Finally got my hands on a chrono!

[DKG]

After the busy season at work started I haven't had much time to shoot, but I finally got my hands on a chrono and could use opinions on when the sweet spot starts and ends on my Maximus. Chrono was about 3ft from the muzzle and all shots were taken with 14.3 grain crosman premier hollow points. There's a few errors due to myself learning where to shoot to get a reading
Shot from 2000 psi to about 500 when the valve started "farting"
42    ERROR 2
41    617      0.00     0.00   
40    ERROR 2
39    ERROR 2
38    657      0.00     0.00   
37    ERROR 2
36    686      0.00     0.00   
35    695      0.00     0.00   
34    704      0.00     0.00   
33    716      0.00     0.00   
32    ERROR 2
31    736      0.00     0.00   
30    737      0.00     0.00   
29    741      0.00     0.00   
28    766      0.00     0.00   
27    761      0.00     0.00   
26    ERROR 2
25    780      0.00     0.00   
24    778      0.00     0.00   
23    786      0.00     0.00   
22    771      0.00     0.00   
21    ERROR 2
20    781      0.00     0.00   
19    776      0.00     0.00   
18    770      0.00     0.00   
17    785      0.00     0.00   
16    768      0.00     0.00   
15    761      0.00     0.00   
14    769      0.00     0.00   
13    747      0.00     0.00   
12    760      0.00     0.00   
11    758      0.00     0.00   
10    754      0.00     0.00   
9     759      0.00     0.00   
8     759      0.00     0.00   
7     740      0.00     0.00   
6     738      0.00     0.00   
5     734      0.00     0.00   
4     714      0.00     0.00   
3     713      0.00     0.00   
2     703      0.00     0.00   
1     738      0.00     0.00   
Average: 741.7 FPS
SD: 37.8 FPS
Min: 617 FPS
Max: 786 FPS
Spread: 169 FPS
Shot/sec: 0.1
True MV: 742 FPS
Group Size (in): 0.00

[Ribbonstone]

In one way...you are so SCREWED....at least in the start, shooting good groups and shooting "flat" are not going to be enough anymore...are going to start worrying about velocity variations and fractions of an inch.  There will be no peace until you've measured everything you have that will shoot.

But it does make sharing data more meaningful,does let you work/tune/mod for a more uniform shot string, and won't just be "guessing" any more.

[DKG]

In one way...you are so SCREWED....at least in the start, shooting good groups and shooting "flat" are not going to be enough anymore...are going to start worrying about velocity variations and fractions of an inch.  There will be no peace until you've measured everything you have that will shoot.

But it does make sharing data more meaningful,does let you work/tune/mod for a more uniform shot string, and won't just be "guessing" any more.

I always get myself down these wormholes haha. Where do you think it starts and ends?

[toddbrat]

That's actually rather optimistic you think it ends 

I finally bought a chronograph a few weeks ago. Final cost was almost $400, $80 for the chrono itself and another $300 for an BSA Buccaneer when I realized I can't get my Maximus anywhere near what that will do.

[DKG]

I'm thinking 8-28 are my best ones?

[Tater]

I'm thinking 8-28 are my best ones?

Looks that way. Try filling to only 1800-1900 psi, that might cut down on the first few low fps shots at the start of the string.

[Tweeter]

In one way...you are so SCREWED....at least in the start, shooting good groups and shooting "flat" are not going to be enough anymore...are going to start worrying about velocity variations and fractions of an inch.  There will be no peace until you've measured everything you have that will shoot.

But it does make sharing data more meaningful,does let you work/tune/mod for a more uniform shot string, and won't just be "guessing" any more.

I always get myself down these wormholes haha. Where do you think it starts and ends?

It starts with getting a chrony and never ends.....

[DKG]

In one way...you are so SCREWED....at least in the start, shooting good groups and shooting "flat" are not going to be enough anymore...are going to start worrying about velocity variations and fractions of an inch.  There will be no peace until you've measured everything you have that will shoot.

But it does make sharing data more meaningful,does let you work/tune/mod for a more uniform shot string, and won't just be "guessing" any more.

I always get myself down these wormholes haha. Where do you think it starts and ends?

It starts with getting a chrony and never ends.....

My (paintball) teammates hate me because of stuff like this! I'm obsessed with air efficiency because of where I play on the field, that is a whole other wormhole to go down and I won't bore you with that haha

[Ribbonstone]

Paintball for old folks...we once did, but the sport passed us by.But I can tell you,from one end of a tyupicl closed field to the other, if out stand on one place long enough for me to sight in...head shot.


Old school..co2..pump action..brass barrel (and actually, there is nothing better)...

[Hoosier Daddy]

S.I.L. is a jerked over profesional paint baller. Worked at the local complex.
He is continuously amazed at my aiguns... Wait until I share that brass barreled pic!

[Ribbonstone]

Neither one is rare or expensive...other than that they both  work and had seen the earlier days of that sport.

Justr in case folks missed when Sheridan dipped a toe in the paintball market:

[toddbrat]

Ribbonstone, that really brings back memories. I started playing around 1990-1991 when we were too young and dumb to realize keeping the paintballs in a cooler full of blue ice wasn't a good idea. Nothing like getting shot with a .68 chunk of ice. Benjamin Sheridon also made the VM-68, that was my weapon of choice along with an aftermarket rifled barrel. Haven't played in 25 years but get my SCUBA tank filled at the same field.

DKG, you may be surprised how much carryover there may be between the paintball markers and air guns when it comes to tuning. Same basic principals of air propelling a projectile unless they've changed that radically over the years.

[DKG]

Will pellet weight affect the sweet spot at all? I do have a few different pellets I'd like to try since the crosman's will not group worth anything

[triggertreat]

Pellet weight will affect the overall velocity and shot count, but the curve should be about the same.


Here is the tune showing the full string along with all shots within a 2% and 4% ES.  Take note of the shot numbers and the fill pressures

[CraigH]

I'm thinking 8-28 are my best ones?

Absolutely!          Read the pressure gauge at those two shots.

[triggertreat]

I'm thinking 8-28 are my best ones?

Absolutely!          Read the pressure gauge at those two shots.

Yep, I'd fill around 1750-1800psi and shoot 20-22 shots.  That looks like the sweet spot.

[DKG]

I'm thinking 8-28 are my best ones?

Absolutely!          Read the pressure gauge at those two shots.

Yep, I'd fill around 1750-1800psi and shoot 20-22 shots.  That looks like the sweet spot.

Thank you for the graph. Now to get some more pellets and play around with the targets.