Shot 'racing' ahead of wad in barrel?

[wwillson]

I've heard from a couple people that as the wad and shot travel down the shotgun barrel that some of the shot will 'race' ahead of the wad.

I'm struggling to understand how this could be?

The stop-action picture clearly shows the shot packed solidly into the wad as it leaves the barrel.

[Moe]

This depends on many factors. This size and shape of the wad along with the length of the case and the powder charge can all contribute to shot leaving the wad during it's dwell time in the barrel. Wad pressure can also be a factor. The way the case is crimped also can cause this. Using a wad designed for 1oz loads and dropping 1.125oz of shot will cause this also.

When reloading for my skeet shooting, I am positive that some shot make cotact with the barrel. I don't worry about it because I shoot lead shot only. 8.5 & 9's. My K-80's barrel is chrome lined which is much harder than lead. Even in my Briley sub-gauge tubes which have ti. chambers and aluminum bores this isn't a problem. I will not use reclaimed shot in these because the quality varies so much.

Now steel shot is another matter. I have never had to load steel and hope and prey I never have to.