Berto wrote:Hi there, here is a picture of my OCW Test that i am hoping to get some help with analysisng. As i dont want to make a mistake and begin reloading the wrong charge. I believe my node is at 37.4 grains and that i should fiddle with seating depth or perhaps a different primer to try bring the groups together. Thoughts?
brett1868 wrote:(I'm not psychic, I was the mod that approved your post on FB this morning
bladeracer wrote:Berto wrote:Hi there, here is a picture of my OCW Test that i am hoping to get some help with analysisng. As i dont want to make a mistake and begin reloading the wrong charge. I believe my node is at 37.4 grains and that i should fiddle with seating depth or perhaps a different primer to try bring the groups together. Thoughts?
I'd be working on the 36.8gn load a bit more. I don't see any need to load hot so if you can get that sort accuracy at 36.8gn I'd go with that.
I'm not a fan of basing these decisions on just a three-shot group with each charge though.
I'd try at least ten of each to nail down an area to focus on.
brett1868 wrote:Maybe as a first post you'd like to introduce yourself but I understand the desire for answers For others reading the thread, the rifle is a .243,CCI LR Primer, Norma brass, AR2208 and Hornady 75gr V-Max projectiles.
Rather then jump in at 37.4gr maybe try seating a fraction closer to the lands on the 36.8 & 38gr loads, by all means load up some 37.4gr loads to try as well. I personally like Federal Match primers or CCI BR2 as I find the standard CCI primers inconsistent.
What is the intended target cause a 75gr projectile might be a bit light for bigger game. Also what's the make, model, Twist and barrel length of the rifle?
(I'm not psychic, I was the mod that approved your post on FB this morning
Apollo wrote:To me that is not an OCW Test... It's just a group test as such.
There is a lot of information and results available to show what an OCW Test is about and shows, if that is a test you believe carries some weight to belief and result. Sorry, but I don't believe it shows much as far as Target Shooting goes. OCW, one shot over many different powder loads and see where the "Node" is... then what, how do you improve...by shooting groups of shots in that zone and work from there.
What I see in the initial post is just a powder load test using 3 shots, nothing to do with OCW. Fine, as long as the barrel was fouled before the first group. Then go on and look at the shape of the groups, as long as the shooter is experienced and can exclude shooter error for bad placement.
The best group is the 38gr being the closest to a circular group with little verticle / horizontal. It could be tightened up some if that is at 100 metres. A good .243W at 100 metres using what should be near ideal for a 1:10 Twist Barrel which most are, using the ideal 70/80 grain bullets really should be one small clover leaf hole. That is using high quality grade bullets, like Berger. Not some cheap rubbish.
If I was instructing, working up a load and keeping in mind that a .243W is a Barrel Burner, I would go with the 38gr Load and just tweak a few things, like seating depth.
Target shooting I do, with a .243W but at 300 Metres and I use Berger 90gr BT Bullets with AR2209 and it that has won a couple of times. I'd use the same for general hunting, BUT shorter range the 70/80 Grain Bullets (Berger) shine with AR2208.
Just my view and experience over the past 40 odd years.
BTW... I found the best results I have had in a Tikka T3 or Sako 85 was using CCI BR2 Primers. ie Tightened my groups. Best of luck.
Berto wrote:
Also the photo is side ways, its should be looked at with the grain ammounts on top.
bigfellascott wrote:If the rifle is only for hunting, just go with the 38gn load and go shoot fur! No need to stuff around worrying about crap that won't effect your hunting (why waste time and money for no real benefit) if it's for target shooting then proceed!
Wm.Traynor wrote:Berto,
Is the horizontal dispersion a result of wind variations?
Berto wrote:I have since reshot the grp at 37.6 and there is far less horizontal spread
sungazer wrote:The theory is that charge weight is only responsible for vertical spread. The ability to group is all based on seating depth. A lot of people will only shoot one shot at each charge normally a bit closer together based on others experience or velocities wanted. then a flat spot selected and that charge weight then shot at different seating depths to look for grouping. Lots of theories out there with some guns you cant afford to shoot lots in load development unless you purchase 6 barrels and have them all chambered at the same time and then also grade barrels.