I've just read this entire post. I don't have any advice for you on handloading but I will make a couple comments that might be helpful in other areas...
1. Initally you said you wanted a caliber that would shoot PD and yotes out to 500 yards. With your 243, if you can get the accuracy, it has the punch to shoot them out to 1k and maybe farther. You will want to use the heavier bullets though to reach that far. Don't think the 55 or 60grain bullets will reach that far.
In terms of deer, use the heavier bullets (80 grains plus) and you can shoot whitetails/mulies out to about 400. (308 would have been able to go farther)
2. Rem 700sps varmint is a great platform to begin with. I have the same rifle in 223 and 308. Intially, float your barrel. Do this by removing the three bolts on the bottom and lift the barrel and action out of the stock. At the tip of your stock you will find two small blocks that contact your barrel. Take a Dremel tool and grind them down. Then put your barrel and action back. Groups should improve. Once you've got a few more bucks saved up....
3. The stock on your rifle is a piece of tupperware junk. Find a better stock that you like and once you've got it, take it to your gunsmith and have him do the installation. The installation is more than just dropping your action in...have him bed the action and since he's got it out, have them reduce your trigger pull to 2 or three pounds. Once done, don't take the rifle and action out to look at the bedding. If you've got a good smith, he will install the action bolts with a torque wrench so the pressure is even on both ends of the action.
4. You made a good scope choice.
I'm not gonna shoot here. I'm gonna shoot waaaaaaaay over there!
I have gotten terrific accuracy from two different .243's shooting 87-90gn bullets with IMR4831. The best groups have come from using an old Winchester Western Match 85gn HP Flat Base, the Nosler 90gn Ballistic Tip, Speer's 90gn FMJ, Hornady's 87gn BTHP and last but not least; Hornady's 87gn V-Max. With the first two bullets accuracy ran/runs in the .2's, .3-.4 for the next three. Unfortunately, for me, I don't think WW makes the 85gn anymore. The primer of choice was the CCI BR2. The powder charge was 44.5gn for the 85-87gn bullets and the 90gn FMJ but I dropped down to 44.0 to find the 90gn Ballistic Tip's sweet spot. I seated all the bullets .010" off the L&G.
The first .243 was a Rem 700 VS; wood stock BDL, 24" barrel, 70's vintage. Great little rifle but I lusted, strayed and divorced her after I met a sweet-talkin' .25-06 Sendero. The .243 I have now I bought while living in Wa. state earlier this year. It is a Winchester 70 HVB (Heavy Varmint Barrel), 26" barrel with H S Precision stock. It is a dream to shoot. I just checked it's zero a few days ago after the trip across the U.S. and it printed 2" high, 1/4" right, three bullets (90gn NBT) same hole. Two "clicks" left on the Nikon Monarch 6.5-20x44 and she's ready.
Hope it shoots as good for you and it does for me. JohnnyK.
i know this kind of a lengthy topic but i dont think that starting a new thread is really necessary. I went out for my final sight in last weekend and got zeroed at 100 then went to 200. I aimed directly at the 200 yard target with my 100 yard zero. I was about 7 in.s low using factory remington 100gr corelokt ammo (i dont trust myself handloading just yet and waiting for my friend to teach me). My dad relayed this information to me and from where i was aiming to where the bullet hit was about the same distance as my first mildot down from my cross hair. This was the next three shot results...
Is this a good group or no? it was my first time at 200 with this rifle. But the 100 yrd group was inside a penny with this ammo too, just like the 80gr. im not a rocket scientist but can tell that isnt moa
My first time at 200, 300, and so on yards was never impressive. But after practicing at that distance, it gets easier and groups will shrink. My first 300 yard group was over 3", but now I got it down to consistently shoot around 1" (+/-) .3" difference for weather, wind, cold bore, etc.
The farther out you shoot that more challenging it becomes. Movement becomes more noticeable than compared at the 100 yard. If your using bags, you need to be sure you minimize contact with the rifle. Lots of tricks to learn.
Just practice and see how it works. If they don't tighten up afterwards, then you may need to look at ammo, shooter, rifle, and other factors.
Well I've been busy and have not been back on here until just recently, glad to see you went with the 243! it's a great round and can be accurate as all get-out. Your group is not bad could be better but it will come with practice and lots of trigger time but you'll get there! we all started at one time and most of us didn't one hole everytime After some time you'll find that you will probably want to do some things to your rifle that will help with your long range shooting and for some cheap fix have someone work your trigger, one of the best things you can do to a rifle is a good trigger, bedding helps and is another cheap thing you can do that helps, floating the barrel is another easy thing that can be done.
There are lots of things that can help you out but trigger time is the most important! get to where you are not thinging about the shot and things will start getting easier, I mean after you figure out your range and other good things and you know your right put the crosshairs on your target and things just happen you'll be getting close. Trigger time dude! you'll get there. Later,