Where to get my rifle chrono'd

[pellet head]

The spring for my Slavia should be here next week and I would like to get it chrono'd before the spring swap and after to compare them. Anyone know of anyone in Winnipeg who could do this?

Thanks

[canshooter]

I ve done a bunch of mods to my 2289 and put a Macari spring in my HW30S. Id love to know what kind of Velocity/Fpe Im Getting. Mississauga On. Here.

[under500fps]

http://groups.msn.com/AirgunsCanada/gen ... 4642529606

[pellet head]

Absolutely brilliant!!!! Thanks for the link. This will work out great.

[MC 84]

you can also get a chrony for cheap if you decide to buy one. check on e-bay thats where i got my chrony. I got a brand new F1 chrony with a tripod for $75.00 USD.

[sniper]

Chrony - Pellet velocity.
Mic. & Comp. - the sound of the pellet.

[hotsky]

Sniper,

doesn’t the crony works the same way? I mean it records the time the it takes the pellet/bullet to pass the two readers and just tells you the number. With the other method you just do the work yourself…

I haven’t tested anything in a while but I remember when I got the hang of it was very accurate; I was getting the same velocities right down to the last number every time.

[canshooter]

Ive tried the PC chrono technique and it does work. I question the accuracy because a real chrono can measure velocity at the barrel over a distance of inches whereas the PC technique is usually done over a distance of muzzle to 10ft. I have no idea whether this makes a difference or not. Perhaps someone who has tried both can give us the answer.

[sniper]

I tried both, since I have the real chrony.
The chrony is actually detecting the pellet travel between the two sensor accurately. Using the PC is detecting the sound from the muzzle and the sound of the impact, it's NOT detecting the pellet travel, you have to assume everything including the delay of mic. and how long is the cable of the mic. It's not so bad result when using a low power rifle because more or less is not a big deal so it does looks like it's working but try it with high power rifle the number would be off by 100's.

[canshooter]

Here are the results that I came up with:

My modded 2289:

50 pumps= 693fps
25 pumps= 656fps
15 pumps= 612fps

My Hw97k .22 =644fps

My HW30s .177
w/macarri spring=626fps

All .22 Pellets are Crosman wadcutters at 14.3 grains
.177 pellets are Kovohute Diabolo standards weight unknown

Even if the velocity results are a little innaccurate this data tells me that 20-25 pumps with my 2289 is optimal. It also tells me that my 2289 is offering very respectable 15.25fpe at maximum pumps and should therefore be a viable hunter.

[hotsky]

Sniper, It detects the time it takes the pellet to get from the barrel to the stop, so I think it does detect the pellet travel. I tried it only with up to 500fps guns. Not sure what you mean by hi power rifle but all you may have to do is increase the distance, but for up to 500fps 10feet works great. As long as you have a separate mic and position it exactly in the middle between the gun and the backstop, (mic sensitivity may have to be adjusted as well) you should have zero problems.

Btw 500fps + airguns are considered firearms and not supposed to be fired at home anyways.

[SharpTeeth]

By using PC Chrono at 10 feet a difference of 1/1000 of a second gives you a velocity change of ~5fps. I'm much more comfortable with 20 feet to obtain a slightly more accurate velocity.

I used it with my unmodified Daisy 953 and JSB Hollowpoints at 20ft and got 493fps (.0405s) for a 5-shot group.

By slightly improving the flow and filling the indent in the piston I made it up to 606 fps with only a slight increase in cocking effort.