Gunsmithing FNAR problem

[Unknown]

I recently received an FNAR from FN as an exchange item for a different rifle that was defective. I noticed that the left side action bar always seemed bowed outward a little bit, and it rubbed on the inside of the handguard. You can see where the blueing has worn off where the bar rubs against the handguard.

I returned the rifle to FN and they noted only "minor repair" on the return sheet without really saying what they did. They also returned a target with a 3 shot group of .4 inch. The left side bar still has the apparent bow in it, and I'm wondering if there is something wrong with this rifle, if I put it together improperly thereby causing the issue, or if all the rifles have this bow in the left side operating bar.

Other than returning the rifle to FN, does anyone have any suggestions? The rifle only has about 100 rounds through it. I'm concerned about the long term effects of this issue if it isn't fixed. It can't help accuracy when parts rub together due to improper fitting.

 

[BOLTRIPPER]

Re: FNAR problem

the only operating bar i know of is the one where there is a happy hour.....

 

[Unknown]

Re: FNAR problem

I sort of suspect if I took apart the rifle to show you the operating bar while we were in your operating bar, I would be asked to leave...and you would get all the drinks... An excellent plan on your part.

 

[Unknown]

Re: FNAR problem

I realize I'm the only one dealing with this issue, but my posting again is so there will be some reference info if someone else has to deal with the problem I encountered.

I returned my FNAR to FN as the left operating rod always appeared to be pushed outward causing it to rub on the inside of the handguard. FN didn't fix the problem. Rather than argue with FN over the problem, I decided to fix it because they wouldn't, or couldn't do so when I gave them the chance.

The rod was not bent, it was pulled outward because of uneven tension on the block that holds the rods. Essentially, the right hand rod pulled harder than the left one causing the block holding the rods to kick out of alignment to the left. This kick pushed the left side rod outward. It rubbed inside the handguard enough to wear the blueing off where it rubbed...and the rifle only has about 200 rounds through it. As the rods are supposed to be interchangeable, they shouldn't be modified. So I looked elsewhere for the solution.

The solution was to remove a few thousandths of an inch of material from the front of the right side of the block where the right rod mates into the block at the forward edge. This evened out the tension, and thereby straightened out the block. The rearward movement of the block was left alone, the modification was done to the part of the block that pulls the rods forward to chamber the next round. That is the part of the block closest to the gas block.

Anyhow, the problem is fixed, both rods sit evenly in the block now, and the rods are interchangeable just like the design hoped they would be. I suspect that almost all FNAR's have the same problem because the block is a mass produced part.

I think it is odd that FN wouldn't notice something like this, but maybe I'm being too picky. I figured that anything rubbing where the original design didn't intend it to would not help accuracy...if anything it would rob accuracy because of uneven pressure or tension.

Hopefully, this posting will help someone else with an FNAR who is having the same issue.

 

[reylor]

Re: FNAR problem

Hey sergant...Im in the exact same boat...my r/h rod seems longer but I swapped them and the problem stays on the left side. So it does have to be on the front r/h side of the block. Im having accuracy problems did you or did you just start messing with it cuz the rod kept poppin out and rubbing? Also if you did have accuracy problems did that fix it? Im kinda reluctant to grind on it maybe you can ellaborate on the procedure...contemplating sending it back to fn...what to do my 100 yard groups are no better than 9inches with a trijicon 5x20x50 burris tactical rings off a bipod or or stand. Thanks for any help

 

[Sidk]

Re: FNAR problem

Mine does the same thing. After 1000 rounds I can tell you that everything is still fine.

As far as accuracy goes. Check your scope rail. Mine was twisted and kept coming loose. I just finished replacing the rail and bedding it. No more accuracy problems. 2" groups at 200 yards with crap ammo. Before, 14" drop at 200(that is not a typo) yards with same ammo. I'm also not a great shot.

 

[Hooper]

Re: FNAR problem

Don't sweat it. I have had a few of those in the shop threading the barrels. They are an Aluminum receivered Browning bar with a heavy barrel.

I do not see where bending the sheet metal action bars will hurt anything.

There is a decent video on youtube showing how to take the thing apart for those needing it.

Are folks really getting bolt gun accuracy out of these things?

 

[Sidk]

Re: FNAR problem

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hooper</div><div class="ubbcode-body">

Are folks really getting bolt gun accuracy out of these things? </div></div>

Yes

 

[Hooper]

Re: FNAR problem

Just had one in the shop and looked it over to see if the action bars had issues. There was a slight bend on the left side bar looking from top. it bent outward.

I had the barrel out of it and installed a AAC Blackout brake.

 

[reylor]

Re: FNAR problem

Hey can I ask when you say yours does the same thing, did you do anything about it as far as modifying the inertia block...or just leave that part alone and focus on the scope rail? Also what about your scope rail...did you replace it with one from FNH or another source. Thanks for the feedback and I'll update you on improvements.