extending zero of .22 with falcon pellets

[gurtwurz 792]

hi guys, i recently had to take the'95 to have the mainspring replaced so whilst it was being sorted(still under warranty) the RFD offered to do some pellet comparisons for me to run the new spring in with.

 

looking at the various groups, the lightweight falcon's(the new 'uns) grouped best but at 13ish grains were grouping much higher up the target line than say air arms. theres not much weight difference between the falcons in .22 than some of the .20 pellets i'd used in the rapid mk1, so i've zeroed in the '95 at 30m instead of the usual 25 cos i wanna see if theres a major trajectory change over 35ish m, which is all i'm shooting the 95 out to in the field.

 

typically, my crappy combro chrony isnt working so i cant use chairgun to see it from the comfort of my armchair, but it should give me an excuse to go and play of a morning in the name of science...

 

so anyhow, i realise the bc of a .22 pellet is gonna be different to that of a .20 but i'd be interested to hear your thoughts on this lads.

 

cheers, wurz

[zini 1,939]

Hi John,

 

Ive done some experimenting for you pal using these pellets (the Falcons) on a .22 rifle based at 11.5 ft / lbs of muzzle energy (standard power).

 

The BC Ive added as 0.0283 which wont be too far off true.

 

(621.6 fps) is the velocity.

 

From a 30 metres zero you will be in your 1 inch kill zone from 6.2 m to 14.6 m then leave it from 14.6 m to 25.3 m, again being within at from 25.3 to 33.2 metres.

 

For me personally I wouldnt expect these kind of results and would change zero slightly.

 

If you were to try a new zero of 27.5 metres you would have a very good point blank range and be within your 1 inch kill zone from 6.7 m to 31.1 metres which is far better and gives you a better chance of a humane kill.

 

Obviously your rifle power may be slightly different to what Ive added but you own results will be very very close to these ones pal.

 

Hope this helps pal and saves you some time in finding a better zero range.

 

Click on the image below to enlarge it pal.

 

Si

Edited March 4, 2011 by zini

[matt_hooks 188]

Si, nice set of results there.

 

My only question would be, is it correct to assume that the rifle runs at a constant power, or is it more likely that it will run at a constant velocity, determined by the spring rate? I know that springs for .177 guns shouldn't be put in .22 guns as they run faster, and so can push you over the limit. Also heavier pellets can be a risk in some guns that run close to the limit, as they can push the ME up.

 

Obviously a lighter/heavier pellet is likely to increase/decrease mv somewhat, but the resistance seen by the spring is pretty small as a proportion of the power available, so the mv should be fairly constant?

 

Just pondering here, not based on any facts other than the "don't use a .177 spring in a .22 gun" info, and a little engineering knowledge.

[gurtwurz 792]

Hi John,

 

I’ve done some experimenting for you pal using these pellets (the Falcons) on a .22 rifle based at 11.5 ft / lbs of muzzle energy (standard power).

 

The BC I’ve added as 0.0283 which wont be too far off true.

 

(621.6 fps) is the velocity.

 

From a 30 metres zero you will be in your 1 inch kill zone from 6.2 m to 14.6 m then leave it from 14.6 m to 25.3 m, again being within at from 25.3 to 33.2 metres.

 

For me personally I wouldn’t expect these kind of results and would change zero slightly.

 

If you were to try a new zero of 27.5 metres you would have a very good point blank range and be within your 1 inch kill zone from 6.7 m to 31.1 metres which is far better and gives you a better chance of a humane kill.

 

Obviously your rifle power may be slightly different to what I’ve added but you own results will be very very close to these ones pal.

 

Hope this helps pal and saves you some time in finding a better zero range.

 

Click on the image below to enlarge it pal.

 

Si

 

 

si you're a star mate, thanks very much for that buddy :notworthy:

 

i've just rang the RFD and he reckons the rifles running at a pretty constant 11.4 so i'll take your advice and re-zero at 27.5 in the morning.

 

once again, thanks loads bruv

 

all the very best, and hi to LJ

john (and jax says hi to you both too!)

[zini 1,939]

Hi John,

 

Going on your new 11.4 ft/lb of data using them pellets.

 

Here are some profiles that I have worked out for you and will be a very close starter to what the actual calibrated profile will turn out to be.

 

As I can’t remember what mag you shoot on I has done a profile for 6,8,10 and 12 mag.

 

The profiles are created from a 27.5 metres perfect zero.

 

Please let me know how you get on buddy with these.

 

Regards

 

Si

[gurtwurz 792]

wow, thanks so much si mate, thats really good of you buddy.

 

i've printed them up and will be trying them out in the morning, weather permitting!!

 

i'll let you know how i get on mate

 

youre a legend,

 

cheers, john

[zini 1,939]

Hi Matt,

 

The velocity and the power are really both joined as you know buddy.

 

A velocity or power will never be constant; if they were it would mean that someone had managed to design a perfect regulator that is shooting perfectly weighted pellets in the exact same weather conditions every shot plus much more etc.

 

When I work out my power / velocity using my F1 chrono I usually take between 10 and 20 shots and then work out the average velocity and power.

 

A good quality PCP / springer will now days have a very slight shot to shot deviation anyway and the majority of time the average shooter over normal air rifle ranges will not notice a difference in POI.

 

The difference most of us see is due to our poor shooting and not the rifle.

 

Once I have my average power / velocity I then use it to get a good pointer on ChairGun of where things lie with different pellets etc.

 

Obviously the results are not 100% correct due to scope height, perfect BC etc, but if you know ChairGun well and I class myself as knowing it pretty well you can get very close to the exact answer that you will get if you calibrate your rifle yourself.

 

Just to give you some idea of the accuracy you can get if time is taken with the software. My r10 and my old Pro Sport springer profiles that I created on ChairGun where the ones that I ended up using and still do in the case of my r10 as they were pretty much bang on to within ¼ of a mildot.

 

When I get back in 2 weeks time to the UK I am going to do the same for my r10 with the Falcon Pellets that Tench advised me to use in the tuned .22 r10.

 

Due to the fact that my regulator has now been tweaked to 90 bar instead of 50 bar the softer Falcon skirts expand better into the r10s rifling creating better and easier down range accuracy.

 

The pellets are also only 13.4 grain so fly flatter than the 15.9 grain pellets while still having a pretty high BC.

 

We will see if the barrel likes them though in 2 weeks time, fingers crossed hey.

 

Si

[zini 1,939]

Not a problem John buddy,

 

The only difference that you will have is due to exact Falcon BC and your scope height.

 

Other than that i expect you to be within 1/4 to 1/2 of a mildot on every profile.

 

ATB

 

Si

[gurtwurz 792]

of course, whether i'm 1/4 to 1/2 a mil dot on target will be a different story ...

 

cheers again si

 

john

[matt_hooks 188]

Haha John, that's my reply whenever someone asks how accurate any of my rifles are. "More accurate than I am"

[gurtwurz 792]

good answer matt! i may have to use that and pretend i came up with it...

 

cheers, wurz

[zini 1,939]

That’s 100% true Matt buddy.

 

I wish I could shoot as good as the rifles I’ve owned in the past and own now.

 

No matter now good we think a group is that we shoot if you were to give someone like Terry Doe, Jose Redondo, Nick Jenkinson or Andy Calpin a go with our rifle they would improve our best group by 100% I’m sure.

 

ATB

 

Si

Edited March 4, 2011 by zini