Internal receiver rails

[Vulture]

I'd like to polish the internal rails for smoother operation of the bolt carrier on a project. Any particular type of polish or dremel tip recommended?

[yari]

Lapping compound, comes in different grits.

[hermosabeach]

In addition to lapping compounds, I have had good luck with Craytex for use with the dremel

Craytex makes abrasive impregnated wheels and sticks

It is good to remove fine machine marks and rough edges.

[hermosabeach]

Flitz metal polish by hand or on a cloth mandrel works well for polishing contact surfaces

[Vulture]

So I could get a syringe of the lapping compound and hit it with a small polishing attachment or buy just the cratech attachment without the compound and debur and whatnot with that?

[wash]

Don't go crazy with lapping compound.

Clean and degrease your action and look for burrs and surface wear.

Put in your bolt carrier without any springs and run it over the rails to see if it hangs up or gets tight anywhere. If you find a spot like that, mark the position of the carrier, then remove the carrier and line it up with the marks outside of the receiver so you can see which parts of the rails it is contacting at that point. Once you have determined what is causing the friction, address that instead of thinning the entire rail.

You can also use a marker to coat the rails with ink and then run the carrier through to see where it is tight enough to wear off the ink.

Once you've addressed any trouble spots, reassemble the action dry to confirm that the friction is gone, then add a light coat of oil and hand cycle it several hundred times to mate the surfaces together a little more.

Only get out the lapping compound if the entire rail is oversized.

I would use needle files, polishing stones and maybe a dremel if there was something big to remove (kind of unlikely if the carrier actually fits on the rails).

[Vulture]

Don't go crazy with lapping compound.

Clean and degrease your action and look for burrs and surface wear.

Put in your bolt carrier without any springs and run it over the rails to see if it hangs up or gets tight anywhere. If you find a spot like that, mark the position of the carrier, then remove the carrier and line it up with the marks outside of the receiver so you can see which parts of the rails it is contacting at that point. Once you have determined what is causing the friction, address that instead of thinning the entire rail.

You can also use a marker to coat the rails with ink and then run the carrier through to see where it is tight enough to wear off the ink.

Once you've addressed any trouble spots, reassemble the action dry to confirm that the friction is gone, then add a light coat of oil and hand cycle it several hundred times to mate the surfaces together a little more.

Only get out the lapping compound if the entire rail is oversized.

I would use needle files, polishing stones and maybe a dremel if there was something big to remove (kind of unlikely if the carrier actually fits on the rails).

Now that's a good idea, thanks.

[hermosabeach]

I had a WASR that had a really rough mag well

I also sat and slid my hands over the gun. Anywhere i felt "sharp" edges or corners I marked with Dykem steel marker. A sharpie would work as well

I user the cratex wheels to polish the metal so it was smooth to the touch

One of the tricks with cratex is that you can shape the wheel to a part

You can hold the wheel on a piece of concrete or steel at an angle and slope a wheel.
Or hold it into a hack saw blade to split the wheel

It give you more options

For the rails and places with critical dimentions- Go Slow!!!

Steel does not grow back

If you place lapping compound on the bolt and rails and run the action several times, this will allow contact areas to accelerate the wear / smoothing process. I did this on mine. I used the cratex on other places but not on the internal rails

I have run the action on some Competition M14/ M1A1 rifles that were butter smooth

I have no clue how to get any rifle that smooth. It is beyond my current skillset

I just wanted my rifle to cycle more reliably and to be dehorned so when I run the gun, my hands are chewed up less.....


The dremel can be a fast way to ruin a gun.