Why did changing buffers change my POI?

[Klem]

i dont think unreliable group size methodology or reporting of group sizes makes it likely that someone would lie or be confused about brass being torn up

xoon,

Of course this would not be the case (non sequitur), but a reluctance to answer questions along with an extraordinary claim to precision polluted his request for help.

The specific reason you have offered belies a number of other more likely reasons. One reason might be his ability to shoot, or the number of shots were so low as to be statistically meaningless - random. If we had more information we could quickly discount a bunch of possibilities.

If you are looking for confirmatory bias for that one possibility you are not going to get it here. The consensus is that bullets have left the barrel before any change in buffer weight influences the gun. This discounts the heavier buffer influencing anything down range. As for chewing up the cases, that certainly does happen after the bullet has left the barrel, but it would help if we saw photos. What does 'chewing' and 'torn' mean?

[peole]

by changing buffer you changed timing of your rifle. That affected extraction, recoil, barrel harmonics and changed poi.

Try changing bullet weights and you will see poi change. Try changing powder charge and you will see poi change. Unless you have super thick barrel - any timing change will shift poi.

[Double Naught Spy]

Well, that post was contrary to what the experts have weighed in so far.

So tell us how changing the buffer changes the harmonics. Be explicit as everyone else seems to believe the bullet will have exited the barrel before the gas starts to unlock the bolt. As such, the bullet is gone before the buffer comes into play. Therefore, the buffer will not affect the harmonics of the barrel while the bullet is in the barrel.

[Klem]

by changing buffer you changed timing of your rifle. That affected extraction, recoil, barrel harmonics and changed poi.

Try changing bullet weights and you will see poi change. Try changing powder charge and you will see poi change. Unless you have super thick barrel - any timing change will shift poi.

Please do not do this. The reasoning behind this advice belies the fact that the bullet has already left the barrel - consistent with the majority advice on this and other forums.

peole, I see you joined the Forum in 2019, yet this is your first post? With that confidence you'd be at 1,000 posts by now.

[LRRPF52]

Again, let’s keep the discussion technical and not personal.

Let moderators worry about join dates and post counts.

Not sure where the disconnect is with regard to making things personal guys.

Knock it off.

[Klem]

Again, let’s keep the discussion technical and not personal.

Let moderators worry about join dates and post counts.

Not sure where the disconnect is with regard to making things personal guys.

Knock it off.

PM sent.

[xoon]

The consensus is that bullets have left the barrel before any change in buffer weight influences the gun.

well i agree it has left *the barrel* but OP said he was using a suppressor.
Suppressors keep the system under pressure until the bullet exits the end of it. The system (16in mid length gas) goes from ~6.5 inches post gas port to ~13.5 or ~15.5 if the suppressor is in the 9 inch configuration.
How could this affect accuracy or POI?
well i believe it is widely acknowledged that suppressors can affect group sizes (sometimes positively sometimes negatively)
i think this demonstrates that accuracy can be affected after the bullet has left the barrel
my conjecture is that whatever mechanism causes suppressors to affect accuracy in general may be causing this particular issue
if i had to flesh it out more with a bit more speculation, something to do with rapidly changing and/or inconsistent pressures behind or around the bullet due to the bolt opening before the bullet has left the suppressor