Different bullet weights, different horizontal impacts?

[mbz hunter]

Hi. New member, old shooter. I have a Mark X Mauser in 270 win. On a recent range trip I was shooting 2 different bullets to test for accuracy. The first was a Sierra 110gr at 3000fps, the 2nd was a 140 gr Nosler Ballistic Tip at about 2750fps. Both shot sub MOA at 100 (bench rest, bedded action, B&C fiberglass stock, lapped bbl and action, neck turned brass, all the good stuff done). While they had different elevation impacts (2", expected), they also had a 3.5" horizontal impact difference. While I have seen something like this on a small scale with this rifle, this has me wondering. Anyone else ever seen this?

Oh, yeah, the barrel has been recrowned.....

 

[CaptainMal]

This hunting section is really not dedicated to barrel dynamics but that is the answer. Barrel dynamics.

Now if you are unaware of this issue, nodal vibration, barrel timing etc., do a bit of research. At short ranges, like 100 yards, you cannot even expect the heavier bullets to hit lower than the lighter ones. Contrary to logic and "old wives tales", point of impact at short range is a product of barrel dynamics. Make no assumptions from your different impact points, vertical or horizontal. Shoot what groups best in the bullet you want to use for your purpose.

Now sight in for that.

 

[mbz hunter]

OK, so can you point me to where I can get more info on that? I am trying to downsize stuff, and the thought of having two workable loads (deer and 350 yd varmints) does appeal to me. Thanks!