AR build questions

[DirectDrive]

So I thought it might be the ammo but it happened with several factory brands and with handloads as well but not as often with handloads.
I thought it might be the hammer spring as well but not sure. I'm hesitant to try and reduce the hammer spring as it's a standard mil-spec hammer and spring.
I did get a new carbine spring and some new buffers h1 and h2 as well to see if that helps.
I'm not really having an issue with recoil but it has gotten a little rougher over time so hoping the new springs help.

Make your trigger springs are installed correctly.

 

[Local Loader]

I bet the hammer spring is backwards

Yeah, it doesn't fit backwards, plus it doesn't work installed backwards.

 

[TTSX]

If you want you BCG to return to battery faster, you need a stronger spring and less mass to push. Use a Sprinco orange buffer spring and empty buffer weight. It may or may not cycle well but it will return to battery with some enthusiasm

 

[Member 34319]

No one has asked, but your light primer strikes aren't the mild dimples the free floating firing pin leaves on rounds before pulling trigger/releasing hammer? IE, chambered a round, didn't fire, ejected round.

Or are they, rack charging handle, chamber round, pull trigger, hammer falls, no bang, eject manually type light primer strikes?

Questions!

Is the gun new?
Has it ever ran a full magazine without issue?
Cleaned, lubed?
When loading rounds does the bolt go 100% into battery?
When bangs occur, does it cycle completely?
No short stroking?

Typical things I know of that cause short strokes.

Chamber issues.
Hammer installed incorrectly.
BCG parts off spec

AR15s are fun when they don't work! 1 issue can be caused by an annoying amount of things on these things.

 

[arrowshooter]

Reno pretty much has it covered, and some good info before his too. As advised, pull your firing pin out and roll it on a table to see if it's bent. Then when you reinstall it bounce it up and down to make sure it's moving freely and fully protrudes.

 

[eldbillbo]

Yeah, it doesn't fit backwards, plus it doesn't work installed backwards.

a friend of mine installed one backwards and it is very easy to install backwards because it looks like the natural way to install it. But he had the exact same problem you are having. Sometimes it would fire sometimes light primer strikes. We flipped the trigger spring and never had a problem after that.

and it's not first time I have diagnosed one of these in a web forum as being backwards pretty common mistake.

 

[eldbillbo]

Wrong way. It will work but you will get mostly light primer strikes


Right way. A little harder to install but it works



Its amazing how many people will get this wrong.

 

[Local Loader]

Wrong way. It will work but you will get mostly light primer strikes
View attachment 1260321

Right way. A little harder to install but it works
View attachment 1260322


Its amazing how many people will get this wrong.

Yeah it's not a hammer spring position problem, I've always kept it installed with hammer inside spring loop. Didn't even know it would work that way with it being flipped backwards.

 

[Dr Prepper]

Is the FP magnetized? If it is its inducing an opposing magnetic field inside the carrier (being a conductive metal surrounding it) and will slow the firing pins ability to achieve max inertia. The way this works is the faster its trying to move the bigger the opposing magnetic field and the bigger the opposition forces. I believe they call this "bucking" as well.
Check your carrier as well, (and your barrel is probably magnetized as well if your carrier is) if any one of these if magnetized it REALLY doesn't help the system.
Also check for carrier bounce if you system isn't setup correctly for the buffer. Having your bolt bounce out and not fully lock again might be causing this.
Also swap the firing pin they are cheap. Could just be out of spec. Measure it.

Keep in mind what's actually happening inside the system is you are hammering steel bars repeatedly. Remember 3rd grade science class and how we made magnets by holding them north and so. And banging on them to align the magnetic structures inside?

 

[red442joe]

Wow....just wow...

Joe

 

[Dr Prepper]

O....k...?
In awe? I love the ambiguity.

 

[Yarome]

Is the FP magnetized?
Also check for carrier bounce if you system isn't setup correctly for the buffer. Having your bolt bounce out and not fully lock again might be causing this.
Also swap the firing pin they are cheap. Could just be out of spec. Measure it.

This is a possibility too.

You can speed carrier return with a stronger buffer spring and light buffer, but that can also lead to carrier bounce. It's difficult to say which way to go without hands on and noting ejection angles as a possible indicator. That can also be exasperated with headspace out of, or on the fringes of spec.

I really does sound more like a firing pin or hammer issue though. Another thing to check might be your cam. If it's burring it may be creating undue friction on your pin(?)

Something's not right in Denmark though.

I liked one of the above suggestions to try another BCG. That would at least help isolate where in the system the fault might be.

An afterthought... you aren't using antiwalk pins on your TG are you?

 

[Local Loader]

No one has asked, but your light primer strikes aren't the mild dimples the free floating firing pin leaves on rounds before pulling trigger/releasing hammer? IE, chambered a round, didn't fire, ejected round.

Or are they, rack charging handle, chamber round, pull trigger, hammer falls, no bang, eject manually type light primer strikes?

Questions!

Is the gun new?
Has it ever ran a full magazine without issue?
Cleaned, lubed?
When loading rounds does the bolt go 100% into battery?
When bangs occur, does it cycle completely?
No short stroking?

Typical things I know of that cause short strokes.

Chamber issues.
Hammer installed incorrectly.
BCG parts off spec

AR15s are fun when they don't work! 1 issue can be caused by an annoying amount of things on these things.

Rack first round fires fine, pull trigger for second round nothing happens. Eject bullet to check and it only has a really tiny dimple on the primer. This only happens when trying to fire in rapid succession. Slow my trigger pulls and it works fine.
Guns not new it's several years old.
No issues going into battery other than not fast enough for what I want.
Never had any mag issues and was cleaned and lubed that week it was used.
Got no issues cycling at a slower rpm than what I want.
Pin is on the older side so might replace it as well for good measure.

 

[Yarome]

No issues going into battery other than not fast enough for what I want.
Got no issues cycling at a slower rpm than what I want.

Sounds a little more like carrier bounce, but than again, a cam issue could do that too.

Bounce could do that if you are pulling on the reverse, the cam is slightly out of wack and creating any impedance on the pin, or the headspace is too great during the bounce.

It "could" be return to battery speed with a weak buffer spring. Ejection angle would be a good indicator. Or.. I guess you could simply swap out your buffer spring and see if that resolves it. No harm no fould there. Even if it's not, who can't use a spare spring laying around, right? They're cheap enough... and an upgrade will only set you back...what? 20 bones-ish.

I would still inspect your cam though, and If you do have another BCG to try... that couldn't hurt either. If it's a much older rifle, inspecting the upper interior for wear wouldn't hurt either. Possibly exccesive wear and a drag issue(?)

 

[Local Loader]

Ok, so this seems to have gotten a fair bit off track of what I was asking about to begin with. This was sent to me by another member and they seem to better explain and understand what I was asking. I really appreciate them for this info.

"I believe I understand what you are saying....you are pulling the trigger just before bolt gets FULLY into battery, resulting in a kind of hammer follow."

This^^ is the issue that I am getting.
I just need to increase the speed of the bcg return to battery to help prevent this issue.
I'm not asking if there is something wrong with the hammer and its spring. I know that that is not the problem.

 

[shoengine]

Ok, so this seems to have gotten a fair bit off track of what I was asking about to begin with. This was sent to me by another member and they seem to better explain and understand what I was asking. I really appreciate them for this info.

"I believe I understand what you are saying....you are pulling the trigger just before bolt gets FULLY into battery, resulting in a kind of hammer follow."

This^^ is the issue that I am getting.
I just need to increase the speed of the bcg return to battery to help prevent this issue.
I'm not asking if there is something wrong with the hammer and its spring. I know that that is not the problem.

I'm pretty sure that has been answered: stronger spring, lighter BCG, lighter weight.

 

[Yarome]

"I believe I understand what you are saying....you are pulling the trigger just before bolt gets FULLY into battery, resulting in a kind of hammer follow."

That "is" a possiblity, but it's not the only thing that could be contributing to what you are describing, and tbh, less likely the of typical culprits.

Not that it isn't, just less likely.

Now that we know it's an older rifle and might have a higher round count, it might just be as simple as a weak buffer spring. Worn areas could be contributing to some kind of drag too. The cam, firing pin, upper interior tracks, etc. Pretty hard to say without first hand inspection.

If it was mine, I would just do a full inspection, a little measuring, and if all appears well, swap in a spring upgrade an see where things land.

 

[Local Loader]

It "could" be return to battery speed with a weak buffer spring. Ejection angle would be a good indicator. Or.. I guess you could simply swap out your buffer spring and see if that resolves it. No harm no fould there. Even if it's not, who can't use a spare spring laying around, right? They're cheap enough... and an upgrade will only set you back...what? 20 bones-ish.

I would still inspect your cam though, and If you do have another BCG to try... that couldn't hurt either. If it's a much older rifle, inspecting the upper interior for wear wouldn't hurt either. Possibly exccesive wear and a drag issue(?)

I am going to try it with the spare bcg that I have and I am planning to swap out the older spring for a new one and see how well that works. I am thinking that I might need a heavier spring with a lighter buffer.
As for excessive wear or drag, I'm not seeing signs of that so far. I keep it cleaned and lubed every time it's used and every 3 months when not in use.

 

[Yarome]

Cheapo upgrade... I've had great luck with spike flat wires and run them in several of mine.

AR Carbine Flat Wire Spring

The SI Carbine Flatwire Spring is an economical, easy upgrade to any ar system with a carbine buffer system. The flatwire spring increases service life of the platform, smooths out the shooting cycle, and greatly outlasts the stock spring. Increased bolt load, in addition to decreased...

www.strikeindustries.com

Obviousy they can be found cheaper elsewhere.

 

[Local Loader]

That "is" a possiblity, but it's not the only thing that could be contributing to what you are describing, and tbh, less likely the of typical culprits.

Not that it isn't, just less likely.

Now that we know it's an older rifle and might have a higher round count, it might just be as simple as a weak buffer spring. Worn areas could be contributing to some kind of drag too. The cam, firing pin, upper interior tracks, etc. Pretty hard to say without first hand inspection.

If it was mine, I would just do a full inspection, a little measuring, and if all appears well, swap in a spring upgrade an see where things land.

It does have a sizable number of rounds through it, at least to me. I do plan to swap out that buffer spring and the cam seem to be in good shape and that pin is my next item to get replaced if things still aren't working right. Even though it's an older rifle there's not a lot of wear marks on it as I've made sure over the years that everything moves with as little resistance as possible.