Does case fill affect accuracy?

[lazyeiger]

I was just wondering if case fill has any affect on accuracy? I see most reloaders want to get close to 100% charge. Does a lower charge say 80% make for a less accurate load?

Jon

 

[300 RUM]

Most of what I shoot is .223 and .308, so I will answer for these two at least in my rifles. In the .223 and .308 I look for 97% capacity, that is filled to the bottom of the bullet of course. The reason for this is that you will get a more consistent velocity i.e. lower (SD)

Example: With a 88%-93% load capacity I get about 12-13 SD, with a 93-95%-97% load capacity I get a 5 SD. A much less change in elevation then if you were getting 15+ SD.

Combine this with a proper seating depth and there you go.

 

[fredhorace77]

yes,maybe, probably, no, you never know till you try, sometimes,depends,in theory,and often physically...hope this helps, lol

 

[BigDMT]

yes,maybe, probably, no, you never know till you try, sometimes,depends,in theory,and often physically...hope this helps, lol

Hahahaha! Perfect answer! It's the truth too

You never know what your rifle likes til you try it. Just try as many recipes as you can. I've had great luck with high and low case fill. That's why I like the answer in the quote so well

 

[300 RUM]

Most loads I have ever put together have been all in the 90%-93% capacity level. If you look at your loading books your never have less then 85% from min to max. Get to light of a load and you can have detonation instead of a smooth burn. Even with that said there is a big difference between a case filled 85% to full capacity.

 

[LHSmith]

Yes, definitely, case fill affects accuracy. This is the reason many BR shooters use long drop tubes....to cram more powder in..........but once in a while a competitor who is shooting large early in the match tries the lower node ( dropping charge way down) and ends up winning the match. It's what the gun likes on that particular day.

 

[amlevin]

I believe the true answer will depend a lot on the powder. I've found that some of the powders I've used give far better "stat's" when the case is full rather than partially empty. I don't think one can generalize.