No objective testing here, but I've noticed when checking a zero at a 6,500 - 7,000 foot elevation (after zeroing at a home altitude of a little over 600 feet), point of impact has been almost an inch higher at 100 yards. Windage virtually unchanged.
How much of this change can be attributed to an elevation difference or a cheap, worn-out rest system on the outfitter's range, I don't know.
Rifles have been chambered in .270 Win. and 7x61 Sharpe & Hart.
