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Adamc55

Trouble with .308 not cycling properly

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So the inside measurement of the buffer tube is exactly 7" to the detent point. Just finished at the range. Bolt didn't lock back once... But it looks like it is no longer making contact with the lower which is good. I again adjusted the gas block from closed to open and everywhere in between. Closed and the brass wouldn't eject, open and it was landing where you see in the pic. Looks like my next thing to change is the gas tube? That or the buffer spring, but recoil still feels kinda sharp, although nowhere near as bad as last time.

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Adam      You are too undergassed to be running the orange Sprinco.....run you a car308 ar plain o spring first.....then go from there...if the stock car spring doesn't work for ya then start looking to drill out the gas port....getting the long gas tube will also help.....easy things first....grab a stock ar 308 car spring and try it first before going off the rails......if you look at the Sprinco website they state the orange spring is for seriously over gassed 308's...I don't think yours is overgassed at all....also do this...with the rifle empty and the bolt held by the bolt catch....pull the bcg back further...you should have a 1/8th inch of play or so until it wont go any further back.  I have several 308's where I use the orange spring heavy buffer combo.....only after finding out they were very overgassed......  Wash

Now that I see the pic of the casings......You are undergassed for sure.......they should be coming out with authority not just to the bench like I see.....And lube that bcg up real good too !:thumbup:

Edited by washguy

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I think you are right Wash, going to order the spring and Armalite gas tube. With the new length of the buffer tube I ended up with almost exactly 1/8" gap when holding the charging handle back so I think I'm good there now.

20190911_153611.jpg

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I agree with @washguy , try the standard spring first then move to the Armalite gas tube if that doesn't work, if it wasn't the spring then it never hurts to have a fresh spring around. That brass looks too close for an overgassed issue. It's a pain when they are not functioning but more rounds down the pipe may help as well.

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25 minutes ago, edgecrusher said:

May not help but how wet are you running this? Larger frame rifles need more lube during the break in process to mate parts.

 

 

I noticed today that I need some more lube for sure. Before the next time out I'll make sure to go over it.

25 minutes ago, washguy said:

Adam  here ya go      https://www.primaryarms.com/dpms-308-carbine-buffer-spring-11-5-inch-dp308-cs-10a    

if you get the midway just be sure its 11.5 inches      Wash

Thank you sir, I'm just as happy ordering through primary. What's funny is a lot of people seem to use that for 9mm, so I took the spring out of my pcc to compare it and it's too short and soft to try for sure

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Adam  you are close to running... if the regular buffer spring doesn't get you there...then its drill time..which is no biggie ar all....have you got a numbered drill bit kit thats in the 40's/30's ?    Wash

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38 minutes ago, washguy said:

Adam you never told us what ammo you were using...or I missed it....use some decent ammo too

Wash

I've been using Federal gold medal match 168grain

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38 minutes ago, Adamc55 said:

I've been using Federal gold medal match 168grain

you got that right !   find you some privy match 168 once you get it running......shoots almost like the Gold does for a lot less   :thumbup:  Wash

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I had issues with my Springco Orange buffer spring, so sent in back for refund. I went with the Aero M5 lower & went with all Aero M5 parts kits including their buffer kit, that shots well ejects evenly at 3O'Clock. With the Sprinco spring it would eject at 1ishO'clock. I would also have the same issues, stove pipes double feeds etc. I also got the Armalite carbine spring, for my Mid-length gas on my barrel, I did go with a standard AR 15 midlength gas tube but it was really short in the upper. After going to the new parts & haven't had any issues. 

 

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3 hours ago, Lr-308FUn said:

I had issues with my Springco Orange buffer spring, so sent in back for refund. I went with the Aero M5 lower & went with all Aero M5 parts kits including their buffer kit, that shots well ejects evenly at 3O'Clock. With the Sprinco spring it would eject at 1ishO'clock. I would also have the same issues, stove pipes double feeds etc. I also got the Armalite carbine spring, for my Mid-length gas on my barrel, I did go with a standard AR 15 midlength gas tube but it was really short in the upper. After going to the new parts & haven't had any issues. 

 

Looks like my new carbine spring and Armalite gas tube are in, when I get back in the country I'm going to try the spring first and see if it makes a difference, if it still needs more I'll install the new gas tube

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On 9/11/2019 at 1:28 PM, Adamc55 said:

 I again adjusted the gas block from closed to open and everywhere in between.

But, you didn't mention a single thing about the gas port diameter, unless I completely missed it.  I'll go back to what I previously told you:

On 9/10/2019 at 7:29 PM, 98Z5V said:

  You need to measure that gas port diameter...

Here's what you need for a gas port diameter:

On 9/10/2019 at 7:46 PM, 98Z5V said:

I just looked at the numbers and you have a dwell time of around (pretty damn close, if not exact) 5" on an 18" Rifle Gas system.  For a 0.750" diameter at the gas port, you'll need a gas port diameter (min/max) of approximately 0.090"~0.095".

 

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OP,  with the configuration your gun is in now, if you ran your adjustable gas block wide-open - and your gun didn't cycle - the gas port is too small.  Don't know how to make it more direct than that.

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9 hours ago, 98Z5V said:

OP,  with the configuration your gun is in now, if you ran your adjustable gas block wide-open - and your gun didn't cycle - the gas port is too small.  Don't know how to make it more direct than that.

I totally forgot to check that. Before I head to the range I will

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13 hours ago, 98Z5V said:

OP,  with the configuration your gun is in now, if you ran your adjustable gas block wide-open - and your gun didn't cycle - the gas port is too small.  Don't know how to make it more direct than that.

I messaged faxon and according to them the gas port size on this barrel is .093". I'll double check when I get back

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On 9/18/2019 at 10:44 PM, 98Z5V said:

OP,  with the configuration your gun is in now, if you ran your adjustable gas block wide-open - and your gun didn't cycle - the gas port is too small.  Don't know how to make it more direct than that.

 So I couldn't find my big bit set but I did find a 3/32" (.09375") I removed the gas block and the butt end of the bit would almost fit, the cutting end fit in but just barely, my guess is because it is slightly worn. Seems like the gas port size is correct20190920_215955.thumb.jpg.48ff63e3bb27d46f17ce66a9288c7700.jpg

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