Tony13 59 Posted August 16, 2019 My first build is an AR9. Had the compensator welded/pinned to the barrel. Brought it home today to discover the barrel nut doesn’t fit over the comp. The comp is aluminum. Is there a chance that it could be drilled and removed or I’m I screwed? Comp is a KAW Valley slim line XL. Handguard is KAW Valley Konza. I’m assuming I’d run into the same problem with all the handguards? Man I’m stupid. Quote Share this post Link to post Share on other sites
Longranger 16 Posted August 16, 2019 Tony13, My first thought is that the weld material covering the pin should be aluminum since the comp is aluminum. A drill should be able to get through that, but you run the risk of breaking the drill bit off when it gets through the aluminum and encounters the pin. I'd try operating on the weld with a Dremel tool or a jeweler's file to get to the pin. Remove enough material to expose the full diameter of the pin. Hopefully it's a roll pin and not a solid pin, right? And it's likely in a blind hole. And it's likely made of spring steel. Trying to screw a tap or screw into the pin usually doesn't work. Pack as much grease into the pin as you can. Or, maybe drops of oil if you have zero luck with the grease. Find a pin punch that's a close fit to the inside diameter of the pin, put it into the center of the pin and deliver a sharp smack to the grease or oil. The hydraulic pressure will force the pin out. I've done this with bushings in blind holes before and this is like a miniature version of that process. DON'T FORGET TO PUT YOUR EYE PRO ON FIRST! -Longranger 1 1 Quote Share this post Link to post Share on other sites
PK90 3,569 Posted August 16, 2019 How big is your comp? The issue should be with the gas block, no? Quote Share this post Link to post Share on other sites
Tony13 59 Posted August 16, 2019 No gas block. 9mm blowback. Comp is 1.2" diameter. I'm assuming all barrel nuts are the same diameter to fit over the barrel collar. Quote Share this post Link to post Share on other sites
PK90 3,569 Posted August 16, 2019 Ok. Yes. All same inside diameter. Take it back to the person who did the pin and weld. Have them fix it. Quote Share this post Link to post Share on other sites
raz-0 1,256 Posted August 16, 2019 Just now, PK90 said: How big is your comp? The issue should be with the gas block, no? It's a 9mm carbine so blowback and no gas port. The comp is 1.2" in diameter. It's a linear comp too. And on a 9mm. So it racks up a stupid trifecta and wins and places for being useless. If it is pinned and welded, the tried and true method of undoing it is to sacrifice the comp. Method 1) Dremel with cutting disk. go VERY, VERY slow and cautious. slice the comp on one side length wise with the pin under the cut. Cut all the way trhough to the bore of the comp in the part that isn't over the threads Get as close to the threads as you can on the part that is over the threads. Then use tools to spread the comp open and peel it off. Usually a cold chisel, vice grips, hammer etc. Method 2) dremel with a grinding bit until you get through the weld to the pin. Then use a cutting disk to notch out the metal either side of the pin, and use a vice grips to pull the pin. Then unscrew the comp. If you get the pin out and can't unscrew it. Use a torch to theat the comp until it is dark cherry red. Let cool and try again. That should destroy most thread lockers. If that doesn't work, it's method 1, or heat it to cherry red and try to unscrew it while it is hot. You may want to invest in some heat block/ heat paste to protect the barrel while heating it. Quote Share this post Link to post Share on other sites
Longranger 16 Posted August 16, 2019 Dang! ID on the barrel nut is what, 1.182"? So it would just clear if you took 0.018" off the comp OD? Or, opened the ID of your barrel nut 0.018"? 0.009" off the thread height. -Longranger Quote Share this post Link to post Share on other sites
Longranger 16 Posted August 16, 2019 Barrel nut ID maybe 1.190"? Even better. Do you need to be a gunsmith in NJ to open up a barrel nut ID on a lathe? -Longranger Quote Share this post Link to post Share on other sites
Tony13 59 Posted August 16, 2019 7 hours ago, raz-0 said: It's a 9mm carbine so blowback and no gas port. The comp is 1.2" in diameter. It's a linear comp too. And on a 9mm. So it racks up a stupid trifecta and wins and places for being useless. Yep. Quote Share this post Link to post Share on other sites
Tony13 59 Posted August 16, 2019 7 hours ago, Longranger said: Dang! ID on the barrel nut is what, 1.182"? So it would just clear if you took 0.018" off the comp OD? Or, opened the ID of your barrel nut 0.018"? 0.009" off the thread height. -Longranger Not enough meat on it to this. I like your thinking though. Quote Share this post Link to post Share on other sites
Tony13 59 Posted August 16, 2019 Took it back to the smith today. Comp might get trashed. Barrel should be good to go. We’ll see. Quote Share this post Link to post Share on other sites