How is this shot string from new .22 cal 2300KT ?

[wahoowad]

Today I logged this shot string across my chrony. I have no idea what the fps should be or the expectations shot count per cartridge. How does this look for a stock .22 2300KT? All I've done so far is lower the trigger spring adjuster to lighten it up, polish the sear contact surfaces and mounted a 6.5 TKO LDC (which is amazing!)

I didn't think to chrony it until after the first few shots of a new cartridge. Temp was about 80 degrees. Cheap Crosman domes. Two things stand out to me and am looking to see if this normal (a) no stable velocity, pretty much a steady trend of decreasing fps, except for (b) several drops of 25 to 30 fps occurring randomly. I know it is not regulated but was expecting more stable shot string.

1	(did not shoot over chrony)
2	(did not shoot over chrony)
3	(did not shoot over chrony)
4	(did not shoot over chrony)
5	(did not shoot over chrony)
6	493
7	489
8	467
9	475
10	480
11	456
12	477
13	449
14	476
15	442
16	471
17	470
18	468
19	433
20	464
21	461
22	449
23	464
24	422
25	468
26	469
27	454
28	439
29	413
30	461
31	445
32	435
33	423
34	411
35	400
36	387
37	370
38	353
39	340
40	324
41	306
42	286

I released the cartridge and only heard a short pfft.

[breakfastchef]

I had a stock 2240 that shot 430-450 fps on average. Your string looks pretty normal. @30 decent shots per cartridge has been my experience.

If you want to feel better about the graph, change the low end of the Y axis to 100 fps. That will take out some of the peaks and valleys and produce a smoother looking line.

[1377x]

how long is your barrel and how long did you wait between shots
that shots are sporadic do you have a power adjuster on it
the fps looks about right

[wahoowad]

how long is your barrel and how long did you wait between shots
that shots are sporadic do you have a power adjuster on it
the fps looks about right

10" barrel, no power adjuster.

Some shots had more time between them than others, for awhile I was walking over to a bench to write and grab a pellet. After awhile I moved the notepad and pellet tin next to me.  At the quickest times I shot, recorded reading onto paper, loaded a pellet and shot again....so 15 seconds between shots sometimes, sometimes more.

Is 15 seconds too quick?

[1377x]

it is said you wait between shot letting the gas warm a little every time you shoot it gets cooler and I think it gives time to fill the valve back up
take about 30 seconds - a minute between shots see it it gets more consistent

[wahoowad]

it gives time to fill the valve back up

Hmmmm, my limited (probably incorrect) understanding is that the CO2 stays in the cartridge until the hammer hits the valve to momentarily allow some gas to escape the cartridge. If so...the valve isn't a reservoir per se, just a metering device...am I wrong here? Perhaps there is some valve lock or valve freezing going on if quick succession shots allow cold CO2 to be released and impact the valve?

[brz-ryder †]

The valve is both a reservoir and a metering device when you first shoot the gun after putting in a new carg you should hear the co2 going into the valve. thats why some valve are bored out bigger to let it hold more co2 to up your fps more gas the fps goes up

Jim

[AaronMB]

If it's nice and warm and your cartridges are at outside ambient temperature, you should be able to get away with waiting less-time between shots (experiment). The faster you shoot though, the more cool-down you'll have on your cartridge temperature (lower efficiency/velocity, theoretically). 30 seconds to a minute, as suggested above is a good time, assuming you're not in cool temps.

[breakfastchef]

Waiting for a minute between shots is fine just to show yourself how (in)consistent your gun is shooting, or for testing the effectiveness of mods and changes to settings. But, it is no fun.

I normally do not shoot that way when having fun and plinking. I just shoot until POI falls off, degas the cart, and load the next one.