Originally Posted by Wlhofer
So what is the except able group at 800 with out trying to hard it shoots under 1/2 all day at 100 yards. It's got a costum barrel pillar and glass beded fine tuned by a gunsmith. Thought .4 would be ok for high powered gun or do I need to go back to drawing board
To answer the "how far" question...It depends... not on caliber and cartridge, but shooter, rifle, load and bullet performance. Assuming I have accuracy, I would use the minimum opening velocity of the bullet as a general guide, and that depends on a lot things.
As for the "accuracy issue" in quote above... I personally don't like using 100 yd groups to evaluate a load. It's OK for initial load development, but after I have an idea of what looks promising, I shoot 200 and 300 yd groups. These still won't necessarily tell you how good your load is for LR. If you have high velocity spread in your load. your groups may be very good close in (showing the shooter and rifle capability) but will open up far out, usually seen in vertical stringing.
I also personally do not trust chronys to give me anything other than very general info to work with as a base. I confirm and adjust with actual drops.
Pick a good day with good conditions and shoot some longer groups to evaluate your load. If it opens up I would try different powders and/or primers.
You might search for ladder testing threads, i think there might be a sticky somewhere.