Home Forums Hunting & Shooting Ask The Gunwriters The 95% Solution - Rocky Raab

I would like to congratulate Rocky on an outstanding article: "The 95 Percent Solution (VARMINT HUNTER magazine Jul-Sept 2009 pg 40).

In this article Rocky addressed something that reloaders have all dealt with - changing components in a pet load - that I have never seen addressed in print with such well thought out methodology and has come up with, IMO, an outstanding and fairly simple plan of using a "Benchmark" or "95% Solution Load" and using that data when changing components.

Once again - thanks for something so helpful, simple and brilliant - at least for those of us who have a chronograph!

Can you elaborate for those of us who haven't read it?

Here is the link: http://www.reloadingroom.com/index_files/95S.htm


good article.

Rocky,

Just got VH today, and read your article. It was excellent, and very helpful.

Good on 'ya.

Steve

Ya know, I've written a summary of that in several of these forums many times - with nary a peep of appreciation. I'm NOT complaining, just slightly amused that it takes "magazine printing" to get a point across.

I'm honored by your praise, truly.

Rocky you look different in the rocking chair than in real life.Which is whom? powdr

Ahm just me'm, Ah guess.

what's with the link? When I click on it the page comes up and then disappears within a few seconds. I am unable to keep the article up long enough to read it.

Any suggestions?

Jim

I'm kind of busy at work so I only quickly skimmed the linked article. If I'm off base just let me know, but I do have a concern.

It seems like the solution is using one point to fix a line, linearity of velocity vs. charge weight being a pretty reasonable assumption within the normal operating range. Mathematically it takes two points to determine a line. I'd be more comfortable if it were the 95%-90% Solution.

The line is actually the 100%-95% solution

The problem there is you can't safely try out the 100% point on the new batch of components, otherwise you don't need the test in the first place. You need two points both in the safety zone, then see if the resulting line extrapolates close enough to the same 100% point.

Rocky, While I applaud you on this very sensible solution, I suspect - based on what I read in the "electronisphere"- that many folks enjoy finding out where things get "sticky". That may explain why little appreciation has been shown when you made these same suggestions electronically. (I'll admit that I've missed it however.) "95S" truly does make a lot of sense.

I see what you're saying, but with the extreme sensitivity of powders and primers it is difficult to predict results that are statistically significant, even with several known points on a correlation line. The 95% rule at least gives the reloader a rough guideline to swap components without spending a fortune.

I'm not saying it isn't a useful idea, in fact I think it's pretty good.

Visiting this link from my machine at work gives a Trend Micro security web error and the page dissapears.

Rocky's 95S procedure very nicely formalizes what lazy folks like me might try to do by "the seat of our pants".

Having found even one data point near the desired solution without taking any risks is sweet. It wouldn't bother me in the least to draw a line through that new data point to find an estimate of my desired new load. I'd probably use a slope determined by a couple of points in the loading manual.

KenO

I'll stipulate that your experience vastly outweighs mine, but I think I'd still feel more comfortable using two points. I can't get rid of the idea that for the given cartridge, components and component change to be tested that there can exist two lines passing through the same single (charge,velocity) point yet having noticeably different fps per grain (and by inference psi per grain) slopes.

If I'm being unreasonable just say so, I've never done this stuff for a living.

Been traveling, so haven't replied. First, those who can't view my page are using Internet Explorer. I created the page using Microsoft software, so NATURALLY the one browser that won't read it is IE, right? (You can either scroll right to view it or get Firefox, Chrome or some decent browser.

Now to the 95S idea. I'm not math talented, but if you insist on two points for your line, they would be your pet load's performance and the 95S performance. Remember, we use your load and 95% of that load's powder charge to establish the "benchmark" load.

Oh, the reason I picked 95% is that I have never observed a single-component swap that changed performance by more than that. Powder lots are supposed to be within 3% to be sold as the same canister powder, for example. Even swapping standard and magnum primers has not shown me as much as a 5% swing.

It's just that I'm very suspicious of slopes determined by two closely spaced experimental points. I'll concede that there are many lines of differing slopes passing through that one point. I wouldn't expect to travel far along the chosen slope, and I'd expect the loading book value of slope to be reasonably near the middle of the cluster of lines, so I'd feel comfortable using the book slope. Just an opinion.

KenO

As I said,Ken, I wouldn't know a math slope from an icy driveway. I came up with that little method to help me keep all my fingers, and so far it has done that just fine. I wrote it so that others might be able to save their own fingers - while burning up as few of their increasingly precious components as possible.