Questions about my drop chart

[DIDIHITIT?]

Try 168 berger vld 71.5 retumbo powder in your 7mm I have same on my cooper model 92 great tracking out to about 900 yds

I've been kicking around

get a kestrel 5700 true it at the right range for your vel and then print your drop charts if you need them if you put all the right dope in to it you will get the righ stuff out

I plan on getting one soon. Saving up for a while

 

[DIDIHITIT?]

Whats your group size at 200 yards.....be honest...
About 1-1 1/2 depending on the day

 

[Arkansasdad]

My chrono is a shooting chrony. Not sure the model. I have nothing to compare it to, I'm the only one I know with one. Hitting high at 800 dialed to 16 moa could have just been me. It seemed to hit more consistently at 15.5. I am shooting a 12" rock that I painted by the way. This is the furthest I've ever shot and it seems like sorcery at this point. I'm going to try the tracking test on a tall target after I hammer the bench tonight. I shot everything I had loaded! Got this gun for Christmas from my wife and have already passed the 250 round mark! That's probably not a lot to you guys, but I've never shot an elk gun that many rounds in such a short time. I'll look back through the comments closely and try these suggestions. I really appreciate your advice guys!

Check your ES. I would check that chrony with another, seems a small error on FPS will magnify itself hyperbolically as distances increase. If you decrease your entered FPS on your calculator by incremental steps until the solution data coincides with physical data that will give you the real FPS. I have a few chrony's and every one is off a small amount. Low light to high light will change a chrony's reading by a few FPS, end of barrel vs 20 ft. will change it, muzzle flash by over loads will change it. I was at the range and a shooter was complaining about the ES on a load, he asked me about it. I could see he had unburned powder out the end and told him what I could see, he went home, reduced his charge by 5 grns., moved his chrony out to 20 ft. and his ES dropped to within 10. His chrony was picking up muzzle flash. He was shooting great groups at 100 yds but would have been all over at 1000. Lots of variables, and being able to recognize and diagnose the the problem is what makes a good shot into a very good shot. Experience is the key, the more problems you can successfully solve the better you will be. All the best.

 

[DIDIHITIT?]

As stated earlier it's garbage in garbage out first off make sure all your bullet information is correct and precise use a G7 BC also I run Shooter ballistics because I can run multiple BC's a lot of apps only take one average and then as far as trueing your data which must be done at greater distances you will see as the velocity drops your BC goes up this may be your problem if you have a chronograph you know your correct speed at the muzzle the app will adjust to speed at different distances but you must use the correct BC for that distance which is why I run multiple BC's this photo is from Bryan Litz his book ballistic performance of rifle bullets 3'rd edition compare it to the data on your bullet make sure everything is correctView attachment 180270

I got the shooter app. Must have plugged something in wrong. On the page you posted, Is the g7 form factor the b.c. I'm looking for? There were some things I didn't know. I'll mess with it more today and get back to you. Thanks for your help

 

[338 dude]

I got the shooter app. Must have plugged something in wrong. On the page you posted, Is the g7 form factor the b.c. I'm looking for? There were some things I didn't know. I'll mess with it more today and get back to you. Thanks for your help

Form factor is a number that is used to figure the BC. BC highlighted will be an average for the G7 ,the BC's listed under velocity starting at 3000 and going to 0 ft./s will be the BC for that speed if you know how to add multiple BC's in Shooter those are the ones you would use for the correct speed and you always use the minimum speed in that category example if you're around 2800 FPS you would use 2500 as your first BC And must finish with zero as your last

 

[Arkansasdad]

Check your ES. I would check that chrony with another, seems a small error on FPS will magnify itself hyperbolically as distances increase. If you decrease your entered FPS on your calculator by incremental steps until the solution data coincides with physical data that will give you the real FPS. I have a few chrony's and every one is off a small amount. Low light to high light will change a chrony's reading by a few FPS, end of barrel vs 20 ft. will change it, muzzle flash by over loads will change it. I was at the range and a shooter was complaining about the ES on a load, he asked me about it. I could see he had unburned powder out the end and told him what I could see, he went home, reduced his charge by 5 grns., moved his chrony out to 20 ft. and his ES dropped to within 10. His chrony was picking up muzzle flash. He was shooting great groups at 100 yds but would have been all over at 1000. Lots of variables, and being able to recognize and diagnose the the problem is what makes a good shot into a very good shot. Experience is the key, the more problems you can successfully solve the better you will be. All the best.

Something else I should mention is make sure you have entered the correct scope height, this won't have much affect out to 600 meters. but after that the data will suffer. I measure scope height to 1/16". Happy shooting.....

 

[338 dude]

Your average for only using one would be 0.256 if you were going to use multiple you would start with 0.258 and proceed towards 0 ft./s

 

[338 dude]

I got the shooter app. Must have plugged something in wrong. On the page you posted, Is the g7 form factor the b.c. I'm looking for? There were some things I didn't know. I'll mess with it more today and get back to you. Thanks for your help

If you still have problems PM me your phone number and I will walk you through it

 

[Canadian Bushman]

Im with Greyfox, im betting your MV value is off because of Shooting Chrony. They are not accurate.

 

[Sterlingb06]

Have you checked JBM stability calculator for your specs. If you are low DA, heavy bullet, slow twist, or slow MV then you might not be fully stabilized leading to lower BC than advertised.

 

[Randel]

I went out again and shot 800, 650, and 550. I have found that to 500 my drop chart is dead on. At 550 I'm shooting a half moa higher than my chart says. The same goes with 650. 800 is nearly 1.5 moa off. The spot I'm shooting is uphill. Maybe a 15 degree angle. But at 650 I was almost level with target and still hit high. I brought it down and put them right in the center. Have you guys had this same experience. I dont wanna change everything and skip a step. This conclusion is drawn after 60 rounds and 2 different shooting sessions. View attachment 180143

Possibly difference in weather conditions and or altitude

 

[Flintlock shooter]

As mentioned, make sure your scope is tracking correctly and that you have correct inputs in your ballistics calculator. Accurate MV measurement is next and very critical. MV can be verified by shooting on a small target at around 400-450 yards. I use a 5" circle at 420. Make sure you are centered top to bottom on that. MV will give you accuracy out to 600-650 yards. After that, BC is going to take over. Work your way out 100 yards at a time. If you are hitting consistently high, you will need to raise your BC....low impacts require lowering BC. When you are doing this, it is important to make elevation corrections until you are on the waterline of the target. Then change your BC value until your solver gives you the elevation that matches what is on your turret. Feel free to message me if you'd like. A phone conversation might be a good idea.

 

[BrianID]

Maybe I missed it somewhere in this thread but are you factoring your elevation above sea level?

I have never found a computer calculation will perfectly calculate bullet drop at extended ranges. All it takes is for one thing to be slight off. Maybe your zero is off by 0.2" at 200 yards. Your scope dial really moves the reticle 0.27 MOA instead of 0.25 MOA per click. Your chronograph velocity being slightly off. Many shooters have proof that the manufactures stated ballistic coefficient isn't likely to be perfect for the conditions they are shooting in. As stated by others "garbage in results in garbage out".


You will find that it isn't easy to make 600+ yard shots in hunting conditions even if you have a scope and gun capable of 600+ yard shots and practicing shooting a couple hundred rounds. At longer distances, so many things can go wrong. I have found judging wind drift my biggest limiting factor on taking long shots. There are many guys who claim they are good enough to shoot a deer at 1000 yards but the truth is very few hunters with long range guns are good enough to consistently kill a deer in one shot at even 800 yards.

 

[LaHunter]

I'm gonna put my money on a scope tracking issue, based on reading the OP.