Help with ELD Match drops

[Elk Hunter 338]

make sure you have an absolute zero to start! i like 100 the best because i can really get a solid perfect zero every time with little movement from bipod and able to really dial it in. I found at 2-300 yard zero's tend to have a little error in them some where ha ha ha mostly human! Drops are drops and Chrono's get you a standard muzzle velocity to start with but they will not get you a true velocity to run in your app out to any distance. This has to be done by getting out there and just shooting at targets to your given range.
I don't shoot many ELD bullets but from what ive seen the BC will need to be fudged a little bit and once your range increases past a 1000 yards you actually need to adjust your BC because as the velocity drops off the BC value also drops so your once 338 cal 285 match .417G7 bc ((****which i have an extremely hard time believing that this bullet has a greater value than the 300 beger but that's another topic***)) is now dropping fast and not flying as true as it once was, most great apps have a advanced BC mode where you can actually add a change your bc through its flight pattern to make up for this. also make sure you have a kestrel and a compass to tell you exactly whats going on at your location at that given time, you can chase your tail around day to day not knowing what the temp, baro, RH, angle, direction of flight, altitude etc. there is a lot that goes into shooting past a 1000 and to get true drops at these ranges you need a few extra tools to accomplish this time and time again!

 

[Snowrun]

Thanks all. I'll be heading to the short range to verify clicks & MV, go from there.

 

[RockyMtnMT]

I had the same problem with a Zeiss optic a week ago. Took 3 more moa at 1000y than expected. This is a huge number! I am pretty sure it is a scope value issue. There is just no way to be that far off with the other values. And there is no way the bc is that far off.

Steve

 

[WiscGunner]

You may already have covered these bases but ....

I would suggest getting a Magnetospeed or Lab Radar chronograph. These both give sccurate muzzle velocity compared to the guestimates provided older standard shoot thru chronographs.

When you have a confirmed accurate muzzle velocity, get an EXACT 100yrd zero. At 100yds wind variances on a calm day have almost zero affect on POI. Be sure barrel mirage is not changing your POA by keeping the barrel cool. It is OK if your group is center vertically but offset because you can true this in a good app but I prefer to have it dead on to insure barrel mirage has not crept in to the calculation. In my experience barrel mirage can add .1-.2mil of false elevation depending on how hot you barrel gets.

I would also suggest if you MUST use a wristwatch for weather that it be removed from your warm wrist and placed in the shade for an hour. There is a reason you will see everyone at a match swinging their Kestrels and WeatherFlows to stabalize their tempts.

Next Iwould to the largest tall target test possible. The larger the test the more accurate the average click reading variable you will get. ALL scope have variables in their clicks as they are mechanical devices, just some more than others. Extended ranges can really show this error. I am not familiar with the X5i but verify if your scope is TRUE MOA or Hunter MOA.

Lastly, use an app that will allow for banded BC input.

 

[jsnell]

I've been looking at how different ballistic apps compare on long shots. At this point, I've concluded that there is only one source of accurate prediction, and that is Applied Ballistics. If you use the available drop data specific to your bullet, and a reasonably accurate muzzle velocity, the results tend to model reality very well.

 

[Farmerbrown32]

What are most people finding the g7 bc to really be for the 285eldm? I am also shooting it in my 338rum. The g7 rangefinder is set at 2880 fps using 89.5 grains of retumbo loaded just touching lands. My drops are great to 1k also but past that they need a few more moa correction.

 

[elkaholic]

What are most people finding the g7 bc to really be for the 285eldm? I am also shooting it in my 338rum. The g7 rangefinder is set at 2880 fps using 89.5 grains of retumbo loaded just touching lands. My drops are great to 1k also but past that they need a few more moa correction.

Use litz's custom drag curve.it usually takes care of the problem of b.c. dropping off over distance.

 

[Farmerbrown32]

I was using the g1 bc with that also. Just switched to using a g7 bc of .400 and adjusted my sight hight a little. Perfect at 720 yards. Havent shot farther yet.

 

[Farmerbrown32]

Dead on at 1020 so maybe it did the trick. Gonna try out farther as soon as the wind isnt blowing 20mph. And i need to get my wife to start spotting for me haha. Kinda tough to watch the impact with a 10 pound 338 shooting a 285 grain bullet haha.

 

[calshipbuilder]

I tested some 225 elds at distance a few weeks ago. 2835 fps from a 10 twist 300 win mag, DA was 3.5k. At 1300 they were on the money. At 1440, no friggen clue what they were doing. Switched to Berger 230s @2825 and went the next 4/5 on the 1440 full size IPSC.

Just one 50 round back to back test (25 of each over identical charges, primers, cases) but it was enough to put me back on bergers.

I was hoping the Hornadys would do the job as the price is right, they shot great groups at 100 and I had inconsistent results from 215 bergers, but it was night and day switching to the 230s

 

[Elk Hunter 338]

I tested some 225 elds at distance a few weeks ago. 2835 fps from a 10 twist 300 win mag, DA was 3.5k. At 1300 they were on the money. At 1440, no friggen clue what they were doing. Switched to Berger 230s @2825 and went the next 4/5 on the 1440 full size IPSC.

Just one 50 round back to back test (25 of each over identical charges, primers, cases) but it was enough to put me back on bergers.

I was hoping the Hornadys would do the job as the price is right, they shot great groups at 100 and I had inconsistent results from 215 bergers, but it was night and day switching to the 230s

ive don't the same test with just about every cal. side by side with same results as you!! been on the B wagon and not jumping now!!

Its kind of like when they switched form the translucent tip (which they said it was a decision based off of another company having it) to what looks like the old amax tip to and i had a buddy bring a new box of 285 with translucent tip again!! ***