I have noticed that while working up loads for a 223 and two 22-250's that in general, the hotter I make the load, the more accurate it is.

Does everyone notice this or am I just imagining things?

I have loaded with several different powders and bullets. In most cases, right at the documented maximum is a load that works well in these three rifles.

Is this just a coincidence?

When the case is filled to a level that provides for good loading density with a suitable powder the ballistics can often be more consistent. If the case is full and the powder is in the same position every time it can also enhance accuracy. I've often found best accuracy at just below maximum loads by a grain or so.

Some cartridges, with large casings, often do not perform well at all unless run at max or near max pressures using a powder that fills the case. My .270 Wthby comes to mind, the best loads are all pretty much full steam.

But there must be more to it than that because there are people on this board that download the WSM's to lower levels and report superb accuracy and consistent ballistics.

This post should get some interesting replies.

I'm inclined to say luck of the draw, although John Barsness has written about this in Rifle/Handloader magazines and says that it's pretty common. He credits tighter tolerances during manufacturing (both bolt lugs bearing evenly, etc.).

Another thought would be that the quicker the bullet travels the less wind will effect it.

I load for over two dozen rifle rounds, and a dozen pistol rounds and have noticed that will almost all of the loading I do, I either equal or achieve my most accurate loads at or near maximum. Sometimes I will have very accurate loads at or near the start load, however, loads near or at the maximum usually equal or exceed the accuracy found in lower powered loads. IMO it is because of the reasons KciH already mentioned. Anything that increases round to round consistency, in my experience, increases accuracy as a general rule.

Maybe, just maybe, it could also depend on the rifling pitch of your firearms. If the pitch is not very fast (designed for light bullets) and you are using bullets at the heavy end of the scale, these bullets are being stabilized better at the higher speeds attained by your stiffest loads.
Then, again, loads that fill the case completely often give better consistency in ignition and that makes for smaller variations between shots hence better groupability.
P.

Thats one of the finer pts of owning one.

With my .308 and my .222 the lower i go the more accuracy I get. But with my 7mm mag the higher i go the more accurate. I think it just depends on the gun.

I have the same thing with my .308 (HB Winchester Model 70)

The hotter loads seem to open the groups up at 200 yards while the mid to light loads group small.

I wonder if its the bullet design? Boat tail = lighter load, PB = max?