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rsterne · Moderator

I wanted one of each for myself and decided while I was at it to run a small batch.... 22XX on the left, 13XX/2289 on the right.... Aluminum & Stainless Steel....

They aren't as pretty as ustilago's (CrustyB), but they do allow you to change out the hammer spring for experimenting without disassembling the gun once installed.... They feature 1/2" adjustment range, and will accept 2200, 2289, or 2240 hammer springs.... You can use them for finding the "sweet-spot" for economy, or to adjust the hammer spring to maximum useful tension without having to precock the hammer.... as well as tuning for a particular power level, depending on your choice of spring.... Cool

Price is $20.00 each, plus postage.... We only get to town on Tuesdays, so only ship once a week.... If this batch sell, then I may make more.... EFT only, please PM your Postal Code for shipping quote.... Wink

Bob

rsterne · Moderator

Just an update on the 13XX/2289 adjusters:

With both the stock 13XX/2289 hammer spring, and one from a 2200, you can adjust the spring all the way to coil bind, at which point the gun will no longer cock.... For safety (to insure reliable sear engagement), back the adjustment out at least 1/2 turn from that point.... Idea

I find that with a "set" Crosman sear spring inside the valve, I get to the point where precocking the bolt before pumping is necessary about 1-1/2 turns before coil bind with a stock hammer spring.... With a 2200 hammer spring, even at the minimum tension, precocking is necessary (but about 100 fps higher velocities are possible with increased pumping).... If you fit a 2200 spring that has been shortened to the same unloaded length as a stock 13XX spring (about 2 coils cut off) you will get something in between.... but you will be able to find an adjustment point where you don't need to precock.... YMMV depending on the spring inside the valve.... Cool

If you have a stock spring inside the valve, you will never have to precock with a stock hammer spring.... and you probably won't with a 2200 hammer spring either, at minimum tension.... What will happen, however, is that with the stronger spring inside the valve it will retain air at a lower pressure (and hence velocity).... Wink

Bob

rsterne · Moderator

An update on the 22XX adjusters.... Bear in mind, the testing was done on a 1750 (.177 cal with 18" barrel).... These conclusions might not be true in .22 cal or larger, depending on other mods.... but they would probably apply to a 2240 pistol....

I found no advantage to going to a heavier spring.... increased trigger pull, increased CO2 usage, no usable increase in velocity....

With a stock hammer spring, the adjuster is best used for tuning for efficiency.... I found it was possible to increase the usuable shot string by nearly 50% with a flatter velocity curve and virtually no peak velocity change....

If you want reduced velocities.... and even more economy.... try shortening the stock hammer spring 2-3 coils.... This will make the adjuster work from virtually nothing to flat out.... If you do this, you may have difficulty in piercing the cartridge, however.... All 22XX adjusters shipped from now on will have a hole drilled through the adjusting screw.... This will allow you to manually pierce the cartridge by using a 3" long piece of 1/8" rod and tapping on the hammer....

For more information, check out this thread:

http://airgunhome.com/agforum/viewtopic.php?p=25118#25118

Bob

rsterne · Moderator

In case anybody was wondering.... the 22XX adjusters will work on a Discovery.... but the degassing tool won't fit.... I can drill and tap the adjusting screw and supply a degassing tool at extra cost.... PM for details....

Bob