ASG Factory Upgrade Tightbore Inner Barrel for McMillan M40A3 Sportline Airsoft Sniper Rifles

"Straightforward upgrade for my Matrix/Double Eagle M40A3. Transferring the hopup unit was a bit challenging but over all a simple upgrade.

"Very happy with this upgrade. It was easy to install but you do need to shave down the barrel spacer as the new barrel does not have the soccer groove of the original. The barrel to hop up fit was identical to the original barrel so no modifications were needed on that end. The M40A3 was pretty accurate out of the box so this just helped improve and already well performing rifle, I’m now grouping all my shots in a 2 inch square at 120 ft.

"Nice upgrade for the M40A3 to a tightbore inner barrel. Mine wasn't made quite right, and was missing the groove for the barrel spaces, so I had to shave down the spacer a little bit... still works great though!

Be careful when opening the hopup as there are a few small parts that you can easily lose... I highly recommend looking it up on youtube before you start!

"it fits in my ASG M40A3 just fine, minus the barrel stabilizer, there's no notch in the barrel to accommodate. luckily the thread adapter on my outer barrel helps hold it in place but it like to think the stabilizer is there for a reason so i may need to see if i can dremel the spacer out