My new 5.45x39 Piston AR-15 (Huldra Mark IV with AXTS ambi lower)

[Garys4598 1,065]

Follow Up:

 

[FAIL -- Refer you to reply post #45 below.]

 

A couple weeks ago I cut and shaped two pieces of lead to sandwich around my Geissele's hammer.  Below is what it looked like, prior to drilling small dimples (or shallow holes) into the sides of the hammer for the epoxy to have something to bite into/hold onto.  I couldn't find a single hardware store that carried carbide straight fluted drill bits, so I purchased a few from eBay (the hammer's tempered steel head wouldn't cooperate with anything less).

 

 

 

The pics below are the completed mini-project (I forgot to take out my camera prior to reinstalling the hammer into the AR's lower).  I ended up going with "Titanium 5 Epoxy" produced by VersaChem, but I hazard to guess pretty much any 2-part epoxy designed for metal would have done the trick.  After letting the epoxy cure and then performing a bit of final shaping of the lead halves, I decided not to drill a hole and bolt the lead encased hammer.  I'm thinking the epoxy will be adequate. . . yet I'll keep my eye on the hammer after a few trips to the firing range to see how well the sandwich job holds up.  Anyway, I'm calling her done for now.

 

 

 

 

 

 

 

Edited January 8, 2014 by Gary

[Garys4598 1,065]

Well, I spoke (wrote) too soon.  SUM-BEOTCH!

 

. . . . . . . . . . . . . .

 

 

After simply hand-cycling and dry firing the rifle a dozen times, I opened up the receiver and wouldn't ya know?  One side of the lead had separated from the hammer.

 

Looks like I'll be bolting the two lead halves together after all.

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[YOT 3,743]

I'm still confused as to why the Geissele set-up won't work without modification. Are you sure you got the right series? They make like 27 different ones.

[Garys4598 1,065]

I'm still confused as to why the Geissele set-up won't work without modification. Are you sure you got the right series? They make like 27 different ones.

Well, I'm not aware of any particular Geissele "series" that works best within an AR that shoots Military Russian Surplus ammunition.  But if you or anyone else can enlighten me, I'm all ears bro.

 

The only two Geissele trigger assemblies that have significantly different or unique hammers, is the Super Select-Fire Trigger (SSF), and the HK MR 762 Trigger... both of which have significantly more steel/mass on their hammers.  The HK MR 762 Trigger was specifically designed for the HK 417 that shoots 7.62x51mm ammunition.

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Edited December 30, 2013 by Gary

[YOT 3,743]

From the man himself.... 

 

Or, perhaps a phone call to the manufacturer. It could be a warranty issue before you alter it.

 

 

Edited December 30, 2013 by Yeoldetool

[Garys4598 1,065]

Yea, I sat through that youtube video a long time ago, prior to my making the decision of which trigger assembly to purchase. Yeoldetool, I appreciate you taking the time to locate that video clip and post it here, as a possible solution to my issue.  BUT, I draw your attention to another one of Bill Geissele's videos immediately below.  Scroll through to approximately the 10:58 mark, wherein straight out of his mouth he states, "... allows our hammer to set-off any type of ammunition; any type of hard primered military ammunition...", and 5.45x39 (USSR) is listed first of a litany of ammunition types Bill states his trigger will function with.

 

http://www.youtube.com/watch?v=w9nfsa7Q5cg

 

Well, I'm just one person; one Geissele consumer and patron.  But this Geissele consumer is here to tell anyone that Bill is full of bologna, specifically with regards to my AR's configuration.  My Geissele SD-E trigger assembly absolutely does not reliably ignite/set-off Russian 7N6 ammunition.

 

[My statement immediately above is incorrect and I could not have been more wrong; reference reply post #45 below.]

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Edited January 8, 2014 by Gary

[YOT 3,743]

Which is why I think it make be a defective set.

[Garys4598 1,065]

Which is why I think it make be a defective set.

I suppose that's absolutely possible, but I tend to believe not.

 

Out over at another forum site, someone else ran into a similar problem with their Geissele trigger assembly.  They contacted Geissele Automatics and were promptly informed that as far as Geissele was concerned, their AR configuration (the upper mated with the lower; different manufacturers) was "out of spec."  Gee. . . although obviously that could have been true, based on how detailed the forum member conveyed his issue, I think not.  It's all a matter of opinion though, when one cannot "lay their hands and see" what the problem(s) is, no?

 

Anyway, as I previously conveyed within an earlier post within this thread, I believe in my case with this AR that shoots 5.45x39mm ammunition, it is simply an issue with the lack of "mass" to the hammer.  I don't fault Geissele Automatics, IMHO they make fantastic trigger assemblies and I do very much like my SD-E trigger.  So. . . I'm determined to make this work. 

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[YOT 3,743]

Just for shits and giggles, have you tried flipping the spring over?

[Garys4598 1,065]

Just for shits and giggles, have you tried flipping the spring over?

No.  But I know what you're driving at.  The hammer spring is installed correctly. . . and I even bent it a wee-bit to obtain a harder/swifter hammer strike.

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[Long Shot 1,287]

Gary,

First off that is a very nice build. I had a chance to hold one of those lowers before they went into full production when we moved in a large CNC machine for the guy that makes them. I've wanted to get one ever since just haven't pulled the trigger.

 

A buddy of mine had a similar issue with an AR we put together with a Frontier lower, plastic hammer and all. Don't remember the complete upper he bought online somewhere.

 

We shaved the tip of the firing pin down about .010" to .015" off the diameter. I just stuck it in a drill motor and pinched it with some 160 grit emery cloth. Figured less surface area = more concentrated strike. Plus worst case it's a $10.00 firing pin. 4000 plus rounds later not one issue. We only use Russian mil surp ammo. Don't know if it would punch a hole in a boxer primer or not.

 

Anyway it worked for him, hope you get yours going.

Good luck.

[Garys4598 1,065]

@ Long Shot -- That's a terrific suggestion.  If what I'm doing doesn't work, I'll definitely give that a shot.  Thank you!

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[ShadowFire 220]

Yeah the weight of the hammer is the reason I went with ye old faithful USGI style fcg.  Even with the basic fcg I initially had issues with igniting 7.62x39 surplus primers in my GP AR.  What I found was switching to a Wolff extra power hammer spring cured it.  You will likely find the same thing.

[Garys4598 1,065]

Well, after dicker'n around with the rifle on Friday and taking it out to the firing range during both Saturday and Sunday. . . and still not getting it to fire consistently, I believe I have finally determined what the problem is, and it has nothing to do with the FCG hammer's weight or mass.

 

...We shaved the tip of the firing pin down about .010" to .015" off the diameter. I just stuck it in a drill motor and pinched it with some 160 grit emery cloth. Figured less surface area = more concentrated strike. Plus worst case it's a $10.00 firing pin. 4000 plus rounds later not one issue. We only use Russian mil surp ammo. Don't know if it would punch a hole in a boxer primer or not.

 

I gave the above a try; I reduced the diameter of the firing pin point from approximately .059" to .049". . . and I experienced even poorer performance out at the firing range on Sunday.  I could only get one cartridge to ignite/fire.

 

What has been occurring with my rifle is:  The hammer has been striking the inside back portion of the bolt carrier, vicinity of the firing pin's head... so, much of the hammer's inertia and energy during firing is being absorbed or transmitted to the bolt carrier instead of solely to the firing pin.  I now know this (and for whatever idiotic reason I did not pick up on it from the beginning) because when charging the rifle's bolt (during dry firing) and pulling the trigger, I can see the bolt carrier move forward a wee-bit via the ejection port, when the hammer strikes.  After removing the bolt carrier/assembly group from the upper receiver and holding it out in front of me with the firing pin back level with my eyes, the fat back portion of the firing pin is exactly even or flush with the inside back of the bolt carrier (instead of it protruding a wee bit).  So, it's no wonder that the hammer has been striking the bolt carrier.

 

My particular Adams Arms manufactured piston driven bolt carrier assembly has a spring that's installed/slips around the bolt which consistently applies pressure; extending the bolt head from the carrier assembly (the bolt has no gas rings).  During my firing session on Sunday, I removed this small spring to determine whether it would make any difference with the lack of cartridge ignition I was experiencing. . . but it didn't.  Additionally, after further examination and comparison to the TROMIX TR-15 rifle that I own, I believe I did not optimize the positioning of the JP Enterprises captured recoil buffer assembly that I am using, via the rear stock's buffer tube emplacement.  I need to screw in the stock's buffer tube at least one more full rotation (if not two) to bring forward the face of the buffer.  It rests approximately a 1/4" back inside the face edge of the AR's lower, vice being flush.

 

Anyway, I've added approximately an 1/8" of steel to the firing pin's head/back which I am relatively confident will correct the rifle's firing issue (and I'll be moving the buffer tube slightly forward as well).  When I take the rifle out to the firing range this coming weekend, providing these actions have corrected the issue, I'll consider possibly removing a tenth or so of an inch of the steel material from the inside rear of the bolt carrier assembly, in the vicinity where the hammer has been contacting and pushing the carrier forward during firing.  I've ordered three more "enhanced 5.45 firing pins" and I'm not confident that the garage gunsmith fix I did to the existing firing pin will hold-up over time.

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Edited January 7, 2014 by Gary

[Garys4598 1,065]

UPDATE:

 

Yesterday evening I reinstalled my lower's buffer tube, giving it an additional full rotation when screwing it into the lower, which brought the face of the captured recoil buffer flush with the front edge of the lower.  After reassemblying the upper to the lower and cycling the AR's action, I immediately noticed that the bolt carrier assembly seats fully forward now (like "duh!", right?).

 

Prior to reassembling the rifle, I installed the newly modified firing pin (which I simply added about an 1/8"+ of steel to the head of the pin where the hammer hits, via epoxy resin) into the bolt carrier.  I hand cycled and dry fired the rifle approximately four times, immediately noticing a difference with how the hammer strikes sounded and how the bolt carrier did not move during the hammer strikes, and then opened the rifle by pulling the rear takedown pin to examine the firing pin.  Well. . . the friggen fourth strike of the hammer was enough to pop off the steel 'button' that I had epoxied onto the head of the firing pin.  So that mod is a total bust.

 

Additionally I noticed that the lead I had epoxied and bolted to the sides of the hammer was once again separating from the hammer.  So that mod is a bust as well.  Tonight I will be removing all of the lead that I had added to the hammer.

 

Anyway, the bottom line is:  The positioning of the recoil buffer was the cause of the problem as to why the rifle was not firing consistently.  It was not the Geissele hammer's mass.  Since the bolt carrier assembly was not in its forward most position during cycling, the hammer was not making correct contact with the firing pin, and was in fact striking the inside back of the bolt carrier during its arc toward the firing pin.

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Edited January 8, 2014 by Gary

[YOT 3,743]

Glad you got it figured out, Gary. Now enjoy shooting it.

[gunfun 3,931]

I guess it's just as well that the epoxy didn't stick.

[Garys4598 1,065]

I guess it's just as well that the epoxy didn't stick.

 

Yea, well. . . via my actions I did pretty much disfigure my Geissele hammer, by drilling a hole through it and drilling dimples into the sides of it (to get the epoxy something to hold onto). 

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[gunfun 3,931]

It's not disfigurement. It's speed holes. For racing or something. Fill them in with color and it's a feature. That's how R&D goes. You can brag about the customized geiselle trigger when you chuck it on gunbroker to finance your titanium STG44 project.

[Garys4598 1,065]

It's not disfigurement. It's speed holes. For racing or something. Fill them in with color and it's a feature. That's how R&D goes. You can brag about the customized geiselle trigger when you chuck it on gunbroker to finance your titanium STG44 project.

 . . . .. . . .   (That's pretty-darned hillarious.)

 

I just got off the telephone with Geissele Automatics. . . I contacted them to learn whether I could purchase a replacement hammer for my SD-E trigger assembly.  Would you believe that after stating up-front that I screwed-up; I personally performed the disfigurement to the hammer, etc., that Geissele simply stated, "...box-up the entire FCG and ship it to us, and we will replace it at no cost after inspecting it."???  Tis true, and I nearly fell out of my seat.  Holy-friggen-cow! 

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[gunfun 3,931]

I believe it. That's why all those trigger kits have a huge mark-up.

 

That way they can afford to give "amazing customer service" For example Dillon Precision stuff. --If we charge you 4 times the manufacturing cost, we can afford to give you a free replacement no questions asked when you screw it up. (and you'll overlook the few times we screw up too.) I often think that the tired saw "you get what you pay for" could be ammended to "you get 25% of what you pay for with high end, and with low end sometimes 100%, sometimes 25%."

[Garys4598 1,065]

@ GunFun -- That's a rather ingenious perspective; I never reflected about it that way.  Hmmmm. . . .

[YOT 3,743]

Gotta love companies with great CS.

[beefcakeb99 572]

Glad that you fixed it and Told you so  

[Garys4598 1,065]

This seems like a duct tape fix on a Lamborghini imo. I'm not gunsmith nor experienced with ar's other than shooting them a few times. But with such a high dollar build with high end parts I'd look for a higher end fix. But that's me talking out of my ass.

Not to say you haven't tried, I'd just search longer...

 

 

I'm sure some shop around you could add some mass and grind it smooth for a nominal fee

 

 

This is an AR we are talking about here!  Sorry couldn't resist.

 

You told me so?  After reviewing your three reply posts. . . I guess I don't see that (other than the implication of the first sentence of your first reply post).  Now, had you commented "Contact Geissele and learn what they have to say?"... then I'd readily agree with you. 

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[beefcakeb99 572]

I was joking that's why I had the grimace smiley. Honestly I had nothing at all constructive to this. It's a beautiful rifle but I know little about them.

[Garys4598 1,065]

Took the rifle out to the range this morning (having removed all the lead from the Geissele hammer), and fired 180 rounds of 7N6 through its barrel.  Not a single hiccup, FTF or magazine feeding issue.

 

I'm ecstatic now. 

[ChileRelleno 7,071]

Gary,

this has been an interesting thread to watch, glad to hear you finally got it figured out.

 

Nice rifle!

[mixednuttz 123]

What magazines are you using with this rifle?

[JESS1344 508]

GARY,

   WITH MORE CONSISTENT "CRUSH", AND THEREFORE IGNITION OF THE PRIMERS, DID YOU OBSERVE ANY TIGHTENING OF YOUR SHOT GROUP?

 

   THANKS,

   JESS1344