Adjustable gas block or AGT?

[prebancolt]

Thanks for all the info thus far guys.

I just picked up a 16" stainless olympic barrel with a block at the pistol position. I'm going to be shooting subs and supers out of this upper. What are the pros and cons of the adjustable gas blocks versus the adjustable gas tubes? Which ones are best i.e. which one should I buy? Any help/suggestions are welcome. Thanks again.

J

[prebancolt]

Come on guys, I know some of you have an opinion! Chime in, I don't want to buy the wrong item.

J

[Artful]

Gas Tube - must have have location either as carbine or rifle as I have not see as pistol length tube. Also you need to have a hole in the right position on the handguard/free float tube to adjust the gas.

Block- may need machining if you want it to go under a free float forearm. Both about same price range. You may also need an allen wrench to adjust it in the one I looked at.

For now I'm going with just a normal tube to see about function with full open and I have set mine up with carbine tube length on 16" barrel with block forward of the carbine full float tube. Leave the option to put either on it later and was cheaper as I already had stock parts which are cheap.

[prebancolt]

Thanks Artful,

It looks like I might not be needing either one. I just loaded some rounds this morning and subsonic AND supersonic both worked in my upper without any hiccups.

My barrel assembly is an olympic with the gas block in the pistol position. I checked and the hole is about 0.080". I loaded a few rounds 110 g with 19.5 g of H110 powder and it worked fine. Then I loaded a few rounds 220 g on top of 8.6 g H110 powder and it worked fine. I then loaded some more of each and alternated them in the mag - super, sub, super, sub, super, sub, etc. and the gun still ran fine.

I was really expecting to have to spend more $ and time tuning this thing, but it looks like I lucked out. We'll see after I do some more extensive testing.

Thanks to everyone for all the excellent info. You guys are the sole reason I own this caliber!

J

[Artful]

Good for you! :smile: my Dies and brass arrived yesterday so I will be forming some 221 into 300 whisper and trying my loads as well. Paperwork still hasn't come thru for Can so unsuppressed for now.

On another board someone suggested if you were getting blow back from the charging handle area the quick fix was JB Weld or Silicone in the last little bit of the channel (from hook area to end) in a wedge shape to force the gas into the buttstock tube.

And it was suggested to put on a good solid brass catcher if your getting too much gas out of the ejection port. they used some sticky insulation tape to keep gas from flowing back towards the shooter.