
Yeah if i did it it would be by hand.


However given the only gun that needs one...is my Tomahawk. i went to a 3 allen base using SS allens on the base and straps....for maximum gorilla torque with no stripped heads..lol

( it might ruin its future value...as its a UK..not a turkish tommy.)
Thanks for the update and suggestions Flyby. Actually, I have a pretty long shopping list for OP, so hitting the free shipping minimum definitely won't be a problem. And the main reason I hadn't already mounted the BB on my Win. 1000X was that the Scope Stop Hole on it is threaded, and too small for the pin on the mounts to go into. So, if I'm going to have to drill that one out, and drill at least 1 new one, and I'll have to take the action out of the stock to use my drill press -- I might as well go ahead and do a tune and the whole 9 yards while I'm at it.
WTFB - sounds like a fun project. Sure would like to look over your shoulder while you're doing all that. :D Since that isn't possible maybe you could post some pics of the steps in getting it all together. :thumb:
WTFB - sounds like a fun project. Sure would like to look over your shoulder while you're doing all that. :D Since that isn't possible maybe you could post some pics of the steps in getting it all together. :thumb:

I'll definitely do that -- just for you shoot! :boink:

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