The $1.00 Power adjuster

[Poorman Plinker]

Ever wondered how to install a power adjuster for under $1.00? Here is one idea for a Poorman power adjuster as posted in the Photo album of the Crosman/Poorman facebook group.  A typical adjuster cost around $15-$20 delivered. I used some 5/32 Fiber washers to adjust the mainspring preload by placing the washers in the receiver end cap. The washers were near .066 thick and cost $0.14 each at a local hardware store. I went in to the store with the receiver end cap and found washers that fit. But, does it work?

The following tests were performed with Crosman Premier Domed pellets off of a bench at 7 meters with the chrono at 55 inches with the standard 2240. The shot count stopped after the first shot under 400fps. The moderate preload with one thick washer (.066") reduced shot count by 7 shots, reduced the group size Extreme Spread (ES horiz-x-vert), increased the Max  and average velocity, but  reduced Standard deviation. Preloading the mainspring with 2 washers (.271") reduced the shot count by 19 shots and did not perform better than a moderate preload.

0 load       ES 1.98x1.94 -    41 shots    HI 447 AVG 426 SD 15.
.066 load    ES 1.67x1.5 -    34 shots    HI 453 AVG 427 SD 11
.271 load.    ES 1.85x1.85 -    22 shots    HI 451 AVG 427 SD 18

For more precise adjustment I would use Brass or Stainless washers to add preload to the striker spring. Brass #4 washers were available and were half as thick at.033" and $0.08 each. Or, #4 stainless steel washers that were .031" at $0.09 each. I think you would not need more than 11 of these to load the spring tension pretty close to coil bind: $0.99.