Shots at 300-400-500yds without Ballistic Reticle

silver star · Oct 7, 2011

Going to Multi Gun Nationals in a couple of weeks and have one fear.
Rifle stage with different range targets from 300 out.
My scope does not have ballistic marks.
How does one practice at one scope setting for different hold overs at different distances.
300yd range only convenient range I can practice on.
I have my dope out to 600.
Stages are posted but without distance.
Any insight or advice?

Michael

mike cyrwus · Oct 7, 2011

whats your zero, Mike?

silver star · Oct 7, 2011

My zero with Hornady 75grain hollow point match is 100yd.
Key word, "IF" there were 300-400-500 yard shots on one stage I would guess I would set my scope for 400 and then hold over or under for the other distance, and that is where my fear is, I don't have a feel for those holds.

silver star · Oct 7, 2011

Here are the 2011 - National Multi Gun stages if this link works.

http://www.nroi.org/...%20090111MV.pdf

Round Count:

Rifle - 163
Pistol - 149
Shot - 112
Slug - 7

DoctorJJ · Oct 7, 2011

I'm no pro, but I think most of them prefer a 200 or even 300 yard zero. A 200 is nice because then anything 0-300 and you can, for the most part, just pull the trigger. You do still have to remember your mechanical offset for those really close shots.

toyfreak · Oct 7, 2011

What scope are u using?

toyfreak · Oct 7, 2011

do your know your avg muzzle velocity?

toyfreak · Oct 7, 2011

Not sure if this will help or not but here you go anyway.
If you have a android device check out the STRELOK ballistic app. It will show you impact with different scopes. A generic cross hair is not a option but you can get close and it will show you the hold over needed for different ranges at different zero's
This info came from me iphone app Ballistic FTE.

silver star · Oct 7, 2011

Thanks for the help.
I have a Trijicon 1x-4x German Cross Hair-Green

Let me ask and someone tell me if I am wrong.
I have my dope from 100 and every hundred out to 600.
"If" I have a stage with 300-400-500 yd shots I would think I would set my scope to the pre-determined MOA on 400yds.
Then hold over or under for the 300 and 500, Yes?
With my rifle, MOA at 400 yd is +7.0
My MOA at 300 yd is +3.0, That is 4 MOA difference, 4 MOA at 300yd=3" per MOA=12". I would hold 12" Low, Yes?
My MOA at 500 yd is +11.0, That is 4 MOA difference, 4 MOA at 500yd=5" per MOA=20". I would hold 20" Hi, Yes?
At least that is a start.
If so, how do you go about practicing those holds with a scope with out marks?
I don't have a spotting scope that can mark 223 holes at that distance.
Where can I practice this?

Chambers · Oct 7, 2011

Matt Wright said:
Not sure if this will help or not but here you go anyway.
If you have a android device check out the STRELOK ballistic app. It will show you impact with different scopes. A generic cross hair is not a option but you can get close and it will show you the hold over needed for different ranges at different zero's
This info came from me iphone app Ballistic FTE.

I won't give my input to the original question since this is Kurt/Trapr's section, but those numbers don't make sense....29" of drop at 500 yds. with a 200 yd. zero?? No way!! Especially with a slow 75 grain bullet.

Ballistic calculators can be great if you REALLY know all the variables and punch them in right, but if not...they can really mess with you.

Spiff · Oct 7, 2011

Yeah, that ain't right. You also need to make sure your sight height over bore is correct for the scope mount you're using.

silver star · Oct 7, 2011

Okay, I question that also, I have been thinking about it ever since I posted it.
Now I question if I know how to determin inches or MOA's between 300 and 400 yds and 500 and 400yds.
So, I need help to determin my hold over and under.
Then I need to go shoot to see what it looks like.
Thanks Mike C., Spiff and Matt.

silver star · Oct 7, 2011

My gun is sighted in and these MOA's are spot on.
100yd zero.
MOA at 300yds is +3, 3" per MOA = 9" from zero
MOA at 400yds is +7, 4" per MOA = 28" from zero
MOA at 500yds is +11, 5" per MOA = 55" from zero
Is that right?
I did not mean for this to turn into a math problem but it seems I do need to know the inches for hold over/under.
Then go do it.

Corey · Oct 7, 2011

I agree with your math.

Spiff · Oct 7, 2011

Me too.

toyfreak · Oct 7, 2011

Chambers said:
I won't give my input to the original question since this is Kurt/Trapr's section, but those numbers don't make sense....29" of drop at 500 yds. with a 200 yd. zero?? No way!! Especially with a slow 75 grain bullet.

Ballistic calculators can be great if you REALLY know all the variables and punch them in right, but if not...they can really mess with you.

agreed
thats why i asked for mv. You kinda need it to use the calcs but i got impatient and used the default values form hornady's load data. As for the drop at 500, when i use the same data but change the mv to 2500fps i get 42.31 inches at 500 with a 200 yrd 0 and a 2.5 in sight height.
43.81 with a 1.5 in sight height.
with a 100 yrd 0 its 47.43 @2.5 and 51.43 @1.5.

So, i agree the numbers have to be right but it dosent take very many to get very close with the ballistic calculators.
i guess i should have asked for more data to put in. Im certainly no expert but I use the same calc to shoot out to 1000 with my .308 and it seems to work well.

I was hoping to give him a image like this

but the scope that he was using wasnt listed in the app so i tried a different route and FAILED. Still with the right data, this android app would be helpful i think. This is the Burris tac30 reticle shown with a 200yrd 0, 55gr bullet@2650fps and a sight height of 1.5.

Might not be right either but i bet its close. Mike, It would be awesome if you could give me your load data and the reticle your using so i could put it in and post a image like this to see if it matches your hold over or BDC.
later

Spiff · Oct 7, 2011

Matt, run those numbers through JBM and I think you'll find there's a discrepancy, at least the 500 yard 75gr Hornady HPBT at 2790:

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

toyfreak · Oct 7, 2011

500 -47.9
so basically what im saying is ballistic calculators are ****! I input the same thing and get a 16in difference. F'it

Corey · Oct 7, 2011

Matt I like the strelock but I think you have something somewhere throwing your calculations off I down loaded strelock quickly put in your basic data 2750 fps.224 & 75gr and got -48 in @500. You might plug in your 308 data see how those numbers shake out

toyfreak · Oct 7, 2011

are you using a Bc of .395? sight height of 2.5 and 200yrd 0?
i get -46.57
close but not close enough, they should match.
maybe the battery is getting low in my phone!