Help me isolate cycling issues **UPDATE**

[G38xOC]

my day started out just like any day at the range .. I had to zero my scope using some factory american eagle ( no issues ) . and finalized with some federal gold match ( no issues )

set up a new target to test out some of my loads for remaining hour or so .. than frustration begins...

first let me give you some specs of my rifle..
ar10 - rifle length gas system - carbine heavy buffer - has adjustable gas block

Lyman 49th edition
150gr Jacketed : 2,800 OAL : Ram Tac : starting 39.5 max 44
since im using LC brass , I subtract 10% .. these were my loads and results ..

Hor 150gr FMJBT : 2,725 OAL : Tac
37.5 , 38 , 38.5 , 39 , 39.5 = I made 4 rounds each and had FTE , bolt not locking up at last round

what the...is my load too light ? is it short stroking ? should I tighten up the gas block or open it more .. I didnt know how to use my adjustable gas block tell you the truth ... so , I tried the another loads

Horn 150FMJBT : 2,720 OAL : Varget : same brass LC09 : -10% and up
38gr - cycle okay - but last round did not stay open
38.5 - 1 FTE - bolt not open
39 -1 FTF - bolt not open
39.5 - 1 FTF - bolt stay open

what do you guys think .. Im not going to get started on accuracy right now...I need to find and fix this issue this first .

there was one load i tested using commerical brass this time 43gr - 44.5 and those didnt have any issues .

any help will be appreciated

[huckberry668]

the loads are on the low side but I think it still should cycle the action with regular gas block. I'd venture to guess it's your adjustable gas block set too low. Turn the gas block up to allow maximum gas volume to cycle the bolt/carrier. Develop the best load and then adjust it down to reduce recoil and proper function as needed.

[G38xOC]

will do ! thanks

[mjmagee67]

Dirty gun? Light loads & dirty gun?

[G38xOC]

^ funny thing is , after trying to a load with fte's , i will load up 3-4 rounds of factory american eagle again and cycles fine . it had to be my load

[Triple R Munitions]

Honestly it sounds light... You need to try some hotter loads as long as its within the load specs.

Aaron

[XDRoX]

It's sad that loading manuals are so damn scared of a lawsuit nowadays that most of their lower end loads won't even function most guns.

[G38xOC]

maybe I shouldn't have subtract 10% on LC brass .. I thought that was normal procedure

[Kappy]

I'm going with light loads. Get them into spec.

[G38xOC]

thats what im going to do , still have more room to go . already opened up the gas blocks . i counted 9 turn from fully open to close . I back out 7 turns out .i think that should be good place to start . thanks

[Horton Fenty]

I don't load for service rifles, but I found the section about reloading for them in Sierra's manual very complete. Looks like most if not all of it is online here. Thought you might find it useful if you haven't read it already.

[mroels]

My starting loads with TAC for 168gr bullets is 41.5 grains. PM your email and I'll send you the manual I got from ramshot

[G38xOC]

^ thanks Mroels

PM coming

[IPSICK]

thats what im going to do , still have more room to go . already opened up the gas blocks . i counted 9 turn from fully open to close . I back out 7 turns out .i think that should be good place to start . thanks

7 turns out from close? I don't reload right now but if you have to turn your gas block out that much, it sounds like your loads are way too light.

Also, adjustable gas blocks and .308 loads are very sensitive from load to load. You pretty much have to adjust the gas block for each load you make.

*ETA: What is your ejection pattern with factory loads? Does it seem overgassed?

[G38xOC]

^
when shooting , the gas block was out about 3 1/2 turns out . I've only turn 7 out after Huckberry recommended that i should turn it all the way out and find load then tune it .

I didnt know 308 gas block were so sensitive , thanks for that information . I will probably stay with 2 loads at the max ( one 150fmj for range , 178grain for hunting down the road) .

as far as observing sign for high pressure and ejection pattern on brass . I did not find has harsh ejection signs . to me it didnt seem overgassed ...

I think Ive found the way though ..
I can do like 2turns out from close for a starting point - put 1 rd test load per shot ( this way i get do two things at once .. load tesing and watching for bolt lock back position ) while adjusting gas block . To me , if bolt locks up back tell me it will extract properly ..

will report back after friday