AAMP84
08-27-19, 12:38
Came across this post on Criterion's IG page about pinned gas blocks effect on barrel accuracy and harmonics. Curious if this has merit and if so, how much it actually effects accuracy in real world situations.
https://www.instagram.com/p/ByAlJmZgQKY/?igshid=lr3tr2a8q1dz
To pin or not to pin: Pinning the gas block negatively effects barrel harmonics and can result in a tight spot in the bore. When pinning the gas block, a hole is drilled through the gas block and the barrel... a pin is then driven through both. In order for the pin to remain in the barrel, barrel material must be displaced, frequently resulting in a tight spot in the bore which can be felt and measured with mechanical gauges. This increases fouling and bullet deformation resulting in accuracy degradation. Furthermore, barrels are like giant tuning forks that launch bullets… drilling a hole in them and driving a pin through it effects barrel harmonics making them less consistent and therefore less accurate. This practice has been used for years but it is antiquated and detrimental to performance. Recent contracts put out by the military specifically state that this practice should be avoided in an effort to improve accuracy (check out the fourth bullet point under “required Characteristics” in the link below). https://www.thefirearmblog.com/blog/2017/05/17/breaking-usmc-releases-rfi-new-infantry-rifles-uppers-optics-suppressors-targets/?utm_source=Newsletter&utm_medium=Email&utm_content=2017-05-20&utm_campaign=Weekly+Newsletter
https://www.instagram.com/p/ByAlJmZgQKY/?igshid=lr3tr2a8q1dz
To pin or not to pin: Pinning the gas block negatively effects barrel harmonics and can result in a tight spot in the bore. When pinning the gas block, a hole is drilled through the gas block and the barrel... a pin is then driven through both. In order for the pin to remain in the barrel, barrel material must be displaced, frequently resulting in a tight spot in the bore which can be felt and measured with mechanical gauges. This increases fouling and bullet deformation resulting in accuracy degradation. Furthermore, barrels are like giant tuning forks that launch bullets… drilling a hole in them and driving a pin through it effects barrel harmonics making them less consistent and therefore less accurate. This practice has been used for years but it is antiquated and detrimental to performance. Recent contracts put out by the military specifically state that this practice should be avoided in an effort to improve accuracy (check out the fourth bullet point under “required Characteristics” in the link below). https://www.thefirearmblog.com/blog/2017/05/17/breaking-usmc-releases-rfi-new-infantry-rifles-uppers-optics-suppressors-targets/?utm_source=Newsletter&utm_medium=Email&utm_content=2017-05-20&utm_campaign=Weekly+Newsletter