So I'm basically going to have a complain, about several things, and hopefully you can help me narrow down the issues.

I recently put together a cheap AR15.

Spikes Tactical lower, CMMG Upper, Daniel Defense stock. Primary Arms dot sight and a magnifier.

14.5 pinned barrel.




Until now, I have been shooting offhand and have seen pretty poor groups. I put this down to it being me because the last time I seriously used a rifle was over 5 years ago.

Anyway, yesterday I went to the range with some sandbags, and the rifle is STILL awful!

At 50 yards, its this.
(Front sandbag only in use, I rarely use the rear)



The sticky targets are 3", so it gives you an idea of how piss poor the grouping is. 9 shots centre target, 5 in bottom.


I am using Federal XM193, 55gr boat tails. The barrel has 1:7 twist.

My last AR was always capable of 1MOA, but it did have a longer, more expensive barrel.

For this rifle I'm wondering if its actually the sight at work, if there is some parallax error because its such a cheap nasty one. That said, this particular sight gets nothing but glowing reviews on ARFCOM and they are critical as rule over there.

Or, is this the kind of accuracy I am to expect from a 14.5" barrel, gas operated AR?

In England, my AR had no gas tube, so it was basically a bolt gun, it was longer, had a 1:9 twist and was a button rifled custom barrel.

 

What are the groupings if you remove the optics and sight in the iron sights?

 

Ever so slightly closer to the the bottom target, not different enough to record a real difference.

I suck with irons though, ideally, I should put a scope on it...

The big difference is, with 50 yards, and OK ammo, I was expecting 1/2" groups to 1" groups max, and I personally will do that with other peoples rifles, however my own seems to be a bag of shit.

 

I'm guessing its an optics problem. My 8" barrel has closer groupings than that.

 

If it's shooting that poorly both iron sights and optics, then I doubt its the optics.

I would disassemble / reassemble to make sure you have everything together properly, or take it into a shop and have it looked over. Even "cheap" Ar-15s should be shooting tighter than that, assuming you aren't drifting the sights all over despite being sandbagged.

 

I didn't notice the part where he used the iron sights. Maybe also have someone else shoot it after checking the assembly?

 

While your groups still should be better than that at 50 yards with that ammo, a 1-7 twist barrel typically likes heavier rounds. After checking to ensure your optics are mounted securely like others have suggested, try some better/heavier ammo. 1-7 twist typically likes 62-77 grain rounds better. If you see a significant improvement than it was just ammo that your rifle didn’t like. If your groups are still bad then it's probably something mechanical, likely the chamber was bored over size or with too much head space.

Also have another experienced shooter try it out. You could be flinching or jerking the trigger despite the bag rest and not even realize it.

 

Hmm...
It is hard to say without shooting this one.
Even a cheap ass AK will shoot tight at 50.

Is your trigger funky? Clugey?

What are you zeroed at?

 

I'm a pretty decent shooter. The Army gave me a little badge to prove it about 10 years ago.

The Upper was bought already made/assembled but I'm borrowing a headspace gauge to check, plus I went out at lunch and got some 62 grains to try with it, so at least my thinking is on the same lines as others.

It's been a little while since I've used a rifle and I was beginning to get scared I'd lost it!

I did have a primer blowout on this very same boxed, expensive federal ammo before (same batch I'm using now) so it may very well be ammo.

 

That was an attempt to zero, Normally for the AR platform I zero at 50.

Trigger is crap but standard AR, no worse or better than default.