Originally Posted by
Coleslaw
Many people are enamored with the 14.5" barrel and probably not for the right reasons. The 14.5" barrel length came about after lessons learned by the XM177 issues from the Viet Nam era. Colt had problems with short barrels - 10" and 11.5" - running consistently. Changes in gas port hole size, moderators, etc. were used in an effort to enable proper function. Other ‘remedies’ i.e. H type buffers, springs, modified carriers, etc., were down the road some years away.
After some testing, the conclusion was the 14.5" barrel offered the best combination of reliability while maintaining some level of efficacy from the M193 round in a 'shorty". So allot of guys get hung up on that length I suppose because it is the length the military has traditionally used for some time now, and/or because of the ‘cool’ factor. It is not like some magic - the 14.5” length.