The deal with it being a perimeter weapon is its just that a perimeter not a long range gun. LE perimeters range out to 100 yards at MOST, you are covering houses not front lines with the LE application.....havent heard or seen of one any longer. Thats why the 20" to 16" barrel doesnt come into play that much.....correct me if im wrong LEO's, this is from an old retired LEO friend so some info may be a bit shotty.

Forgot to add that thats what the 223 round is for close shots that result in no unnecessary damage or collatoral damage

Perimeter distances vary depending on your surroundings/situation/environment. Perimeters can be fluid & dynamic just like anything else in this business so nothing's set in stone. Your friend may have been trying to convey that many OISs take place within 100yds & more often than not they are within just a few feet depending on the suspect's choice of weaponry.

Quoted: ... thats what the 223 round is for close shots that result in no unnecessary damage or collatoral damage

The .223 was origionally designed for varmints.  The 5.7x28 was designed little/no collateral damage (no pass-through).

Quoted: Quoted: ... thats what the 223 round is for close shots that result in no unnecessary damage or collatoral damage The .223 was origionally designed for varmints.  The 5.7x28 was designed little/no collateral damage (no pass-through).

Wrong on both accounts.

From Wikipedia:

The .223 Remington was developed specifically for the Armalite AR-15, a version of which later became the U.S. military's M16 rifle.

The SS190, the de facto 5.7x28 mm standard cartridge for military and law enforcement, was originally designed for the modern battlefield where troops may be wearing body armor and conventional pistol or submachine gun rounds may be ineffective.

Bottom line, everything on that gun had a purpose, and none of it was "fail".

Once again I would like to point out


MET-T

Mission

equipment

time

terrian  
terrian dictates mission execution, equipment, and time to complete.

A pereimter weapon may be a sidearm or a barret .50.  It depends, are we trying to keep a suspect from leaving a car in an urban area or in a draw in a rural area.

I would recommend looking at the recce threads they should point the way.