Air Gun Home :: View topic - Crosman 2100B/Remington AirMaster77 Improvements

AirGunEric · Site Admin

Someone on another board was asking about improvements to a 2100 (also sold as the Remington mentioned in the title with different cosmetics). The AM77 is available virtually everywhere and is relatively cheap, even if you get it in a "kit" with a scope and shooting glasses. The 2100B a bit pricier- but still not an expensive gun.

So, I thought I'd do some research to confirm what I thought I already knew Wink

and would post it up here for future reference.

First- the reference tools (by the way I like the Chambers diagrams- they are in a graphic format and are usually clearer than those available on the Crosman web site).

Parts Diagram: http://www.airgunhome.com/forumdocs/c2100plist.jpg

Mods to a 2100B/AM77 that will improve things:

Barrel Work:
Barrel re-crown (for accuracy)- see sticky in Rifles topic (this area).

The 2100/AM77 has a "pea shooter" barrel- i.e. a thinner-walled barrel inside a tube/shroud. The front sight is actually what holds the barrel 'centered' in the tube. Unfortunately- this allows for alot of play/movement. The solution? Get the shroud off the breech, find a wooden dowel, push the sight off, reinstall the barrel and pack the front of it just rearward of where the sight will fit back in with something than will take up any slack- for example cut-down plumbing pipe insulation or a couple of rubber grommets of the correct size. Then reinstall the sight. The barrel will now be in tight and won't wobble/wiggle around- improving accuracy.

Trigger Work:

Trigger smoothing, spring change- like alot of Crosman guns- the trigger pull could be considered "excessive" at around 9lbs- so sanding off casting lines and smoothing all the areas where it contacts the breech parts, then lubing it with PellGunOil or silicone-based lube is useful. But- while that will eliminate some of the reported "grittiness" of the pull- it'll still be around 9lbs- so the spring behind it has to be changed to a weaker unit. Seeing as how I don't know of anyone/any type of business that would have a spring tester capable of testing the size of spring we're talking about here laying around- this has to be done more by estimation than anything else. Seems the common opinion of the "best" trigger spring is one that has about 50% of the compression tension as the stock unit. Some people suggest cutting down the existing spring and stretching it to maintain it's former length- but I personally wouldn't do this as my first option- I would go to the local hardware store and find other springs in the same size, but weaker to just swap in.

Valve work:

http://www.network54.com/Forum/275684/message/1114190727/Updated+valve+mod+how+to...

Yes- the topic above is for a 22xx series gun- but the 2100 is using the same design for the valve assembly- so the same mods apply.

Also- if you happen to have a gun that was put together intentionally for an output of less than the US-Spec'd 2100 (725fps)- there will likely be an exhaust hole in the valve (I don't have a de-tuned 2100/AM77 to check, sorry) which needs to be plugged. The best way is by soldering it up, although some people have suggested tapping it and putting in small machine screw with a sealant like Loctite Red (high strength)- but that seems like alot of work and if the screw isn't the exact right size- it may extend into the valve chamber and cause problems.

There are a couple more, minor mods to be found out there that people have done- but the ones above are the most useful for improving the accuracy and/or output of the 2100/AM77.

Note: Valve mods will increase the output of the gun. If you are in a region where air guns can be classified differently; for example as "firearms"; depending on their output, either don't do any valve mods, or be sure to check and follow your local laws appropriately. If the valve mods listed above are done - the estimated output of the 2100/AM77 would be somewhere in the vicinity of 800fps- but use a chronograph on your gun to verify this as it can vary.

Good luck and happy shooting.

Yietspingle · Member

I bought this multi-pump to see how the valves worked when I got back into air rifles.
It is sold at Canadian Tire stores, Crosman 200 magnum, 22 cal.

I was really interested in PCP and got the idea to change this into a rifle with a reservoir. Nothing fancy, used a hydraulic male plug to fill and seal the air.

Its not pretty, but beats pumping!

The reservoir plugs into the existing valve. If remember correctly, the rifle was filled to 1000 PSI. Anything to high the plastic bolt pops back when fired, even at 1000 to pops back abit.

Thought someone might be interested as I posted this long ago in other forums.

Reservoir and Valve
http://i25.photobucket.com/albums/c62/yietspingle/My%20Airguns/CrosmanD.jpg

http://i25.photobucket.com/albums/c62/yietspingle/My%20Airguns/DSC03053.jpg

With Barrel Band
http://i25.photobucket.com/albums/c62/yietspingle/My%20Airguns/CrosmanA.jpg

AirGunEric · Site Admin

Maybe this should be another separate topic- seeing as it's a different gun we're talking about?

And- how did you plumb the air reservoir on that- just yank out the entire pump assembly & chamber and use the stock valve?