{"product_id":"retro-arms-cnc-hop-up-kammer-pro-m4","title":"Retro Arms CNC Hop-Up Chamber Pro, M4\/AR15","description":"\u003cp\u003eThe Retro Arms CNC Hop-Up Chamber Pro is a complete hop-up chamber for AR-15\/M4 AEGs, CNC-machined from EN AW 7075 aircraft aluminium and anodised. The Pro version builds on Retro Arms' well-known Basic chamber but has an adjustable feed lip, so the chamber can be adapted to receivers and magazines that don't seat or feed correctly.\u003c\/p\u003e\n\n\u003cp\u003eThe hop-up chamber is one of the parts that affects accuracy the most: it centres the barrel, holds the bucking and determines how the BB is fed in. Many AEGs have problems with magazines that don't lock or don't feed cleanly, because the feed lip sits at the wrong height relative to the receiver. The Pro chamber solves this by letting you adjust the height in 0.2 mm steps with the included shims.\u003c\/p\u003e\n\n\u003ch3\u003eWhat makes the Pro version different\u003c\/h3\u003e\n\u003cp\u003eKey features of the Retro Arms Hop-Up Chamber Pro:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdjustable feed lip:\u003c\/strong\u003e The feed lip height is adjusted in 0.2 mm steps with the included shims. Without shims it sits as on the Basic chamber, so you can adjust from a known starting position.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBarrel collet nut:\u003c\/strong\u003e Instead of a centring ring, a collet nut at the front clamps barrel and chamber together and eliminates barrel movement. It fits barrels with an outer diameter of typically 8.4–8.5 mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eR-hop ready:\u003c\/strong\u003e The chamber is prepared for R-hop, so you can upgrade the hop system later without changing the chamber.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eO-ring in the feed lip:\u003c\/strong\u003e An O-ring in the feed lip holds the last BBs in place when you change magazines, so they don't fall out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e7075 aluminium:\u003c\/strong\u003e CNC-machined from EN AW 7075 aircraft aluminium and anodised – stiffer and more dimensionally stable than plastic and standard chambers. The fine-tuned main body and feed lip suit most hop-up buckings.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eMaintenance and safety\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSecure the adjustable feed lip with medium-strength threadlocker after setting it, as Retro Arms recommends.\u003c\/li\u003e\n\u003cli\u003eMake sure the barrel doesn't rotate in the chamber when the collet nut is tightened.\u003c\/li\u003e\n\u003cli\u003eSet the feed height gradually and test with your own magazines before locking the setting.\u003c\/li\u003e\n\u003cli\u003eOur workshop in Aulum, Denmark can fit and adjust the chamber to your receiver and magazines.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Retro Arms","offers":[{"title":"Default Title","offer_id":48102613057590,"sku":"RA-9426","price":439.0,"currency_code":"DKK","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0645\/1222\/9430\/files\/4695_hop-komora-ar15-pro_8245.png?v=1792402067","url":"https:\/\/hanktactical.com\/products\/retro-arms-cnc-hop-up-kammer-pro-m4","provider":"Handelshuset Aulum","version":"1.0","type":"link"}