Hello, I am building an AR for the first time, and just got a ballistic advantage barrel in the mail. I was looking at the gas block however and am concerned about the method by which it is attached (coiled roll pin). I'm looking at it and am not 100% sure that it would be able to keep the gas block perfectly aligned like a taper or solid pin would. It also includes 2 set screws, however I am not sure if I should use some sort of loctite/rockset at all, or just torque it down to a certain specification. If so, does anyone know what specs Ballistic advantage suggests for their screws?

Also, has anyone installed one of these before? and if so, what tool did you use for the gas block pin?

thanks!

-Ashley

The pin is to hold the gas tube in the gas block, I just use a flat drift punch that I happen to have.  I start it with a small hammer and needle nose.  I have never used any thread locker on the set screws and have never had a GB come loose.  Line it up and tighten it down.

I’ve assembled several - used a roll-pin starter punch, then roll pin punch.  No problems with alignment, etc.  A couple got a drop of Rocksett on the set screws, others Red Loctite.

You can double-check alignment by tightening the set screws a couple times (not a bad idea anyway), then remove ‘em and pin it.  Odds are you’ll see the screw marks through the threaded holes to verify it’s GTG.

actually, there are 2 roll pins. One to hold the gas tube, another to hold the gas block. That's how ballistic advantage does their gas blocks/barrels.

How well does the rockset work? I hear people tell me it doesn't always set up properly. Is it easy to remove the screws still afterwards?

Get the set screws nice and tight. Red loctite or Rockset works well.

Never had issues with the red loctite.

Between proper torque, thread locker, and the roll pin the gas block is going to be plenty solid.

Roll pin punch or really any punch for the gas block pin, although you can mushroom the end of the pin with a standard punch if you start whacking away at it too much.

As for the set screws, clean and degrease both the screws and screw holes and then add a small dab of Loctite 272 (Rocksett will work as well).

The vast majority of LPGBs only utilize set screws, so the addition of the coil pin only adds strength and helps with alignment, you shouldn’t have any worries there.

BA drills and pins their gas blocks to their barrels utilizing a coil pin if the barrel is sold with a LPGB.

ETA:  May only be the Hanson series barrels.

I have 2 BA barrels and neither has a hole for a pin.

I have 2 BA barrels and neither came with cuts for pins.

I have several set screw-attached GBs. No locker. Only one did I dimple only for the experience. None loose. Believe on the ones I used a fat wrench on I went to 35 inch pounds. The remainder I just tightened the crap out of them.

Has to be a Hanson barrel

Then you didn’t buy one that comes with a pinned gas block.

I can most certainly tell you this barrel is drilled for a pin. Infact, I specified as such when I ordered it, so it better be :)

On that note, lets say that the screws *somehow* backed out or failed, the coil pin is going to be sufficient for maintaining alignment?

Since it’ll be under a (most likely) handguard, yes.

Regarding Rocksett, just clean the threads and set-screws with a solvent like Naptha or Acetone (same as any other adhesive).  I’ve never had an issue with it not curing.

Really though, that’s thinking too much about it - kind of like worrying about a tiny speck of bare aluminum barrel threads causing weapon-impairing electrolysis due to the barrel nut being a different metal (usually steel).  Not in our lifetime...

Assemble that stick & shoot it!

True. Very sharp. Basic Modern series. But I wrongly interpreted the OP's statement "That's how ballistic advantage does their gas blocks/barrels." as gas block or barrel, independent of one another.

Perhaps but I'm thinking not. No real need to machine a "trough" for a roll pin as would be for a tapered pin. I've seen a Hanson video where "Hanson" speaks to correcting an off-center "pinned" Lo-Pro by loosening the set screws, realigning, retighten set screws. Both pins have advantages and disadvantages. I see their choice of a roll pin as a hobbyist - oriented decision. Should be fine though because normally GBs with only set screws do well assuming the GB is installed properly.

Op you are not crazy, BA does offer pinned gas blocks with their barrels. Yes the pin is not a solid tapered pin but either is geiselle's. From an accuracy (precision) stand point, a straight pin whether solid or coil is preferable over a tapered pin due to not having the wedging effect a tapered pin has. AK's use (solid) straight pins for everything attached to the barrel including barrel to breech block, rsb, gas block and fsb; I have never heard of pinned AK component failing that was installed with a proper fit pin.

The coiled straight pin in combination with threadlocked set screws should be plenty solid. I would not worry about it at all, especially under a gas block.

As others have said degrease the set screws and holes in the gas block before applying your thread locker of choice. Rockset will be super solid and the screws will not back out until you break it down by soaking it in water. As far as torque, personally I would thread the screw in until it interfaces with the dimple and use a single finger to put a very slight amount of additional torque from the allen key into the screw..thats it. You do not want or need to crank the screws down with monkey strength, the loctite or rockset will keep them from moving.

Check out this video for a better understanding of how little torque is required.
https://m.youtube.com/watch?v=aSi75yrTIKQ

If all I had was a coil pin I wouldn't be concerned, add in the set screws with some red Loctite and it isn't going anywhere. It isn't a load bearing part, if there's a rail over it then it is protected, and to top it off alignment isn't micrometer critical.

They most likely go with a coiled pin because a coiled pin will compress a bit to fit securely without the need for wedging (taper pin) or having a precise interference fit (solid pin). Taper pins normally used in fsb/gb combo (A2 fsb) retain themselves via the wedging effect of the taper, it also does not require precision measuring instruments and the skill to use them. AK barrel component pin holes are meant to be drilled slightly undersized and then reamed to a precise final diameter, the solid pins are oversized by 0.002 for a interference fit which retains the pin. Both the A2 fsb with tapered solid pins and AK barrel components with straight solid interference fit pins are exposed withhout the shielded protection of a handguard.

thank you! I think I'm just overthinking this because a few people have told me that coil pins will have a wobble.

You have 2 set screws, right?  Where's it gonna go.  Pin might be nice for positioning the GB but other than that I see no reason.  Have several set screw GB's and none have moved.

Ballistic Advantage has two videos that can be helpful with this on their Youtube Channel

Q&A Ballistic Advantage E:29 – How to Build Out Your New BA Hanson Barrel!

Ballistic Advantage Low-Pro Gas Block Install

Same as a Geisele, red loctite and run it.