Thread: ar15 short stroking

Ok so poblem.

Band new RRA 6.8spc, tested with reloads, working fine, stock standard. Gas block was the clamp style.

Got the barrel milled down and fitted low pro gas block with the two grub screws, free float handguard ect.

Same reloads now are making it short stroke. e.g will eject round but not pick up next one. What do you guys reckon the issue is?

Cheers

I don't know much about AR15s but you have changed the gas block so I would have said that its the gas block. Is the gas block aligned with the gas port in the barrel? Otherwise gas port diameter etc ...

Is your gas block lined up correctly with the hole?

When you say milled down,was it shortened? If so this would shorten the amount of time gas is entering the gas system.
You could also have fitted the new gas block slightly off and it's blocking part of the gas port in the barrel.

I need to type faster

Make sure you dont have the gasblock pushed hard up against the shoulder. There should be a gap between block and shoulder because the ar15 was designed to have a handguard endcap placed in between. Google the thickness of the endcap and adjust accordingly. Theres a chance the gasblock is half obscuring the port because of this, some gas blocks will, some wont. If you have shortened your barrel then there is a chance the gas port is not big enough anymore. I dont know if rock river over engineer there gas port sizes or whether they skate close to the edge of reliability when they set them up.

cheers guys, bit more info...

The barrel was not shortened. Profile was taken from .75 in front of block and .9 behind to .65" all over excluding gas block so there is no shoulder to butt up against.

I have removed gas block and repositioned it and then sprayed the hell out of my bcg with wd40 and it worked perfect at the range just then so quite happy.

Im going to get gunworks to put dimples in my barrel and might get my gasport made a bit bigger, no harm in overgassing is there??

Cheers fullas

Over gassing results increased bolt velocity, which can cause a myriad of issues, cycling problems and premature component failure among them. Did they touch the gas block journal when they reprofiled it? Also WD40 sucks shit in AR's.

the gas block area was not touched at all.

What should i use on it beavis? i read about some people running them wet some dry ect ect

Whats best?

Wet - diesel engine oil