Case capacity and SD

[absolutchris]

I've done some ladder tests and I've noticed that I tend to get lower SD's when I get closer to max loads.

Is this just a coincidence? To me it somewhat makes sense that it would be more consistent with less dead space but I don't know

The main reason for my question is that I wasn't planning on running high nodes because I just shoot for fun/hunting and I figured it would be easier on my rifles. But if it's consistently more accurate I would definitely change my load.

I have a load for my 308 that is Lapua brass, fed210m, 42.1 gr varget 0.055" off the lands 178 gr eldx at 2480 (16.5" barrel w/ suppressor) that is pretty accurate (0.5-0.75 MOA at 100), didn't know if it would get significantly better in the 44gr range in terms of accuracy

 

[Steel head]

I’ve noticed better SD and vertical when I’m barely starting to crunch powder on a few occasions.

I tend to develop two loads for my 260.
One mild load with excellent accuracy but no care about SD for close and casual shooting(1000 yards and under) and a hotter load with a definite emphasis on SD and vertical for my 1 mile load.

 

[____________]

This is why most lobby for an approach of pressure testing to max pressure (were you get pressure signs not where the rifle blows up) and backing down a full grain from max pressure then testing then test for your node.

Example, Max pressure found at 42.5, drop to 41.5 and begin testing by going up two tenths at a time (41.5, 41.7, 41.9, 42.2).

What does this do? It maximizes case fill and velocity.

Oh and by the way, while testing for max pressure you should use a chronograph. This has the added benefit of letting you see where the flat spots are in your velocity.

 

[absolutchris]

Ok thanks guys, will do that with my 6.5. My 308 will be mainly 100-200 yards. Thanks for the feedback