picked up my cz 550 american, in .243 saterday, and tried it out on sunday.
the rifle is well made and atractive, there are of corse a few things I would have preferd to do differently, The scope rings are functualy excelent, but if they were gloss they would match the rifle much better. I never have been a fan of detacable magzines on a hunting rifle, and even though this mag is well designed and works well enough I had a misshap with it that even though it was caused by my clumsynes, could not have happend with my CZ 7X57s hinged floor plate. The mag slipped out of my hand and I tired to catch it but instead I just knocked into the fender of my truck and scratched the fender.
I was shooting under very poor conditions at 97 yards from the hood of my truck, I was completly suprised by a rain storm that ruined one of my targets before I could get close enough to look.
But I did try 3 loads, and 1 was a very good 1st try of 4 rounds into an inch,and that was with one being pulled, toss the flyer out and I had .7. That was a 95 grain balistic tip, I also shot a couple loads with a 100 grain hornady interlock, the load with RL-22 was awfull at 3 inches. but the load with h-4350 was decent for the conditions at 1.5.
My next plan it to try the speer 90 grain bullet over varget , and the nosler b-tip over IMR-4350.
It seems like a good rifle , if it had a better looking set of rings and a hinged floor plate , it would be better in my eyes...tj3006

Try the 95 grainer with 36 to 37 grains of IMR-4064 with OAL at 2.69". Works well in mine.

if it likes the nosler ballistic tips, try 33.5 grains of Varget under one of those. my .243 shoots that into 3/4."

-Matt

I think your on the right track using 4350 and the 95 grain ballistic tip. I think you can get a few more fps with H414 but nothing to get excited about.

All powders mentioned are ones I use with other rounds. I loaded some speer 90 grain bullets with 38 grains of Varget. I will give 4064 a try too. H-414 gives me a great load with the 100 grain tsx in my little Roberts, I will give it a try too !
...tj3006

Thomas: I'm not a fan of the .243 Winchester, however, I am a huge fan of the CZ 550 and the CZ 527. I'm glad your experience with the CZ 550 American in .243 has been good. Most people's experience with them tends to be on the positive side. That's not to say CZ fails to produce a bad rifle every now and then, however, you just don't hear about it nearly as much as with some of the other manufacturer's products. Tom Purdom

In my sons .243 ( Win M70 Lightweight Carbine 20" barrel) the 100 grain Sierra's are the top performers in accuracy. This gun will consistantly deliver sub MOA groups and on occasion will turn out a .5" or under 100 yard group. My load for this is 42 grains of IMR-4350, WW brass, CCI large rifle primers and Sierra 100 grain bullets and both the flat base and boat tails are very accurate for this gun.
I must admit for a lightweight rifle this thing is a shooter.
On another note the gun also shoots Sierra 60 grain HP's with 46 grains of IMR 4350 to the same point of aim at 100 yards, which is handy.
Good luck with your CZ it sounds like fun.

Yes so far the CZ has been fun.
It does not seem to like the 100 grain hornady, but the 100 grain sierra 90 grain speer and 95 grain Balistic tip, all shoot prety well...tj3006

Here is a load I worked up for my CZ550 in .243:

3 shots @ 125 yards
Sierra 85 gr. HPBT
CCI BR2 primer
35.5 gr. Varget
2.615 OAL

I also don't really car for the detachable mag, I have a 308 in varmint config, I would much prefer just regular magazine set up on it. one of the reasons is because you are pretty much stuck with 08 cases if you ever wanted to rebarrel. I am much more of a fan of the 527 series, the 550 is a little too big and clunky, the wood stocked models need a serious diet, a 3 pos saftey would also be a big inprovement