I have been shooting Hornady 140grBTHP (81482) out of a Ruger RPR 6.5mm Creedmoor with a Vortex Razor HD Gen II 4.5-27x, and doing a respectable job at 650yd. Today I switched to Hornady 140gr ELD Match (81500). Both conditions were no wind as it was early in the AM. I plugged my info into Strelok Pro. The 5 round group was nice, SUB-MOA, however the match rounds were approximately 9 inches to the left, elevation was spot on. My stupid question is as follows. Can a change in ammo bring about a change in the zero point for windage?
Windage zero change with ammo change?
- Thread starter Joeg1717
- Start date
Yep. Use Strelok Pro's "zero offset" feature for different ammo than that used for the original zero.
Any change at all will affect zero.
Honestly, I'm surprised your elevation was that close considering the drastically different BC from the BTHP to the ELD.
Changing the primer, powder (type or charge weight), brass, bullet, seating depth have all shown a variation in windage and elevation when doing load development.
Honestly, I'm surprised your elevation was that close considering the drastically different BC from the BTHP to the ELD.
Changing the primer, powder (type or charge weight), brass, bullet, seating depth have all shown a variation in windage and elevation when doing load development.
It makes me want to pull my hair out. The smallest change effects everything when you are shooting for one hole accuracy . What works at 8:00 am will be a little off at 11:00am . I have just settled on RL 15 at 43.0 175 SMK for my 308. I love my RAZOR!
Yep... including windage.
So, pick your favorite ammo and zero the rifle with that. Then, when you use a different ammo... or add a suppressor... Shoot a group without changing your original zero. Then note the group's offset. Then use Strelok Pro's Zero Offset feature to automatically make that adjustment in the future. Then you're all set.
Works a charm!
There are reasons why two separate shots will very seldom hit the some on the target.
Trying for on hole targets is very stressful, and honestly, counterproductive (unless you're a BR shooter, and honestly, a lot of those folks are hopelessly OCD. I know, I tried being one, and believe me; I do NOT have the required temperament.).
Accept that there will always be "fudge factors", get some insight into figuring them out, and roll with the flow. You'll be a lot happier in the long run.
A two inch "miss" on a buck is just "Minute of Venison".
Always confirm zeros, even if "nothing has changed...".
New guys always ask this question eventually, and no; this is not a stupid question. It's a lesson we all have to learn.
Greg
Trying for on hole targets is very stressful, and honestly, counterproductive (unless you're a BR shooter, and honestly, a lot of those folks are hopelessly OCD. I know, I tried being one, and believe me; I do NOT have the required temperament.).
Accept that there will always be "fudge factors", get some insight into figuring them out, and roll with the flow. You'll be a lot happier in the long run.
A two inch "miss" on a buck is just "Minute of Venison".
Always confirm zeros, even if "nothing has changed...".
New guys always ask this question eventually, and no; this is not a stupid question. It's a lesson we all have to learn.
Greg
if he's getting a 9" shift at 650 there is more in play than BC. like he should check his 100y zero first. then wind.
either way though. BC still wont have much of an effect here assuming he entered the data correctly for each bullet. it's going to be more his zero offset at 100y
He mentions the zero at the end, when I switch ammo I start with the change in zero. Hence my confusion.
You missed the part where he DIDN'T adjust zero.
He said his elevation did NOT change, which I found odd considering his change of load.
His windage moved 9" at 650 with a completely different load. I'd call that damn close since he didn't adjust zero.
nope. didnt miss that part. just coincidence that it was only a change in wind (maybe).
without a confirmation at 100y, which we would expect wind to be off 1.5"ish and no change in elevation, we cant say what happened whether it was ammo or bad wind reading. with the zero for elevation being the same between the two, entering the right data would be more than enough at 650
i've shot 88s at 3170 and 95s at 3140 from my 22LRV. i think i had .1 left shift in wind and no change in zero elevation. not only different weight but shape and construction.
If you change ANY component a Verification of zero should be assumed a fundamental starting point for refernce
No 2 barrels or bullets will ever have the same reaction. Just because you had that experience once doesn't mean anyone else will.
Resetting and establishing zero for every load is essential.
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