SOLGW COMBO DRIVE GRIP SCREW

[Ned Christiansen]

Of all things to worry about on your AR, this one is way down on the list. A recent survey showed that only .03% of gunfights are lost due to the grip screw

But seriously, I get why the convo on this. It's a matter of convenience and, let's be honest. When you have a system that is highly developed over decades, when almost everything has been standardized and perfected or nearly so, when it has evolved to a point where a mfgr almost has to make a special effort to F it up (and, oh yeah, many do!), then you start reaching of the little details inside other details. So I say good on 'em (SOL and MagPul)for the screw. My only thing would be, now it's a non-standard socket size-- but if ya got all the wrenches, that's no biggie. The slot is a great idea that one of my mentors has been wishing for for years; I took some standard screws a few years back and slotted them so he could stop talking about it for a while.....

As to US-made or not, if SOL says US I have no reason to doubt it, my impression of them is "totally credible". In truth these screws aren't really what you could call a "critical fastener" and I'll wager that the slotted, plated pan-head or round-headed screws that were a Colt standard for so long are made from mild steel and not something like heat-treated chrome-moly (4350 usually, I think). It's not a bridge or a space shuttle.

If I were gonna make grips screws I think I'd use a standard 1/4-28 cap screw with the standard 3/16" socket, slot it, and the end would have a pilot, in other words, the last 3-4 threads would not be present, it would be of a diameter where it would just enter the tapped hole (I think about .210) to help prevent cross-threading.

Or how about-- a double-hex head screw, with a 3/16 socket too, and slotted. Just throwing this out there and haven't checked any dimensions, but could the hole in the charging handle that passes over the carrier key be broached to make a 12-point socket that could reach into the pistol grip? Or maybe the CH could have a blade machined in the end to work in the screw head's slot. I know the CH is only aluminum but these screws don't need a ton of torque. I'm a big fan of "all the tools to take the machine apart are in the machine".

https://www.mcmaster.com/mvD/Content...=ImageNotFound

[prepare]

Finding a verifiable American made mil spec equivalent with decent pricing for 10-20 quantities is the difficult part.

[the AR-15 Junkie]

I searched thru all my M16A1 and M4A1 TDP drawings and not one mention of the grip screw specs lol. Everything else is in the drawings though. Cant figure why they left out the screw.

Before anyone replies its 1/4 X 28 X 1, we all know that but the TDP usually gives far more in-depth information as to material, hardness, type etc.

[the AR-15 Junkie]

A few things about screws:

1. Star-type lock washers don't really do much to "lock" the screw in place. In testing plain washers are just as effective at preventing unwanted rotation.

Interesting but,...........if you look up inside the plastic grip after its been installed with a star washer and then removed you can see clearly where the star pattern has dug deep into the plastic. The star washers that Colt uses has sharp raised teeth that grab, you can see that on the washer side of the screw after first use as well.

[556Cliff]

Of all things to worry about on your AR, this one is way down on the list. A recent survey showed that only .03% of gunfights are lost due to the grip screw

But seriously, I get why the convo on this. It's a matter of convenience and, let's be honest. When you have a system that is highly developed over decades, when almost everything has been standardized and perfected or nearly so, when it has evolved to a point where a mfgr almost has to make a special effort to F it up (and, oh yeah, many do!), then you start reaching of the little details inside other details. So I say good on 'em (SOL and MagPul)for the screw. My only thing would be, now it's a non-standard socket size-- but if ya got all the wrenches, that's no biggie. The slot is a great idea that one of my mentors has been wishing for for years; I took some standard screws a few years back and slotted them so he could stop talking about it for a while.....

As to US-made or not, if SOL says US I have no reason to doubt it, my impression of them is "totally credible". In truth these screws aren't really what you could call a "critical fastener" and I'll wager that the slotted, plated pan-head or round-headed screws that were a Colt standard for so long are made from mild steel and not something like heat-treated chrome-moly (4350 usually, I think). It's not a bridge or a space shuttle.

If I were gonna make grips screws I think I'd use a standard 1/4-28 cap screw with the standard 3/16" socket, slot it, and the end would have a pilot, in other words, the last 3-4 threads would not be present, it would be of a diameter where it would just enter the tapped hole (I think about .210) to help prevent cross-threading.

Or how about-- a double-hex head screw, with a 3/16 socket too, and slotted. Just throwing this out there and haven't checked any dimensions, but could the hole in the charging handle that passes over the carrier key be broached to make a 12-point socket that could reach into the pistol grip? Or maybe the CH could have a blade machined in the end to work in the screw head's slot. I know the CH is only aluminum but these screws don't need a ton of torque. I'm a big fan of "all the tools to take the machine apart are in the machine".

https://www.mcmaster.com/mvD/Content...=ImageNotFound

Quite literally, more possibilities for grip screws than I could have imagined... This thread could go indefinitely.

[556Cliff]

Interesting but,...........if you look up inside the plastic grip after its been installed with a star washer and then removed you can see clearly where the star pattern has dug deep into the plastic. The star washers that Colt uses has sharp raised teeth that grab, you can see that on the washer side of the screw after first use as well.

I'm still somewhat on the fence when it comes to lock washers, I don't believe they do much especially with the smaller diameter head screws like Colt's or the socket head cap screws that don't fully cover the locking teeth of the lock washer.

I'd still love to see a vibration test done with all methods of screws, washers and lock washers before I made any real final judgments one way or the other. I wonder if this is something Ned could pull off???

[m4luvr]

i’ve used Belleville and NORD-LOCK
Wedge Lock Washers - both work satisfyingly