I have an adjustable gas block. It's the bleed-off type made by a reputable manufacturer. I adjusted it to the ammo I shoot. Good so far.

I had a new trigger installed. I have this trigger on another rifle and just love it. It reduces the pull weight from 6 lbs. to 2.5 lbs. But now with this particular rifle approximately one in twenty shots is a double shot. Some people refer to it as the 'bump stock effect'. But in my case the shots happen in such rapid succession the range boss didn't notice. Then too, the range was extremely busy that day.

What's the best course of action to fix the problem. Should I risk taking it to the range again and tinker with the gas block adjustment, or do I take it to a gunsmith immediately? I don't want to run afoul of the ATF.

Thank you.

"Doubling" can be bad, something is amiss in the trigger that can lead to a "runaway", rifle empties the magazine. When the rifle doubles, the second shot goes high right somewhere, not where you are aiming.....

I had a rifle double on me recently, a used DPMS. the front trigger pin had walked out. The rifle started doubling, then fired about 3-4 rounds in succession. Cured that with a Rise Anti Walk Trigger Pin kit, rifle is good to go now.

Whatever you do, fix the rifle before it gets worse. If you can't figure it out, give it to a gunsmith......

Just a suggestion...Straight out-of-the-box triggers work very well, even if they feel a bit heavy. Consider shooting a gun enough to get used to the trigger. You won't have to deal with unreliable functioning and a variety of other problems that can occur with a gun that's been tampered with. A light trigger won't replace shooter skill. Perhaps the only people that will truly benefit from a light trigger are the true experts.

I can`t say exactly why your double occurred but when I put a CMC trigger in my Sport it doubled once. May have shot it from the hip and got a belly bump. Since then, I`ve only shot it snug off the shoulder. Never happened again.
Good luck,
Jim

You didn't mention if this new trigger is new parts for the trigger group or one of those modules you drop in. Oh, the gas block has nothing to do with it.

If new parts, there might be a fitting issue or one or more springs weren't installed correctly. While the parts are supposed to be interchangeable, that doesn't mean every hammer works with every trigger. Run, don't walk, that firearm back to whoever did the work.

If module, have it sent back to the manufacturer.

Double check to make sure the disconnector spring is installed correctly. If it is not, or if it's not installed, that can cause doubling.

If everything looks to be installed correctly, something is wrong with the trigger group. If it is an aftermarket trigger kit, look to see if it has a warranty. If it does, see if the warranty is still good. If it's still good, contact the manufacturer for a warranty claim.


If your rifle is a range queen, there is nothing wrong with that trigger weight. If it isn't, I would strongly suggest you reconsider the pull weight you have installed. I wouldn't go any lower than 4 pounds for a rifle you are going to carry in the field.

I somehow missed the trigger weight. 2.5 lb is unsafe for a self loading rifle. Bolt action varmint/target gun, fine. Auto loader NO! The spec for the AR is 5-8.5 lbs. Some competitions limit trigger weight at not less than 3.5 lbs, 4 is better.

Thanks everyone for the advice thus far.

In the interest of full disclosure it's a drop-in trigger module, the Hiperfire Hipertouch Competition trigger. I have the same trigger in my MP15 Sport, adjusted to 2.5 lbs. and it works flawlessly! The doubling occurs with my DRD Tactical Aptus chambered in .300 BLK while shooting a 150 gr. bullet. I've not tried other ammo.

The trigger module comes with two sets of springs: 2.5 lbs. and 3.5 lbs. I think I'll have my gunsmith install the 3.5 lb. If it doesn't stop the doubling then I'll go back to the OEM trigger. BTW, Hiperfire's warranty covers exchange due to defect but not a cash refund.

FYI, DRD Tactical doesn't use the traditional AR buffer spring & weight. Rather, they rely on their patented BCG to manage recoil along with an adjustable gas block. I believe the 2.5 lb. trigger pull is just too light for this configuration.

I've emailed Hiperfire for advice but they've yet to reply. Please understand I'm new to all of this and I'm finding my way.

Thanks and happy holidays!!

Thanks everyone for the advice thus far.

In the interest of full disclosure it's a drop-in trigger module, the Hiperfire Hipertouch Competition trigger. I have the same trigger in my MP15 Sport, adjusted to 2.5 lbs. and it works flawlessly! The doubling occurs with my DRD Tactical Aptus chambered in .300 BLK while shooting a 150 gr. bullet. I've not tried other ammo.

The trigger module comes with two sets of springs: 2.5 lbs. and 3.5 lbs. I think I'll have my gunsmith install the 3.5 lb. If it doesn't stop the doubling then I'll go back to the OEM trigger. BTW, Hiperfire's warranty covers exchange due to defect but not a cash refund.

FYI, DRD Tactical doesn't use the traditional AR buffer spring & weight. Rather, they rely on their patented BCG to manage recoil along with an adjustable gas block. I believe the 2.5 lb. trigger pull is just too light for this configuration.

I've emailed Hiperfire for advice but they've yet to reply. Please understand I'm new to all of this and I'm finding my way.

Thanks and happy holidays!!

There's a lot of people who try to make a buck by "improving" a system with demonstrated reliability. The patent office will patent something that's different. That's no guarantee that it's practical or that it will work. Every once in awhile someone does an article on totally impractical/useless patents. There's an old saying about not fixing what ain't broke that comes to mind.

I believe I'd be inclined to stash the "patented" carrier and install the bolt in a standard carrier with buffer & spring.