1 pull, 2 rounds, thoughts?

[Rancid Coolaid]

Gun:
mil spec AR15 lower
Wilson TTU trigger group
ARPerformance 6.8 upper and BCG
Nosler 100-gr Accubond

Firing suppressed from the bench.

Loaded 1 round into the magazine and fired (new scope on the rifle, one round after bore sighting to zero.)

I made the dope change, loaded 3 rounds, and fired: "boom-boom" in rapid succession. The third round was in the chamber.

This was my first double-fire on a single pull - from a gun not designed to do so.

I have previously put probably 100 rounds through this upper, never with this lower, and never with this problem.

Trigger? It is a 3-pound trigger. Did recoil impulse trip it?

The same lower has seen hundreds of rounds from a 300BLK upper and a 5.56 upper (SBR), never done this before.

Thoughts?



With a dope change, I loaded 3 rounds into the mag,

 

[jwsnydes]

Re: 1 pull, 2 rounds, thoughts?

The AFT wants to talk to you.

 

[ponchair]

Re: 1 pull, 2 rounds, thoughts?

Any possibility you are bucking the trigger?

Example, you fire one round, and your finger comes off, when the recoil impulse of the first round is done, your finger hits the trigger again causing a second round to fire...?

Maybe try keeping your finger pulled to the rear, holding the trigger till the recoil impulse is done. (Of course this may not be your problem, just a thought.)

 

[Emilio]

Re: 1 pull, 2 rounds, thoughts?

My brother was having a lot of doubles with his rifle. We found out that is was poor follow through. Once he started holding the trigger back through the recoil and going to trigger re-set, the doubles went away.

 

[Awesymoto]

Re: 1 pull, 2 rounds, thoughts?

either you bump fired, have a select fire weapon and are messing with us, or have a defective fire control group.

Do a functions check. On unloaded weapon, Rack the bolt and slingshot. Squeeze trigger, let hammer fall, with trigger held to rear rack the bolt *charge the weapon* and then slowly release the trigger. You should hear a click (the trigger reseting). Squeeze the trigger again, and you should hear the hammer fall. Repeat 2-3 times.

If the weapon has no defect. Try holding the rifle firmly into your shoulder, with a high firm pistol grip. Squeeze and follow through.

 

[Lowlight]

Re: 1 pull, 2 rounds, thoughts?

You're being bitch slapped by a 6.8 which is even worse than being bitch slapped by a 308.

 

[Greg Langelius *]

Re: 1 pull, 2 rounds, thoughts?

Have seen this with Garand/M14/M1A type triggers, caused by a lack of trigger follow-through. Not familiar with this issue from an AR, though. I would suggest concentrating on follow-through and seeing if the problem repeats. If it does, there's a hardware failure occurring.

Greg

 

[Captain Kirk]

Re: 1 pull, 2 rounds, thoughts?

Some people pay a lot of money for that feature........

I'm thinking bump fire, also drop the bolt on a live round (at the range or in the field) then eject it without firing, inspect the primer to see if there is a substantial primer dent from the firing pin, its ok to have a slight dimple but you may be getting full ignition when the bolt drops (?) thats bad

Kirk R

 

[Strangedays]

Re: 1 pull, 2 rounds, thoughts?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">You're being bitch slapped by a 6.8 which is even worse than being bitch slapped by a 308. </div></div>
Thats some funny shit right there

 

[Rancid Coolaid]

Re: 1 pull, 2 rounds, thoughts?

Many years in the Corps, it weren't a bump fire. Rifle function checks just fine.

I appreciate that the assumption has to be the shooter is an idiot and is over-gunned or undertrained; let us, for the sake of argument, assume neither is the issue in this instance.

 

[ddavis]

Re: 1 pull, 2 rounds, thoughts?

The AR I use for comps does it occasionally. It has a terrible Bushmaster 2 stage "National Match" trigger. The trigger is a single stage about half the time and you never really know if it will be a two stage or single stage until you pull it. Also it is pretty light. I tried making it a very long single stage and it would double just about every shot. I immediately changed it back to its crappy 2 stage setting and it's the same as it always was. I would wager that it's a combination of the light trigger and your follow through. That's what my problem is anyways.
-Dan

 

[kujo929]

Re: 1 pull, 2 rounds, thoughts?

That problem is usually the hammer nose engagement with the trigger but can also be the disconnector in standard trigger set ups. I've only seen it will mil-spec triggers and don't know anything about the Wilson trigger you have. If it is not you then I would pull the trigger group and test with another.

 

[SJshooter]

Re: 1 pull, 2 rounds, thoughts?

This is gonna sound stupid, but have you tried it unsupressed.

So see if you can get it to happen again suppressed then take the can off and try again.

 

[Texasshooter30]

Re: 1 pull, 2 rounds, thoughts?

I had this once, Disconnector.

 

[daxromana]

Re: 1 pull, 2 rounds, thoughts?

Part if the trigger assembly. Happened to me on. RRA NM trigger that was worn out. Had John Holiger at White Oak tune it and no probs since.

 

[Badshot308]

Re: 1 pull, 2 rounds, thoughts?

Since you're a veteran shooter and know about proper follow through and bump firing, I would pull that Wilson trigger group out and give them a call.

 

[Mustafa]

Re: 1 pull, 2 rounds, thoughts?

I was shooting an AR10 once and had it fire once when I pulled the trigger, then, again when I released it a full few seconds later! Replaced the trigger and never had a problem again...

 

[phxfa]

Re: 1 pull, 2 rounds, thoughts?

I have a high round count (10k) Wilson TTU that does the same thing. just send it back

 

[Strangedays]

Re: 1 pull, 2 rounds, thoughts?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Texasshooter30</div><div class="ubbcode-body">I had this once, Disconnector. </div></div>
In most cases this is what causes that, or the pins are walking out. If the disconnector spring is faulty it can do this also. Or if there is no spring at all

 

[Sespe]

Re: 1 pull, 2 rounds, thoughts?

Worn trigger group caused the exact same problem for me. Replaced it with a Geissele and never had the problem again.

 

[Drifter™]

Re: 1 pull, 2 rounds, thoughts?

Doubling with a live round left in the chamber sounds like accidental bump firing to me. Not uncommon in a recoiling semi-auto with light trigger and short over-travel, and sometimes difficult to detect for the shooter. Hold the rifle differently and concentrate on trigger pull follow through, or change trigger.

 

[HANDYMAN]

Re: 1 pull, 2 rounds, thoughts?

Were you using reloaded ammo or factory? I once had a AR double from a primer being seated out to far. It slam fired but the action did luckily close all the way. Surprisingly it also put the second round right next to the first one.

Just another thing to ponder however it sounds like others have had similar problems with that particular trigger group so I would look there first.

 

[*greenhorn*]

Re: 1 pull, 2 rounds, thoughts?

+1 on bump, I know this could sound stupid, but had same thing happen to me, all the guys at rang said all kinds of stuff we tor it apart ar range, ended up being i had a loos grip and bump fired it on the 2nd. just throughing it out their

 

[WilsonCombatRep]

Re: 1 pull, 2 rounds, thoughts?

Rancid Coolaid,
First, I want you to know we stand behind our products 100%, and we will be more than happy to take a look at your TTU, and either ensure that it is functioning correctly, or make it right. We have shipped thousands of these units, with a VERY low rate of failure. While I am certainly not saying that it is the case with your unit, the majority of the issues we are contacted about involve shooters with the rifle in a slow fire, precision setting( like on a bench rest), and they are carefully working the trigger shooting groups. When the gun fires, there is more movement than expected, the rifle "bounces off the shoulder" back into the trigger finger, and you get another round fired, as others have described above.

The standard weight TTU, whether it is single or 2 stage, features a light, crisp trigger pull. That is probably what drew you to the TTU in the first place. We do have the heavier Mil/LEO version, if that is what is needed.

Again, we will be happy to take a look at your TTU, as we want you to be a happy user/customer. If you would like to send it in, please contact us at 870-545-3618 x104. That is Tressa's extension, and she will get you the shipping info you need, and keep a personal eye out for your TTU. This offer is out there for anyone with issues with a TTU, no matter the age of the TTU, round count, who purchased it, etc.

Thanks for being a customer!

 

[coldboremiracle]

Re: 1 pull, 2 rounds, thoughts?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rancid Coolaid</div><div class="ubbcode-body">Gun:

Firing suppressed from the bench.

</div></div>


I've had the same thing happen, when I first put the can on, it would happen all the time, quite irritating. I was told here that I need a tougher buffer spring or heavier recoil buffer. Excess pressure from muzzle embellishments causing it to slam shut hard enough to fire a second shot.

 

[Beef82]

Re: 1 pull, 2 rounds, thoughts?

Slam fires, the firing pin carrying enough inertia forward to fire the next round aren't that terribly uncommon either. I have no experience with suppressors but from what I've read if you can't regulate the gas they make cycling considerably more violent which increases the chances of a slam fire. I get very light indents on my primers all the time, its never doubled, but I could see it happening with a slightly out of spec soft primer cup. I understand there's a "mil-spec" for primers and cup hardness is one of the things it addresses due to this problem.

 

[LoneWolfUSMC]

Re: 1 pull, 2 rounds, thoughts?

If you are sure it's not operator error, send it back to Wilson for a checkup.

If it's new, it shouldn't have the worn or incorrect engagement angles that will cause this in a mil-spec trigger group. It's a captured assembly, so worn/walking pins is unlikely.

A 5.56mm gas gun is about as heavy a caliber as I would run a light single stage trigger on.

 

[SuckitTrebek]

Re: 1 pull, 2 rounds, thoughts?

Had the same problem with a Timney trigger. Changed it to a Giessele and presto, perfect.

 

[Shatuponthee]

Re: 1 pull, 2 rounds, thoughts?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: YourMotherTrebek</div><div class="ubbcode-body">Had the same problem with a Timney trigger. Changed it to a Giessele and presto, perfect.</div></div>

Giessele is the way to go.

 

[AshMcg23]

Re: 1 pull, 2 rounds, thoughts?

What type of bolt carrier group are you running? If it's a lighter group not made for a suppressed rifle that could be your problem (as opposed to the heaver group). Otherwise it sounds like maybe its the trigger itself.

 

[r1rn04]

Re: 1 pull, 2 rounds, thoughts?

follow through with the trigger, I had the same problem after i installed a JARD 3#, thought it was defective Bought a timney drop in, same deal on the bench. local bench shooter showed me it was my technique, not the product. sad thing is after 2 units I could have dropped in a jewel, Live and learn.

 

[ZLBubba]

Re: 1 pull, 2 rounds, thoughts?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: strangedays</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Texasshooter30</div><div class="ubbcode-body">I had this once, Disconnector. </div></div>
In most cases this is what causes that, or the pins are walking out. If the disconnector spring is faulty it can do this also. Or if there is no spring at all

</div></div>

This is my bet as well. I had a JP trigger that did this. Replaced it with a RRA NM 2-stage and haven't had the issue since. Let us know how it turns out.

 

[Drifter™]

Re: 1 pull, 2 rounds, thoughts?

On the link below, click on the "Summer 2011" issue, then check pages 7 and 8 for an article on this very subject:

http://www.arshunt.com/arshunt