Senco, DS440AC, Screwdriver Kit, 20-3/4 in

I was building an addition that has tongue and groove sub-floor and though that this tool would be a back saver. All I can say is why didn't I get this sooner? I have built and remodeled five homes and this would of saved me soo much time, let alone the fences I built. The tool is very easy to setup and use. I screwed in a 4x8 sheet of sub-floor in 1/3 of the time, at least, it I had to use a standard driver and screws. The screws are more expensive, but the ease and speed make up for the additional cost. It comes in a very nice bag, but because of the shape of the tool, a little cumbersome to store. A few things about the tool now that I have installed 400 sq feet of sub-floor, 1000 sq ft of sheathing, and 120 sq ft of decking:1. If you go on an angle, sometimes the screw will not go completely in. For example, your sheathing only has 1/4" of 2x4 available, I would hand screw the screws.2. The forward/reverse button isn't in the best location. When I was loading up the screws, I accidentally knocked it into reverse. I didn't know it and was freaking out because the screws weren't going in.Besides those minor items, a superior product and a must have for any serious DIYer or has a large project (i.e., new deck, fence, etc.)

I had a big project to do....new 1/2” subfloor on a 1750 sq ft house to firm up some spongy OSB original subfloor. I’m not getting any younger and I found this screw gun after seeing it on some home repair TV show. The price was right and after reading the directions, it was put to the test. WOW...what a back saver, and saves a lot of time! I use a square bit drive and 1 1/4” screws. The magazine is easy to load and you can drill 50 screws before you know it. Yes, it is a little touchy as you need to be pretty much vertical for the bit to align with the screw or it won’t go in all the way, but once you develop a rhythm, you are an instant expert. This gun is well made and the system works....don’t wait like I did!

There is a small learning curve, but if you carefully read the instructions, this is a great time saver. More importantly to me it eliminates the jumping up and down, driving screws one at a time, painful knees and back strain. If you set it up as per instructions, the only thing you should remember is run the drill at full rpms as you drive them. A great tool.

Amazing tool. This decking and floor screw driver is truly a huge time saver and knee saver. On a scale of 1 to 5 I would give it a 6 without reservation. It was a little dicey to operate at first, but once I read the instructions (duh), it worked perfectly. The only thing that slows you down is having to stop and insert another strip of screws. This is one of the best tools that I own.

The DS320 auto-feed attachment is unreliable. I bought it hoping to save many hours screwing down the subfloor on a new home we are building. It worked at first, and was wonderful. It installed screws very quickly, with only a few misfires. But, after driving two buckets of Senco collated screws, the included square-drive bit had rounded off, and so needed to be replaced. I carefully followed the instructions for bit replacement in the included owners manual, replacing it with one of the identical Senco replacement square-drive bits I had purchased along with the gun. But, after bit replacement, the DS320 auto-feed mechanism would not synchronize with the SG4100 screw gun. When the spring-loaded tip of the DS320 was depressed the strip of collated screws advanced, but the bit did not engage and drive the screw.I then carefully disassembled the DS320 attachment from the screw gun, and reassembled it three successive times the same way I had initially assembled it after purchase, following the step-by-step instructions in the owners manual. I ensured that all components were securely connected, per the instructions. The result was the same all three times: the strip of collated screws advances, but the bit does not drive the screw, so the screw just falls out of the plastic screw strip. The relevant entry in the troubleshooting section of the owners manual suggests taking it to a Senco authorized service center for warranty service. I am thus left with no choice but to sacrifice the time required to take it to and then later pick it up from a Senco service center.Given the time required to assemble the tool when received, then attempt to troubleshoot when it failed, and then take it to and pick it up from a Senco warranty service center, it would have been more time effective to simply install the subfloor screws the "old fashioned" way--with my very reliable impact driver. On balance, I have spent more time, and of course lots more money, than if I had just used my trusty impact driver in the first place. The $$$$ spent on this unreliable tool were, therefore, wasted.I will update this review after I get the tool back from the Senco warranty service shop. But given my frustrating experience, I cannot recommend that anyone buy this tool.

Made building a deck much easier. I bought some spare bits but one bit lasted for my entire 12 x 24 deck. I had one jam on my first use when the plastic strip fed back in on itself. My only quibble is the extension occasionally loosens up.

This thing is the bomb!! Purchased it to screw subfloor sheathing down over planed 2x6 T&G ... 15 minutes a sheet (approx 80 screws) turned into 90 seconds a sheet ... and I didn't have to get on my knees. So nice.Effortless feeding of screws and works with continuous engagement of drill trigger ... you don't have to stop the drill when repositioning - Best tool purchase I think I've ever made.Minor note: Be sure the wand extension is fully seeded/attached to drill. Otherwise, you won't be able to countersink your fasteners.My fault ... remedied in 2 minutes