So before I ask, let me give y'all a little background.

I had a low cost 16" AR I basically built from spare parts It was set up as a home defense-type weapon (budget red-dot, budget weapon light, etc.). One of my childhood friends caught wind of the fact that I built and knew a little bit about AR's. His son had gifted him an Ares Armor 18" SPR rifle. The rifle had a Magpul PRS stock, Geissele flat-faced trigger (which one...I don't know), Ares Armor Effin-A compensator, a bipod, and a couple of other improvements. It was built on what I assume was an Ares proprietary 80% lower. The 18" barrel was 416R, mid-length gassed, 1:7 twist, and the rifle ran a standard buffer weight. No optic, no magazine.

So anyway, this old friend wanted to bring his rifle over for me to inspect and tell him what he had. What he really wanted was a home defense weapon. To make a long story shorter, we ended up trading weapons.

I mounted an old piece-of-sh*t BSA Platinum Series 24X (dot reticle) on it to fire it at the range to see what kind of groups I could ring out of it. It was the only scope I had that was not already on one of my rifles that had enough power to attempt small groups.

At the range, I fired quite a few groups at 100 yards with bullets (handloads) ranging from 55 gr. to 75 gr. The smallest group I fired was around  2". Most of the groups were around 2 1/2 to 3 inches. There weren't fliers, just a lot of larger-than-I-like cloverleaf patterns. I noticed the cases were literally ejecting at 1 o'clock no matter what bullet weight I was firing.

My my 2 questions are 1.) What are your suggestions I try and remedy before I spring for a new barrel?  And 2.) Can a rifles inaccuracy possibly be linked to improperly sized gas ports and/or buffer weights/springs?

Any help/suggestions will be appreciated. I should know this stuff, but as my age increases and my life just seems to keep getting busier and more complicated, my mind is drawing total blanks on this. Regardless, I think I made out pretty good on the trade.

PopGunner

2-3 inch at a hundred is plenty good for home defense.  as long as is it goes boom every time you’re ok. HD is usually 50 ft or less. I’m not sure, but I think mil-spec for military barrels is bigger groups than yours, like 3” or more. If your not using a scope that’s pretty good.

With the group sizes, I was referring to the 18" SPR barrel/rifle that I traded FOR. The rifle was more of a medium-to-long range setup. With the ammo I was using and a 24-power scope, I wanted groups no worse than 1-1/2 inch and smaller.

I can shoot a home defense setup with a red dot at 100 yards almost as good as this rifle was grouping.

PopGunner

I'd check for loose barrel nut, and light ejector spring (thumbnail should flex before the plunger descends). Is the PRS on a carbine or rifle extension? Was the bore cleaned well and refouled? Any idea of round count?

25gr H4895/50gr VMAX (or any stubby 50gr class bullet) is my index load. Others use 24.5gr Varget/69gr SMK.

Could be bad scope, bad scope mounting, loose barrel nut.

Other issues could be sight picture, not familiar with that flat trigger.

Can you remount the barrel?

Good luck, keep us posted.

Are you using good ammo?

All used gun barrels need a serious cleaning. I use a copper remover first, followed by oil to neutralize the chemical reaction. Sweet's is my go to, but any copper remover will work.

Bullet quality is the number one factor for shooting small groups. That, and bench rest technique. I need bags front and rear to shoot my best groups. Bipods are okay, but only for field use. Bags get it done proper on a bench.

Try 52/53 grain Sierra Match Kings and you'll discover that barrels potential.

I think your scope is suspect as well. Any scope made in China gives me the willys.

A 1.5-5 or 2-7 is excellent for home defense. Low power inside the home, high end for long range.

I used very accurate handloads (at least in my other SPR-ish rifles) including Sierra MK bullets. I'm 100% sure the ammo wasn't the problem. I've been mounting scopes for most of my adult life (I'm 67), so I know 100% it isn't mounting. The scope being a BSA is a tad suspect, but it was an older model and has never been mounted on another rifle (or out of the box for that matter). The buffer tube is definitely carbine length with no markings on the buffer (and I don't have a scale). Buffer spring looks new or fairly new. Ejector spring was strong. Gun and barrel were given a white-glove cleaning. Barrel looked free of pitting and the bore was shiny

Sight picture was very good. 24x with a fine reticle with a dot made for a great sight picture for the target I was using. I have no idea of the round count of this rifle.

I'm going to take the handguard off in the morning and check the barrel nut torque. If it checks out as okay, then I'm giving it one more range session. If results don't improve (it was windy with high humidity), I may just order a new barrel.

I'll keep y'all updated after the next range session this weekend.

Edit to add: Barrel nut was GTG.

PopGunner

I'd first suspect the scope.  BSA is airsoft grade Chicom junk and there are more than enough people who have reported failures with similar types of scopes at very low round counts, so it being new out of the box doesn't mean much.

If you have access to a higher quality scope, even if it's mounted to another rifle, I'd swap it out and give it a shot just to rule out the scope.  Having to use a bit of ammo to re-zero an optic is much cheaper than replacing a barrel when it isn't needed.

I've got a new Vortex ordered today. Going to need it anyway because I'm going to get this rifle to shoot smaller groups. I may or may not fire this rifle again before I get the new glass mounted.

What do you think about the cases ejecting to the 1 o'clock position. Stop thinking about it and blast away or maybe go with a heavier buffer? I wish I knew what the gas port size was. Gas block set screws are Loctited so I'm not going to know unless I decide to replace the barrel as I'm not messing with that part of the rifle at this time.

PopGunner

Typically forward ejection is an indication that the gun may be overgassed.  Swapping to a heavier buffer isn't going to hurt anything, so it's something I'd probably try.  Have you determined if it's got a carbine or rifle RE on it?  

Either way, overgassing in itself isn't going to affect the mechanical accuracy potential of the rifle, but an increased or more sharp recoil impulse from the gun could negatively effect the abilities of the guy pulling the trigger.

It's got a carbine extension on it.

Since they are inexpensive, I may try a heavier buffer.  I think I'll pull an H2 buffer from one of my carbines and try it in the SPR to see if it makes a difference in ejection direction. If it cycles properly, I may order an H3 and give it a go too. Like I say....they're inexpensive enough to give it a try.

PopGunner