Hi! Am new to your site as of now. Have a problem with a older version 5mm Crow Magnum. The scope ring mounting plate is extremely thin and tapped for single bolted screws ( which I can nort find and need ) which hold the rings to it. The Bushnell 1" scope 6x24x50 had big plastic spacers insered ino the rings. The rifle just got back from David Slade Airgun Werks getting new overhaul. I can not reuse spacers as one cracked in half plus would like new mounts or higher rings so to allow 50mm to clear, even one of my 44mm's will touch receiver tops. Any suggestions for rhe fix?
Capt. Mark Maloney
Welcome to the forum. Afraid the only thing I can offer for your situation is this link to a previous thread here on the forum. It has some good info regarding the scope mount on the Crow Magnum. Hope you find some of the info useful. And be sure to let us know how things work out for you because it may help someone else. Good luck!
https://airgunwarriors.com/community/airgun-talk/crow-magnum-theoben-eliminator-mount-options/
not to mislead my scope ring spacer problem is in NO way related to Airgun Werks excellent service of my rifle. The cracked spacer was installed decades ago and now I think is a large part of my issue with my wildly scattered grouping. Thus me wanting to put this sighting problem back together the right way to take advantage having it professionally serviced.Hi! Am new to your site as of now. Have a problem with a older version 5mm Crow Magnum. The scope ring mounting plate is extremely thin and tapped for single bolted screws ( which I can nort find and need ) which hold the rings to it. The Bushnell 1" scope 6x24x50 had big plastic spacers insered ino the rings. The rifle just got back from David Slade Airgun Werks getting new overhaul. I can not reuse spacers as one cracked in half plus would like new mounts or higher rings so to allow 50mm to clear, even one of my 44mm's will touch receiver tops. Any suggestions for rhe fix?
Capt. Mark Maloney
Capt. Mark Maloney
@marlindaddy Are you using the inserts I've seen? I think they're for pcp. I'd throw those away and mount an appropriate scope. I'd save that big honking 6-24x50 for looking at Saturn.
I do have a Leupy 6.5-20x40 EFR that I don't usually use because I don't prefer giant scopes on my gun. I have Airmax scopes and a Japan Bushnell 4-12x40 on my Theoben Gas Slammers
Maybe you need a big ole telescope for some reason. IDK
@jim_ Hi, I called them as you suggested. They informed me that they only made dovetail mounts. I asked for any other ideas and she said NO Thanks for trying to help. I was infomed today that my Crow was so old that the bolt I need is something called a BA which I am now trying to find out the measurement and whiere to locate as it is supposedly obsoite. This would at least get the rings on and then a buy new scope which, again had help finding out, I could go up to 40mm. With the mounts I have.
You don't give good descriptions, sir.
Are you saying it's British Association thread? No big deal I make my own screws for my Theobens, and even prewar BSA that have proprietary threads that haven't been available for almost 100 years. There are no taps or dies available for the old BSA's anywhere in the world. At least BA taps and dies are available. BA threads are 47.5 degrees included angle. All you need is the major diameter and pitch to single point them on the lathe.
Show a picture of what you need. This is like pulling teeth. You ask for help and don't explain well. Your OP doesn't really even make sense. At all. "Single bolted screws"......... What on earth is THAT?
Replacement screw I made for a Theoben because a previous owner doesn't know how to use a screwdriver. Fortunately, the other screws are allen. Pretty hard to goof those up. Have a blessed evening.
Yes am the Newbie, and new to most of this type of info gathering and proper lingo for asking for everyones seasoned input. The rings are installed with one nut/screw to hold it on the mounting plate. And yes i found out it stands for British Ass. I retired this year and do not have access to engine room fabracators or tools and am not a machinist in any field. I do not know angles or pitch, just meteric and inches and every gun/archery shop within 50 miles of me and they did not figure it out. Dr. Beeman guided me on this 5mm Crow decades ago. The big ass scope was for light gathering as we had few hundred lbs. corn dumped in barn bays and red lighted/lasered up Wilard and his smaller minions with tails over many winter evenings. Hope I am not enbarrassing myself with my thought patterns here on your site. I usually try figuring things out myself but with this I did hit the wall. I appreciate any and all help as time is something we can not buy. THX
Capt. Mark Maloney USMM ret.
The elongated cylinder shaped bolt on top of ruler is the correct piece. The bottom bolt will not recess below the bottom of ring curvature therefore scope willl not mount flush but was sent to me hoping it would
The first thing I found. I had seen this listing previously. I have some of those screws with a spare set of rings. I will check their thread size when I get a chance over the weekend. Search "Theoben scope" on eBay UK for options.
Now we're getting somewhere! You might try tracking down Martin Rutherford, or I don't know why David Slade couldn't offer assistance
I am still trying to figure out what I need. I emailed David Slade he was the person who told me it was a BA bolt and this was after he repeatedly told me to send him a picture of it, which is my fault, anyway he said he had not used them in 30 years. I have emailed Airguns USA looking for Mr. Rutherford and called I have not gotten a reponse yet. The Ebay route has helped but response from sellers they could not confirm matching. I do not know if it is same for Rapid or Sirocco and they did not know either. Am still waiting to hear back from other sellers in UK. Thanks for the lead.
Capt. Mark Maloney USSM ret.
I have a spare set of Theoben rings with mounting screws. I just went out to my shop and found the screws to be 5mm x .8. These fit my Siroccos. I've handled an Eliminator but they never interested me because I just don't like large porky air rifles. To me the Sirocco is the perfect size and plenty of energy. So I've never worked on the Eliminator/CM Dampa mounts but I would bet the base has 5mm x .8 thread same as my guns. I do however have a Theoben Evolution but they have standard 11mm dovetails which are fine because it's a lower energy rifle.
I also have an 11mm dovetail adapter to fit early Theoben Gas Slammers. But for your gun and the desire to mount a 50 mm scope I would simply mill a Weaver or Picatinny base to fit the Theoben and bolt that on and now you can easily mount a 50mm scope with an array of rings to choose from.
If you don't have a way to measure threads, take your screws to the hardware store and see if they match the metric threads there. Specifically 5mm x .8 . Line the threads up and see whether you have standard 60 degree thread or not. I see no reason why they would have used an odd obsolete thread just for the Eliminator mounts. Doesn't make sense, the rest of the gun uses metric. The socket head cap screw in your picture looks the same as mine.
as far as i know all the older theoben scope mount screws were British Standard threads not meteric. Should be 2BA thread. A standard bolt is so close it will thread in. Not at home right know or i would tell you. Use a stand pitch gage. Think it was a 28 or 40 pitch thread. this is info for the rapids.
Original Mk1
Hammer adjuster: 1/2" BSP
Barrel location grub screw: 2BA
Front scope Mount: 2BA
Rear Scope Mount: 2BA
Barrel Clamp Bolt: 2BA
Valve retaining grub screw: 4BA
Cocking Bolt: 1/4" UNF 28tpi
Valve spring cap: 3/8" BSP
Bottle Holder: 3/8" BSP
Bottle external thread: 1/4" BSP
Front Trigger Guard/Stock Bolt: 1/4" UNF 28tpi (1” long)
Rear Trigger Guard: 2BA
Hammer Pip: 2BA
MK2 / New MK1
Hammer adjuster: M20 x 1mm pitch
Barrel location grub screw: M7 x 0.75mm Pitch
Front scope Mount: 2BA
Rear Scope Mount: 2BA
Barrel Clamp Bolt: 2BA
Valve retaining grub screw: M3 (5mm long)
Cocking Bolt: 1/4" UNF 28tpi
Valve spring cap: 3/8" BSP
Bottle Holder: 3/8" BSP
Bottle external thread: 1/4" BSP
Front Trigger Guard/Stock Bolt: 1/4" UNF 28tpi (1” long)
Rear Trigger Guard: 2BA / 1/4" UNF 28tpi
Hammer Pip: 2BA
Bottom Access plug: 1/4" BSP
Bolt Guard Top Screw: M3 (8mm long)
Bolt Guard Bottom Screw: M4 (6mm long)
Silencer Thread: 1/2" UNF 20 tpi
Bottle External thread: 1/4" BSP
200/280cc bottle internal thread: M14 x 1.5mm
400/500cc bottle internal thread: M18 x 1.5mm
Probe Adjuster Screw: 2BA (5/8" long) grub screw (2BA x 3/16” locking screw inline with adjuster on very early rapids).
Probe Locking Grub Screw (accessible through bolt gate slot): M3 x 5mm long (later rapids) / 4BA x 3/16" long (earlier rapids with updated threads).
Oh, I ran a die over the screw and came up with metric. BUT after actually measuring I see that it is in fact BA.
If I couldn't get the screws on eBay UK I would personally make them from long 5mm screws. Of course everybody can't do that.
BTW a standard pitch gage doesn't fit. A metric gage is closer at .8mm while the BA pitch is actually .81 mm. or 31.35 TPI, and a 55 degree thread.
Thank you, Chris for the clarification.
