Are AR's "hard" on scopes?

[The_Duke]

Well, took my brand new RRA Predator pursuit out today, and was a bit dissapointed. Currently the only scope I have is a nikon buckmasters 4.5-14x40, it took forever to even get on target, example-I would sight in at 25 yards than move to 100 and it would be 12 inches high and 10 inches to the left. After I did get on target I was getting groups in the 4"-5" range at 100 yards. It wasn't uncommon to have 2 shots inside a half inch, than have random wild fliers. I'm somewhat new to ar's (obviously) and was a little puzzled by this. To be fair the rings are a bit cheap, but I triple checked everything and nothing "seemed" loose. The scope came off a 7 mag several years ago and has been sitting since, I do remember some getting on target issues but nothing like this. Any ideas? Suggestions? Thanks


Mods please move if I'm in the wrong forum

 

[Wintermute]

Re: Are AR's "hard" on scopes?

Could be the scope itself...could be the rings (did you check them for proper contact and torque them to the appropriate settings?). Upgraded rings aren't that expensive...just getting a set of weaver tacticals may show a difference and they won't break the bank.

Could also just be the rifle. Do you have a different scope you can test the rifle with? Also, have you tested the rifle with just iron sites?

--Wintermute

 

[The_Duke]

Re: Are AR's "hard" on scopes?

Haven't had a chance to test with iron sights. I did put the scope/rings on a FN SPR, and although groups were much larger than expected (3 1/2 inches), it didn't appear to be as sporadic. Ill try an pick up some rings and see if that helps. I was shooting hornady super match 75 grain as well as some 55 FMJ and they both had comparable results.

 

[ms6852]

Re: Are AR's "hard" on scopes?

I have the RRA predator pursuit too. It has the Nikon monarch with bdc reticle. I have shot 4 groups of 5 shots at 100 yds using Hornady match superformance 55gr. for an avg of .683 groups. I believe there is something wrong with your mounting system or scope. Now my rifle did no like any of the longer bullets like the 69gr through 75gr. Only addition I have done to my rifle is the magpul prs stock.

 

[mtrmn]

Re: Are AR's "hard" on scopes?

AMMO?
Different ammo will make a HUGE difference in group size.
If you're new to the ARs, you need to consider the large distance your line of sight is above the bore.

Push out the 2 pins and sandbag your upper with bolt carrier group removed. Boresight on an object at least 100 yds away and adjust your scope to the same point. This will get you on target quicker. If you boresight any closer in, you'll be extremely high with first rounds.

 

[DT1]

Re: Are AR's "hard" on scopes?

Yes, ammo is a huge difference maker in AR accuracy. I've got AR-15's that will shoot 1/2 inch groups @100yds with 69 gr SMK or 55gr V-Max loads, then open up to 3-4" with 55gr "blastin' ammo".

Try better ammo (if you haven't already). Get stable with a combo of bipod & sandbags. If the groups are still big, might want to look into your ring/scope quality. Your rifle should shoot better than you're experiencing with good ammo.

 

[BCP]

Re: Are AR's "hard" on scopes?

I would try a different scope and different rings. Also make sure that you have a good, bagged rest for testing.

 

[The_Duke]

Re: Are AR's "hard" on scopes?

Thanks for the responses, I'm going to try and get ahold of another scope/rings and see if that helps. I did try the bore sight trick initially with not much luck, like I said I ended up sighting in at 25 yards and I was still way off when I moved back to 100. I was shooting off a bipod. In case everybody was wondering but too polite to say anything, the shooter is capable of better

 

[ms6852]

Re: Are AR's "hard" on scopes?

I hope you realize that when you do sight in at 25 yds your point of impact will be high at 100 yds.

 

[The_Duke]

Re: Are AR's "hard" on scopes?

I hope you read the original post

 

[Powder_Burns]

Re: Are AR's "hard" on scopes?

Is your barrel nut loose by any chance?

 

[The_Duke]

Re: Are AR's "hard" on scopes?

It shouldn't be as its new, although I haven't considered that. Is there a quick way to check

 

[ms6852]

Re: Are AR's "hard" on scopes?

If it is brand new did you clean your rifle good. Mine had a lot of oil and grease all over the place. I had a lot of trouble getting good groups as well at the beginning because I was not following through properly. Go back to basics and ensure everything you do such as sight alignment, breathing, trigger control and follow through are the same.

If that does not help have someone else that you know is a great shooter shoot a few groups for you. This would eliminate many factors to include the scope and mount.

I shot many brands of ammo before I found what my rifle liked. rem, winchester, american eagle, fiocchi, blazer, hornady match,hornady steel match, various weights.

If everything checks out you might have to handload to find the right recipe your rifle harmonics will like.

You may consider measuring headspace to ensure you have plenty of space but not to much that could be stretching your brass to much.

 

[donws2]

Re: Are AR's "hard" on scopes?

I shot a guys AR last week. He was complaining about how poorly it grouped. I shot five rounds of his 5.00 a box cheap ammo and the rifle would not hold a six inch group. I made a couple swag adjustments and shot five rounds of my 73 gr. Berger match loads. All five rounds under an inch at 100 yards at six o'clock in the ten ring. I handed the rifle back and didn't say a word. The rifle had a NCStar scope on it so I was affraid I could not duplicate the group, LOL. AR's do seem to be ammo selective. I'd check a couple differnt loads as well as your scope set up.

 

[fastex500]

Re: Are AR's "hard" on scopes?

^^^ yep, ammo in AR's is big. Brow Bear, Wolf, etc.. will open way up at 100 yds. Run by your local store and grab a box of Federal Gold Medal, Hornady or another "premium" load (62gr or under for 1-9 twist, 62-77 for 1-8, 75 or up for 1-7). See if that helps. Also, make sure your barrel is fouling free and dry, but make sure the bolt is lubed.

https://snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1501391

and a link form that article:

http://www.m4carbine.net/showthread.php?t=35490

 

[Andy T]

Re: Are AR's "hard" on scopes?

How cheap are the rings? Is the scope properly mounted in the rings? Are the rings properly mounted to the upper? Did you push them forward while tightening them?
Is the scope ok?
Were you doing POA/POI at 25 yards and expecting POA/POI hits at 100?
I had RRA Varminter with Nikon Buckmaster and ARMS rings and had no problem going all the way to 500 yards with my setup and PPU 69gr ammo.

 

[The_Duke]

Re: Are AR's "hard" on scopes?

Update- went out for a bit after work today, same rings, different scope, HUGE improvement. Took no time at all to boresight, on target with the first shot and consistent groups. Ill take the old scope back out the next chance I get to double check it but for now I feel much better. I was a lil dissapointed that 75 grain hornadys I had didn't group better but am confident with some trigger time and ammo variation ill see improvements

 

[SGT TickleFight]

Re: Are AR's "hard" on scopes?

Sounds like a marginally stabilized bullet. What twist rate barrel and bullet weight are you using?

The 7mm will put way more shock into your scope than an ar.

Also - if the gun was used your barrel may be toast.

 

[SGT TickleFight]

Re: Are AR's "hard" on scopes?

My 1 in 9 does not stabilize 75gr bthp bullets. The difference may be the temperature and humidity if you are marginally stabilizing the bullet. This may not be scope related at all.

 

[The_Duke]

Re: Are AR's "hard" on scopes?

I don't KNOW, but I haven't personally seen temp and humidity make groups go from 4-5 inches to 1 1/4" in 2 spring days, at least at 100 yards anyway. The gun is brand new,bullets were 55 grain FMJ and 75 grain BTHP. Twist is 1 in 8

 

[splean]

Re: Are AR's "hard" on scopes?

As mentioned above try, good ammo, scope, rings and/or mounts. Having said all that keep in mind semi-autos are harder to "drive" than bolt guns. I remember a few years back I put together a high-end AR and took it out to the range. I took my time and shot it like a bolt gun. I was bump firing the rifle to the point I thought my trigger was screwed up. I know you are having other issues but just keep in mind gas guns run differently, just my .02. Good luck and keep us posted.

 

[BOL556]

Re: Are AR's "hard" on scopes?

If possible post a picture of your target the next time you go out. If you rounds are up and down its your breathing, left and right trigger control, all over the place sight picture. You may not have the correct eye relief for that scope. The other thing it could be as well your scope when remounted may not be level. Ammo find Federal X193, American Eagle black box, or PMC. If you want to try the match stuff and was a lot of money until you figure out whats going thats solely up to to you.

 

[The_Duke]

Re: Are AR's "hard" on scopes?

Good info havoc..the groups are all left to right. I shouldve been more clear, it is a predator pursuit upper and RRA lower with a daniel defense LPK, so I guess its not a true Predator pursuit. The trigger is a bit different than what I'm used to. As far as what's going on I feel the issue is taken care of, jus need some more range time. Thanks for all the responses so far

 

[ms6852]

Re: Are AR's "hard" on scopes?

One more thing Duke, on your first scope you had mounted you could have issues with parallex. Which would explain shotgun groups escpecially if your cheek weld and picture sight were not the same.