Again, I did not say the shotshells had setback. I used the example to make a point. "Projectile setback can spike pressures. Beware."
I wanted to make the point It could be a safety issue, not get drawn into what the meaning of is 'is.'
Not being snarky so don't make something out of the...
Suggest you take your issue to a reloading forum where people understand how reduced case volume affects pressure.
Be sure to not listen and be pedantic there as well. They like that.
Barrels can be darn hard to find. Getting a defective one? Ugh.
It took me a couple years to find an 18.5" non-BB for the 590. Got some nice ghost ring XS sights on it now!
FWIW the breacher barrel on my 590 had a screw in sight.
A normal height sight is not very helpful with the large diameter of the BB. A Big Dot front sight works very well with the BB and can be epoxied on where you want it.
Normally you use a supplied small post screwed into the barrel to...
Springs don't seem to suffer from being compressed for long periods of time. The last round in the magazine requires quite a bit more pressure to insert than the rest therefore I keep the magazine loaded one shy of it's capacity to spare the cartridges.