I recently watched an old western from 1950 starring Gregory Peck as Johny Ringo, called “The Gunfighter”. In the movie, wherever he went Johny was challenged by young guns who wanted to prove themselves against him. I had to laugh at the familiarity of the story.
When I started writing books, teaching about gunsmithing and gunsmithing tools I was a little naïve. I had no idea that people would feel the need to argue. But it has proven to be the nature of the territory I have staked out. Most of the time I don’t put much effort into responding, but once in a while the comments demand a better explanation.
I have to remind myself I started out with a lot of passion and very little knowledge. Often this is the case when people choose to disagree with information. They mean no harm, but their passion outstrips their experience. Maybe that’s where the old line fits in, “The path to Hell is paved with good intentions.”
That brings me to the comments I am responding to. I recently, released a YouTube video that simply shows a tool and explains its general use for gun tinkerers who do not yet have or cannot justify the expense of a lathe and all the associated tooling. First, Here is the video: Annular Cutter for Barrels.
Here is the comment I am addressing in this blog post:
“Aw, c’mon Fred…so it’ll create the major diameter for common muzzle thread pitches, Might be barely adequate for a flash hider or short brake (with an oversize hole for clearance) but the annular cutter won’t create a perfectly perpendicular shoulder and the threads would need to be cut with a piloted tap. Again, this isn’t precision work- and you really should clarify that this isn’t suitable for suppressors or other muzzle devices that require absolutely precise alignment to the bore centerline. If a for-pay “gunsmith” used something like this he’s a hack… Want to be a licensed gunsmith? Invest the $$ in the equipment and tooling necessary to do the work to the highest standards so you don’t end up maiming or killing someone.”
I agree with the comment that it’s unlikely that such a tool will be as precise as a lathe. But that dose not make it imprecise or impractical for specific jobs. Additionally, there are gun/barrel assemblies that are not easily placed in a lathe, I.E. Mosin Negant, SKS and many others. Over the decades I have seen surplus guns that were of little value so they were used for practicality; Expending premium labor on them is literal waste or money. When large numbers of surplus guns exist and are cheap it’s often more about fun, what if and/or a cool factor; rather than precision. There are always projects that fit these parameters.
The first two thirds of the comment are about the tools suitability or perceived lack thereof. For clarity, this part ends with the words “bore centerline”.
Here is the description of the video as posted on YouTube: “You don’t own a lathe, but you want to install muzzle breaks or Flash hiders. Here is a great solution. A tool that does not need a Lathe to do quality job. See how they work.”
About 4 years ago I did a budget build with the Ultimate Reloader to show that quality work can be done without bringing all the premium tools to bear on the project. Today the focus seems to be on extreme accuracy. While that approach has clear value it is not always cost effective or necessary depending on the end users’ needs and desires. Here is a link to that video. For accuracy results on the rifle in the video you can skip to 46:08.
Since I still have that gun, I pulled it apart to take measurements. We used the earlier version of these annular cutters to reduce the muzzle of the barrel and then used a thread alignment tool and die to thread the muzzle. First, I will say that the 2nd generation tools shown in the YouTube video above, is better quality than the 1st generation used in the Ultimate Reloading video to thread the muzzle of the 300 Blackout we barreled. The 2nd generation has a better pilot system and a better drive adapter for the annular cutter.
The result of our low-cost build was a gun that shot under ¾ MOA without doing any load development for that gun. Was the shoulder where the muzzle was threaded out of square, YES. Were the threads out of alignment with the bore, NO.
About deflection: In machining, “0.001″ out of square” is typically understood as:
0.001″ deviation per 1″ of height/length, since we are comparing to a 90 degree face the calculation is simple. (line 2 of the table below is equal to .001” out of square.)
“projected error = squareness error per inch × distance”
| Out of Square (“/in) | 1″ | 2″ | 3″ | 4″ | 6″ | 12″ |
| 0.0005 | 0.0005 | 0.0010 | 0.0015 | 0.0020 | 0.0030 | 0.0060 |
| 0.0010 | 0.0010 | 0.0020 | 0.0030 | 0.0040 | 0.0060 | 0.0120 |
| 0.00135 | 0.00135 | 0.0027 | 0.00405 | 0.0054 | 0.0081 | 0.0162 |
| 0.0020 | 0.0020 | 0.0040 | 0.0060 | 0.0080 | 0.0120 | 0.0240 |
| 0.0050 | 0.0050 | 0.0100 | 0.0150 | 0.0200 | 0.0300 | 0.0600 |
The muzzle device you’re installing will dictate how much error in alignment can be tolerated without danger of a bullet strike to the device. True flash hiders are so far oversized that there would never be an issue with any flash hider as they are normally less than 3” in length and come nowhere near the bore. Make no mistake, I am not suggesting that an out of square shoulder is desirable or good. Only that it can be tolerated if it is not too extreme.
Muzzle brakes come in a wide variety of dimensions as provided by literally an unlimited number of manufacturers. All such devices have clearance over the bullet diameter to prevent bullet strikes. Simply by choosing a muzzle brake that utilizes more clearance, any concern would be removed.
Extra clearance is needed even with a concentric barrel and device:
- Thread tolerances (barrel and device)
- Shoulder square
- Mounting system play
- Bullet yaw on exit
- Heat and fouling buildup can all shift the projectile slightly off the theoretical centerline.
Best practices to prevent strikes
- Use an alignment rod to verify concentricity before firing (especially for suppressors) but this tool would work for any muzzle device.
- Follow the device manufacturer’s specifications first and foremost.
- Ensure proper barrel threading and shoulder by a competent gunsmith.
- Avoid stacking tolerances (e.g., adapters on adapters).
- Re-check alignment if the device is removed/reinstalled.
Here is an aspect of the threaded muzzle that is being ignored in the above information; is the threaded tenon threaded in alignment with the bore? Or, how well is it aligned with the bore?
Below is a picture of a split die (adjustable) with a thread alignment tool (TAT) installed. The pilot on the TAT keeps the die aligned to the bore of the barrel. The TAT should have either a screw driver slot or a hex socket in the head so the gunsmith can manipulate it. The pilot goes in the bore of the barrel, the TAT should start far enough back in the die so that it can start to cut.
Make sure the TAT does not bottom out on the muzzle as this will cause a bind between the tools and the barrel, potentially damaging or stripping your new threads. It is necessary to back the TAT up through the die as the cutting advances, until the TAT is no longer aligning the die, then just remove it.
The split die allows the user to make multiple cuts, if necessary to get the correct fit of the threads to match the muzzle device as desired.
My suppressor calls for .625”x24 with approximately .750” length. All I will say about this is that the longer that threaded area the less an out of square shoulder can force the attached item out of square. The very nature of ‘V’ threads is that they self-center, this combined with a good match of the diameters of the threads (minimal slop) the better the threads will align to each other. Naturally, a shorter tenon will be more subject the being forced out of alignment by a shoulder that is out of square.
Now on to the second half of the comment which is more gritty and filled with hyperbole.
“If a for-pay “gunsmith” used something like this he’s a hack… Want to be a licensed gunsmith? Invest the $$ in the equipment and tooling necessary to do the work to the highest standards so you don’t end up maiming or killing someone.”
Aside from the liberal strongholds of California and New York. The only license requirement for a gunsmith is the appropriate class of FFL. I have not seen any states that require any formal or informal education in gunsmithing in order to become a gunsmith, but I am no lawyer. The term licensed gunsmith holds about as much water as a fishing net, at least when associated with precision.
As for investing money in tools and equipment. The American Dream is based on people being able to pull themselves up and build a career. Few people start life with a silver spoon that allows them to buy everything they need for a chosen trade. Everyone has to start somewhere, and in most cases investments are made over time, as they can be afforded.
I wholeheartedly agree with the comment that gunsmiths should work to the highest standards of quality and workmanship that they are able to perform. However, it is possible to perform this quality of work with lesser tools. A talented technician who understands his tools and their limitations can produce work all out of proportion to the quality of the tools. Don’t believe me read about Harry Pope. Understanding what is required to produce good quality work is far more important than how much you paid for your tools.
There is no pervasive problem in the gun industry with substandard work causing injury or death, as implied in the comment. Why? I believe it is because most gunsmiths and wannabe gunsmiths are careful and endeavor to do the best they can.
In the machining trade or gunsmithing trade there are always arguments over the best way to perform a job. An honest tradesmen will tell you, if there are 50 ways to do something it’s entirely possible they will all produce acceptable results. Likely, some are not cost effective, some produce more accurate results, and still others are highly cost effective. What is truly best practice depends, in part, on the required outcome. Not every customer has the budget of a Fortune 500 company. In truth of fact, most work is done in small one-man shops, with very little money and customers that work for a living. So, price is a factor.
All that being said, don’t be ashamed if you can afford Beluga caviar and Cristal champagne.
But, you should not shame the person who’s budget is more in line with bacon and Coors.
GunsmithTalk 