Surefire Suppressors on SBR's

[MikeCLeonard]

Just looking at Surefire's website regarding their 556 suppressor. It says it is for 11.5" barrels and longer. Is this critical? Do you guys think it would operate reliably on a 10.5" bbl?

Any help would be great!

-Mike

[Mongo]

If anything it will increase the reliability of a shorty. What they are concerned with is durability and also mounting clearances.

[bigbore]

Just looking at Surefire's website regarding their 556 suppressor. It says it is for 11.5" barrels and longer. Is this critical? Do you guys think it would operate reliably on a 10.5" bbl?

Any help would be great!

-Mike

The 556M4 will only fit on a 11.5" barrel if you a have a short, low pro gas block. It wont fit on a 10.5" barrel at all.

The 556K will fit on ANY barrel length.

[MX5]

With barrels less than 11.5" in a 5.56 weapon, boat tail bullets can yaw upon exiting the barrel and could strike the suppressor baffles. This tends to occur when using the wrong weight bullet in relation to the barrel rifling twist. A call to Gemtech came back with the response that although their owners manual indicates 11.5" minimum bbl, you could use the 10.5" bbl as long as you're careful about matching the bullet weight to the rifling twist. It can be safely done, but improper use could void any warranty and severely damage the internal architecture of the can. It's all about bullet stabilization and product liability. ie: if using a 10.5" bbl with a 1/9 twist, stick to 55gr. when the can is attached. If using 1/7 twist, use a heavier bullet accordingly. Anything less than 10.5" in this caliber with can attached is at your peril.