American Eagle rounds not going off in buddy's AR

neK

New member
My buddy had the trigger lightened in his Ar. Its a Diamond Back DB 15. Its not hitting the primers hard enough to shoot the American Eagle rounds and some problems with other loads as well. Tigger is set at 3.5 lbs. What should he do? He doesn't really want a heavy trigger.
 
First of all make sure it is oiled up real well. If the pins are dry it will drag enough to light strike.
I also use a lighter titanium firing pin so the hammer strike doesn't have to move a heavier pin.
It all adds up when using lighter springs.
 
Had exactly the same problem after a trigger job on a Bushmaster Varminter. The American Eagle ammo uses mil spec primers and says so in very small print on the box. The same ammo functions fine in my Colt CSR. I may have to try that titanium firing pin trick though.
 


For Mil Spec primer to fire you have to have a 4 1/2 pound hammer fall.
That means you have to light a hammer spring.
Trigger pull has nothing to do with this.
 
Originally Posted By: willy1947

For Mil Spec primer to fire you have to have a 4 1/2 pound hammer fall.
That means you have to light a hammer spring.
Trigger pull has nothing to do with this.


+1 this.
 
Originally Posted By: stealthmanId try bobbing the tail off the hammer like a "speed hammer" first, then go back to the factory hammer spring if all else fails.

What do you mean by bobbing the tail off the hammer?
 
Last edited:
Here's a picture. The left one is the JP speed hammer, the next one to the right is one that has been bobbed, the next one is marked to be bobbed, and on the far right is a normal milspec hammer. I normally use a Dremel with a cutoff wheel or a 4 1/2" angle grinder with a thin cutoff wheel and put the hammer in a vise to cut off the extra area. Eliminating the extra mass allows the hammer to fall faster and have a positive strike on even hard military primers. I ran into the same light strike problem doing trigger jobs for some local law enforcement guys. They had the occasional round fail to ignite at the range. These were personal rifles, not duty weapons, but it was still embarrassing. I tried bobbing the tail off the hammers and haven't had a problem since. By bobbing and adding back the factory spring, there should be no chance for issues at all. So far I've never had to go that far as the hammer bobbing has fixed the problem and I was able to keep the lighter spring.
10pdet5.jpg
 
LIGHTENING THE HAMMER SPRING IS NOT THE BEST WAY TO LIGHTEN TRIGGER PULL.YOU NEED TO CHANGE THE SEAR ENGAGEMENT. YOU WANT TO MAINTAIN A SHORT LOCK TIME. LIGHTENING THE HAMMER SPRING SLOWS LOCK TIME & NOT ONLY WILL CAUSE MISFIRE BUT WILL HURT ACCURACY AS WELL.
 
Back
Top