Installing a pre-fit barrel on a Remington 700

Installing a pre-fit barrel on a Remington 700

In this post we are going to look at installing a pre-fit barrel on a Remington 700 action.  This is the third post on a similar topic.  In previous posts, we looked at using a REMage conversion barrel and short chambered barrels.  Each of these methods has it’s own advantages and disadvantages. The REMage conversion is accomplished without a lot of tools, but it leaves you with a thinner barrel shank as well as a barrel nut system. The short chambered barrel has a cleaner look, however you’ll need a reamer, t-handle and more knowledge of gunsmithing.  In the spectrum of ways to change a 700 rifle barrel, this pre-fit barrel fits neatly in between the REMage and short chambered versions.

Before we get started, let’s read the disclaimer:

The contents of are produced for informational purposes only and should be performed by competent gunsmiths only. and its authors, do not assume any responsibility, directly or indirectly for the safety of the readers attempting to follow any instructions or perform any of the tasks shown, or the use or misuse of any information contained herein, on this website.

Any modifications made to a firearm should be made by a licensed gunsmith. Failure to do so may void warranties and result in an unsafe firearm and may cause injury or death.

Modifications to a firearm may result in personal injury or death, cause the firearm to not function properly, or malfunction, and cause the firearm to become unsafe.

In short, make sure you know what you are doing.  It is possible to headspace a rifle correctly and still make it explode every time you fire it if your counterbore it too deep or barrel tenon too short.  If you don’t understand this, find a gunsmith who does and have him complete the installation.

The pre-fit barrel I ordered from McGowen barrels comes threaded, chambered and ready for installation.  This barrel is a stainless steel #7 contour, 25″ long with a 1:10″ twist and chambered in 308 Winchester.  McGowen Barrels offer a wide range of calibers and contours for pre-fit barrels; check out their site here.

Installing a pre-threaded Remington 700 barrel isn’t quite as simple as screwing it on.  Depending on how tolerances stack, you may have to make slight adjustments to either the barrel, recoil lug or receiver.  The first step is to measure the barrel and the action and see how they line up.  On the action you’ll need to measure the distance from receiver face to the bolt face, bolt nose and fronts of the bolt lugs.  On the barrel you’ll need to measure how far a headspace gauge protrudes, the length of the barrel tenon and the bolt nose recess.

I like to measure my barrels both with, and without the recoil lug in place.  In this case I’m using a factory .186″ thick Remington recoil lug.  I left the “go” headspace gauge in the chamber to see how far it protrudes.

When I finish checking my measurements, I determine if I need to remove .010″ from either the recoil lug thickness or the front of the receiver ring.  If I had a surface grinder, this is about a two minute job.  But I don’t have one so I elected to use a Manson Receiver ring tool from the receiver accurizing kit.   I’d say for 99% of guys in the same situation, driving a few minutes to a machine shop and having them grind the lug down .010″ would be the prudent sensible choice.

The Manson kit contains a tap, which in turn is used as a guide for a tool that can cut the receiver ring.  It is guided into the action with two tapered bushings.  The one shown here is a 1.062 tap, it isn’t oversized, so I can simply thread it in place.

Now I can take a measurement to the front of the receiver ring to get a reference point.  This dimension needs to increase .010″, that’ll indicate the receiver is cut enough.

This is the Manson receiver ring tool.  Just a few turns with this bad boy and I’m all set.

Now the barrel, lug and receiver are torqued together.  I use a recoil lug alignment tool to hold the lug in place and a port entry action wrench to tighten the parts.  A headspace check shows the new chamber measures 1.631″, just .001″ over minimum.  Ready for cleaning and reassembly.  Pretty easy, wasn’t it?  With a surface grinder it would have been even easier.

Here is the finished rifle.  Not to bad for a couple hours worth of work.  The real question is how does the it shoot….


BOOM!  Five shots at 100 yards with the Sierra 175 gr. MatchKing (SMK).  How’s that for no lathe work?

Learn more about McGown Precision barrels here.