2900fps is WICKED fast for 140gr Hornady Factory ammo from a 23" barrel. Although it is 5R rifling and melonited so you may be onto something there. Any pressure signs on the case heads or primers? If not roll with it and enjoy your "freak" of a rifle.
No pressure signs and primers look good, a little flattening but nothing crazy. I've double and triple check all the info in my ballistic app to make sure but it all correct. This is my dope card.
3.2 mils to 600 and dead on the 8" poppers
Yards. Elevation. Wind
25 -1.2 -1.4 19 0.1 0.1 1
50 -0.6 -0.3 4 0.2 0.1 1
75 -0.1 -0.1 1 0.3 0.1 2
100 0.0 0.0 0 0.5 0.2 2
125 -0.1 -0.0 0 0.8 0.2 3
150 -0.6 -0.1 1 1.2 0.2 3
175 -1.3 -0.2 3 1.6 0.3 4
200 -2.3 -0.3 4 2.1 0.3 4
225 -3.7 -0.5 6 2.7 0.3 5
250 -5.4 -0.6 8 3.3 0.4 5
275 -7.4 -0.7 10 4.1 0.4 6
300 -9.7 -0.9 12 4.9 0.4 6
325 -12.5 -1.1 15 5.7 0.5 7
350 -15.5 -1.2 17 6.7 0.5 7
375 -19.0 -1.4 19 7.7 0.6 8
400 -22.8 -1.6 22 8.9 0.6 8
425 -27.1 -1.8 24 10.1 0.7 9
450 -31.8 -2.0 27 11.4 0.7 10
475 -36.9 -2.2 30 12.7 0.7 10
500 -42.4 -2.4 32 14.2 0.8 11
525 -48.4 -2.6 35 15.8 0.8 11
550 -54.8 -2.8 38 17.5 0.9 12
575 -61.7 -3.0 41 19.2 0.9 13
600 -69.2 -3.2 44 21.1 1.0 13
625 -77.1 -3.4 47 23.1 1.0 14
650 -85.6 -3.7 50 25.1 1.1 15
675 -94.6 -3.9 54 27.3 1.1 15
700 -104.2 -4.1 57 29.6 1.2 16
725 -114.4 -4.4 60 32.0 1.2 17