Matching pellets to the barrel - theoretical approach

[Val]

Suppose that we are faced with the task of finding *the best* pellet for a particular barrel, as opposed to "good enough". (suppose, for the sake of argument, that we have an obscessed benchrester that wants to make 0.5 mm c-t-c groups at 25m).
The performance of any particular pellet depends on a number of factors, such as the size, weight, consistency of the size and weight, velocity, etc. If we consider 3 brands, and 5 different sizes (forget the batches), we have 15 types of pellets to test, and what makes it difficult is that each type will have its own optimal velocity.
I'm wondering whether the following selection procedure will produce the optimal pellet choice.
1. Weigh the pellets, and select the brand which has the least standard deviation of weights.
2. Push pellets of that brand of different sizes through the barrel, and select the one which provides most consistent resistance (*SUPPOSEDLY*, a pellet too small might "fall through" at some places, whereas a pellet too large might get resistive at some portions of the barrel). Selecting the size with most consistent travel will guarantee that the projectile will leave the muzzle consistently with respect to the barrel vibration pattern.
3. Find the optimal velocity for that particular brand/size/batch as to match the pellet to the barrel harmonics. (I heard that when gunsmith and coach of one european shooter were doing pellet matching for her rifle they had hard time deciding between 175m/s and 176m/s).
Do you think that the above procedure will yield the (near)optimal choice, or should one stick with the good old trial and error method?
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[LesJ]

O.K. we found that combination that gave as "perfect" group. We shoot on the different day, different temperature, pressure and humidity. Those thing will have some affect.
How much?
Would the result apply only to the condition present at the time of conducting the test?
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[LesJ]

Also pressure behind the pellet will expand the skirt against the barrel walls. Softer metal will expand more as harder will expand less.
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[Steve Maly]

I think that the trial and error method will give the best results. After all, I'm not sure that the initial assumptions you have mentioned are relevant at all. If they are not (ie. barrel vibration, friction between the barrel and the pellet, etc.) only the trial and error method will find the correct pellets. For example, the old Gamo pellets used to shoot out of my FWB-65 with far greater accuracy than the more precise RWS pellets. I think it had something to do with the lesser mass, and the recoil of the mechanism of the gun but I'm not certain. The lighter pellets were out of the barrel faster than the more precise but heavier ones. In any case, my score was up from 10 to 15 points in a match. The less precise Gamo pellets I was using would not have entered your test, but they gave better results. The resistance at slow speeds (pushing the pellet through the barrel) may be quite different than at 500 fps. With enough pressure from behind, the pellet skirt will be expanded to fit the barrel; "falling through" is not going to happen.
I would get rid of all initial expectations, and test every kind of pellet you can find. You may be surprised by the results.
Anyway, good luck in your testing!

smaly-at-kes.ns.ca.45074.45070

[Mike Stimson]

The way I test pellets is to see if the first five from a fully charges gun, the middle five and the last five shoot a group I am satisified with.
stimson590-at-texasairnet.com.45169.45070