ar15 wont cycle with my loads

[cjmac]

So my varmint rig wont cycle my reloads but will do fine with factory loads,so thats telling me my lodes are to "lite" for my AR. is that correct ?? Im using sierra ar15 load data. 25 grains of TAC with a 52smk. And 23 grains of TAC with a 69gr smk....verry accurate just wont cycle

 

[civil82]

Are you full length resizing?

 

[brian427cobra]

And does your rifle have a adjustable gas block?

 

[cjmac]

Yes i FL resize every time. It ejects fine just wont pick up the next round. .... and no i wish it was adjustable.

 

[mac86951]

First off:

AR Gas test:
Single load one round in the magazine, if the bolt will catch fully open (not on BCG but on Bolt) then your rifle is cycling fine, watch the feed ramps and Cartridge OAL.

If bolt won't lock open, then yes your bolt is short cycling and more gas is needed, CAUTION, this might mean you are using a different burn rate powder. I'd recommend and adjustable gas block as the ultimate solution to shoot what you want, however, you can continue pressure testing and find a higher acceptable pressure load to shoot with. Watch for case head swipe.

-Mac

 

[1shot]

Try a small based sizing die. That little bit pressure that is being used to unlock the bolt is keeping the BCG from having enough inertia to make the full travel to the rear.
I hope this helps,
Lloyd

 

[wapiti25]

Try removing the gas block and try cleaning the port, gas block, and tube. You could see if you can get a lighter buffer spring that would be used only for your loads. I like the adjustable gas block as it allows you to control the gas when you have too much. when you remove the gas block you could open the port hole in the barrel one drill size ( a few .002" or .003") and that may do the trick for light loads but then I would make sure that an adjustable gas block is installed.

 

[cjmac]

Well all the parts are new, i had an A2 buffer and spring i thought maby it was to strong, so i used a M4 buffer. Didn't work.... could it be lite charges ?

 

[brian427cobra]

Make sure the gas key on the bolt carrier is not moving, the screws should be staked to prevent them from coming loose, inspect the gasblock for any signs of gas leakage(ie black soot everywhere) since you swapped recoil spring and buffer, what lube are you using on the BCG(bolt carrier group)

 

[pwdrbrn]

I lightened the buffer itself by three tenths of an ounce to make it work with 40 grain bullets and 55 trainers too. Couldn't find lighter springs, like a pistol, to use to tune.

 

[searcher]

Go on the net to Wolff springs. They make "reduced power", "normal" and "extra power" springs. Very reasonable. Cycling problems in A/R's occur regularly with light bullets, especially in those that are heavy. The heavier the rig, the lighter the bullet, the more problems without changing your buffer spring to accomodate. I shoot 36 to 40 grainers in .223 and 32 grainers in .204 through my A/R's with no problems. I automatically start with a light spring when putting together a new varmint rig, changing only if it seems my bolt carrier is slamming to the rear a bit hard. Changing the springs will also change the accuracy of your load (for better or worse) and can be an aid to tuning your A/R. I'd try the reduced spring before messing with port size or the expenditure of an adjustable gas block. If you ever lose your setting on an adjustable gas block, you will have to re-tweak your load to shoot the same (assuming your gun is accurate) My 2 cents.

 

[cjmac]

For lube iv tried clp and FP10 BY shooters choice . Gas system seem all good, its weird works good with LC 55 grain fmj . I think there kinda hot loads anyway. I think im going to bump my charge a little.im still one and half grains below max in my sierra book. If that dont work its got to be spring ,buffer is to strong. I have a m4 carbine one it now.