Home Forums Hunting & Shooting AR and Tactical Rifles Adjusting Gas Block

I've got a 224 Valkyrie that I am shooting 75 gr American Eagle ammo in trying to accumulate brass. I have enough to start reloading some 90 gr Sierra with and was wondering if I would need more or less gas adjustment for this. PSA states the gas block is adjusted for 77 gr bullets as it is now, but I think it is a little over gassed. I held up adjusting because I really wanted to try the 90 gr bullets and see how they would shoot first. I had a hard time getting the locking Allen screw loose the first time I tried loosening it and was wondering if I should apply Never-Seize or something on it to help keep it from seizing? Thanks for any advice, I've never worked with an adjustable gas block before. Anything obvious that I should know would be greatly appreciated, as I know nothing about them now.
Thanks, Chuck.

I believe the critical factor is more to do with charge weight than bullet weight.

More powder makes more gas volume. Going to a heavier bullet might call for less powder, or maybe more of a slower powder.

Then, the heavier/slower bullet will cause longer dwell time, so that is another factor.

I think you will just have to play with it and see how it goes. Then maybe close the gas enough to cause failure, then open a little at a time until it runs right.

Yeah, that's what I was thinking also about adjusting until it wouldn't lock the bolt open. Than opening up gas port. Just feel better hearing that from you and a couple others here before I venture into the unknown for me. Some of this AR stuff is new to me. In past I just shot a lot of cheapest Federal Brass factory stuff I could find in the 5.56/ .223 ammo I could find.
Thanks for the reply and advice, Chuck.

My adjustable gas blocks (SLR) do not have set screws to lock the setting in place, rather, the sdjustment screw has detents that keep it at the desired setting.

So I think it might be a good idea to put a little never seize on the set screw, & it shouldn't hurt anything.

As to adjustment, different loads may need to be fine tuned, depending on how you want you gun to function & where the brass ejects.

I usually set mine so that the ammo that I want to use (most of the time) ejects at about 3 o'clock.

This will usually allow for a little hotter ammo to eject a little bit more forward, & softer ammo a little bit behind that.

Depending on how much difference there really is in your ammo extremes, you may end up preferring specific settings for the different ammo.

Adjustable gas block are a nice tool, you just need to decide how fine tuned you want a given load to perform & how many different loads you want to shoot respond to a single setting.

They a pretty much a must if you want to fool around with lightweight BCG's.

MM