.22 LR ballistics

[Gerald89]

Hello,
I am just starting out using an external ballistics calculator and my results are not adding up !

Factory data for bullet :-
40Gr hp sub sonic CCI MV 1050fps

coeficient .125 ?

zero at 50 yards
100 yards table result says 923 fps , -7.6" , 7 MOA come up
150 Yards table result says 877 fps , -25.4" , 16 MOA come up

Do these look right?

My field results are 100 Yards needs 16 clks @ 1/2 moa per clk
150 yards needs 52 clks @ 1/2 moa

Scope is schmidt & B PM1 But has no marking for moa per clk maybe I am wrong with the 1/2 moa per clk ?

Anyone that could shed some light would be great!

 

[abinok]

A couple of thoughts,
I ran your info through my ballistics program, and got pretty much the same moa come ups you did (wihin .5moa). My program has the bc listed as .145.
I know that 1050 is the mfg listed muzzle velocity, but are you shooting through a chrony? if not, post what barrel length you are shooting them from and ill run out and hammer off a few rounds /ubbthreads/images/graemlins/grin.gif Ive got data for 26" barrel for this bullet, but most are shooting shorter.
oh, and a lot of the s&bs are 1/3moa, I don't know about your particular model, but something to think about.
ive shot 22lr to 400yds, and even with a calculated bc, measured mv, and real time atmospherics, with a bullet ive never shot past 100, im happy if the program gets within 1 moa, especially past 250.
Without a measured mv, you are really kinda shooting in the dark.

 

[Gerald89]

Cheers for that !

I dont have a chrony.

My rifle is AMT with 20" barrel .

I just ran 1/3 moa and it came up with 22 @ 100
and 49 @ 150 seems close for 150 but prob too high for 100

10mm @ 100Yard clks , would give 18 and 41

 

[abinok]

Ive got a 20" Remington 597. Weve got to cut some firewood after the daytona 500 is over... but I should get some velocities up by tonight.

 

[abinok]

There are definately advantages to living on a ranch. A 400yd range with benchrest within walking distance of the front door is one of them.
1075
1036
1053
1046
1040
=== (error reading on these shots)
1058
1057
===
1059
1027
===
1055
1049
1013
===
===
1064
1057
1050
1029

Average: 1047fps (the closest to factory I have ever seen)
59fps ES
32fps ES without highest and lowest

I started at 50 yds since that was the zero range you said you would be using. My scope has 1/8 moa clicks. This is what I got:

50-100: 57clicks
100-150: 71clicks
150-200: 78 clicks
200-250: 84 clicks

It works out to:
50 yd zero to:
100: 7.125 moa
150: 16.0 moa
200: 25.75 moa
250: 36.25moa

You can compare that to what my ballistics program spit out given the same information:
50 yd zero to:
100: 7.3 moa
150: 16.2 moa
200: 26.2 moa
250: 37.0 moa

 

[Gerald89]

Wow how can I thank you enough for that !!

Hmmmm 400Yard range in England no not very near my back door.Most of the areas I shoot struggle to get that distance (farms)!

That proves that the calcs are very accurate. The table of results I have been working off fits with what you have in your results.

It must be my unknown scope moa and my shooting adding up to the errors.

Does wind affect vertical path of bullet at all ? Its been quite windy during my tests but I figured compared to foward movment 10-20 mph wind would not effect it.

I will try and contact S&B to find out for certain what the adjustment is on my scope because I still cant work that out from my results.

Thanks again jez

 

[700]

Jeza

Nice to meet you here at LRH. I am from Ireland so I guess we are neighbours.

Being a European Police / Military scope, I thing you will find that your scope has click values of 0.1 Milliradians.

That is 1 cm at 100 meters.

This translates to

0.3937 inches at 100 meters
0.3612 inches at 100 yards
0.3473 MOA

I hope this helps.

Regards

700

 

[Gerald89]

Hello 700

Nice to meet you too , the wife is half irish (southern) so we might even be related !!

That might be the case then 1cm @ 100 I think I need to get back out there and loose off some more groups.

 

[abinok]

Does a cross range wind cause vertical deflection?
You betcha.
This is one of those strange quirks that are is very readable in smallbore rifles (22s) even at 50 yds, but you rarely see them in centerfires unless you are shooting benchrest, or beyond 800ish yards.
This is probably the best graphic that shows this effect.

The graphic says deflection is 10 o clock to 4 oclock, and thats a pretty good estimate. 10-4 is a 30 degree deflection. This translates to .573 inches of vertical displacement for each inch of horizontal deflection. maybe an example will make this clearer.
10mph, wind from 3 oclock
100yd wind drift=7.5 inches of horizontal drift, and 4.29 inches of vertical, in this case, up.
150yd wind drift=25.5 inches of horizontal drift, and 14.61 inches of vertical, in this case up.

30 degrees is about the most extreme vertical I have ever experenced.
I find that 10-15 degrees is usually a bit closer.
10 degrees translates to .172 inches of vertical for each inch of horizontal deflection. The above example would look like this:
10mph, wind from 3 oclock
100yd wind drift=7.5 inches of horizontal drift, and 1.29 inches of vertical, in this case, up.
150yd wind drift=25.5 inches of horizontal drift, and 4.38 inches of vertical, in this case up.

This effect seems to vary from bullet to bullet, and I havn't shot this particular bullet enough to quantify a value for this effect, with this bullet. I would speculate that this bullet will fall somewhere between the 10 degree, and 30 degree data. As you can see, it wouldn't be difficult to get quite a bit of vertical in a 10-20mph cross wind.
Most of my "LR" shooting with 22's is done with either the PMC Scoremaster (bc .165) or a hollow point bullet formed from the same on a set of custom dies, so I can't give you an exact value but the above examples should get you pointed in the right direction. They were calculated for the CCI Subsonic Hollow point bullet.
Keep in mind that 25" of wind drift at 150yds for a 22 is equal to 500yds with my preffered long range rifle, the 300WM.

 

[Gerald89]

That has to be it!

No reply from S&B yet.
I am going to have to bench it and look at a scaled target to see how much movement the clks give me then Im all set I think!

Thanks abinok

 

[Gerald89]

Schmidt & Bender just got back to me! Would you believe my PMI 3-12x50 has an adjustment of 0.7cm @ 100M!
Reshot some groups last night and I am getting impact at the right level for new/identified clk value (PS the wind was a lot less as well)