View Full Version : Barrel Inspection Tips

11-17-2007, 9:31 PM
I'm not really knowledgable when it comes to inspecting ar-15/m4/m16 barrels. In other words, if I were to buy a used barrel. What are the important things should I be looking for? Does dent mark on the outside means something? How can I tell the condition of the bore? I'm pretty much a noob in this so please help me out. Thanks!

Utha Schleigle
11-17-2007, 11:16 PM
These are my opinions if I were shopping for a Barrel.

If anyone feels I left something out let me know.

I do not own a M16 - AR15 stlye rifle, but I think you want to start with intended use of rifle. Short handy barrell ( hunting - quick to aim - carry easily or in side motorized armor) Long barrel ( more FPS and F-LBS ) Target Barrell ( accurancy - long range hunting - ?) Barrel that will accept accessories you want.

Look at out side of barrel anf look at general fininsh and condition. PAY CLOSE attention to treads on chamber and muzzel of barrel to see if they have been man-handled. Inspect crown (the end that is beveled near the muzzel) - Is it clean and even or ovaled and gouged - this will effect accuratecy.

Used barrell must be inspected for use and over use. Ask yourself why was the barrell taken off that gun. They wanted a different barrel or barrel is used up or had a problem. Was it taken off well or by a BUBA's plumbing.
Look inside the barrel with light. Look up barrel SLOWY. First look at crown - Then move into bore and look at rifleling and bore ( are their any pitts and rust, can you see the rifleling is destinct and sharp or is it faint and worn. Next look at chamber (where bullet goes in) are threads OK - where the bullets feeds into chamber gouged scratched worn - is inside chamber pitted scratched - can you see uneveness in the light(like looking at a dent in a car door) Any probs might mean a trip to the gun smith.

On any surplus and hot cartridge gun you must check the (Throut or bullet chamber or projectile chamber) section of the barrel. This is where bullet first starts out of the cartridge and cuts into the lands and rifleling. The pressure and heat can vaporize a minute ammount of metal. This is compounded with close target head space and full auto. Look at throut and see if it is a different color constancey than rest of the barrel, does the throut look metal is missing or black sand blasted. Ask how many rounds have been through the tube. I feel that 223 is a hot cartridge gun.

Bullet test place bullet face-ing crown so tip of bullet is going inside barrel at crown. Take any muzzel ends off. If bullet stops before casing should be good rifling (1 to 3 mm above case of shell). If bullet goes to casing or beyond (rifleling may be gone and barrel is junk. IS M16 barrels counter sunk???????:confused:

Ammo Brother's in Cerritos sell many M16 type barrells and uppers and ask advice. Go to gun show and look at a new barrel and the go to the used surplus junk for parts box and look at that barrel.

Inside the Cerritos Communty College Library there is a book AMERICAN RIFLE DESIGN AND PROFORMANCE. It is one of the best bestest books on barrels in general and overall gun function. If you can get to read it.

Utha Schleigle
11-17-2007, 11:22 PM
All-most forgot I reccomend a new barrel, unless it was taken off almost new because the they wanted a different type/use barrel. You don't want a shat out/f-d up/gunsmithing nightmare/BOZO barrel!!!

Utha Schleigle
12-03-2007, 7:06 AM
Great picts and article on barrel inspection.