Velocity change: virgin vs once fired?

[SDHNTR]

Assuming all else constant, anyone noted a consistent change in velocity between once fired and virgin brass? Is there a general concensus? Faster? Slower? Negligible?

My once fired and resized (Redding FL type S) brass (ADG) seems to have swollen .003-4” vs new. Seems that would increase volume and decrease velocity, right? In theory? Can any conclusions be drawn?

 

[amassi]

I've had some ob magnums drop velocity and need a .5 or 1 grain increase to hit the same velocity as Virginia brass. Don't notice it with standard cartridges

Sent from my SM-G991U using Tapatalk

 

[SDHNTR]

I've had some ob magnums drop velocity and need a .5 or 1 grain increase to hit the same velocity as Virginia brass. Don't notice it with standard cartridges

Sent from my SM-G991U using Tapatalk

Yeah that's what I figured. This is a .300 wsm. The range is not close to me and requires a full day commitment to visit so I need to kinda think ahead. I'm gonna try some at same charge as virgin, then load more at .2 gr and .5 gr over and see where I am.

 

[TraskI]

If it was a full day commitment for me I would be mounting my press to a portable tabe so I could do load development while there. Just thinking?

Sent from my SM-G996U using Tapatalk

 

[SDHNTR]

If it was a full day commitment for me I would be mounting my press to a portable tabe so I could do load development while there. Just thinking?

Sent from my SM-G996U using Tapatalk

Yes, the thought has crossed my mind!

 

[N2TRKYS]

Never made a difference for me in any of the dozen rifles I load. I don’t give it a second thought anymore.

 

[MidGAHunter]

More times than not it is negligible in my experience. However, when I have noticed a change it was an increase in velocity with fire-formed brass and same powder charge (albeit slight).

 

[thebigcheese109]

In theory, there would probably be a difference. Not sure how much though and if it would really matter for hunting purposes. Could maybe matter for long range competetive shooting though? I don't think I have any comparisons between virgin and once-fired brass using the same load, but, just some food for thought, consider how much variation you have from shot to shot with the exact same load (i.e. using brass that's in the same condition). This could easily vary across a range of ~30 fps or more. If your variance from virgin to once-fired falls within this range, then you could probably say the difference is negligible. Could be worth testing if though if you're concerned about a high level of accuracy at longer distances.

 

[philcox]

This is what I have seen as well.

More times than not it is negligible in my experience. However, when I have noticed a change it was an increase in velocity with fire-formed brass and same powder charge (albeit slight).

 

[docdoc]

Inline stand for a press makes it really easy to reload at the range. Measuring powder is not so easy.