Thedrifter wrote:But what if there is a best combination?
If there were, given the extent to which research, planning, testing and development have been a part of the sport, not only would it have been found by now, it would be universal. The fact that this hasn't happened would strongly suggest that it's not that simple.
So far all I can tell you is that there will be a 1-2 mm gain from an Aftermarket barrel over a Factory barrel, not very unexpected but still. I can also prove that over 4 different barrels and 45 Lots of ammunition if your rifle shoots 18mm it is shooting average. (40 shot groups)
You've really not got enough there to even tentatively suggest that. My factory-selected Anschutz has, in consecutive tests, consistently grouped around 13-13.5mm for ten shots at a time. Having been tested with Lapua, there's no consolidated forty shot group, but I don't think the authority of such a measure has been sufficiently demonstrated either, since, as I said earlier, shooters will put on a click or two here and there throughout a match often enough that the overall measurement of a forty shot group without any sight changes seems of questionable relevance, whereas a given ten shots being tight and nicely formed seems far more useful. Now, if it were in the form of an electronic printout giving the value and direction of forty consecutive shots, along with the group sizes for each ten, as well as the overall forty, that would be useful, but quite possibly no moreso than the individual ten shot groups. I'm not sure it would be possible to make an objective determination of that value.
And the information collected will answer these questions, but to do so you must know:
what is “good ammo for your rifle?” To answer that question good ammo for your rifle will be below 18mm (group of 40) or perhaps it is 17mm. The average will only change as the results grow. And right now it is 18mm
How many batches must you test to find a competitive lot?
What is competitive? 13-14 is rare to my understanding but perhaps 15-16 is more common?
And the same information will be collected for Lapua and 10 shot groups as well. But I still value 40 that are placed on the same X/Y axis over a good 10 shots.
Competitive is going to depend on what level you plan on shooting at. If you're shooting local matches only, it's probably not terribly hard to find something that won't hold you back. If, on the other hand, you're shooting in ISSF world cups and similar matches, particularly on the new system of decimal scoring, then competitive is a different story, and probably going to require a gun that shoots around 12mm for ten shots at a time, consistently. Good ammo "for your rifle" is a bit of a red herring, since you're trying to figure out what's the best you can get out of your rifle, which means you're disregarding the question of whether the rifle itself is good enough to be competitive, the central issue. To answer that, you'd need to know what it takes to be competitive at the level of competition in question.