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Should I get a new rail?

Leatherneck

Well-Known Member
Joined
Oct 25, 2014
Messages
65
Location
Pennsylvania
I started the task of making sure my scope reticle was plumb. Removed the scope and put a level on the rail and leveled the rifle. To my uncalibrated eye it didn't look right so I removed it to check it for square. The pics below are what I found. My workbench is very close to level as a reference. Should I toss the rail and get a new one? I checked it in different locations and it was skewed the whole length.

IMG_0930.JPG


IMG_0931.JPG
 
I used 2 levels, a CTK precision and the one shown in the pic. I'm shooting a Rem 700, is the tang area with the safety pushed forward a good place to get the receiver level? My CTK fits across it nice.
 
That looks concerning to me, even if the level were cheap as it doesn't have to be accurate so much as repeatable for this evaluation. What brand rail are you using?
 
If there is an apparent issue with a product, I recommend contacting the manufacturer.

I've run across a few rails and rail to receiver fit ups that don't come out level. Setting the rail on the table as shown isn't a good method check it. This is due to the radius cuts on the bottom. The bottom edges that rest on the table could be off, even if the radius cut and holes are true to the top side. Putting the rail on the rifle and measuring it to the receiver is a better 'at home' way.
Is your receiver a factor or aftermarket custom? Its very common to see tangs and bolt race ways that are not level. Make sure your level on the receiver is bearing flat. Sometimes it can get hung up in tight fitting areas. I find the tang is the most consistent point to measure from. However, at the end of the day, the tall target test will tell you if the reticle is level to the bore. I'd recommend performing this test with a few shots prior to buying a new rail.

Another thought...when mounting the rail to the gun, set the rail on top and lightly install the front two screws. Just enough pressure to seat the rail. Check the level front to back and see if there is a gap between the back of the rail and receiver. Torque down the front two screws and check again. Install the back two screws and check again. If everything reads the same, then it could be the rail or something to do with the receiver. Use process of elimination to identify the issue.
 
The rifle is a factory 700. Trying to find a square flat surface to fit a level is proving tedious. I did remove the stock and used the bottom of the receiver as a reference. The rail did show level doing this. When I first bought the rifle it was my hunting rifle. I did have to bed the rail to the receiver. There was a gap when the front was screwed down. Now that I've transformed this rifle to shoot long range I'm just trying to remove as many variables as I can. I've plumbed the reticle and just need to get to the range and try it out. I'll definitely try a tracking test to verify.
 
I started the task of making sure my scope reticle was plumb. Removed the scope and put a level on the rail and leveled the rifle. To my uncalibrated eye it didn't look right so I removed it to check it for square. The pics below are what I found. My workbench is very close to level as a reference. Should I toss the rail and get a new one? I checked it in different locations and it was skewed the whole length.

View attachment 383998

View attachment 383999
Your rail is defective for sure - it's gotta go. Thankfully a new Picatinny rail will not cost that much, I also recommend you bring your levels and check the new one at the store before you buy it. This old rail you tried to mount must've shifted in its clamp while being machined at the manufacturer.

I was a production specialist at a lock company and have some experience with machining parts to tight tolerances.

Your rail is so far out that its error must be obvious to the naked eye as well.

Good luck my friend.
 
Level the action, set the rail on it, level it and screw it down. There should be more than enough clearance in the rail screw slots to get it done. If not, toss it.
 
ws If there is an apparent issue with a product, I recommend contacting the manufacturer.
I've run across a few rails and rail to receiver fit ups that don't come out level. Setting the rail on the table as shown isn't a good method check it. This is due to the radius cuts on the bottom. The bottom edges that rest on the table could be off, even if the radius cut and holes are true to the top side. Putting the rail on the rifle and measuring it to the receiver is a better 'at home' way.
Is your receiver a factor or aftermarket custom? Its very common to see tangs and bolt race ways that are not level. Make sure your level on the receiver is bearing flat. Sometimes it can get hung up in tight fitting areas. I find the tang is the most consistent point to measure from. However, at the end of the day, the tall target test will tell you if the reticle is level to the bore. I'd recommend performing this test with a few shots prior to buying a new rail.

Another thought...when mounting the rail to the gun, set the rail on top and lightly install the front two screws. Just enough pressure to seat the rail. Check the level front to back and see if there is a gap between the back of the rail and receiver. Torque down the front two screws and check again. Install the back two screws and check again. If everything reads the same, then it

could be the rail or something to do with the receiver. Use process of elimination to identify the issue.
Or if you know what valve grinding paste is spread a little on the mount and rub it where it mounts. The full finish is where it is mating well the unscratched surface means nothing is touching here and the shinny part is the high spot😉
 

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