AR-10 Questions

[gpr]

I finally pulled the trigger on a Stag AR-10 6.5cm lefty with 24" barrel. I was wondering what a few things I could do to get the most accuracy.

I plan on installing an adjustable gas block since I will be running suppressed.

I see a lot of people recommend the Tubbs flat wire buffer spring. Is this a stiffer spring? What is the purpose of it? I installed a JP silent capture spring in my AR-15 and really like how much it quieted the gun down, however they are pretty spendy. Is the flatt wire spring similar? Is it as quiet?

I see a lot of people added mass to their BCG or there buffer. Is this essentially doing the same thing as turning the gas down to control the ejection? What are the advantages of a heavy buffer?

When tuning a gas gun I have noticed over gassed it will throw the brass forwards at the 2 o'clock position. Where should you tune your gun for ideal precision? Should it be ejecting the brass out straight sideways? Or maybe possible back slightly?

 

[hlee]

An adjustable gas block is probably not a bad idea on any large frame ar. However, beyond that I would recommend buying ammunition. Don’t get wrapped around the axle about what you can change on the rifle to make it shoot better before you shoot it- you may be pleasantly surprised. If you are not set up to reload, buy as many different brands and loads of ammunition as you can afford. Shoot 5 shot groups of all of hem to see what shoots best in YOUR GUN. It doesn’t matter what works best in other guns, although that is not a bad starting place- like fgmm. Shoot the rifle before changing the stock or the grip or the hand guard. Shoot the rifle before changing the gas system components.

The advantage of the heavy buffer(or stiffer spring or both) is that it slows the rearward travel of the carrier, mitigating the effects of an overgassed gun. The potential disadvantage of this is more mass slamming around in the rifle.

The advantage of an adjustable gas block is that it can restrict the flow of gas, thus resolving an overgassed situation in a rifle. The potential disadvantage of this is more components with small parts to fail or gum up.

 

[7mmFanBoy]

Bolt can start to move back or shift before gas more mass along with add spring pressure keeps bolt locked harder. Walking a fine line with AR brass pressure signs down "a bit". I find out that adjusting gas doesn't help out brass pressure signs. If its over gassed rims can bend on the extractor side and gas residue on primers adjusting down gas is necessary. Adjustable gas benefit of reduced recoil

 

[JZimm9mm]

John Paul of JP Rifles discusses gas regulation vs. mass regulation with suppressed rifles.

 

[gpr]

That is a very good and informative video.

I will mostly use the gun for long range shooting and hunting. If i end up going with a silence capture spring i will most likely try out the heavy version, and tune the gas system accordingly as this seems like it would benefit more and allow me to shoot both suppressed and unsuppressed.

Also in the video the heavy weight buffers he said are so that the bolt speed is in the idea area in a wider range of gas port pressure. However, does the heavier weight buffers cause a harsher recoil? As he stated the light weight versions are for light recoil and fast target acquisitions in competition scenarios.

 

[JZimm9mm]

I have run the large frame low mass bolt carrier with standard silent capture spring and the heaviest VMOS with heaviest SCS, both suppressed and unsuppressed. In 308 Win the recoil impulse between the two setups is different but neither is harsh. I do find the heavy setup is a little easier on brass and a little more reliable as the rifle gets dirty. However, the heavy carrier and spring are expensive and I can't say it made a huge difference. As was posted above, go ahead and shoot your rifle as is and then decide if you want to drop hundreds to change out parts.

 

[bfoosh006]

Some spring weight measurements from David Tubb...

A2 (old) - 7.6lb closed, 14.5lb open
A2 (new) - 9.1lb closed, 16.7lb open
Tubb Flatwire - 10.5lb closed, 16.3lb open
Tubb .308 Flatwire - 13lb closed, 16.7lb open
SpringCo White ? (standard) - 8.3lb closed, 16.3lb open
SpringCo Red (extra) - 10.5lb closed, 18.4lb open
SpringCo Orange (increased) - 13.9lb closed, 24.8lb open


IMHO, an extra power spring isn't needed , nor wanted.

I tried both the "Red" and "Orange" ... both caused needless muzzle dip, and were slamming the BCG really hard into the breach face


You can see the .308 Tubbs has extra spring weight on the closed ( locked ) BCG ... and traditional weight for function with the BCG retracted in the buffer tube.

Watch the video... it is a little long.. but worth it... watch clear to the end.

https://www.youtube.com/watch?v=8fMVZbrnvu8

Not only is this easier on your brass , with an adjustable gas block, ( I also run a .308 rifle length 9.3oz buffer ) it makes it easier for me to stay on target... those added milliseconds of added delayed Bolt unlocking really makes a difference.... less abused brass... staying on target easier, brass flips out at about 4:30...

As for the Tubbs spring sprong noise.... I grease my buffer tubes and spring... no more sproong.


OOP's ... as others have said...don't worry about adding this stuff until you have fired your OEM rifle.... Mine was ( .308 middie ) kinda Linda Blair ( Exorcist ) like cycling.... it is now a pussy cat.