Thread: AR-15 Bump firing

Hi guys I am new to the forum, was up at the range on Sunday and my AR-15 starting double firing. The rifle is a Rock River Arms Predator with a Timney 4lb trigger the only mod is grease on the buffer spring to cut down on the noise. I have checked the back machine screw on the butt and it is not blocked. Do any of you have any semi intelligent solutions to this problem. Thanks

do you have another triger to fit to try? does the timminy still look shiny and clean? after it doubles is there a light strick on the next round?

Make sure there is no oil or grease on the trigger unit.
If there is, remove the trigger and clean with Brake Clean or something like it.
Read the Timney instructions as I think they mention about the no oil thing.

For starters this is a PUBLIC forum as anyone can see, not the best move but your just wanting help so I understand as your circumstances can be rather awkward.

Give a gunsmith a bell( NOT Hardy rifle engineering, he doesn't know fuck all about AR's).

Give NZRAC a bell and that will definitely help.

What's wrong with asking for gunsmithing help on a public forum?

It's a malfunction not some silly attempt to go full auto.

Cant hurt to take the bolt group apart and make sure the firing pin is sliding smoothly. I cant say I thought that much of the Timney AR15 trigger myself. While the small light hammer reduces your trigger pull they don't seem super robust.

Does it fire one single shot when you pull the trigger and keep it held back and then another single shot when you release the trigger.
If so its a "fire on release/reset" type situation and means the disconnector timing is out or worn disconnector at least this is the case with std type ar triggers

Thanks for the replies even the mystifying ones. I have checked everything suggested and all seems ok I don't have the original trigger so I can't try that. To answer the last question I fired about 10 shots and it fired two shost twice both when the trigger was pulled not released.

Why try fixing it....

BTW welcome to the forum @Dermastor

It sounds like your trigger. Standard ones turn up from time to time and cheapish.

Either something isn't right with the sear/disconnector angles or its trigger technique or both. I recently saw a somewhat fucked after market trigger that would bumpfire without really trying.

Does the Timney AR trigger have a couple of very small grub screws that tighten down on the trigger location pins that go through the lower? The one in my 10/22 does, and if the screws come loose, it will fire a round as you squeeze the trigger, and then another as you release the trigger. Tighten the grub screws and the problems goes away [on the 10/22]

I'll give $100 for it as is? If that helps?

Originally Posted by systolic

What's wrong with asking for gunsmithing help on a public forum?

Read the arms act in relation to semi autos and the number of shots fired per pull of the trigger.

Can't spell it out much clearer than that

I have seen the same thing happen with the same trigger. Make sure it's clean (flush out with solvent) because carbon build up in the sears and lighten the trigger pull. Suppressed ars get dirty real quick. Make sure you are holding the gun tight.

Bump firing isn't full auto, is two shots with two trigger pulls, the second being caused by recoil.