Ruger Forum banner

1 - 20 of 23 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
Took my new MPR to the range Sat to fire for the first time. I mounted a Trijicon MRO on it with their AR type mount and a set of Yankee Hill iron sights.

Shot my first group at 15 yards with the red dot scope. It printed the group 6 inches left and 2 inches low. I was unable to get the scope to adjust right far enough to zero. As well, when using the iron sights, I could not get it to adjust enough to zero.

Any ideas to look at before I send it to Ruger? I thought about taking it to a local gunsmith to look at it and maybe check the barrel nut torque.

By the way, it did shoot quite good groups. I was able to only shoot a max of 40 yards at this indoor range. It grouped about 2 inches at 40 yards which is good for me.
 

·
"The Real Deal"
Joined
·
6,527 Posts
Hmmm, never seen that on the ar platform, but a few thoughts come to mind.

First, the far left or far right or even being unable to sight the rifle may be caused by a canted front sight post. The retaining pin holes may not have been drilled correctly on the barrel causing a crooked mounting, which in turn can make it unable to sight the rifle in. This was common to early century arms rifles of the ak family.
The correction for that problem if you choose to retain the a2 style front sight post is usually a new barrel that has the holes drilled correctly, OR do away with the front sight post, and go to a free float rail which you can use same plane sights on it, OR you could replace the front sight post with a railed gas block which will allow the use of a compatible folding front sight. Then you can level, the sight block with the receiver and secure it by set screw or clamp on means.

Another thought that comes to mind is the distance your shooting. The minimum I start with is 25 yards if I do not have the rifle boresighted. If its bore sighted I use 50 yards, then permenantly set my irons at 100 yards. The thought I had was maybe your trying to sight in at too close a distance. That could explain the reason it cannot be adjusted enough. Try a farther distance.

Also makes sure you use loctite on the mounting screws for the irons and optic, they can work loose, which can effect your groups. I use purple loctite or blue on all my sights being irons, scope with rings, or red dots.

Also make sure its not you pulling or having a rough trigger pull as in jerking while firing, which can effect the accuracy. I use a a caldwell lead sled solo on the bench to sight in, that way I no movement, no real recoil, so you can concentrate on the sight picture and trigger pull and less on rifle movement. Then when I am shooting normally to the shoulder I know if the groups are off its me not the setup.

Make sure the sights are compatible, meaning some irons are made for same plane or same height as in a full top rail. There are also front sights that are made a bit longer for mounting on non same plane setups like a reciever thats one height and a gas block thats lower which requires a longer aka taller front sight post to allow proper alignment.

Just a few thoughts that could be of relevance.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #4
Hmmm, never seen that on the ar platform, but a few thoughts come to mind.

First, the far left or far right or even being unable to sight the rifle may be caused by a canted front sight post. The retaining pin holes may not have been drilled correctly on the barrel causing a crooked mounting, which in turn can make it unable to sight the rifle in. This was common to early century arms rifles of the ak family.
The correction for that problem if you choose to retain the a2 style front sight post is usually a new barrel that has the holes drilled correctly, OR do away with the front sight post, and go to a free float rail which you can use same plane sights on it, OR you could replace the front sight post with a railed gas block which will allow the use of a compatible folding front sight. Then you can level, the sight block with the receiver and secure it by set screw or clamp on means.

Another thought that comes to mind is the distance your shooting. The minimum I start with is 25 yards if I do not have the rifle boresighted. If its bore sighted I use 50 yards, then permenantly set my irons at 100 yards. The thought I had was maybe your trying to sight in at too close a distance. That could explain the reason it cannot be adjusted enough. Try a farther distance.

Also makes sure you use loctite on the mounting screws for the irons and optic, they can work loose, which can effect your groups. I use purple loctite or blue on all my sights being irons, scope with rings, or red dots.

Also make sure its not you pulling or having a rough trigger pull as in jerking while firing, which can effect the accuracy. I use a a caldwell lead sled solo on the bench to sight in, that way I no movement, no real recoil, so you can concentrate on the sight picture and trigger pull and less on rifle movement. Then when I am shooting normally to the shoulder I know if the groups are off its me not the setup.

Make sure the sights are compatible, meaning some irons are made for same plane or same height as in a full top rail. There are also front sights that are made a bit longer for mounting on non same plane setups like a reciever thats one height and a gas block thats lower which requires a longer aka taller front sight post to allow proper alignment.

Just a few thoughts that could be of relevance.
Thanks for your response.

The MPR has a free floating handguard. The iron sights I added, mounted on the Picatinany rail. All shots were taken from a bench rest.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #8
Hmmm, never seen that on the ar platform, but a few thoughts come to mind.

First, the far left or far right or even being unable to sight the rifle may be caused by a canted front sight post. The retaining pin holes may not have been drilled correctly on the barrel causing a crooked mounting, which in turn can make it unable to sight the rifle in. This was common to early century arms rifles of the ak family.
The correction for that problem if you choose to retain the a2 style front sight post is usually a new barrel that has the holes drilled correctly, OR do away with the front sight post, and go to a free float rail which you can use same plane sights on it, OR you could replace the front sight post with a railed gas block which will allow the use of a compatible folding front sight. Then you can level, the sight block with the receiver and secure it by set screw or clamp on means.

Another thought that comes to mind is the distance your shooting. The minimum I start with is 25 yards if I do not have the rifle boresighted. If its bore sighted I use 50 yards, then permenantly set my irons at 100 yards. The thought I had was maybe your trying to sight in at too close a distance. That could explain the reason it cannot be adjusted enough. Try a farther distance.

Also makes sure you use loctite on the mounting screws for the irons and optic, they can work loose, which can effect your groups. I use purple loctite or blue on all my sights being irons, scope with rings, or red dots.

Also make sure its not you pulling or having a rough trigger pull as in jerking while firing, which can effect the accuracy. I use a a caldwell lead sled solo on the bench to sight in, that way I no movement, no real recoil, so you can concentrate on the sight picture and trigger pull and less on rifle movement. Then when I am shooting normally to the shoulder I know if the groups are off its me not the setup.

Make sure the sights are compatible, meaning some irons are made for same plane or same height as in a full top rail. There are also front sights that are made a bit longer for mounting on non same plane setups like a reciever thats one height and a gas block thats lower which requires a longer aka taller front sight post to allow proper alignment.

Just a few thoughts that could be of relevance.
Thanks for your detailed response.

All shots fired were from a bench rest. I have used this process in the past and have had no sight in problems. I often sight a AR type rifle, that only has open sights or a red dot, at 50 yards so I can see the target well. I usually sight about 1 1/2 inches low at 50 yards and it's pretty true at 100.
 

·
"The Real Deal"
Joined
·
6,527 Posts
My post above was relating to ar sight problems in general. I took a look at the mpr so I know exactly what your using.

Is the rail even with the upper receiver where they both meet on top? Can you slide a 1913 mount across it without it binding? Sometimes when the rail is tightened in the manner that the mpr uses it could be off. Have seen that with other rails troy, midwest and others that use that style of mounting. Try placing a level on the rail and receiver to see if its equal.

I would not think the barrel nut would be loose, however that could be possible. More so with the barrel nut that rail uses. Should be torqued to between 30 and 80 ft lbs. Most do not have much side to side play between the barrel nut and gas tube. On the yankee hill rails they are tight. The method midwest uses is that you put green loctite on the barrel nut before installing the rail to add strength when you tighten down the clamping bolts.

Remove the upper, charging handle, and bolt carrier and look at the gas tube. See its relation with the receiver, is it centered, or slighty off, or angled right or left? This could also give clues.
 

·
Registered
Joined
·
2,778 Posts
Interesting problem. I mounted Magpul MBUS sights on my MPR and they were pretty much on target right out of the box with very little adjustment. Have you checked to ensure that the handguard is mounted correctly and the screws are tight?
 

·
Registered
Joined
·
12 Posts
Discussion Starter #11
My post above was relating to ar sight problems in general. I took a look at the mpr so I know exactly what your using.

Is the rail even with the upper receiver where they both meet on top? Can you slide a 1913 mount across it without it binding? Sometimes when the rail is tightened in the manner that the mpr uses it could be off. Have seen that with other rails troy, midwest and others that use that style of mounting. Try placing a level on the rail and receiver to see if its equal.

I would not think the barrel nut would be loose, however that could be possible. More so with the barrel nut that rail uses. Should be torqued to between 30 and 80 ft lbs. Most do not have much side to side play between the barrel nut and gas tube. On the yankee hill rails they are tight. The method midwest uses is that you put green loctite on the barrel nut before installing the rail to add strength when you tighten down the clamping bolts.

Remove the upper, charging handle, and bolt carrier and look at the gas tube. See its relation with the receiver, is it centered, or slighty off, or angled right or left? This could also give clues.
I've looked at the handguard closely, and see nothing that stands out. Haven't put a level on it; didn't think about that since the aimpoint only mounts on the upper receiver rail. Have not looked at the gas tube. That's a good idea. I'm not with the rifle now, but will look tomorrow.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #12
Interesting problem. I mounted Magpul MBUS sights on my MPR and they were pretty much on target right out of the box with very little adjustment. Have you checked to ensure that the handguard is mounted correctly and the screws are tight?
Thanks for the response. No I have not checked the handguard mount. Don't know if I would know if it was mounted correctly or not. Maybe I'll take the handguard off and see what makes it tic! I'm going to watch some Youtube videos tonight; that ought to make me an expert very quickly!
 

·
"The Real Deal"
Joined
·
6,527 Posts
I've looked at the handguard closely, and see nothing that stands out. Haven't put a level on it; didn't think about that since the aimpoint only mounts on the upper receiver rail. Have not looked at the gas tube. That's a good idea. I'm not with the rifle now, but will look tomorrow.
Glad I could contribute. I know the ar platform very well, so I hope I can help you narrow down what the issue is. As for the rail, if you decide to remove it, this process will be of help. Loosen the two bolts on the bottom side of the rail near the receiver. Then place something between the two tabs to expand them, I would use something plastic, or wood, so you do not scratch the surface. Then once loose you should be able to rotate the rail maybe 5 or 10 degrees that will detach it from the notches on the barrel nut, and the rail should slide off toward the muzzle. Once apart then ypu can inspect the internals. He is a similiar rifle of mine I did that uses the same type of fastening and dissassembly a midwest SS free float . If you have questions just let me know. I suspect the barrel nut on yours is similiar.
 

Attachments

·
Registered
Joined
·
12 Posts
Discussion Starter #14
Glad I could contribute. I know the ar platform very well, so I hope I can help you narrow down what the issue is. As for the rail, if you decide to remove it, this process will be of help. Loosen the two bolts on the bottom side of the rail near the receiver. Then place something between the two tabs to expand them, I would use something plastic, or wood, so you do not scratch the surface. Then once loose you should be able to rotate the rail maybe 5 or 10 degrees that will detach it from the notches on the barrel nut, and the rail should slide off toward the muzzle. Once apart then ypu can inspect the internals. He is a similiar rifle of mine I did that uses the same type of fastening and dissassembly a midwest SS free float . If you have questions just let me know. I suspect the barrel nut on yours is similiar.

I removed the handguard this morning. Loosened the two socket head screws and the handguard just fell off. The handguard loosely fits the barrel nut and has nothing to locate in on the receiver. Not too impressed with this setup.

The barrel nut is a round cylinder with a hex head on it's end. It appeared to be torqued ok. I would of liked to take it completely apart and look at the face of the receiver. But, since I'm going to send it back to Ruger, decided they would not appreciate me tampering with it.

I looked at it very closely and could not see anything that stood out. I did look at the back of the gas tube, as you suggested. It looked to be centered.

Will send it back to Ruger for adjustment.
 

·
Registered
Joined
·
30 Posts
You said it would not adjust out with scope/ red dot nor sights ,was scope mounted to handguard or upper receiver ????

Sent from my Moto G Play using Tapatalk
 

·
Registered
Joined
·
1,592 Posts
You're having a problem after changing sights and adding a red dot and think it needs to go back to Ruger?

Does it shoot to point if aim on iron sights? Did you bore sight it? Can others shoot it correctly?

Jeff

Sent from my XT1254 using Tapatalk
 

·
"The Real Deal"
Joined
·
6,527 Posts
I removed the handguard this morning. Loosened the two socket head screws and the handguard just fell off. The handguard loosely fits the barrel nut and has nothing to locate in on the receiver. Not too impressed with this setup.

The barrel nut is a round cylinder with a hex head on it's end. It appeared to be torqued ok. I would of liked to take it completely apart and look at the face of the receiver. But, since I'm going to send it back to Ruger, decided they would not appreciate me tampering with it.

I looked at it very closely and could not see anything that stood out. I did look at the back of the gas tube, as you suggested. It looked to be centered.

Will send it back to Ruger for adjustment.
Sending it back to ruger is the best bet. The setup you described sounds identical to the troy mrf rail and how its constructed. I am not a big fan of that setup, the barrel nut is hard to torque needing a special wrench thats not easily found in my experience. Kinda like it needs a crows foot large enough that can be attached to the torque wrenchs shank.
The mounting design of the yankee hill diamomd is threaded on, its ultra strong. The midwest ss also uses a design similiar to the troy however has more bearing surface to bite into increasing strength.

I wish I could help further, but do wish you success in getting it going as it should be.;)
 

·
Registered
Joined
·
12 Posts
Discussion Starter #19
You're having a problem after changing sights and adding a red dot and think it needs to go back to Ruger?

Does it shoot to point if aim on iron sights? Did you bore sight it? Can others shoot it correctly?

Jeff

Sent from my XT1254 using Tapatalk
No I did not change sights; the rifle comes with no sights. I first shot it with the red dot and then with a set of irons sights. Neither can be adjusted far enough right to sight in. The elevation is good and shot groups are good. Just can't get adjusted right enough. I have not had others to shoot it.

I believe the barrel must be a little out of square with the receiver.

Have packaged the rifle and will send to Ruger for adjustment.
 

·
Registered
Joined
·
30 Posts
That is what kept confusing me when others kept mentioning loose or misaligned rail .if it is with open and scope ( same poa problem) it is in the barrel or upper receiver barrel interface .I agree send it back ( I'd send a Target with it .


Sent from my Moto G Play using Tapatalk
 
1 - 20 of 23 Posts
Top