.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 [img]/ubbthreads/images/graemlins/grin.gif[/img] 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