AR-15 grip screw length?

[6bg6ga]

The grip thread screw size is 1/4-28 and the length seems to vary with the manufacturer. I recently purchased a grip screw with and internal adjustable set screw which when adjusted correctly all but eliminates the extra travel associated with the cheap triggers. So my question is this... could one simply go to the hardware store and purchase a longer 1/4-28 screw and either cut it down or shim it in order to do the same function as one of those special $15 screws?Attachment 157122

Normal screw on left special setscrew on the right.

[imashooter2]

Or you could just use a set screw and Loctite, then put the factory screw under it.

[montana_charlie]

special setscrew on the right.

Where did you buy the special screw?

EDIT: Nevermind ... it was easy to find.

[rtracy2001]

Yes and no. The setscrew is adjustable because not all triggers will need exactly the same length screw to eliminate the play in the trigger. If you had several firearms to service, you could buy one special screw and use it to determine the exact length needed, then cut down a longer screw for permanent installation. Then the special screw can be used on the next firearm and so on.

Another alternative would be to get a length of 1/4-28 all-thread and a couple of matching nuts. Screw the all-thread in enough to adjust the trigger, then tighten the nuts down to hold the pistol grip on. Any excess is simply trimmed off.

In both cases, it may be necessary to shape the ends of the screws as the full diameter may interfere with proper trigger function, or in some cases, the pistol grip hole isn't fully threaded, so a pilot shaped tip would be needed (or re-drilling/tapping of the pistol grip hole).

[6bg6ga]

After starting this thread I torn down several AR's and did some fiddling around and arrived at a conclusion. My first thoughts would be that I could simply purchase a longer 1/4-28 and screw it in until I got rid of the play. In practice it doesn't seem to work. There are differences in the lowers between manufacturers and even between batches from the same manufacturer. In simple terms buying a longer 1/4-28 screw isn't the solution. What seems to work is a screw no longer than 1.2 overall. This screw has to be drilled and tapped in order to install the small internal set screw. Note... I didn't disassemble the lower to take the trigger group out for further inspection to see why a longer bolt didn't work.

So if someone is handy and happens to own a lathe and wishes to sell a bunch of these at a price lower than $15 each I would assume there would be a market for them here on the forum. They certainly don't have to be stainless steel in order to function. I figure someone could make at least 20 of these an hour with the correct equipment.

So, one of these little gems a small tube of Loctite blue 242 and a long 6" allen wrench and one has the makings of obtaining a decent trigger with run of the mill parts. In my experience I took the dremmel and polished the trigger contact points installed the set screw and obtained about a 4lb trigger pull without creep.

[montana_charlie]

In my experience I took the dremmel and polished the trigger contact points installed the set screw and obtained about a 4lb trigger pull without creep.

The mil-spec hammer and trigger is machined to specs, then 'hardened' ... but that is 'case hardened', not hardened all the way through.
So, when you start grinding on that thin case, you remove it from the underlying metal.

The polished surfaces you end up with may shine like a mirror, but they are 'soft' and will wear quickly.

If yours wears out and you need to replace it, you should consider two products.
They would be the QMS trigger from ALG Defense, and the ACT trigger from the same source.
The QMS is the trigger you tried to create with your Dremel tool, but done by people who are experts at working on triggers.
The ACT trigger is still a mil-spec trigger, but it has been enhanced in a couple of ways to make it better.

Check them out, and make up your own mind about which is most likely to satisfy you.

Either one will STILL benefit from the adjustment screw you are using.

[6bg6ga]

The mil-spec hammer and trigger is machined to specs, then 'hardened' ... but that is 'case hardened', not hardened all the way through.
So, when you start grinding on that thin case, you remove it from the underlying metal.

The polished surfaces you end up with may shine like a mirror, but they are 'soft' and will wear quickly.

If yours wears out and you need to replace it, you should consider two products.
They would be the QMS trigger from ALG Defense, and the ACT trigger from the same source.
The QMS is the trigger you tried to create with your Dremel tool, but done by people who are experts at working on triggers.
The ACT trigger is still a mil-spec trigger, but it has been enhanced in a couple of ways to make it better.

Check them out, and make up your own mind about which is most likely to satisfy you.

Either one will STILL benefit from the adjustment screw you are using.

Sir,

Thank you for your reply. Upon inspection when I put the lower together I formed the opinion that my lower parts kit had to have been assembled by a chimp in need of a fix. The surfaces that are supposed to be somewhat clean and smooth were filled with machine marks. Absolutely nothing fit correctly. It was more like a group of parts that never made it past inspection but somehow made it into a clear plastic bag and were shipped. I will keep your recommendations for trigger replacement on file for future use and I appreciate the information. I felt I had nothing to loose by gently polishing some of the high spots off and yes I realize what I did was questionable. Thank you for mentioning that a person shouldn't try this. I did however end up with a trigger 99% free of slop and no more gritty feel. Chalk it up to a learning experience.

[montana_charlie]

You are quite welcome to the information, and both of those triggers are pretty reasonable in price if you get around to needing one of them.
Beyond that, the title of 'Sir' is truly unnecessary when speaking with me.

CM