Heavier buffer spring?

SksA1

SksA1

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I took my ar out again today and it seems every so often it has a light primer hit.

If i #### it again it fires, its almost like the BCG isn't closing hard enough, can one get a heavier buffer spring? So it pushes the BCG closed a little harder?

Anyone know any fixes?
 
Usually only does it 2-4 rounds out of 20 and not always the same rounds some times doesnt happen at all (ie. #2 round and then #9, than other times it #4 and #7 etc.), im running the RRA LAR mags, and its thuroughly lubed

And yes its like the BCG doesnt go all the way forward..if i pull the charge handle back about an inch and release it again it will fire the same round...
 
You should eject the unfired round to see if the primer has indeed been struck. If it has, then I would look to your hammer/hammer spring to ensure that something isn't amiss there. Have you done any "trigger work" on the rifle? Have you changed out the trigger/hammer springs?
If there is no evidence of a light strike on the primer, then the problem will be more serious....your bolt is not going into battery. This could be caused by a number of things, the most likely is the gas tube is not aligned to the gas key properly. With the upper separated, try sliding the BCG forward into battery to see if it goes all the way without rubbing on the gas tube.
 
If you're getting light primer strikes and everything else is fine (bcg in correct position & locked in), inspect your firing pin. It may be bent, causing it to bind as it travels forward. The tip of your pin may be damaged, or your firing pin channel might just be gunked up and need a thorough cleaning.

The culprit is just as likely to be lube (or lack thereof) that's just too heavy, especially in the cold, on the carrier travel surfaces or even the hammer.

If your bcg isn't hammering home hard enough, switch to an M16/full auto carrier. It's slightly heavier. You could also try a rifle buffer spring as opposed to the carbine (shorter) one. You might also have luck playing around with different buffer weights.

Inspect your upper and BCG for unusual wear, especially on the gas key and tube. Damage to these might indicate a bent gas tube, or a loose or canted gas block leading to misalignment of the gas tube. A loose barrel nut would also pull on the gas tube.

Are your bolt lugs showing any unusual wear?
 
Jäger said:
If you're getting light primer strikes and everything else is fine (bcg in correct position & locked in), inspect your firing pin. It may be bent, causing it to bind as it travels forward. The tip of your pin may be damaged, or your firing pin channel might just be gunked up and need a thorough cleaning.

The culprit is just as likely to be lube (or lack thereof) that's just too heavy, especially in the cold, on the carrier travel surfaces or even the hammer.

If your bcg isn't hammering home hard enough, switch to an M16/full auto carrier. It's slightly heavier. You could also try a rifle buffer spring as opposed to the carbine (shorter) one. You might also have luck playing around with different buffer weights.

Inspect your upper and BCG for unusual wear, especially on the gas key and tube. Damage to these might indicate a bent gas tube, or a loose or canted gas block leading to misalignment of the gas tube. A loose barrel nut would also pull on the gas tube.

Are your bolt lugs showing any unusual wear?
Click to expand...
Quoted for wisdom. I'd try the same.
 
Six- The BCG opperates smoothly, its an RRA LPK with a 3lb JP trigger spring kit (checked and everything seems in order)

All The extracted rounds had impact marks from the firing pin

Jäger- i clean and oil it after every range day, as for lube quantity i was told to lube it up pretty generously. Its an 11.5" with a standard buffer and carbine spring


Edit
Ran down to my gun room

BCG definitely operates smoothly and no odd wear marks on bolt, gas tube and key show no obvious signs of damage

Will too much lube cause issues? Maybe im putting on too much
 
SksA1 said:
Six- The BCG opperates smoothly, its an RRA LPK with a 3lb JP trigger spring kit (checked and everything seems in order)

All The extracted rounds had impact marks from the firing pin

Jäger- i clean and oil it after every range day, as for lube quantity i was told to lube it up pretty generously. Its an 11.5" with a standard buffer and carbine spring
Click to expand...


Borrow a H or HH buffer from someone.
 
Sounds like your firing pin may be bent or worn, or your hammer spring is weak. If you did the trigger kit install yourself and still have the original parts try switching back to the original hammer spring.
If it's not going fully into battery try cleaning your chamber really well. Try pushing the forward assist between every shot to see if the bolt actually moves forward a little, if that stops the light strikes then it sounds like a chamber cleaning issue.
I bought a parts kit from P&D last year and it came with a pile of new springs and a new firing pin. If it's a spring issue what you need is probably in that bag if they have any in stock. I think it was under $50. It even came with a new buffer spring.

What ammo are you using? If it's MFS steel case try something else.

It's hard to diagnose without looking at the rifle. I'm not far from you and could bring a few spare parts and meet you at a range to try to help if you can't figure it out yourself. I'm no expert but sometimes a new pair of eyes will see something your overlooking. I'm out of town till Dec 17 but could meet between the 17th and Jan 6. PM me if your interested.

Good luck and let us know what the problem was once you figure it out.
 
My money is on the lighter trigger springs. I installed them on my AR with a dedicated .22 upper and I was getting light strikes and it would not fire at all. I swapped back to the factory trigger spring and it works now.

With that being said, I also have them on 2 of my other AR's and they woke fine.

Start with that, it's a quick and free option (If you still have the factory springs)
 
SksA1 said:
Six- The BCG opperates smoothly, its an RRA LPK with a 3lb JP trigger spring kit (checked and everything seems in order)

All The extracted rounds had impact marks from the firing pin
Click to expand...

I'll bet that's the cause right there....try re-installing the original RRA hammer spring. I found the JR trigger spring kit causes light primer strikes on certain brands of ammo.
 
T has the light primer strikes with all different ammo ive shot through it....

I do have the RRA springs still so ill try that next time im out.

Its also intermittent like i said, it only does it for a couple rounds in two LAR mags sometimes it doesnt do it at all
 
Sorry for the very late update..

So i replaced the JP spring with a standard RRA spring set and that seemed to do the trick....put 150rds through without a single issue...

Any one know how i can use this JP spring kit and have it work? Or should i just turf it?
 
Yes, too much lube can slow things down.
MFS sucks.
You generally get a heavier buffer, not a heavier spring.
I was raised by the school who said you NEVER lube the firing pin, I never do. My rifle always goes bang, and only when I tell it to.

I wonder if the grease on your trigger pins might be gunked up and getting hard in the cold.

There seems to be a lot of this going on these days. The case of the Frozen AR strikes again.

Lube minimally and with precision. Pop into your nearest "The Source" (Formally Radio Shack) and ask about their "Precision Oiler".
ht tp://www.thesource.ca/estore/product.aspx?language=en-CA&catalog=Online&category=Misc_Tools&product=6402301

The oil is light, laced with teflon, (sound familiar? CLP?), rated to 500F, and makes lubing your AR a breeze. I've been using it for months now. Carbine still ran great even in 20 below.

Get some Gun Grease and a small artistic pain brush. Lightly paint grease on bolt lugs. Heavy Paint grease on cam pin.

Squirt a few drops of the oil into the gas ring holes. Run a bead along the slide/bearing surfaces. Call it a day.

It works for me.

I seem to be in a chatty mood today.
 
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