thisnewday

A couple of months ago, I finished the modifications on my Crosman 2240 CO2 air pistol with a Bushnell red-dot sight mounted on the custom, multi-shot breech that I'd fitted to it earlier.

The breech is designed with an 11mm dovetail for mounting whatever optic might be desired, and I'd first mounted a cheapo Centerpoint 2X pistol scope which had come with a Crosman 2300KT which I'd had built in their custom shop.

I hadn't liked the 2X scope on the 2300 because I'd decided to configure it as a carbine and the long eye-relief required for a pistol scope just wasn't possible. So I'd boxed up the 2X and mounted a 3-9X32 I'd had on my Benjamin Trail instead.

Then, after I'd gotten the bare-bones 2240, I figured I'd just throw on the 2X since I'd be using it as a pistol. But it turned out that an optical phenomenon called "parallax" was making the 2X very difficult to use at the short distance I have available in my basement. And so I opted for the Bushnell which, with zero magnification, would present no problems in short-range situations.

And, once zeroed-in, I LOVED it. I'd go down nearly every day and shoot 30 rounds at three different "splatter targets" and end up with half-dollar size groupings, including some shots right on top of the others. Not bad for an old guy with bad eyesight and not very steady hands!

THEN, I got the bright idea that I'd tweak the sighting just a bit by resting the pistol on the Bog-Pod tripod that I'd gotten for the Benjamin Trail.

Of course, the whole point of using the 2240 in pistol configuration was to have something  that I could shoot "free hand." But it's also true that pistols are often zeroed-in on a bipod or other rest. And so I figured I'd try to tighten my already satisfactory groupings.

But, using the Bog-Pod, BIG surprise. And not a happy one. My shots were suddenly all over the paper and mostly very low. WTF?!?

However, because I mostly believe what I see, I went ahead and adjusted the red dot--quite a few clicks, to be honest--and actually tightened my already-good groupings. Cool! Still inexplicable, but cool.

And, because the whole point of having the pistol was to shoot free-hand, I ignored the voices, set the tripod aside, breathed in, exhaled, held, and... hit the target well above the bullseye. Pulled back the cocking arm, breathed, held, fired and... same result. Double WTF!?!

Next target, went back to the tripod and BINGO, on the money. Ten good shots, one full rotary mag, in the bullseye. After which, I ditched the CO2 cartridge, reloaded the 2 mags, turned off the lights, and came upstairs.

And now sit here pondering whether to repeat the whole process by re-zeroing free-hand in hopes of a better result when doing the type of shooting I'd originally intended.

But also still puzzled as to what factor, what law of optics, might yield these results...

LPK
Dreamwidth
5.12.2019 

As mentioned previously, the Crosman 2240 has long been a favorite of basement hobbyists as a platform for modification. And the two things that have made it so are its low price combined with acceptable levels of performance and durability.

Among the many available aftermarket products available for such projects is the multi-shot breech which I've just installed. Someone else might opt for a longer barrel for improved aim-point and increased velocity. Which is what I did with my factory-modded 2300.

A more experienced hobbyist, certainly one whose interest is in precision target-shooting, would opt for a better trigger. And that's what slowly dawned on me, once I got over the thrill of completing my first home-based modding project on the 2240.

And I think one of the reasons that it didn't occur to me, after I'd put my new 2300 through its paces--especially considering that it's basically a modified 2240--is due to the difference in its use and configuration.

With a shoulder stock and rifle scope, the heavy and somewhat harsh trigger pull could be more easily compensated for than when encountered in a pistol held at arms' length while sighting through a small, single-power scope.

Which, as I said, is something I started to think about after the excitement of a successful modding experience had begun to wear off.

So this afternoon, I took my project back down to the basement, removed the grips from the frame and the frame from the gas tube, and set about determining what I could do--besides laying out $90+ for a custom-built frame and trigger group.

First I removed the trigger, which actually looked OK, and then the sear and sear spring. The sear is what the trigger moves against to release the hammer causing the gun to fire.

Next, I filed and polished the surface where sear and trigger meet and then--the thing that made the biggest difference--I started experimenting with different springs.

The critical factor with respect to the sear spring is that it must be strong enough to push the sear into position to hold the hammer when the gun is cocked but not so strong as to require a heavy trigger pull--which would have the same effect as jerking the trigger, something beginning shooters are ALWAYS told not to do.

I'd already picked up an assortment of springs for this purpose at the Home Depot and found one which, although overly long, did work significantly better than the original.

But because I'm one of those crazies who has to get it "just right"--or, I suppose, go totally off the deep end--I ventured out into what's supposed to be the beginning of a weekend blizzard, trekking down nearly-deserted streets to Harbor Freight.

I got there about 10 minutes before they were scheduled to close, joked with the cashier and a manager for a minute about--what else--the weather, and then headed back home.

And, "lo and behold," in Harbor Freight's $4 assortment, I found the perfect spring.

After swapping it out, I proceeded to unload 3 of the new 10-round magazines downrange while scoring an astonishing--for me--number of bull's eyes. (All part of the required testing program, ya know, lol.)

Anyway, for the second time this week, I have to extend kudos to Harbor Freight for saving my project. (I still haven't heard from the hex keys I ordered from Home Depot.)

If this keeps up, I might find myself in the unaccustomed position of having to show HF some real respect. Maybe even shopping there first.

Naw, that's walkin' the edge of crazy again...

LPK
Dreamwidth
1.19.2019