They work great! As advertised they lock onto the bottom of my uppers keeping the good junk in and not the outside dirt and grime. Seventy five percent of the time that I would grab an upper to mess with the bolt would slide out and almost kill a toe. Especially the pistol caliber bolts. They are just heavy enough to break free from the dust cover tension and blam! That used to be a toe!!! Simple but great device.
TopStop AR Upper Receiver Cover
The TopStop cover is designed to snap on most AR15 or M4 type upper receivers when they are detached from the lower receiver. The TopStop completely seals the upper receiver preventing fouling from getting in or out and it stops the bolt carrier group and charging handle from sliding out as the upper is moved around. The TopStop is made out of super tough polymer and is impervious to most solvents and chemicals. This product is perfect for storing or transporting your spare upper recievers, especially in low-profile bags where the rifle must be broken down to fit.
I purchased this to keep dust and dirt out and lube in my gun during transport to the range. I carry my rifle broken down in a backpack on my motorcycle. Works perfectly for what I need. I do wish there was something for the lower to protect my Geissele trigger pack but otherwise great product.
I have several dedicated purpose uppers and needed something to protect the internals from getting garbage in them, I tried a different top receiver cover first and it just didn't stack up. This cover is rigid, holds on tight, but still is quickly removable. Well worth the money for storing a gun broken down or as a way to keep a second upper clean and ready.
Super simple; slap it on and it covers your upper receiver. No pins to lose like the bolt savers. Grabs on via the rear receiver pin hole; the inner lining is dimpled a bit so that it locks into the pinhole. Doesn't grab at the front, but slips in and forms a nice seal with the receiver.. It's a little stiff at first to get off, but this breaks in with time.
I have a 9mm ar15 that Is broken down to fit in a discrete case. I wanted something that would keep the bolt from slideing out of the reciver and also keep lubricant off the case The upper reciver is a side charging New Frontier Armory,the topstop cover fits perfectly holds on great but comes off with ease for quick assembly .this accessory works as described I like and recommend it!
A good little piece of gear at a good price, works as advertised. If you have to travel with your weapon in two parts, or your lower pulls double duty, or more (multiple uppers, varying lengths, and/or calibers) then this is a good investment.
I use the TopStop alot for transporting my BCM M4 fits perfect and isn't too tight (unless you put it on backwards I digress). Overall great price of gear if you need to transport your rifle broken down so you can be worry free.
Fits snug and holds BCG & CH securely. Some are complaining about difficulty removing the cover. I found that by rocking the cover side to side while pulling down it comes off easily.
Although the fit is very tight at the locking nubs that hold the cover on, I expect it will become easier to put on and remove the more it's used. The molding to match the shape of the upper receiver openings is accurate and fits perfectly. The material is quite hard and I expect it will work as advertised for a long time.
I have a handful of AR uppers, more than i do lowers, and reciever covers work well keeping the BCGs in place. Either in storage case or in one of my small weapon case, or in my discrete carry bag (rifle has to be seperated to stow in the case). Also makes it easy to carry a second upper when i feel like it.