300 blk and gas system optimization

[blasternank]

I'm looking at the 300 blk and will probably go with a 16" but my go smaller and go suppressed. If I go with a 16" is it better to go with a carbine or midlength gas system? Also, if I decide to use a suppressor on a 16" will that make a difference in the gas system I choose?

Thanks.

[blasternank]

Also, what is the preferred twist rate?

[rsilvers]

Midlength gas will not work at all.

Your choices are carbine or pistol. Either one works fine, as long as the maker picked the correct has port size.

[Spooky130]

Also, what is the preferred twist rate?

1/8... Think of it as 1/7 for 5.56.

[MistWolf]

Why will the mid-length gas not work with the 300? Does the pressure drop off too much?

[rsilvers]

Yes. Carbine is the longest gas that works.

[crossgun]

If I run a pistol gas system can I shoot both super and sub sonic?

I have couple of blanks. Who would you recomend to do the rest of the work on the 300?

[rsilvers]

Yes, provided you pick the right gas port size.

I am not sure who to recommend if you don't have drawings for the barrel you want.

[Todd.K]

Why will the mid-length gas not work with the 300? Does the pressure drop off too much?

Larger bore for the gas to expand into, with a smaller charge of faster burning powder.

[rsilvers]

I tried rifle length gas on a 20 inch barrel, and it did not work, even supersonic with a suppressor and a carbine buffer and with the gas port at 0.125.

So stick to carbine gas for barrels over 16 inches, carbine or pistol gas for barrels that are 16 inches, and pistol gas only for barrels in the 7.5 to 14.5 range.