12-22-2020, 02:51 PM
I have no personal experience with the Vltor A5 buffer recoil system. I did a little reading and it sounds like they use an intermediate length buffer tube with rifle length buffer spring with the option of various weights for the buffer. Since the lighter weight bullets are having the functioning issue your rifle sounds under gassed.
If I were in your situation Id put my upper on a different lower with a carbine buffer tube, carbine buffer spring and carbine buffer. Another option would be to put your upper on a lower with rifle buffer tube, rifle spring with rifle buffer. If the upper functions 100% with either the carbine lower or rifle lower then you know your A5 buffer system needs the buffers tweaked (maybe lighter weight).
Without knowing the specific gas port size on the barrel and having no first hand experience with the A5 buffer system I cant offer any more advise.
Determining whether a rifle is over gassed or under gassed is difficult because the symptoms can appear to be the same. You might be able to tell if the bolt is traveling to fast by filming the action as your shooting. If the impulse is to light the BCG may not be traveling far enough to the rear to lock the bolt back. In your situation I think this is the cause since your rifle functions with ammo with heavier bullets and more recoil energy.
If I were in your situation Id put my upper on a different lower with a carbine buffer tube, carbine buffer spring and carbine buffer. Another option would be to put your upper on a lower with rifle buffer tube, rifle spring with rifle buffer. If the upper functions 100% with either the carbine lower or rifle lower then you know your A5 buffer system needs the buffers tweaked (maybe lighter weight).
Without knowing the specific gas port size on the barrel and having no first hand experience with the A5 buffer system I cant offer any more advise.
Determining whether a rifle is over gassed or under gassed is difficult because the symptoms can appear to be the same. You might be able to tell if the bolt is traveling to fast by filming the action as your shooting. If the impulse is to light the BCG may not be traveling far enough to the rear to lock the bolt back. In your situation I think this is the cause since your rifle functions with ammo with heavier bullets and more recoil energy.