The KIDD aftermarket replacement for the .22LR Fluted Stainless Steel Bull Barrel is one of the best-looking barrels on the market and performs with the expected KIDD Quality. The fluting enhancement in a .22 rimfire is more of an aesthetic or cosmetic feature rather than for cooling purposes. But this refined barrel doesn't just look good it is also guaranteed to group 1/2" at 50 yards. This bull barrel will slip into your factory 10/22 receiver or other aftermarket 10/22 receiver. KIDD believes these are the finest barrels on the market, each one is hand lapped. Their stainless-steel barrel is bored and rifled by Lothar Walther in Germany. Tony Kidd then performs all the final machining to make their match barrel a worthy KIDD product. A proprietary chamber reamer is used to ensure the cartridge and bullet feed smoothly. KIDD barrels are chambered to accept .22 LR ammo and have a 1:16 twist. Their muzzle threading is 1/2"-28 and is available with a protective cap. Barrel installation: Depending on your receiver, if there is paint build up in the receiver mortise be sure to scrape that out. KIDD recommends using an anti-seize compound to assist in installation. Anti-seize is readily available at automotive stores. It is best if you can get the barrel tenon started into the receiver mortise, then turn it over and tap the back of the receiver with a rubber mallet. Be sure to line the extractor slot up as you are installing the barrel. Your barrel is ready to shoot, just run two magazines through it before you really start looking at group size. Do this each time you change brands of ammunition as well. Keep the chamber clean, but don't clean the bore too much you will decrease accuracy. Depending on the ammo, clean the bore around every 500 rounds. FEATURES: Aftermarket 10/22(R) FLUTED BULL barrel Slip-fit design STAINLESS STEEL HAND LAPPED individually 11 degree crown, 1:16 twist, convex extractor slot Muzzle threading available 1/2" - 28 1/2" at 50 yards 5 shot group guarantee 1:16 twist