In the first phase of the test, I took the tools into our shop and ran hundreds of screws through each one to get a feel for each model. The good news is that they all operated effortlessly; I could happily run subflooring with any of them. However, when all the tools in the test group are this good, it makes it pretty hard to pick a winner.
When I finished my shop testing, I took the tools out to the field where they got a real workout. We used them on a big job installing 3/4-inch OSB subflooring over engineered joists. We also ran a fair amount of 2x6 redwood decking fastening into ACQ-treated-wood deck joists. We looked at ergonomics and ease of use, quality and performance, and how the tools shook out in terms of practical applications.
Once the guys had a chance to work with all of the tools, we compared notes and made our recommendations.
Muro's extension handle adjusts easily, but its T shape doesn't offer the same feeling of control as the pistol-grip-with-side-handle designs.
Credit: Photo: David Sharpe
The length of the tools in the test group range from approximately 36 inches to 42 inches. If you're tall like I am, the longer autofeed screwguns will appeal to you. If not, then maybe a 36-inch tool is going to be just right for you. The important thing is to be able to work in an upright position and reduce fatigue and back strain.
The good news is that some of these tools can actually be adjusted to fit your height. The length of the Senco AC can be adjusted from 31-1/2 inches up to 41-1/2 inches.
Makita's tool has an adjustable-length extension that gives you about a 4-inch range; with extension handle in place, it starts at 36 inches and can be extended out to just under 40 inches. You adjust the shaft length on the Makita by turning a thumb screw, but then you need an Allen wrench to adjust the tension cable that operates the trigger. This was enough to discourage me from adjusting the length of the tool very often.
Both Muro models use length-adjustable extension handles. The FDVL41 extension adjusts the tool from 35 inches to 42 inches and the CH7390 goes from 36 inches to 43 inches. The Muro extension handles don't have triggers, so you have to bend down and lock the motor in the "On" position to operate and bend down again to turn it off.
The Grabber/Hitachi, PAM, Senco S2, and Simpson Quik Drive are all fixed-length tools. Their extension tube is between the motor unit and the autofeed attachment, which puts the weight of the motor in your hands and keeps the nose of the tool light and easy to maneuver. By placing an extension tube on the handle of the screwgun, the Makita and both Muro autofeed systems put all of the weight of the motor at the bottom of the tool. I found the Grabber/Hitachi, PAM, Senco S2, and Simpson Quik Drive much easier to handle than the Makita or Muro models.
Grips & Handles
The Quik Drive kit we tested uses two driver attachments: one for thin screws 1 inch to 1-5/8 inches long and one for thicker screws from 1-1/2 to 3 inches long.
Credit: Photo: David Sharpe
The grip and handle configurations of these tools vary, too. The most common is the pistol grip drill with a second handle coming off the extension shaft. The Grabber/Hitachi, PAM, Senco S2, and Simpson Quik Drive all use this design. The angle of the shaft handle is adjustable on all of these models except the Senco S2; its side handle is fixed at 90 degrees to the pistol grip, which is where you'd probably want it anyway. The handle on the S2 can be installed on either side of the tool to accommodate right- or left-handed operators.
The Senco AC also uses a pistol-grip design, but to hold this heavy tool with both hands in a standing position you have to put your free hand on the end of the tool. I could make this work, but it felt a little awkward. After swinging it around to place a hundred or so screws, I found myself wishing it had a side handle like its little brother, the S2.
The Makita extension has a wide-grip D-handle set at 90 degrees to the shaft and a wraparound grip lower down the extension tube, which I found uncomfortable. My left arm began to tire after running this tool for only a short time.
The Muro FD uses an extension tube with a T-bar handle. This is a solidly built tool that uses a big 150-screw-capacity drum set behind the driver nose, and weighs more than 11 pounds without screws. You have to sort of walk around the drum as you move the tool along. It takes a little getting used to, but in return you get the added fastener capacity. With the T-bar handle, the big drum, and beefy tool weight, I couldn't help but feel a little like I was operating a floor buffer instead of a fastening tool. It's a big tool, and it's all business, punching screws through floor deck effortlessly.
The Muro CH uses the same T-bar handle as the FD, but instead of the large drum it has a 30-screw collated strip-feed. Its lighter weight and smaller size make the CH a lot easier to handle, but I didn't feel like I had as much control of the tool with the T-bar handle as I did with the pistol grip and side handle configuration of some of the other tools.
I preferred the pistol grip and side handle configuration to any other. The weight distribution and maneuverability of the Senco S2 made it one of the most comfortable in the group to work with, even though it doesn't have height adjustment or even the capability to swing the side handle around to a more comfortable angle.