Just got into the long game. I was able to pick up a Bergara HMR Pro in 6.5 CM and I just finished a four day class and on first day out shooting was able to work my way out to 700 for a hit. Pretty happy with that, but that was on the fourth shot. First question, I am using Strelok pro and am a little confused on how to “true” up the ballistics. (am I even saying that correctly). So, I input all the info and then the shots are still off based on the data. So, after more adjustments, I get a hit, but now I need to adjust (True) my app, right? How do I do that?
Are you missing high or low? If you’re missing high or low, it sounds like your FPS is incorrect. Which chrono are you using, and are you dialing or doing holdovers? If you are dialing, you can see how many mils or moa you “truly” need to hold to hit at that distance, and then reverse engineer your fps to get the true speed. For example, your ballistic calculator says to dial 5.4 mils, but really, you have to dial to 5.9 mils to make your impact, so you can see what true fps gives you a 5.9 mil call.
Also, keep in mind, most barrels will actually speed up after the first 100 rounds, sometimes by as much as 50+ fps, so you may be seeing an fps increase.
I am doing holdovers. I was high and low. I think there was def some user error. :jester: We used a Magneto (?) on day three of the class to chrono the fps. Did ten rounds. I am heading out this weekend again. I’ll see how it groups. Thanks!
What scope are you using? Can you dial? As a general rule, unless i’m competing on a timed stage where I have to make multiple quick shots at different differences, i almost ALWAYS dial for elevation, and only do holds for wind, or quick follow up shots. You can easily get lost when doing holdovers, and generally using the center crosshair will be more precise.
Also, if you’re shooting at distance, and not under time, make sure you get as stable as possible. A good bipod and good rear bag is essential to help you get super stable, so you take out as much human error as possible.
Let us know how it goes, and i would chrono again to see if that changed since you chrono’d last.
if you want to get good, forget about distance for a while, and forget about all the ballistics etc. Just dry fire indoors a few hundred times. Focus on getting a decent prone position (not bench), aiming at a tiny target with no wobble, and pulling the trigger straight back. try to minimize the movement of the crosshairs relative to the target. They should move less than a tenth of a mil when dry firing. note which direction they move and work your body position until you can control it.
next, go to the range and set up a paper target at 100yds with as many 1/2" dots as you can. Preferably at least ten rows of 5+ dots, 2-3" apart. Dryfire 2,3, or 4 times, then take a shot. Focus on pulling the trigger straight back and keeping your eyes open, and absolutely call your shots. The goal is to know a good trigger pull from a bad one, and which direction you missed. This is the basis for self-diagnosis, without which, you’ll never really progress. HOWEVER, your rifle/ammo combo may naturally group somewhere between .5 and 1.5 MOA, so just because a round went .5" left doesn’t mean you pulled it left. You’ll get a feel for what is your fault and what is the guns’ after a few hundred rounds. Keep dry firing several times before each live round, and shoot as many dots as you can afford ammo.
once you have some confidence and know how your gun shoots, and get some consistency, you can stretch it out. if you stretch it out first, it will take you 10x as many rounds to figure out if you missed because of your trigger pull, or position, or the wind, or dope etc. once you do spend a little time at distance, like 300-500 yards and get consistent groups, go home and dry fire thousands of times.
As Jacob at Rifles Only always says believe the bullet. What is the actual drop and drift? Get that and truing a calculator gets a lot easier.
I’d much rather get hard dope at distance and record that. Thats what the bullet is actually doing. Knowing that your setup takes 2.6 mils at a certain distance and 5.4 at another is confidence inspiring. I’ll create a drop card of hard dope, shot on paper first.
Then you can true your ballistic calculator to match what your bullet is doing. Velocity first, then BC works for me.
Write down your data from your app for each distance you’re shooting. Record any adjustments at the range in a separate column.
When you get home tweak the calculator until you get them to match up. It’s not something I would recommend doing at the range. Next time you’re out you should be able to verify the data and build confidence.
Sorry I cannot answer about the ballistics calculator either, because all I ever used was a Hornady online drop calculator. The only data I had to input was the caliber, bullet weight in grains, bc, muzzle speed (fps), zero distance and altitude. I didn’t bother calculating wind at that time. I planned to hold for it.
I took a 308 Savage from 0.75 MOA at 300 yards to on target at 1,000 the very next shot from a bench rest. All I did was dial my scope to the point between what my bullet drop print out said and what my spotter/coach calculated on his plastic cards. I was about a foot low at first, then came up another full MOA (4 clicks) and I made 10 hits spread across the 1m target but in a straight horizontal line like an equator in the middle of North and South pole. Coach told me that’s good, your drop is calculated and precise. Now it’s all bout practicing for wind holds and not pushing the muzzle left or right on let off. I just needed to practice from there on out. It was finalized at 29.5 MOA come up from 300 to 1000 IIRC. It’s written on a paper and rolled up inside the stock of the gun now. Sad to say I was using rolled up towels as my rests. I was such a noob.
What I had that you have not mentioned was a really good spotter behind me with a 60x scope and a guy in a “pit” below the targets. They communicated on radios. You had the 4 day class, so I’m sure you had something of the sort. But did anyone at the class identify if your misses were all in the same direction or if they were all over the place? Same question for the hits. Were they grouping at all?
FWIW about a month after that (with a proper bipod and a rear squeeze bag) I had my wife out there in the pit and I was practicing again from the bench. After I was happy with my grouping that day I let her sit behind the rifle and I was in the pit. Now, she’s never looked through a scope at anything beyond 100 yards, much less shot at it. I can proudly say she was on target the first shot and 9 more times after that one too at 1,000 yards. Grouped about a foot to the right. All I’m saying is, once you have all your equipment dialed in it is a beautiful thing.
Strelok pro has a trajectory validation feature. I don’t have a chrono, so I used this feature to true my velocity. It works by applying your actual drop at distance to adjust either your velocity or BC, your choice.
I chose velocity because my 20" barrel length is a bit less common.
In the App, press the icon at the bottom right of the main screen for your setup. It is an arc hitting a target with an up/down arrow.
Plug in your actual drop and it shows you the velocity (or BC) to use.
I use the ballistic X app to accurately measure drop from the center of the group being measured.
After doing this. I was dead on at 200 and 300, but I don’t have access to a longer range yet to fully test.
I’d wager most PRS type shooters who shoot at lots of different ranges in lots of conditions, never have to true their calculator. A combination of a good calculator, litz’ BC, and velocity from either magnetospeed or labradar, will pretty much get you on target. For me, the only time i needed to true was when I was goofing with something, like i shot pointed bullets for a year and that changed the BC slightly. earlier, i used some calculators like Field Firing Solutions on a Nomad, and it required truing.
however, if you are going to true, this is the way (like sendit said above, velocity first then BC):
start with published BC in your calc. shoot at 300-400 yards on a tall target with your 100 yard zero dialed on scope. put a POA like a small shootnsee at the top, and let the bullet fall and hit the target. be sure you know the precise distance with a LRF.
measure the distance from POA to POI on the target. Use that to calculate your actual muzzle velocity.
enter your actual muzzle velocity in your calculator and get a new solution. confirm with hits if desired.
now calculate how far away the transonic zone is, and place a target shortly before that. e.g. if your bullet goes transonic at 1200 yards, put a target around 1000-1100.
shoot at that target and adjust your BC until the calculator gives you a solution that matches what you actually needed to dial on the scope to hit the target.
confirm calculator is giving you good data by shooting multiple distances.
note: a single BC, even g7, will not give you a great solution at all distances because it’s velocity dependent. if the vast majority of your shooting is going to be limited to say, 700 yards, then use that to true your BC instead of the transonic zone. It will give you better data up close, but way worse at distance. (this is kinda similar to a 50/200 zero on ARs. if you zero at 200, you’ll be close at 50. if you zero at 50, you could be quite a ways off at 200)