Barrels and Chambers, Corrosion and Erosion!

By Ammoland

By John Farnam

Ft Collins, CO –-(Ammoland.com)- A friend in our State Prison System passed-on information to me about Central Armory’s experience with department AR barrels.

He has been tracking service life and found that original Colt chrome-lined barrels show less throat erosion and are staying in the “good range” far longer than are untreated barrels. New barrels that were installed, which were not chrome-lined, were discovered to be “shot-out,” (ie: “ insufficiently accurate”) and thus in need of replacement, at as few as 4k rounds. By contrast, chrome-lined barrels are nearly all still serviceable after 10k rounds.

Of course, the foregoing is greatly influenced by kinds of ammunition used and how hot rifles get during certain exercises.

Here are sage comments from several noted colleagues and gunsmiths:

Ned Christiansen:

“When we ream a .223 chamber to correct 5.56 dimensions, the question is often asked, and rightfully so:

‘Will that process remove chrome plating in the reamed area?’ The answer is yes. I leave it to the individual to choose between keeping the chrome and suffering the tight-chamber issue, or having a barrel that is not restricted …Read the Rest

Source:: AmmoLand