Yes I do happen to have a SSK 14" Stainless-Steel Contender Barre in .250 Savage. The .250 Savage is an interesting cartridge in the Contender, and is perfectly safe PROVIDED SAAMI Maximum Loads (45000 CUP) are not exceeded. What the problem is is that the .250 Savage Case Design and Case Capacity are capable of producing more Case Head Thrust than the Contender is capable of handling.
I have used (am using) 75gr. Hornady Hollow Points loaded to about 2900 FPS for Coyotes and Varmints. While this bullet / load shoots quite well, I think when this ammo is shot up I am going to try a 75gr. Hornady V-Max next time. I have taken a few Coyotes with the 75gr. Hornady Hollow Point and all were Bang / Flop kills. I also took a large Badger this past fall with this bullet and it too was an instant kill. When I last was out shooting Prairie Dogs with this Bullet / Load I was a little disappointed in the bullet performance. YES all of the Prairie Dogs were killed instantly, but I guess I was expecting more dramatic results in terms of air time.
For Whitetails I have used the 100gr. Nosler Ballistic Tip with quite good results. I just recently worked up a new load for the 100gr. Nosler Ballistic Tip using H-4895. Accuracy is quite good (sub 1" 5 shot 100 yard groups) at an average muzzle velocity of 2558 FPS. I had recently used H-322, but H-4895 provides me with as good or slightly better accuracy, at about the same velocity with what appears to be less pressure.
I think in the Contender if a person wants ONE BARREL / CALIBER to use on both Varmints, Coyotes and Deer in a Factory Cartridge (ie not a wildcat) the .250 Savage makes a good choice. For the record while I have not shot any game with them, I have shot a few boxes of Remington Factory Ammo (100gr. Pointed Soft Point). Accuracy is from 1 to 1 1/2" 5 shot groups at 100 yards and the average velocity is 2400 FPS.
While I dreamed of a 14" .300 Savage Contender for years I never have had one. Performance in a 14" Barrel is about on par with what can be achieved with the .30-30 Ackley Improved from what I have read over the years. Some claim that the .300 Savage suffers from extraction problems when max loads are reached in the Contender. I guess it all depends on how you look at it, one train of thought would be that that would be a safety / perssure indicator rather than a hinderance. However without actually having owned and or shot a .300 Savage I am just speculating.
As per the Rimless Cartridges in a Contender, I have shot many over the years and with proper case care, and loading I have never had any problems.
Good luck with your quest.
Larry