I have had several .22-.250's since 1968. I started out with 14 twists now all 4, .22-.250's have 7.7 twist barrels. Bullet of choice is the 75 ELDM at about 3150. Powder of choice is any of the 4350's - Hodgdon. Accurate, IMR or Shooter's world. Ball powders like R-S Hunter & Staball work with magnum primers. Low price bullets & powder charges in mid 30 grain range - cheap to shoot.
Experience has shown the 75 ELDM at about 3150 fps, to be a capable performer up to 600 yards. The Hornady 4DOF ballistic program supports this.
The 75 ELD also has a low (good) form factor, under 1.0.
For a read on form factor effect:
In 2009, Berger Bullets introduced G7 BC’s for boat tail bullets. For those who are unfamiliar with G7 BCs, it’s simply a Ballistic Coefficient referenced to the G7 standard projectile instead of the G1 standard projectile. The G7 standard is a better match for modern long range bullets, so the...
bergerbullets.com
"However, form factor is a more universal indicator of a bullets efficiency and performance potential. The form factor of a bullet is essentially a measure of how efficiently a bullet flies,
regardless of the bullet's weight." and "The reason this is important is because if a bullet has a high BC just because it's heavy, it will suffer from having a depressed muzzle velocity, and performance will not be as good as the high BC implies." Berger guys did the bold & italics.
A read of page 346-347 of Berger Bullet, 1st Edition, Reloading Manual describes the .22-.250 favorably.
The .22 CM is on my list for a replacement barrel - Rem 7 1/2 primers are avail at my LGS. The Rem 7 1/2's seem to do better with ball powders than other SRP's. .22 CM brass is availble with SRP's
A pic of my latest rodent rifle. What a deal, donor M77 MKII, like new condition picked up at local Cabello's for under $300 inc. veteran's discount.
Sunshades have been proven to be useful, all my rifles when they are being used have a sunshade. This sunshade is from MK Machining, 3D printed nylon. For shooting deers, I would opt for a solid copper bullet of 62 or so grains & limit shots to 300 yards or less.