Light Primer Strikes and Feeding Issues

[JK81]

I just finished my 6.5 Grendel build several weeks ago and have had nothing but issues. This is my third AR build and haven’t had any issues like this, however it was inevitable as I’ve been very lucky it seems.

Issues are light primer strikes, noticed primer strikes when the gun cycles and feeding issues i.e. double feeding and some not extracting. The very first shot did not go bang. Worst feeling ever! I have tried two triggers, different buffers, cleaned and lubed etc.

Most recent is that my rifle won’t go into battery. It lacks about 3/4 - 1” before fully going in.

My build is as follows:

Weapons Smart Skeletonized Lower
Elftmann Push button safety
Elftmann 3-gun trigger
H2 Buffer w/ Giselle Spring
Grendel Hunter 18” Fluted Upper
ASC Magazines

This is my first Grendel so I was/am just trying to get advice. Don’t think Grendel Hunter did anything as I am just trying to find a solution and make a reliable hunting rifle!!!

Thanks in advance for the help and advice!

[Whit]

I've never messed with the Elftmann triggers (or their crossbolt safety), but the first thing I would look at is to double check the trigger installation.

Edit: Nevermind, I completely missed where you had said you tried two different triggers.

[BCHunter]

What ammo are you using, factory or reload? One type or does it do it with all rounds tried?

Load and fire one round, verify it's locking open.

Double feed? So fails to extract fired round but picks up new round? Can you elaborate post pic of miss feed?

[JK81]

I’ve tried multiple ammos however I did fail to mention that it as getting stuck when it was short of battery. Will try to post picks tomorrow from my computer.

[VASCAR2]

JK81 did you buy the Grendel Hunter as a complete upper with a Matching bolt or BCG? You didn’t mention if this was factory ammo or reloads. One other question is whether your using a fixed gas block or an adjustable gas block. If you know the diameter of th barrel gas port that can be helpful.


If you chamber a round into an AR-15 the floating firing pin will put a small hit on the primer. This is the reason you see the recommendation to use rifle primers with thicker cups like CCI 41 military primers, CCI 450 magnum primers, Federal AR rifle primers or some match primers. If you use small rifle primers like CCI 400, Winchester or Remington standard small rifle primers you run the risk of slam fires or pierced primers.

[JK81]

VASCAR2 I ordered it with the matching bcg.

Sorry I didn’t explain, I am using both reloads and factory. Had the most issues with the Hornady Custom and the light strikes are pretty deep. It’s done it to all factory loads including a few reloads with CCI450 primers.

The reloads are the ones with the battery issues and I’ve ordered some additional factory loads. The bcg seems to have trouble lining up correctly but I am no expert and could be normal.

BCHunter thanks as I will try the single load this weekend with and without the mag to see what happens. I believe it has done both types of jams but will pay closer attention when it happens again.

Which trigger is best or would you all suggest? Can always use an extra.

[JK81]

[ATTACH=CONFIG]12380[/ATTACH]
[ATTACH=CONFIG]12381[/ATTACH]
[ATTACH=CONFIG]12382[/ATTACH]

[Whit]

Ok. When you said “light primer strikes,” are you talking about rounds that you squeezed the trigger on, or are those rounds that simply got manually cycled with the charging handle, but never fired? Because those are two different animals. If the rounds in the picture were manually cycled, the light dimple is normal, and one of the reasons it’s not a great practice to manually cycle the same round over and over.

As far as not going into battery, what’s the COL on your reloads, and how far back are you bumping the shoulder? My guess is that either the case shoulder is too far forward, or you have the bullet seated too far out. Check it against your manual just to rule those things out. If your cartridges are in spec, the only other thing I know is to make sure the gas tube and the gas key are aligned, and not hitting each other as the BCG tries to come home.

[JK81]

Hey Whit, I am talking about squeezing the trigger and no boom. When it cycles the dimple is much smaller or non-existent and doesn't concern me very much.

The COL is < 2.245 and I even made a dummy round with brand new brass and a bullet around 2.150 and it acted the same. I can drop it in and it will single feed some. Might be the magazine partially, however when I slowly slide in the bcg it feels like it is catching so I will have to check and see if the gas tube is hitting per your suggestion. Its almost like the bolt isn't lining up or is slightly off.

[Whit]

Take the upper off, and run your bcg out and back in and see if you can find a hang-up somewhere. If you have one of your dummy rounds, you can check to make sure the bolt can close on it and lock up.

I did find this: http://www.elftactical.com/faq

It talks about some of your symptoms, but you said you tried a different trigger, so ??? I don’t know. Hard to diagnose this stuff sight unseen, but I would double check those things and see what you come up with.

[VASCAR2]

JK81 you may have a couple different issues so it best to make one change at a time to try and isolate the problem. The photo of the spent brass shows very light primer indentations. I’d suspect your Elfman trigger/safety is not adjusted correctly as Whit indicated. On a standard milspec hammer it is very easy to improperly install the hammer spring which contribute to light strikes. Sounds like the Elfman trigger group your using is installed as a complete unit so it is not likely to have the hammer spring improperly installed.

Like Whit mentioned I’d take the upper off the lower and see if the bolt and carrier move freely. The bolt and carrier should be wet with lube like Slip 2000, Breakfree CLP or synthetic motor oil. If the BCG does not move freely inspect the carrier key for wear. The gas tube might not be properly aligned with the carrier key. The gas tube or carrier key might show finish wear if not properly alligned. If the rifle is not ejecting a spent brass the gas block may not be properly centered over the gas port.

If everything in the upper appears normal I’d find someone with a proven lower. I’d put your upper on their lower and check for function. Load one round into the mag. Using the charging handle charge and fire the weapon. Spent brass should eject cleanly and bolt should lock to the rear. If the bolt is not held by the bolt catch this generally indicates the rifle is undergassed. The gas block is likely not centered over the gas port, wrong size gas port or to heavy a buffer. Grendel Hunter used to use Satern Liberty barrels which were known for having large gas ports. I’d suspect the gas block needs adjusted.

If the rifle fires the round ejects and the bolt catch holds the bolt try two rounds. If the rifle functions with two rounds try three rounds. If the rifle will function with three rounds you know the rifle is capable of feeding from both sides of the mag and there appears to be adequate gas. I’d then add a few more rounds to the mag and fire a few more rounds. The location of ejected brass can indicate if the gun is over or maybe under gassed. If the rifle is under gassed the brass may dribble out. Over gassed AR’s generally eject to 1-2 O clock. If the gun fails to feed with more rounds in the mag this can indicate a mag problem, a timing/gas issue or failure to feed (ejector problem).

Another issue is the ejector can interfere with chambering rounds on larger case head cartridges in the AR-15. If you are encountering failure to feed the ejector can cause feeding issues. Here is a link describing a mod to a ejector to improve feeding.

http://bulletin.accurateshooter.com/2014...artridges/

When testing a new rifle I try to use a proven magazine with factory ammunition. I’d also remove the bolt/carrier from your upper and try to drop a hand loaded cartridge into the chamber. Push on the base of the cartridge to ensure it is seated in the chamber. Raise the muzzle and the cartridge should fall out. If the round will not fall out of the barrel use a cleaning rod to push out the cartridge. The bullet could be seated to long and is pushed into the rifling. You can color the nose of the bullet with a black marker to see if the bullet is into the lands (reinsert color bullet into chamber). Another problem with hand loaded ammo is not completely full length resizing the brass. The shoulder of the brass needs to be bumped back .003-.005 to fit into the chamber properly. If you have a factory cartridge drop it into your barrels chamber. Raise the muzzle and if the factory round will not fall out of the chamber the chamber might be out of spec.

[bj139]

I bought one of those single stage light triggers and after many light primer strikes I decided not to get any more.
Did you contact Elftmann to see if they have a stronger spring they will send you for free?
I did that with my Rise Armament trigger and they sent me a new spring immediately.
I can't recall a misfire since with this trigger but I can hear the lighter hammer fall compared to a LaRue trigger or milspec.

Does the Trigger have a solid surface at the bottom of the FCG housing? Maybe you need the metal insert that Elftmann mentions on their website.

[cwlongshot]

I generally like ACS magazines and use them in a number of calibers... BUT I too had feeding issues attributed to them as switching to E-Lander eliminated the feeding issues...

Now was it just MY ASC sure could have been as neither of them was new. But there where blue followers made for the 6.5. I ordered two E_Landers the morning before hitting the range and tossed the box in my range gear. I opened the pkg with a 4 rnd mag on the range, charged it to cap inserted into the rec and fired 4 rounds in rapid succession just to see if it fed...

Hope you find your problems and can enjoy your build.

Good luck,
CW

[JK81]

Thank you again Whit. The bcg does slide fairly well in and out. I'm going to try and contact Elftmann and see if they have much input.

[JK81]

Thank you all. I am going to try all of your suggestions over the weekend along with seeing if I can get some stronger springs for my trigger. I have a feeling most of my issues are in the trigger and magazine but have to rule out one thing at a time.

Side note: This is my first time ever posting on a blog and wow it is amazing at the help out there. Thank you all again and wish you all straight shooting.