[quote
Peak pressure is just that - pressure readings taken at the highest pressure developed by a given load. It stands to reason that if the peak pressures are reduced, they are lower at all times or places as the bullet passes up the bore. However to prove that would require pressure readings taken every inch or perhaps closer points maybe further apart would suffice, along the barrel and compared directly with identical readings with whose bullet, what load? It is possible a 'solid' bullet produces higher muzzle pressure or mid barrel pressure than does a 'standard' bullet. Again, pressure readings must to taken to prove or disprove this. As well, strain gauges would need to be placed to show whether or not the 'solid' solids produce more or less barrel distortion as the bullet travels up the bore. We are talking about an entire repetoire of tests needed to prove just one aspect of the claims.

They have been testing the pressures in the chamber together with the pressures in front of the chamber and midway of the barrel for at least 140 years. Then it was the old lead crusher, now they are a bit more adcvanced. But there are for sure beeing test where the pressure curve from ignition to mussle are beeing made. It not that hard as only one "hole" in the chamber is all you need, in this you plug the pressure gouge and you dont stop watching it untill the bullet is out of the barrel. Ofcourse it helps if you slow it down with a computer.

And the peakpressure drops as soon as the bullet starts moving or at least a couple of inches infront of the case, but it could substain longer even if its lover than peak.

The thing i wanted to state is that if it needs to be undersized and half of its metal removed, it is probably prone to produce overpressure. And that it works for a heavy bolt barrel doesent mean that it would if you thin the barrel down. Its not hard to understand why a soft solder joint would fail if you concider that the barrel is incresing in diameter as the bullet passes. And a thinner one surely will flex more than a thicker.

Btw, all the break open rifles i have checked, the free travel of the bullet is huge, and this is as i understand a way of reducing the problem with pressure.