Question about BSA Big Cat 3.5-10X 42mm (3.5-10x42 mm)

1 Answer

Nitrogen gas refilling in a rifle scope.

How is nitrogen gas filled into a newly openned and cleaned frifle scope?

Posted by on

1 Answer

Re: nitrogen gas refilling in a rifle scope.

At a factory, the scopes are emptied in a vacuum chamber and nitrogen gas is used when the chamber is allowed to repressurize to the surrounding environment.

One possible solution is to re-assemble the scope in a clear plastic bag filled with nitrogen gas (working through the bag to re-assemble). Large plastic gloves can be taped into the sides of the bag.

Posted on Oct 15, 2008

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


3 Points

Related Questions:

1 Answer

How to disassemble my bushnell sportsman rifle scopes coz i wnt to clean it

On my Bushnell scope I have an adjustable angle ring that will bring in the view, it is held in place with 1 screw. remove it and pull down towards the windage and elevation adjustment screws. There are 3 tiny phillips screws, remove them. Then unscrew the end of the Eye Peice end peice with the lens in it. inside on the outer edge of the main tube there is a locking ring that keeps the eye peice from unscrewing off, remove it and unscrew the entire eye peice. you are now ready remove the inner tube. Be careful here this is where you can damage the cross hairs and lose the leaf spring that maintains pressure against the windage and elevation screws. When you reassemble after cleaning and with the elevation screw at 12 o'clock and windage screw at 3 o;colck, the leaf spring will be in the 7 or 8 O"clock position, it just sits in there up against a little ridge inside, with the bow facing to the center. Back off the elevation and windage screws all the way so they don't block the inner tube from going in all the way. Once it is in adjust it so the cross hairs are orented correctly and put it back together. If you want to refill with Nitrogen remove the front lense and take to someone that fills tires with Nitrogen and inject the nitrogen into the scope, Quickly reinstall the front lens as nitrogen is about 3% lighter than air and if you take too long it will all escape.
This worked well for me. Good Luck and Happy shooting

Apr 27, 2011 | Bushnell Sportsman 4x32 Riflescope (4x32...

1 Answer

My scope has moisture in it. How can I get it out

At the factory they fill the scope with nitrigon to keep them from fogging once it is gone the only way to fix it is send it back to the factory. Good luck.

Nov 17, 2009 | Simmons Outdoor AETEC 2.8-10x 44mm WA...

1 Answer

Rifle scope is hitting 5 feet high but dead center

mounts are probably too high.....had the same prob on a .22 rifle with high mounts for open site shooting also. i bought a lower mount and zeroed it in with no prob

Nov 24, 2008 | Bushnell Sportsman 4x32 Riflescope (4x32...

1 Answer

Tasco Rifle scope repairs

Try calling Customer Service at 1-800-423-3537. They should be able to assist you with your needs.

Sep 22, 2008 | Zeiss CONQUEST 3-9X40 MATTE Z PLEX

1 Answer

How do I disassemble a bushnell scope?

You don't if you want it to work right again as they are filled with nitrogen gas to keep them from fogging.

Jul 20, 2008 | Bushnell Sportsman 4x32 Riflescope (4x32...

1 Answer

Bushnell Sportview rifle scope wide angle 4x38 T4389 limited adjustment inconsistant results

I had the same problem but was able to solve it by shimming the scope mounts with a thin piece of plastic. Put it under the rear to raise the sighting and under the front to lower. I still plan to buy my son a better scope.

Mar 02, 2008 | Spotting Scopes

3 Answers


Follow these steps

1) Mount your scope.

2) Use a bean bag or rifle mount and make sure that your rifle doesnt move much from its original position throughout this process.

3) Aim with the scope and shoot at a large backstop which will allow you to see where your shot lands, where ever that may be, it doesnt matter at this point. Again, make sure your rifle doesnt move much when firing.

4) With the rifle in the same position, look through the scope and adjust the crosshairs over to where your shot landed.

5) The scope now sighted in with the rifle. Minimal adjustment may still be required but at least your well within the ball park.

Happy Shooting

Nov 13, 2007 | Bushnell Trophy Multi-Reticle Red Dot...

1 Answer

BSA rifle scope

its a metric 1.5 for the cam adjustments

Nov 11, 2007 | BSA Big Cat 3.5-10X 42mm (3.5-10x42 mm)

Not finding what you are looking for?
BSA Big Cat 3.5-10X 42mm (3.5-10x42 mm) Logo

1,728 people viewed this question

Ask a Question

Usually answered in minutes!

Top BSA Spotting Scopes Experts

Michael Thomas
Michael Thomas

Level 3 Expert

3051 Answers

Brad Brown

Level 3 Expert

13369 Answers


Level 2 Expert

223 Answers

Are you a BSA Spotting Scope Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides