Home Forums Hunting & Shooting AR and Tactical Rifles AR-15 upper/lower tightness question

Good day,

I purchased an AR-15 on another board that a guy put together from some trades. The lower is a DPMS based D-tech AR-15 lower and it works great but the problem lies in putting the upper on it. Now the lower was checked with a different upper and it all went together just fine. The upper that came with it is so tight that you have to tap the rear pin in and out to lock it together. We took it apart and beveled the pins (we replaced them with Yankee Hill Machine pins) so they do work but are tight. With the upper not in place the pin moves freely.
My question is will this loosen up once I shoot it some? I haven't shot it yet as I just got the pins modified the other day and haven't made it to the range yet. I know I could buy a new flat top upper and switch the parts but I don't want to spend $100 plus time to swap everything.
Thanks for any input and I plan on shooting it some this week either way to see what it will do. The gun is fantastic other than having the rear pin so tight and the trigger has been gunsmithed down to just over 3 pounds so I am dying to shoot some paper.

- Frank

What are you worried about? next time you are at a gunshow find a take -down pin punch that goes on your keychain--they are nylon/plastic and cost 2 bucks. I'd rather be tight than loose.

Amen brother.. Leave it together and shoot it..... You have already fixed one of the issues on an AR.

Tight > loose

I had the same issue with 3 lowers I recently put together. I was told by my gunsmith that tight is definitely better. Now I need to trade an Accuwedge for one of those take down tools.

Best takedown cheap tool... get a round shanked wally world screwdriver, less than .250 in diameter, grind off the tip till its flat like a punch and slightly beveled. A good rap on the handle or firm push and its done....

There really isn't much difference between tight and loose in accuracy, but tight is better actually. I bed my uppers to a lower to get them tight.

Jeff

Thanks guys for the responses. I didn't have any local AR15 experts to ask, just ex-military guys.

I think the tight/loose issue depends on what you want to do with it.

rost has found that for long range accuracy a tight fit is better but for someone who needs to get into his gun and fix it quick, loose is definately better. The design was as a battle rifle and built so you can do field repair with only a bullet point.

Some HSLD type guys don't even like an accuwedge because of the possibility of it getting in the action.

Most of us don't fit either category so it shouldn't make much difference either way. I like a "tighter" fit but I don't want to use any tool to get it open.

That said I do use KNS pins on my trigger/hammer so yes I still need a tool to do much maintenance... but hopefully no one's going to be shooting at me.

Excellent idea! Thanks!

i was issued an M16 at PI that sounded like it had rocks inside of it. it was so loose i shoved a cig. butt behind the rear takedown pin during qual and still shot 10 for 10 from the 500.

The qual at 500 doesn't take much accuracy. I'm not taking anything away from you at all, its not meant as a negative, but expert with a rifle in quals has never impressed me, we did it from time to time just goofing around and it wasn't hard the first time and never was. Even with issued rattle trap guns.

The accurarcy issue I'm talking about is maybe a quarter to half inch differnece and from weird to round groups at 300 yards for 10 shot groups. Thats being anal and trying to get from say 2 inch groups to 1.5 inch groups or less.

Jeff

i am impressed. for most people hitting a target that is half the width of the front sight post isnt as easy.
perhaps you should have joined my beloved Corps and put some of that super human ability to good use.

at 500 yards things like wind and ammo have as much to do w/ reliable hits as a little slop in the halves. but in theory a 1" gun is a 5" gun at 500. those of use who actually have trigger time beyond a county rifle range can attest to the fact that the only sound practice is practice.

My best in rattle battle is dumping 42 rounds on the D?? target at 600 yards in 50 seconds time exposure. And FWIW 600 is exponentially tougher than 500 for some reason. Much like 1000 is not 100 yards tougher than 900, it seems a few hundred yards tougher. 500 winds are almost fairly easy to grasp.

Once you understand the basics its not hard. Wind yes, but shooting, nah thats fairly easy. Of course I'm saying that having shot the game with irons on ARs since the late 80s, IE 89 and having run upwards of 20K rounds between the wife and I each year at our efforts up to 2003... we might have more trigger time than some.

But the point being, the qual target is actually big. Leaves room for error and so on. Such that slop or no slop in the upper/lower isn't really an issue at all.

For one to assume a 1 inch at 100 is a 5 inch at 500, well it rarely goes that way.

BTW I've been beaten more than once by your beloved Corps, and Iv'e beaten them more than once too!

The only sound practice is accurate practice. Simply flinging rounds doesn't guarantee a thing. As to country ranges. Lets just say most folks don't have their own range out to right at 1000 yards just out the door. It allows one to do a lot of tweaking and practicing. Though in later years most of my practice was dry fire and 22 in the yard with a dedicated Krieger barreled 22 AR15 service rifle upper.

High Master in both XC and LR with the AR service rifle only. Never shot a match gun..... irons only.