I believe that it's actually a polymer coating, not lacquer.
I've actually drawn my own conclusion that it's nothing more than teflon. No scientific backing to that claim, though. We need someone with one of those fancy apparatus to give us the chemical composition of some scrapings, someday.
To the OP:
White35 said:
My question for people with experience with loading this cartridge, is if I stripped the coating from the cases, and loaded 55gr projos, to fire at slower than normal speeds, say somewhere around 1,000 fps, would these function the pistol just fine, and not cause any danger pressures?
You are courting disaster with this.
It's not about "loading at slower than normal speeds" so much as it is getting that heavy projectile launched with the given combustion space.
The 5.7 pistol is already notoriously tricky to load for and get decent performance because you're dealing with a bottlenecked cartridge with a tiny chamber, and a short barrel. You have to use a powder hot enough to get the bullet moving quickly as it travels those wee few inches, but NOT hot enough to exceed chamber pressure, rupture the (very thin) casing, and cause a catastrophic failure of the (relatively flimsy) frame.
When you strip the "lacquer" you are defeating one of the design elements that *helps* make the round safe. 5.7 works a little different than other firearms in that the chamber is tapered and the casing is DESIGNED to slip and move rearward while it's still under very high pressure; the PS90 and 5.7 are straight blowback. If you defeat this coating the ass end of the cartridge moves but the middle and front of the casing is still seized tightly against the chamber. The casing rips in two and you blow up a gun, and get a trip to the ER to learn what "debraiding a wound" means, and discover how atrociously painful that procedure is. If you are especially unlucky, your wife gets to open the pickle jars for you the rest of your life.
Now, that above scenario is assuming you are using a normal 40 grain bullet. When you use a 55 grain bullet you REALLY up the chances of a case rupturing and ruining your day. When you go from 40 to 55 grain you are now working at a mass 137.5% of the original design.
Remember that old "equal and opposite reaction" fact?
The pressure to get the bullet moving is pushing forwards AND backwards. It now takes FAR more energy - to propel a mass 137% of the original you have to have expend FAR more than 137% energy. the reaction curve of the smokeless powder ignition is rapidly accelerated, as the bullet is getting started slower and the bulk of the powder ignites while the bullet is in the first few mm of travel - smokeless burns faster when it is contained, remember - and the forces involved spike well above what the design was planned for.
The "option" is to use a slower burning powder to offset this ramp up in forces, but there simply isn't enough barrel length to take advantage of it.
Bottom line; do not go through with your idea. It is unsafe.
You may read about people saying "oh it's fine, blahblahblah" - but seriously, the physics behind what is happening is not copacetic. They want to risk their hands and expensive gun, fine. Their hands and gun to risk.
But no way in hell would I ever advise someone that this is a good idea and I'm not going to do that today!
The only stupid question is one that is never asked. Thank you for taking the time to post and learn - I hope what I've written helps you on your decision.
Go buy some 40 gr V-max, use an ultrasonic cleaner with simple green diluted 10:1 for 10 minutes (no more!) to clean your cases, and call it a day man. They'll shoot just fine as long as you stick to published data.