Home Forums Hunting & Shooting AR and Tactical Rifles Accuracy - lower

I know we have the pinned thread and I've skimmed it but figured a fresh restart/reset might be interesting.

Anything, other than a good trigger, in the lower that would contribute to accuracy? Especially from a "legal for high power" perspective?

I'm thinking there's probably not a ton in the lower that does but I don't know what I don't know.

Currently marshalled my bits n pieces - Aero Precision lower, NIB from about 2010/2011. Geissele High Speed National Match Trigger, A2 grip and LPK from Geissele as well IIRC. Stock is a Gen2 UBR.

I anticipate a WOA upper being ordered soon.

What am I missing?

Might want a riser on the stock, depending on your physique & fit.

MM

Basically the lower has nothing to do with accuracy. Even the trigger has nothing to do with it. BUT the better the trigger the easier it is to shoot better.

I did some tests on bedded and none bedded upper to lower 20 plus years ago probably. What I found was that simply tight fitting upper to lower really made no difference IE noticeably better.

But if you bedded the upper to the lower with bedding compound it made the groups more consistently round and a slight bit more accurate. Like on the order of .1 or .2 MOA and noticeable really only at 300 and beyond to any decent degree obviously.

I can't fathom a thing has changed RE accuracy.

The other thing, getting a trigger and pistol grip that fits your hand if you are not dealing with rules, will make em easier to shoot accurately. I just adjust my finger position for a straight pull since we followed service rifle rules.

Thanks, I was hoping you'd chime in.

Intuitively I figured there was little, to no accuracy "to be found" in the lower but - wanted to confirm with those who know more than I. Parts are sitting here, I might assemble during my lunch break.

You will likely want some weight in the stock. I like the Gen 2 UBR. Stealth Ballistics has the weights.

Not a fan of the A2 grip, prefer the A1. I believe CMP changed rules this year to allow some aftermarket grips.

If you do not have a scope the Sightron SR scope seems to be the best of the lower priced scopes.

Maybe upper/lower fit would help the shooter be more consistent. An accuwedge or tension pin would take that out of play.

Good post. Those do help with accuracy. Also, a captured spring system (like the JP enterprises, or Armaspec stealth recoil spring system) also helps with consistency. When dealing with accuracy/precision every little bit you do, helps. How much it helps, depends on the rifle itself. Too bad the OP didn't buy a newer "enhanced" Aero Precision matched upper/lower receiver set with the tension screws. That helps to ensure there is no slop between upper and lower.

Iv'e never found the accuwedge or tension pin to help accuracy. Bedding did but very minutely. Lots of tests on that when we shot. I think both put a weird tension on one side only kind of thing that doesn't hurt, doesn't help.

Weight does not help accuracy. Helps me shoot better though.

I can see the idea of a captured spring but it seemed when you lubed your spring with light grease things were pretty consistent. Dry springs I can hear and feel the drag

Having the "right" (tuned) buffer and spring will help some.

I personally like flat coil chrome silicone springs. From Tubbs/Superior shooting. There are a few other companies selling them these days, but I've been using Tubbs for years and have never had a problem. No reason to try anything else at this point.

They seem to keep better tension on the back of the bolt and during cycling than traditional round coil music wire springs, which makes the timing of the bolt unlocking more consistent shot after shot. I'm not really a fan of round music wire buffer springs.

Also, having the right buffer or buffer weight helps too.

Less recoil and movement at the muzzle = less distance the bullet is moving at longer ranges.

I've been in and around countless AR's for more than 30 years. The barrel and shooter and sights and ammunition are going to be the biggest contributor (or detractor) from accuracy.

Freefloat the barrel and a good buffer system and good trigger are the last in line for it. Still there but not to the degree as the more important stuff.

How much better accuracy from groups are you getting with a flat spring vs round.

Same question on the tuned and proper buffer weight in the gun?

I'm trying to think here but I think the bullet should be out of the muzzle before the bolt unlocks maybe? Negating some thoughts possibly?

That's a valid question.

And truth is, I seldom never get to shoot long enough range to notice due to the terrain and vegatation and stuff where I live to test between the two.

And you're not wrong about the bullet exiting the barrel so fast that the bolt hasn't unlocked.

But, when you take into consideration the shooter and the gun during all of this, the flat coil spring with a proper weight buffer, keeps the gun more steady, and less movement, and lends to letting the muzzle stay flatter.

Which in my opinion does help in the accuracy department especially since we're talking about shooting more than once and the ability to put a 2nd shot as closely to the first shot as possible.

The only way it'll help the gun be more accurate for that first (only) shot is keeping the bolt closed either longer, or unlocking at the same amount shot after shot so the energy of the gasses pushing that bullet down the bore stay as close to the same each shot. Flat coil springs are better for that than round music wire springs.

Super reply. Thanks.

I keep making sure we try to delineate between what can make a gun easier to shoot more accurately so to speak.... and what makes one more accurate.

Its 2 separate things. One thing is that if you actually make it more accurate even if you are not the best shooter you should see that. If you make it easier to shoot more accurately you may or may not see that.

I may have to try a flat spring at some point. The round ones allowed me so many wins and shooting so fast at long distances that I was totally happy with the results so never tried anything different.
In fact I liked the noise of the round ones. If you heard the spring you knew you were not mentally in the zone and you better get there. So most of the time you didn't hear it.
I suspect the flat spring is probably a quieter one all around too.

These the are the springs that I use...............guess I'm having a hard time thinking that flat springs are going to really perform better.

Lubed properly, I never hear them.

Anyone using "music wire" springs in any level of a "precision" or high end SD build gets what they may deserve & pay for.

Note that the Sprinco springs are heat treated, stress relieved, shot peened (for fatigue strength & life) SiCr spring steel (same as used for valve springs) that maintain consistent compression levels as well.

YMMV

Sprinco Springs

MM

This is one of those times you should see for yourself. You don't know what you don't know.

I have a very hard time believing that if you got a flat coil spring that you wouldn't immediately like it. You'll be able to tell the difference just pulling the charging handle back.

Seriously, before you change the spring, pull the bolt back. Then do the same after you swap it out.

Then take her out and put a few through her.

I've been using them for more than a decade and have never heard anyone say "I want my old spring back".

“ This is one of those times you should see for yourself. You don't know what you don't know.”

This is funny.

But what does the spring do better? Make it easier for you to charge it? Quieter? I've zero issues with folks doing what they want. But if you say its better, why is it better? Longer life? More accurate?

Just curious.

When I read "legal for high power" my brain ran off in a different direction. I think in terms that my rifle is more accurate than me, so what can I do to shoot better scores. Thanks for properly answering the question that was asked.

I much prefer a round SpringCo spring to the flat ground springs.

The flat ground can have more preload at the expense of total feed energy. The preload difference does not keep the BCG from moving sooner in my testing where as unsprung buffer/carrier weight has a noteable effect on slowing the the initial carrier movement.

Add in the pain in the ass of installing and removing a flat ground buffer spring.

One can polish the outer diameter on a round spring and significantly reduce the noise of cycling.

The Gen 2 UBR can use the A-5 buffers and rifle buffer springs so I would use a Green SpringCo and an 8 oz A5 buffer.

We can all be accurate but not precise or precise but not accurate. Or none of the above... Thankfully you know me and knew I wasn't being an azz. Just pointing out things.

In the early days of the Match AR, we tried to apply the same accuracy tricks that worked for bolt rifles such as minimizing unnecessary movement of the parts and such. Some tweaks were valid and some were just "feel good" measures. Bill Wylde told me AR's shoot better with a little bit of upper/lower rattle. Coming from a guy that pioneered AR accurizing, who won a benchrest match shooting an AR and who did his testing on his own 500 yard backyard range, I decided it wasn't an area where I would put any effort.