New rifle/MPBR question

[tmwtrfwler]

I'm shooting a Weatherby Vanguard in 6.5 creedmoor with a Swarovski Z5 3.5-18x44 with a brx reticle. This rifle is for my 12 year old so I'm setting it up for MPBR at the moment with the expectation he won't shoot at an animal past 200 yards. As he develops as shooter I want to teach him to use the reticle. I will of course use it some too.


I got it to shoot 3.5" high at 100 hoping to get myself to a MPBR setup that will allow him to hold on shoulder or hot gongs from 0-300 yards. That puts my zero, per the app, at 286 yards and at 300 I would be -1.13 inches. I plugged the load, rifle, and scope data into the Swarovski ballicstic app and into iStrelok's app. Both apps show very similar results for drops. Interestingly I could hit the 6" gong 200 yard target routinely but had no consistency with the 8" gong at 300 yards. I will put a white board behind the gong this weekend to better view where I'm missing. I know I'm low but not how low. Interesting that the ballistic apps would be that off so it has to be me or maybe bad data that I'm not seeing. These are gongs I routinely hit with other rifles, loads, scopes, etc. so I know I'm capable of hitting them. The three rounds that did hit the 8" gong were at the very bottom of the gong.


Like anything what the apps say is only a starting point. You need to shoot and shoot often to really know what the gun will do.

any advice on what to look for in data that could be wrong or to better tune this new setup?

 

[cohunt]

try tuning your muzzle velocity with known drops--often times the MV can be the main culprit

other issue could be the angle you are shooting at--angles will affect the drop considerably

streelok pro has always put me within 1 moa out to 800 yards, but I often times have to adjust MV or my poi @ 100 yards to bring that last 1moa into its correct "zone"

I too set my daughters 6.5cm for MPBR-- she shoots a 110hh at 3150 from a 22" TC compass-- her 100 yard trajectory is 2.3" high at 100 yards which puts her zero at 277 and her mpbr at 321 using a 3" max trajectory height (6" vitals) in my streelok pro app

her paper punching load is a 140 eldm @ 2617-- this shows 2.7" high @100 yards with a zero of 235 and an mpbr of 277

what numbers are you using in the app? and how are you getting the MV numbers? sounds like your "vitals" zone might be too large, or your MV might be off

 

[blackdog]

I would suspect the muzzle velocity is way off from what's advertised. I started shooting a new Howa 1500 in 6.5 Creedmoor recently with Hornady factory ammo. Ammo box stated 2700fps for muzzle velocity. My MagnetoSpeed chrono showed 2525 so that's a huge discrepancy which if you're experiencing similar, would account for those gong misses at 300.

I expect the barrel to speed up significantly after another 100-200 rounds so I'll keep track of it and adjust my MPBR accordingly.

 

[Coyote_Hunter]

All my bolt rifles get MPBR zeroed for a 6" diameter target. I've found the best thing to do is zero (plus or minus the expected drop) at 200 or 300 after an initial check at 100. Just did that with my .257 Roberts and found, as expected, zeroing for about a 3" drop at 300 gave better results with the turret at 500 and 600 than when zeroed at +2.x" at 100.