Tension screws: Useful or no?

Catfish

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I'm talking about the extra screw in a lower that's supposed to push up on the rear lug of the upper and tighten the fit between the two halves. These non-standard add on gizmos are a new topic for me and being the noob that I am I'm not able to tell if it's a good idea or just shinola.

What's the real deal? Can this improve precision? And if so where does it fall in the list of important stuff?
 
I personally think they're a bit of a gimmick. A little rattle between upper and lower won't affect function, and if its bothersome, you can put an earplug or buy one of the spacers that midway sells that will tighten it right up.
 
I personally think they're a bit of a gimmick. A little rattle between upper and lower won't affect function, and if its bothersome, you can put an earplug or buy one of the spacers that midway sells that will tighten it right up.
I think I got a dozen accuwedge knockoffs on Ebay for $10 made from urethane...haven't used any of them in any of my cheap ass Anderson PSA rifles
 
I recently discovered this, posted about it, and thought it was neat.

Needed? Probably not. Satisfying when the wobble was gone? Indeed.

Personal preference, I suppose.
 
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I have a couple of lowers that have it. I find it useful, but I have a number of other lowers without it.

A feature of some higher end lowers I REALLY like is when the rear takedown pin detent hole is tapped. Trim a bit off that detent spring. Drop detent and spring in hole. Install plug screw and never have to worry about that detent and spring ever again on that lower. Change stock setups, change end plates, no problem.

Once I discovered that my nicer lowers had that feature I started tapping my Anderson/PSA lowers before building them.
 
I have a couple of lowers that have it. I find it useful, but I have a number of other lowers without it.

A feature of some higher end lowers I REALLY like is when the rear takedown pin detent hole is tapped. Trim a bit off that detent spring. Drop detent and spring in hole. Install plug screw and never have to worry about that detent and spring ever again on that lower. Change stock setups, change end plates, no problem.

Once I discovered that my nicer lowers had that feature I started tapping my Anderson/PSA lowers before building them.

Hmm. I have seen the tapped holes before, but not on any of mine. I do like the idea, though.

Do you recall what size tap/screw you used?
 
I have a couple of lowers that have it. I find it useful, but I have a number of other lowers without it.

A feature of some higher end lowers I REALLY like is when the rear takedown pin detent hole is tapped. Trim a bit off that detent spring. Drop detent and spring in hole. Install plug screw and never have to worry about that detent and spring ever again on that lower. Change stock setups, change end plates, no problem.

Once I discovered that my nicer lowers had that feature I started tapping my Anderson/PSA lowers before building them.

YES.
And, throw in a threaded bolt catch pin hole too!
And I’ll take the tensioner screw as well, please.

I use the accuwedes. They work well. Rattle drives me batty. But just got a new lower (M4E1) for a competition rifle and has all that stuff and can’t wait to get it together!
 
A feature of some higher end lowers I REALLY like is when the rear takedown pin detent hole is tapped. Trim a bit off that detent spring. Drop detent and spring in hole. Install plug screw and never have to worry about that detent and spring ever again on that lower. Change stock setups, change end plates, no problem.


Picture if you can
 
I'm at work (at an actual office) today and tomorrow. I'll check the tap/screw size and take pics either later tonight or tomorrow if I can.
 
I'm at work (at an actual office) today and tomorrow. I'll check the tap/screw size and take pics either later tonight or tomorrow if I can.

I can figure it out pretty easy if you'll tell me whether you drilled the hole for a particular tap size or just tapped the hole without.
 
I can figure it out pretty easy if you'll tell me whether you drilled the hole for a particular tap size or just tapped the hole without.

Just tapped the hole without it. I believe it was a 6-x tap but it might have been a 4-x. I just don't know without looking. Really as long as the tap fits down the hole without drilling and you buy the appropriate size plug screw for the tap it really doesn't matter much. When I did mine I matched it to the thread pattern of the existing lowers I had that already had that feature. Not really critical though because as I said above once you install it you never have to worry about it again on that lower. I just did that for my own particular brand of OCD :).
 
Just tapped the hole without it. I believe it was a 6-x tap but it might have been a 4-x. I just don't know without looking. Really as long as the tap fits down the hole without drilling and you buy the appropriate size plug screw for the tap it really doesn't matter much. When I did mine I matched it to the thread pattern of the existing lowers I had that already had that feature. Not really critical though because as I said above once you install it you never have to worry about it again on that lower. I just did that for my own particular brand of OCD :).

I'll most likely go the metric route since I'm covered up in metric taps and set screws.
 
Hmm. I have seen the tapped holes before, but not on any of mine. I do like the idea, though.

Do you recall what size tap/screw you used?
6-32. I bought a little lower build kit on Arfcom years ago that came with the tap, some set screws, a nylon “amorer’s block”, and a pin to help install the front take down pin detent. I use the tap and TD pin tool on every single lower I build. I just get more set screws at the local small hardware store for like 8c/ea.
I’ve noticed a lot of PSA lowers are already tapped now.

As for he OP’s question, I think it’s perference and doesn’t really do much.
 
I use 4-40 flat point set screws and nip 1/8" off the spring. A 0.05" Allen key fits the set screw.
 
Pretty sure I used a 4-40 too now that I've thought about it. I know it was a tap I didn't already have and ordered specifically for this purpose.
 
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