Do you know the exact twist rate of your barrel ?
Chart for TC barrel twist rates;
http://www.tcarms.com/firearms/chart_contender.phpalthough I have heard that older barrels can have different twist rates.
With a 1:12", you would expect to accurately stabilise from 40 - 60gr typical flat base lead core/spitzer type projectiles,
but might also depend on the length and weight distribution of the projectile, and the altitude, when marginal.
A 1:9" would expect to stabilise from 40 - 73gr typical lead core projectiles.
With a 1:14, then around 55gr would probably be the heaviest projectile weight, although lighter pills, esp the ballistic tips would probably group better at shorter distances.
As ever, take advice and guidelines with a pinch of salt,
as I have personally found that barrels and projectiles are not always equal, and ones own experiences and results always rule !
The Contender should handle any safe .223 load, if not, you can sue TC, ...that is if you live !
Maximum velocity will depend on the lightest weight projectile that will stabilise.
A 40 gr will probably do 3,500fps with the optimum fast powder.
With a heavy projectile ?
You might get less than 3,000 fps with a 60gr
and a bit more less with the 70gr.
but again, as ever, you need to work up with these loads, and the brass and powder that you are using.
I believe that the TC is recommended to handle a max of 48,000cpu, although it is probably tested in excess of this.
.223 maximum loads, depending on powder and cartridge used can exceed this pressure, so take care.
(I always remind myself of how close the rear of that action is to my face !)
I prefer to develop accuracy (grouping) loads rather than velocity.
cheers,
SS
