Suppressor acience, part 1
When you finally get your tax stamp approved and bring a new suppressor home, the natural instinct is to immediately thread it onto your rifle, tighten it down by hand, and head straight to the range. It seems like a foolproof mechanical connection. The barrel is threaded, the suppressor has matching threads, so they should just screw together perfectly straight. But a massive number of shooters destroy their expensive new silencers on the very first shot because they completely misunderstand how barrel threads are actually machined and how a suppressor aligns itself to the bore.
To understand the danger of a baffle strike, you have to look at how a rifle barrel is manufactured. The process starts with a solid bar of steel. The manufacturer deep-drills a hole directly through the center of that bar to create the bore, and then cuts the rifling into it. After the bore is established, the barrel goes onto a lathe to have the outside profile turned down and the muzzle threads cut.
In a perfect world, the outside threads are cut perfectly concentric, meaning they share the exact same mathematical centerline as the bore. But in reality, especially on mass-produced factory rifles, the drill bit can wander slightly inside the steel bar. The outside profile of the barrel might look perfectly straight, but the internal bore could actually be sitting slightly off-center. If a machinist cuts the muzzle threads based on the outside diameter of the barrel rather than indexing off the actual centerline of the bore, those threads will be slightly crooked relative to the path the bullet is traveling.
When you thread a muzzle device like a basic flash hider onto crooked threads, it doesn't really matter. The flash hider is incredibly short and has a massive exit hole, so the bullet just passes through safely. But a suppressor is a completely different mechanical lever. A rifle suppressor is usually six to eight inches long. Inside that tube is a tightly packed stack of metal cones called baffles, and the holes drilled through those baffles are only a few thousandths of an inch wider than the bullet itself.
Because the suppressor is so long, it acts as an angular multiplier. If your barrel threads are cut off-axis by just one single degree, the base of the suppressor shifts a tiny amount. But by the time you reach the end cap eight inches away, that one-degree angle translates to a massive physical shift. The bullet exits the bore perfectly straight, but the suppressor tube is pointing slightly downward. The copper jacket violently clips the edge of the first baffle, destabilizes, and rips through the entire stack, destroying the suppressor and turning the tube into shrapnel.
This is exactly why checking your thread concentricity is a mandatory step before you ever load a live round. You use a specialized, perfectly straight steel alignment rod. You drop the rod down the bore of the rifle so it protrudes through the mounted suppressor. You look closely at the gap between the steel rod and the hole in the end cap. That gap should be perfectly even all the way around. If the rod is touching one side of the end cap, your threads are out of spec. When I am setting up a new host gun, I pull my alignment rods, shims, and muzzle devices directly from https://www.brownells.com/gun-parts/muzzle-devices/ to ensure the geometry is absolutely perfect. Don't trust factory threads blindly. Check the alignment, verify the math, and protect your investment.