Hey Hot Core, use your PRE method and tell us how many peak PSI some of your loads are generating. You claim to have a calibrated, repeatable system, and such a system will easily give you the answer. Why do you keep us waiting?

Hot Core = no facts, no figures, no physics, just an opinion based on an opinion he read somewhere. Invited to take part in an experiment to determine the repeatability of PRE and CHE, he ran like a scalded cat. The results are in, he doesn't like them, so he has nothing but sneers for the people who rolled up their sleeves and did the work needed to gain direct knowledge.

Denton,

We can't ask HC for the pressure in psi, if we can't find a use for psi relative to the real limit, primers falling out.



He may be able to develop a load with higher velocities without the primers falling out, using his micrometer, than someone else can with a psi measuring system.



We just have not figured that out yet, to my knowledge.



And if you take SAAMI as a given, he will beat you every time, except maybe with the .270 or 454.





With the strong bolt action and Mauser case head, the primer pocket growing is the real limit for me.





That is not the real limit for beginning handloaders or factory loads. For them, SAAMI is a given.



Here is my anecdote:



==============================

For my VZ24 I have a quantity of Win 257 Roberts +P brass prepped as carefully as I can, fire formed, and the primer pocket is so loose, it will not hold a CCI or Win primer



Or if I fire form with 10 gr. Unique and Cream of Wheat, and then load too hot with bullets:



257RAI 75 gr. Vmax .257 bullets that I had moly coated.



1) 49.4 gr. of IMR4895 gives 3942 fps and the extractor cut grows .0035"

The primer is loose and the brass is no good any more



2) 48.3 gr. gives 3757 fps and the extractor groove grows .0005"



3) 47.2 gr. gives 3736 fps and no extractor groove growth



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The real problem is that we are discussing BOTH deterministic and heuristic approaches to safe pressure estimation. The labs take a deterministic approach and not only measure pressure as precisely as possible, but try to fit results to mathematical models as a second check. Just good engineering.

Most reloaders use a heuristic approach....more like "rules of thumb" to infer safe, marginal, max or dangerous pressures from observations that do not involve the direct measurement of pressure, but other convenient signs.

Now, the shocker is that the deterministic approaches are only slightly better than the heuristic ones, as long as the heuristic ones are coupled with measurement of velocity. If you spend some time with your rifle with different bullet styles and weights, along with some variation in seating depth, velocities and variations thereof will tell you a LOT about how your rifle transplates charge weight, burn rate and primers into muzzle energy. Fixed combinations of components will either be slower or faster than published data and you either will or won't encounter any heuristic pressure warnings on you way to charge weights that yeild the Max velocity in a manual.

Denton,

Thanks for the feedback. I may have to pick one of these systems up. I lost my DA card so I am looking at ~ $150 anyway. You still need the laptop with your system, correct?

Goodluck on blowin' away the MK thread!

ASS_CLOWN