Building a custom Howa 1500 in 223AI

Building a custom Howa 1500 in 223AI

.224 Valkyrie and 22 Nosler are the hot new cartridges. They offer superior external ballistics to the 223 Remington in a compact package, but require proprietary brass, ammunition; and in the case of the Valkyrie, a 6.8 SPC sized bolt face. The 223 Ackley Improved, mirrors many of the characteristics of these cartridges while preserving the ability to shoot plain old, run of the mill 223 Remington ammunition in the same gun. Pretty neat trick, ain’t it? (You can read more about the 223 AI here)

In this post I am going to build a custom 223 AI on a Howa 1500 action. I’ve built quite a few different rifles on Howa actions and they perform well. The 1500 does share some similarities in with the Winchester 70 and Remington 700. (To read more about the Howa 1500, click here.)

Before we get to work, let’s take a few minutes to read and understand the following disclaimer:

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.

The following tools and supplies were ordered from Brownells:

The finished rifle was placed in a Modular Driven Technologies (MDT) ESS chassis.

This rifle started life as a factory Howa 1500 in 223. We removed the barrel (click here to see how that is done) and grabbed a new barrel blank.

I always begin by measuring the action to make sure my barrel will be properly fit. In the case of the Howa, I am measuring from the front of the receiver face to the bolt face (headspace), bolt nose, and the front of the recoil lugs. These measurements will allow me to determine how I should cut my barrel tenon.

I am using a Shilen select match barrel I ordered from Brownells. Shilen recommends that the first 1″ or so be removed. I do this on my band saw. Time to head over to the lathe.

This is my lathe, a Precision Matthews PM-1440GT. I love it.

Now I need to dial in the barrel on the lathe. The goal is to have the bore concentric with the machine. You can hold the barrel and indicate off of the bore in a number of different ways. In the picture above I had faced the barrel then used a range rod to help indicate the bore. This method works well, however, you are still measuring off of another tool.

A better way to dial in the bore is to use a long stem indicator like the one shown about. This reads directly off of the bore so you don’t have to worry about another tool affecting your readings. In this case I am using a set-tru 3-jaw chuck. This kind of chuck can be dialed in like a 4-jaw. I am also grabbing the barrel where a slight taper begins so it can be gimbaled with the help of the spider on the other side of the headstock (not shown).

With the bore dialed in, I can begin work on the tenon. I start by facing the barrel and cutting the tenon to the correct length with a clean shoulder.

Next, I have to get set up to thread the barrel. This is a M26x1.5 thread. The Precision Matthews PM-1440 GT makes changing over to metric threads fairly straight forward. Once the change-gears are in I have to leave the half-nut engaged and power off the lathe after each cut is made. This means I am cutting threads at a lower speed than I normally do and the metric threads take slightly longer. I used a carbide insert tool here, but I think a high-speed steel tool would have been a better choice at the lower speeds that I use with change-gears.

Like the Remington M700, the Howa 1500 requires a counterbore for the bolt nose (sometimes referred to as the bolt-nose recess). This can be cut with either a boring bar or a form tool. In this case I am using a piloted form tool. With the counterbore in place, the action and bolt can be test fit on the tenon. The action should snug up and the bolt should freely close.

I can now cut the chamber. I am using a piloted Manson reamer. The reamer is held in a floating Manson holder. The reamer is coated in cutting oil, inserted into the barrel; the lathe is turned on and a short, slow cut is made. The lathe is stopped and the reamer is cleaned. The process is then repeated.

As the reamer cuts closer to the final depth of cut, I start measuring the headspace with a go gauge and depth micrometer.

When the chamber is the proper depth, the action, when snug to the barrel tenon, should close on go and stay open on no-go.

I cut a small chamfer on the edge of the bolt nose recess to allow feeding. I also polish the rear edge of the chamber with a maroon abrasive pad to prevent it from scratching brass.

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I still need to cut the muzzle so my barrel set up is reversed. I also change out the 3-jaw set-tru chuck for a spider that will allow me to hold the tapered barrel. Once again I am dialing the bore in directly off of the bore.