Broke the seal on my B21 .22 and so made up a seal of Teflon with a good sliding fit.
The previous owner had chopped the barrel to 10" length. Has a factory spring and a bit of a lube job.

Shooting today over my chrony:

13.9 Chinese pellets go 740fps
14.5 grain JSBs go 708fps
21 grain Kodiaks go 570fps

Does this sound reasonable? if not what should I expect to get to with a proper seal and spring from JM? am hankering to get the Apex seal and the spring for this gun.

thanks in advance.
Walter...

BTW this is better than the gun was at 675fps with 14.3 grain Crosmans.

Although the Kodiak numbers look a little low?



Mike

I'll tear it down tomorrow and see how th eseal fit is doing.
Thanks
Walter...

Where did you get the parts break down of your B21?? I have a B21[.177] but no schematic/break down/parts list.Would you be interested in sending me that info?? Let me know the price
Thanks========Frank

...if I'm not mistaken: http://www.fortunecity.com/olympia/kickbox/377/sm1kindex.html#very%20top>
I tuned one of these in 177cal and it shoots unreal HARD! Oh yeah, if you got the plastic spring guide either change it to the new replacement metal one ( that's why I had to go in this gun in the first place!) or send the spring and the old guide to Rich and have him make a new one!