Laser Range Finder, Chrony, Ballistic Software, and Rifle Data Card

[Siskiyou]

For years I have been generating data cards for my rifles.  At times a data card has been taped to the stock of my rifle when I am out hunting.  By the time I am on the hunt the data is firmly in mind.  And I have found that a number of rounds are close out to 300 yards.  But there is a big difference if I switch from a .270 Winchester, to a 30-30 Winchester. 

My ballistic software shows the maximum point blank range for my 30-30 is 208 yards when zeroed for 160 yards.  That means the bullet is approximately 2.38 inches high at one hundred yards.  And low 4.09 inches at 200 yards.  I also know that the energy level is a hair less the 800 pounds.    I prefer not to stretch the 30-30 Winchester beyond 200 yards.  My winter shooting range gives me an estimated 80 yards to shot.  The ballistic software says I need to be putting my group 2.38 inches high at 80 yards.  I will be checking the distance with the new rangefinder.

I cannot visualize using the rangefinder on a deer at 200 yards if I am carrying a .270 Win.  But it would be the right thing to do on a deer at 200 yards when carrying a 30-30 Winchester if you have a rangefinder.  Real world experience tells me that most of the deer I have taken have been at one hundred yards or less.  And if I had taken the time to use a rangefinder I would have been eating track stew.  What I plan on doing is some pre-shot intelligence gathering.  I have taken a number of deer on the far side of a draw.  I have moved the deer from in front of me out of the draw and they become exposed on the far side.  When I hit a draw I can use the Rangefinder to get a high and low reading so when the action starts I can make better shooting decisions.

Consistency has been a rule of mine for years.  And I have sighted my rifles in at approximately 2.75 high at 100 yards.  A check of the software tells me that if I sight the 30-30 in at approximately 2.7 inches high at 80 yards the bullet will be 2.86 inches high at 100 yards and 3.13 inches low at 200 yards.  The one thing that has not changed is the amount of energy the bullet delivers at 200 yards. 

The real value of a Chrony comes into play when you are working at the limits of a round, be it the 30-30 at 200 yards, or the .270 Winchester, which is producing more energy at 1000 yards then the 30-30 at two hundred yards.  At this point I am exceeding my shooting ability on a small deer at 400 yards.  My data card shows that the 30-30 has dropped close to 67 inches at 400 yards.  I’ll have to pass on the shot and wish I were carrying a different rifle.

So deer season is a little more then nine months away for me.  I need to start preparing now.  Item number one is a daily walk.  Item number two will be getting field experience with the rangefinder on deer.  And the gps has dropped to number three because I have had a lot of practice with.  Hopefully the weather will permit one or more monthly shooting sessions.  The nice thing about 1,2, and 3 is that I can step out the front door and return in an hour having accomplished all three.

Every few years I go on a tangent and carry my Dad’s rifle during the hunting season.  My hunting partners and I have spoke about carrying our Dad’s rifles in their memory this year.  This may or may not happen.  I generated a data card for Dad’s rifle a few years ago.  I expect it to be valid, but I will check it out. 

I feel critical elements in creating the data card for a round is a Chrony or like brand, sighting in at a known range using a tape measure or rangefinder.  And ballistic software, in my case I am using Serria Infinity. 

Developing a Data Card based on publish factory ballistics is filled with pitfalls.  After firing rounds from a number of factory cartridges across my Chrony I have confirmed the published ballistics are over stated in many cases.  I believe the data card needs to be created from data from the intended firearm.  You may have two or more firearms in the same caliber and different makes.  You might find a fifty f.p.s. difference in velocity between the rifles.  Or you may choose to load them with different bullet weights to accommodate different hunting conditions.

[Friar_Tuck]

I have been suprised by the rangefinder.  Of all the tools I have bought for hunting, it is by far the most helpful.
I said the same thing, that I didn't need it under 200 yards, until a dusky oportunity, in unknown territory, caused my to drastically overestimate the distance a couple years back, and shoot over a deers back 4 times!
I have owned a couple, the first one was accurate out to about the point it would be needed, but then failed.
The second one was the bushnell elite 1500, and it is great.
I shot a deer this year with confidence, at 431 yards, because I knew exactly what the range was.
It is very interesting to go afield with it, and a few guys, then have them start argueing about ranges.
Pull the elite out, and they are often suprised at how far off they were.
It is deffinately on my keep list!
Jim