X2.

X3.

Look at the most recent post the Mississippi turkeys hunters page on Facebook. Check the comments out. Crap of of pics from apex loads causing damage, failure to fires, blowing guns up, etc.

I sighted in with a fella last year and he was shooting the apex 7/9 load. His Mylar Was all chewed up and petals missing from almost every wad from each shell he shot. I shoot the big 20xl and there was a astonishing difference in comparison of the post shot shell components.

I'll be honest....there is nothing within me that can understand why folks want to shoot such a payload at a turkey, much less through a 20 gauge. This post is just another (and the most compelling) reason to not fool with such.

I will say though that those pressures are not to the point of being imminently dangerous. I too would swap from that load instead of continuing to shoot it though (cumulative effects that could lead to a fatigue failure over time with continued shots).

I think your signature block could be used to answer your curiosity.

BINGO

The problem with hull walls splitting, brass rims getting chinked, primers getting pushed out, load reports, breach handles getting knocked out - are not necessarily, and generally are not, a PSI issue. They are an issue of a gas auto trying to eject the shell too soon. The ejector is grabbing the hull and trying to eject it while the shell is still firing. It's basically has to do with the gas ports and engineering them for steel shells, not TSS.

Here's an explanation from BPI's "The Curmudgeon" :

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"HOT LOADS & AUTOMATIC ACTIONS
A load may appear to be "hot" or have high a pressure when fired through an automatic-action shotgun. A shotshell may become a damaged hull. This may NOT be due to high pressure.
The engineering of the automatic action requires a gas port. The gas port bleeds back some of the hot gases (pressures) produced by the burning powder. These gases help operate the bolt action in the receiver – to eject and reload the next shell. The diameter (size of the opening in the gas port) is determined at the factory. The gas port diameter is set I size for a particular type of shotshell.

Years ago, narrow ports were set for lead loads. Today the gas port is set for steel loads. The gas port is larger to allow greater flow.

Recoil (setback) is also a function of shotgun automatic actions. Setback assists the ejection of the fired shell in coordination with the gas port moving a piston or twisting a cam to unlock the bolt and ejecting the fired shell.

When an automatic shotgun (which is manufactured for steel loads) is used for lead loads, HeviShot™ loads or any other shot heavier than steel pellets… the combination of increased recoil (setback) from the heavier load and the rush of pressure down the gas port – overwhelms the automatic action. The hull may become damaged owning to the premature opening of the action. (Lingering internal barrel pressures or because of the aggressive thumping of the action.) Damage to the action is a possibility.

Your Solution:
Carefully read the handbook provided by the shotgun’s manufacturer. They often warn the owner to only use steel loads in automatic shotguns. (Because the shotgun was designed for steel loads.) Problems increase when the shotgun has 10-gauge or 12-gauge 3-1/2" chamber.

If the shooter wishes to fire differing shot types - anything heavier than steel shot – the solution is to purchase a pump action. With the exception of steel shot being used, any heavy field automatic-action shotgun may fail to operate "normally." A pump action is a better choice for shotshell change-ups. Pumps operate with any type of shot or weight of load.

The Reloading Curmudgeon"
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I prefer guys to shoot pumps or break action guns for these heavy TSS shells. Keep in mind that before I started developing them, the now standard 1-5/8 oz 20 ga TSS payload was unheard of, and radical. Now, it's "standard". So, 1-3/4, 1-7/8, 2 oz and 2-1/8 oz payloads are more radical for a 20 ga gun. Until they start building autos that keep up with TSS shell development, we need to keep in mind that guns may or may not be able to handle them - regardless of chamber pressures. Guns are generally proofed to much higher PSI than the SAAMI standards, so powder lot variations are not really the biggest concern - it's whether a particular gun can handle the radical payloads we are shooting with some of these loads.... or even the now "standard" 1-5/8 oz payloads....

Interesting Hal. Thanks for sharing.