doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Jug Choke "hot center"

The recent thread on jug choking reminded me of a question lingering in my mind from a recent Julia's auction catalog entry. Does jug choking produce a "hot center" in a pattern and is this desirable?. The entry in question is from the description of King Alphonso's hammer pigeon gun:

"Bore diameter: left -.730, right � .731. Bore restrictions: left � .031 with .001 recess (full), right � .033 with .001 recess (full); (This is standard Purdey boring for pigeon guns. Recess giving superb tight patterns with a hot center). (Factory records indicate �both fullest choke�.) "

I think that you will find that 'hot centers' are the norm when using quality shot and the harder the shot and the better its sphericity the more that holds true, regardless of choke/constriction. It has been an observed phenomena since the 1880's in trials run at that time when few guns were choke bored.

All chokes produce patterns with hot centers. I've seen many hundreds of patterns in my life, and the only gun I ever saw that shot a pattern that didn't have a hot center shot donut patterns every shot, a B2000. That said, some are hotter than others.

By the way, the choke in that B2000 was very slightly honed and it went to throwing normal patterns ................. with a hot center.

SRH

Note that patterns are near normally distributed --- from muzzle to the ground. The concept of hot centers is a misunderstanding of the distribution. The more the choke effect the greater distance for given pattern diameter. That is to say at distance X aIC pattern is the same as a full at distance Y.

DDA

When I, and others, say hot core we mean that the density of the shot distribution increases from the edge of the pattern toward the center. You can break a clay bird, showing you the belly, every time with a .005" choke at 30 yards if you have the bird in the center of the pattern, because of increased density. If it is on the edge of that pattern the probability of a break is the lowest, because of lack of density. As the bird is nearer the center of the pattern the probability of a break increases, to a maximum percentage at dead center. This is because of density .............more at the center, lessening as you move out towards the edge. Thus, the colloquialism "hot center".
I do not agree this is a misunderstanding ..............it is an observation of hundreds of patterns and tens of thousands of breaks. Center of pattern = smoke, fringe of pattern = chip.

I would like to think we mean the same thing, Don, but I'm saying it in layman's words and you in scientific terminology. "Normal distribution" for a typical shotgun pattern is for it to possess a distribution that has higher density as you move from the edge towards the center.

SRH

That is very helpful. If anyone has comments on the combination of full choke and .001 recess choke specified by the King I would love to hear them, especially as to how the combo is more successful at producing a hot center.

Stan, I do think you and I have a common understanding of patterns and how they work. I use "normal" in the statistical meaning of the specific "bell curve" distribution. My issue with "hot core" is that shooters seem to me to try to divide patterns into "hot core" and "fringe" and lose the idea of a relatively smooth change in pellets per square inch from center to edge. Say 5 pellets per square inch in the center, 2 pellets/sq inch half way out to the edge, and less than 1 pellet at the edge.
DDA

For an interesting discussion of chokes, especially Purdey chokes, check the gunsmithing by Bill Nittler video. I had it in the past but have since lost it. Quite interesting.

I seriously doubt that it has any effect per se. Choke effect is a relatively smooth transition by thousandth of an inch from cyl (0.000 constriction) to full (about 0.040). We generally use about 0.005" as constriction increments as steps.

DDA

We're on the same page, Don. Just different terminology.

SRH