How to stop bump fire AR9?

[Mlunyou]

I was at a uspsa match over the weekend and I have a palmetto state lower kit for AR9 and a bear creek upper 16in. While shooting later in the day I stated to get a bump fire, what do I do to get rid of it?

[Beef15]

If it is actually bump firing hold it tight against your shoulder and hold the pistol grip tight. 

[GregJ]

Had a PCC guy on my squad sat have a bump fire while I was ROing.    He was running a HyperFire, and said afterward if he doesnt hold it tight enough, the light trigger springs will sometimes result in a bump fire.  He will be putting in little heavier springs. 

[gdboytyler]

You should be like Max L. and learn to bumpfire your AR9 on demand!.  0.1 sec splits sounds like a winner.

[Chuck Anderson]

Suck it up buttercup.  I mean that seriously.  Suck it up into your shoulder.  The looser it is, the more likely to bump fire.  You can also adjust your buffer weight/spring/recoil system.  The bump fire happens because the gun moves back enough in recoil your trigger finger comes off past the reset point, then the bolt comes back forward.  When it hits home, the gun moves back forward and the trigger hits the finger.  Reduce that movement and the potential is reduced.  

[Patrick Scott]

18 hours ago, Chuck Anderson said:

Suck it up buttercup.  I mean that seriously.  Suck it up into your shoulder.  The looser it is, the more likely to bump fire.  You can also adjust your buffer weight/spring/recoil system.  The bump fire happens because the gun moves back enough in recoil your trigger finger comes off past the reset point, then the bolt comes back forward.  When it hits home, the gun moves back forward and the trigger hits the finger.  Reduce that movement and the potential is reduced.  

This, all of it. 

[Flatland Shooter]

Decrease the PF of you ammo, increase the buffer weight, increase the buffer spring weight, or any combination of the three will reduce the chance of it bump firing.

 

I agree that pulling it harder into your shoulder should also help but I prefer to make the other changes.  If you decide to use a laser on hard leans, you may want to shoot without the buttstock on the shoulder.

 

You might get a few dirty looks from your RO when it bump fires but as long as it is otherwise safe and can be fired in semi-auto mode, it cannot be penalized.  (See Rule 10.5.18 for more details.)