Remington 700 SPS 243 Win to 6 Creedmoor conversion: Budget precision rifle

6 Creedmoor precision rifle on a budget?

We had great results with our Remington 700 SPS Varmint chambered in 243 Winchester.  Approaching 1/3 MOA accuracy at 500 yards, this modestly priced rifle exceeded expectations.  The only downside is the cartridge, the 243 Winchester is a great hunting round and quiet capable for use in matches, however, for the competitive shooter, there are smaller, more efficient rounds that approach the 243 Win in performance.  Since this rifle had good bones, we decided to rechamber it in another cartridge, 6 Creedmoor.

rem 700 sps review 2

95 TMK 243 win at 500 yards

Why 6 Creedmoor?  The rifle was equipped with a Remington Varmint contour barrel with a 1:9 1/8″ twist from the factory.  This barrel shot well and worked with our favorite 6mm match bullet, the .243″ diameter 107 grain Sierra MatchKing (SMK).  I knew I wanted something that burned less powder than the 243 Winchester, and came up with a few different options, the 6mm BR, 6 Dasher, 6×47 Lapua, and 6 Creedmoor.

Commonly encountered match cartridges, left to right: 6mm BR, 243 Winchester, 6x47 Lapua, 6 Creedmoor, 6.5x47 Lapua, 6.5 Creedmoor, 260 Remington, and 308 Winchester

Commonly encountered match cartridges, left to right: 6mm BR, 243 Winchester, 6×47 Lapua, 6 Creedmoor, 6.5×47 Lapua, 6.5 Creedmoor, 260 Remington, and 308 Winchester

The 6mm BR is known to be one of the most accurate cartridges produced, especially at mid range distances to 600 yards.  The short powder column, steep shoulder, small rifle primer and quality brass make for a compact accurate cartridge.  The 6mm BR can be made to feed well, but the relatively short length of the case can be problematic with the constant tension ejector on the Remington 700 action, making extraction an issue.  The 6mm Dasher, an improved version of the 6BR, suffers the same problem.  While I’ve built two different 6mm BRs on 700s that extracted well, I elected to avoid potentially dealing with this issue and pick a cartridge with a longer case length.  For this reason, 6 BR and 6 Dasher didn’t make the cut.

Now the decision was between 6×47 Lapua and 6 Creedmoor.  Similar in size and performance, both are necked down versions of their more commonly encountered 6.5mm parent cartridges, the 6.5×47 Lapua and 6.5 Creedmoor.  For both cartridges, the 6.5 brass is simply necked down to 6mm in one pass and the brass is formed.  Easy.  For the 6 Creedmoor you can buy brass from Hornady.  The Lapua uses a small rifle primer while the Creedmoor uses a large rifle primer.  Perhaps the biggest difference between the two is the brass, the Lapua can be formed from Lapua brass, while the Creedmoor requires either the use of Hornady brass (which isn’t very good) or Norma brass which isn’t always encountered.  Decisions, decisions… I already have a 6×47 Lapua that hammers, so 6 Creedmoor it is!

6 creed 95 TMK cartridges with box

Let’s customize this 700 SPS!  But first, read the disclaimer below…

The contents of Rifleshooter.com are produced for informational purposes only and should be performed by competent gunsmiths only. Rifleshooter.com 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.

For this project, I ordered the following products from Brownells:

The barreled action is removed from the stock.  With the bolt and trigger removed, the action is secured in an action wrench.  Removing factory barrels can be difficult, use of a port entry action wrench can bend the action, a wrap around wrench, like the Brownells shown in the picture above, is a better choice for this type of operation.  A piece of painters tape is used to protect the outside of the action from becoming marked up.

700 SPS conversion rosin

The barrel shank is coated in rosin.  This is important to prevent the barrel from slipping when it is help in the barrel vise.

700 SPS conversion barrel in vise

The barrel is held in a barrel vise.  This vise, from Brownells, uses a set of aluminum or steel bushings matched to the outside diameter of the barrel.   I prefer the aluminum bushings because they are stickier and resist slipping fairly well.  The vise is attached to the leg of my work bench.  A pipe on the handle of the action wrench helps break the action loose.

700 SPS conversion factory threads 2

This is what the factory barrel tenon looks like, note the left over thread locking compound from the factory.

factory threads 700 SPS conversion

Another view of the factory barrel tenon, this one with the factory recoil lug in place.

cut off chamber end 700 SPS conversion

I’ll be reusing the barrel on this rifle.  Since the original chamber is for 243 Win, a larger cartridge than the 6 Creedmoor, I begin by cutting off the threaded end of the barrel.

700 SPS conversion dialing in

I mount the barrel in the lathe between centers.  In this case a spider (4 screws) is used to gimbal the barrel concentric with the lathe.  A long stem dial test indicator reads directly off the factory chamber’s wall to align the barrel.

700 SPS conversion tenon no lug

The tenon is cut to 1.062″ in diameter with a 3/8″ high-speed steel insert tool.

700 SPS conversion tenon

The recoil lug should fit over the tenon with little to no play.  I decided to reuse the lug on this rifle since it was flat when I checked it.

700 SPS conversion stop groove for threads

A 35 degreee high-speed steel profile tool is used to cut a small stop groove between the threads and the part of the tenon the lug will sit on.

700 SPS conversion threads

An insert threading tool is used to cut the thread at 16 TPI.

700 SPS conversion test fit action

The action can now be test fit on the barrel.  Everything looks good.

cutting counter bore

A 3/8″ high-speed steel insert boring bar is mounted in the lathe to cut a new bolt nose recess in the rear of the barrel.   A piloted form tool will not work in this application since the barrel already had previously been chambered.

test fit action

The action, lug, and bolt all fit now.

700 SPS conversion reamer set up

I will be cutting the chamber with a piloted high-speed steel reamer.  This one is equipped with a reamer stop to help control the depth of cut.  I gave up on the reamer holders I used to use in the past and now hold the shank of the reamer with locking pliers and push the reamer with a flat MT3 blank in the tail stock.

chambering 700 SPS conversion

The reamer is coated in Do-Drill cutting oil and inserted into the chamber.  The lathe is run at 70 RPM and the reamer is gently fed with the tail stocks feed.  The reamer is stopped and cleaned often.

700 SPS conversion close on go

I like to sneak up on final headspace.  I take it slow, a few thousandths at a time as I reach final depth.  The bolt should effortlessly close on the go gauge.

open on no

And stay open on the nogo.

radius mouth

The last final lathe operation is to cut a chamfer on the outside of the bolt nose recess and break the inside edge of the chamber.  This allows for smooth feeding.

alignment lugThe barrel is now removed from the lathe.  A recoil lug alignment tool is used to make sure the lug is correctly positioned when the barrel is tightened.

DSC_0271

The barrel is placed in a vise and torqued in place with an action wrench.  Note I use a different wrench (Surgeon) and vise to install the barrel than I used to remove it.  This is because this type of vise is faster to use and installation doesn’t require as much force as removal of the factory barrel.

6 creed preheat

Ready to Cerakote.  The part are placed in a heat curing oven and allow to heat, this will allow any oil in the metal to leech out.

soaking 6 creed parts

The parts are then soaked in acetone.  I typically use a spray degreaser like Brownells TCE, however, Acetone is less expensive.  The parts are placed in a fiberglass bin.

6 creed dry parts

After a long soak the parts are allowed to dry.  The acetone doesn’t evaporate as fast as the TCE.

6 creed blast cabinet

Over to the blast cabinet.  Silicone plugs are placed into critical parts like the bore.

6 creed after blast

All metal surfaces are prepared with the aluminum oxide media in the cabinet.

6 creed ready to coat

Back outside with the parts.  I hang them on a rack so I can blow off any residual media from the cabinet.

6 creed coating

The parts are coated with a small HVLP gun.  The color is MAGPUL flat dark earth.  The parts are sent back to the oven and allowed to cure.

grayboe 0

The barreled action will sit in a Grayboe stock.  Grayboe is a new company, started by Ryan McMillan.  The Grayboe (front) has the same basic shape as the McMillan A5 (rear, green) but costs significantly less.

6 creedmoor rem 700 4

Looks good doesn’t it?

Price wise how did we do without optics or accessories? (Prices as of 8/2016)

$1,218- without the cost of resetting the barrel and cutting a new chamber.  Not too bad and under the price of a Ruger Precision Rifle and approximately the same cost as a custom action.

The rifle is finished off with the following parts:

6 creedmoor rem 700 76 creedmoor rem 700 26 creedmoor rem 700

This rifle shoots great as well!

6 CREED 107 SPS GROUP