Gas System?

[Jammer Six]

When do I need to learn about the gas system?

S&W MP. 16" barrel.

So let's say I start loading for it. (I've already started, I just haven't done any serious testing yet.)

I take the recipe straight out of the manual, start at the bottom. Now, I expect some of the lower loads to fail to cycle the action. Just like a 1911.

Here's my question: if I find a load somewhere in the middle that runs the gun, what, if anything, do I need to know about my gas system? Is my gas system adjustable? Why (and when) would I worry about the gas system on the gun?

Can't I just find the lowest load that runs the gun and be happy? What is there to be gained by adjusting the gas system? When would I do so, and why?

Thanks, gang!

[AKDoug]

In stock form your rifle does not have an adjustable gas system. Find a load that provides reasonable accuracy and functions reliably. Nothing else more you really need to do.

[Iraqgunz]

Most of the M&P rifles I have seen were overgassed. The most recent was a 16" carbine gas with a .068 gas port. You'll be fine with lots of different ammo.

[AndyLate]

I was concerned about cycling when I started reloading for the AR. That has not been an issue and I found it an easy cartridge to load. Tons of load data, wide variety of available bullets, and a decent range of powders that it works with.

I have learned to hate crimped primers with a passion though.

Andy