Hey guys!  I've looked around web and arfcom and can't really nail down a firm answer.  I have an 18" wilson combat barrel it has rifle gas system.  Looking for buffer/spring combo that works best with the 204 in terms for reliabilty/function.  I know 204 can be tempermental when it comes to gas system.

Thanks in advance for any help!

Have a 20” with an A2 fixed stock and standard rifle spring/buffer.  Normally run 32gr Vmax but have played with heavier and never had any cycling issues. Is fun caliber - you’re going to enjoy it

Thanks!  Good, I was wanting to do a rifle stock setup, glad you have had good luck with it!

Ultimately it is going to require you to test there is no way that we can say X or Y setup will work 100% or be a complete failure.  Generally there is a fairly wide range of buffer weight/spring setup that will function with most differences being the ejection pattern.

Agreed!  Also gas port size and barrel length plays a big part in that too, each barrel setup can be different.  Mainly I was trying to get some idea on where to start.  I have a few different buffer/springs combos I can try, from what I read it was suggested that the ejected cases land somewhere around the 3'oclock to 4'oclock position.

Setting aside going the adjustable gas block route the gas port/barrel length would kind of be the static part that do not change.  I know you can drill the port out more but the buffer and spring are the easiest to change to get the timing right unless you are way overgassed.  Really the range that is going to function is fairly wide.  Ideally you want somewhere around that ejection but if it is kick out and functioning 100% at 2 or 5 I would not be alarmed.  What you want to avoid if you reload your brass is the brass getting pounded on the deflector during ejection.  If it were me I would try a standard rifle buffer and spring and work from there.  More than likely you are going to function but if you are getting your brass beat to hell then increase the weight of the buffer.  If you are having issues of the rifle not closing or stripping rounds off the mag then increase the spring weight or if the rifle is cycling to fast before the round is presented from the magazine then lighten the spring.  You might also have variations on the ejection based on the load you shoot one may give you the perfect 3-4 but another may be a little forward or back of that.  What I like to see is that my brass is being ejected somewhere between 2-5 and the same load is ejecting fairly consistently in the same direction almost making nice little piles of spent casings.

You're probably way outside the normal operating window running an 18" barrel rifle gas system, with a bullet moving 4,000fps.  It's not dwell distance, it's dwell time, and you don't have any at 4,000fps.
That gas port is going to be very large, with your little 20 cal bullet running over a significant size pot hole in the barrel.
Unfortunately, the ARFCOM group-think is so thick, Wilson would never be able to sell one with a correct mid gas system.

Tony