doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Patterning, high pressure vs low pressure

I understand that the thrust of the powder igniting and the gases pushing, will damage some of the pellets in a load. The thought has crossed my mind numerous times, "could lower pressure loads give better patterns than those higher pressured ones. So take one load at 1200 fps with 8000 psi and another at the same velocity with 11,000 psi. I was wondering if any of you have ever experimented with comparing such loads.

Lenard

I haven't experimented with this variable but would think hard shot, which we already know is the secret to better patterns, is the limiting factor on whether the pressure makes much difference to the pattern.

I am convinced that I know choke constriction changes the rate of spread of patterns. I am convinced that I know that X-post wads make spreader loads that undo choke constriction. Beyond that, I'm not sure I know what affects patterns and what not. My work to date shows that patterns must be treated statistically to avoid conclusions based on insufficiuent data. Right now, I don't have the time to do the kind of work necessary to analyze definitive numbers of patterns. Dr. Andrew Jones has given us a very powerful pattern analysis tool, but, even so, it takes more time than I have right now.

Shot hardness, plating, buffer, forcing cone profile, choke constriction profile, powder burn rate, peak pressure, wad cushioning and sealing, various spreader materials, ----!???! So many questions. So much shooting and analysis needed for real answers.

Rocketman...if we needed all that how did Greener do it ?

Or did he ?

"Rocketman...if we needed all that how did Greener do it ?

Or did he.?"

Or Oberfell & Thompson, for that matter?

Last time I read any comments by Dr. Jones relative to his "analysis tool", it caused me to seriously doubt the practical application of his theory. It was a question of how often a single pellet strike will break a clay target. Dr. Jones, if I recall correctly, gave a percentage figure high enough to cause me to believe that he hasn't looked at nearly enough unbroken clays with a single hole through them--or even two--to know as much about the practical application of his theoretical construct as he should.

Can't remember where I read it, but the theory is that shot "bounces" around in the shot string so that complicates a situation PROBABLY existing wherein only so many pellets in the barrel have the opportunity to deform for whatever reason.

Are you saying that you would expect the same number of pellets to be in contact with something which causes deformation but the degree of deformation would be less?

We already know that rate of deformation has been reduced by all of the above factors right?

During the muzzleloading period the normal charge would be equal volume of shot and powder measured by volume not weight. However in order to increase the density of the pattern which would decrease the spread they would decrease the volume of the powder charge in relation to the volume of the shot charge. To reverse and increase the spread or decrease the density of the pattern they would increase the volume of the powder charge in relation to the volume of the shot charge. I have tried this with results that are somewhat in line with this procedure, in other words, pattern percentages did change but nothing that I would describe as noticeable.
All the best

The $2.75-$3/10 pack of Rottweil 'Express' non-buffered SG load patterns better then most "premium" US-made loads. The key is Europeans understand "equilibrium" of the load and Americans just use MAX dr.eq.
Why do Federal 'Gold Medal' target loads pattern beautifully? That's because of perfect "equilbrium" between load weight, velocity and quality of components used.

I think Greener tried to draw too many conclusions from too little data. O&T failed, IMO, to use available statistical methods to look at their data. They would have, IMO, been better served by statistically accurate data over a much narrower range of work. Counting pellet holes is really grunt work - this I do know. I also know that relying on one or two patterns to characterize a set of conditions is worthless except at the grossest level of detail. Five patterns averaged is risky - you really need ten. Also, you need true statistical analysis and that means the only practical approach is computer aided.

LB - it is a real shame that the easily provable part of Dr. Jones's program got mixed up with application. One step at a time - first, what do patterns really look like? Then, we can talk about what it takes to do which job - corridors of effectiveness. Initially, I agreed with you as I have counted stacks of recovered clays on numerous occasions. However, I'm now thinking that what we know is rate of failure to break the clay and not how often a single pellet actually does the job. Are you aware of any tests where a target is struck by a single pellet? Seems like that should have been done, but I sure don't have any data.