Using jbm and setting up holdover reticle

[russ10x]

Guys,
Some folks were asking, and just using Word, and JBM "Trajectory" ballistics I set up this reticle, hard laminated it and keep it in my DOPE book. I used it on the range, and was dinging 8" targets with my Savage MK II out to 200 just using the hold overs.
There were some folks that said that the Bal Calcs were really not practical for rimfire. I disagree, especially when you are shooting a timed precision rifle match. Very easy to do, the BCs and velocities have been posted here before on this site. It was actually fun to create.
This was with a 50 yard zero...

 

[RicosRevenge]

Don't know which folks were saying that Ballistic Calcs were not practical for RF... but I'm guessing they weren't here. You'll generally need to tweak ANY computer generated calculations to your particular equipment but they give a great head start when creating your own DOPE.

As the weather and conditions change, you will notice that you will need to adjust. Sometimes as much (or possibly more) as 1/3 MIL in elevation.

Thanks for posting this, I'm sure there will be several who appreciate you giving them a graphic starting point!

 

[Conaso]

Why all the fuss? Go to the Hawke scope website and download the PC, Droid, and Ipod app. You can even print a reticle range chart for yor scope flipup lid. It's free.

 

[russ10x]

Those people are those that use JBM and other calculators as a crutch and not as a tool.

Calculators need to give accurate data but it doesn't have to be spot on perfect.

The job of the shooter is learn what his particular rifle/ammo do in the given environment.

As the environment changes....the dopes change.

The human brain can easily grasp trends....I don't need to run a calculator to know today when it 4 degrees out that I will likely need 9 MOA for 100yds and once the temp gets modestly warmer I will need slightly less. And there is a point where your dopes will hardly change at all regardless the weather.

Guys who bounce around like a ping pong balls between ammos will get some marginal benefit from the calculator since they come closer to tuning for the flavor of the day.

But they still have to go back and re-zero the rifle for each new ammo. Which may be where some have problems as they will call the old zero good enough. So a flawed zero, typical muzzle velocity variation, and more than likely poor bore prep for "new" ammo can really skew results.

The guy who has his data wrote down (as he should) and sticks to that ammo hardly ever needs to go back and check. His card (combined with common sense and the occasional monthly/weekly shooting session) will be every bit as close to the guy running a calculator with a round that has muzzle velocity spread of +/- 40fps.

I would even say rimfire is easier as I have ran .125 as a ballistic coefficient, the grain weight, and muzzle velocity regardless of ammo maker or bullet type and came up with cards that were "close enough".

Army and Marine sniper schools have evolved so much since I have been there, and the battlefield changes so much, the lot numbers of the manufactured ammo is so different, that these guys live by the range data for that day and moment givin by the apps. We have evolved into a technical age, and being 56 years old, it is hard for me to change also, but change I have done. When I am shooting, I know my DOPE, mostly without reference. But, you get that reference, and train with it's repeatablity using modern tools. Can't denie it. I still have my hold overs in my Butler Creeks, but the I Phone is right there now too.

 

[russ10x]

Not that I necessarily disagree with with you....but we are talking in context of rimfire where the majority (not all) of shots is likely under 100yds with occasionally shooting farther.

My point was there are individuals who use the tool for a crutch....if you shoot mostly 100yds and in there is zero reason to have to resort to turning on the phone, accessing the app, getting GPS signal, THEN FINALLY getting dope for a shot. THEN finally shooting.

Granted, this is the hide. And we have plenty of individuals who shoot 200, 300, and sometimes even farther. But those shots are hardly the norm and having data like I listed above out to say just 100yds will serve you well.

Getting on a phone is just not needed. Carry your data (like you should) and you'll be ready.

I come from a background where targets prefer to stay alive and dicking with my phone often ends up in missed opportunity. A target shooter has more of a luxury I suppose.

My background is not much different than yours, and I agree 100%. I believe that the data should be used to make your charts, or, what I prefer and have used, Mildot Diagram for hold overs for a particular MV. My rimfires are trainers, and not just to have a cool rifle. I am retired, and it is just an extension of every day life now, something I like to do rather than have to do. But, compitition training, ( having shot service rifle till injuries prevent me from getting into a sling) is way too expensive with centerfire. That is why I keep plugging Rimfire Precision Matches on other posts. That, is where data will come in handy, as there are matches that do shoot longer than 100 yards....
Have a great holiday Brother. Be safe.