Barrel length

[Rifleman1 0]

Hi there,  I haven’t posted anything in awhile..  I’m almost done making a new barrel for my JSAR.. the hard part at the chamber-end is done..  I need to install the middle bushing, bayonet lug and front sight..  then cut to length....       One thing crossed my mind.. Is there such a thing as “the correct barrel length” for a JSAR.? Or is there lots of variation..?  My original barrel measures 22-5/8” total length incl. the locking bushing.. I would like to know from other JSAR owners before I make the final cut...

Thanks,    Bill

 

[ArtR 0]

Hi Bill

I am trying to "verify" this, but both the 1941 Johnson Semi-Automatic Rifle Instruction Manual and the "Johnson Rifles and Machine Guns" by Bruce N Canfield, with Robert L Lamoreaux and Edward R Johnson,  list the barrel as 22 inches. When I say "verify", I am only checking to see if the length is an exact 22" or possibly some fraction one way or the other.

ArtR

 

[Ed Johnson 0]

If there were a slight difference at the muzzle end, this would not interfere with semi-auto recoil unlocking operation. As long as the dimensions at the chamber end are not modified, as "Bill" indicates above, you should be OK and just use the 22" as a guide. One of our Website members, "48 Tanker," has made barrels previously. If he reads this, he can wade in.

[M48TANKER 0]

I've observed several different "original" barrel lengths. Most likely due to where you define the beginning and the end of the barrel. I think some "authorities" say the barrel is measured from the chamber face to the end of the muzzle. Others probably include the locking lug bushing in the length. Most all agree that the 1941 Johnson JSAR barrel is 22 inches at least. Many I've encountered are more like 22&1/4 to 22&5/8ths. I would measure from the face of the closed bolt to the desired end of the muzzle. That is what BATFE goes by.

This is just one of many charts I've found on the internet listing barrel length as "22" inches. This chart adds .01 to that length. One thing is for sure....if you make it 22&5/8ths to include the locking lug bushing, and later decide to make it shorter, you will have the extra length to work with. The most important measurements now for your project are the location of the center guide bushing, bayonet lug, and front sight. At the bottom of this posting I'll quote Joe Scott for those measurements.

And here is a diagram:

                       

All this being said: Check the inside diameter of the parts you are going to install before just turning the barrel down to specs on paper. Turn the barrel down to diameters which make a tight friction fit with the parts of be installed.

[ArtR 0]

Hi all:

 I agree with the barrel being measured from the bolt face to the muzzle end.

One thing that must be considered is pure mathematics. The sight radius is measured from the rear of the rear sight to the rear of the front sight post. Moving the front sight out on any barrel, to fit either a 22.01",  22.25" or 22.625" length barrel, will in fact affect the sight radius. As you increase your shooting distance, say out to 1000 yds/meters, this will definitely affect your point of aim. While some may think this trivial, in the hands of a competent shooter, a longer sight radius can be a distinct advantage.

[Rifleman1 0]

Hi all

Thanks for all the input and I cut my barrel to the exact same length of my original.. I have installed the center-bushing and tried it out today, put a box of ammo through it and no issues at all... ejects every time and feeds another...

so now that I know this barrel is good..  I would like to parkerize it. Oh and put the bayonet lug and front sight on... I have included some pictures...

 

[roverboy 0]

Did you start with a 1903 barrel? Looks good by the way. Do  it yourself, is about the only way to go on these. Its a shame the barrels are so rare and expensive. May I ask why you decided to make a barrel? Was yours damaged or had a bad bore?

[Brian Alpert 0]

A few words on the JSAR finish.  Several years ago Joseph Scott looked into this.  The blueprints called for "blackening".  Joseph had an original tested by a metallurgist who found the finish to be blue.  I have since been told that the finish applied  was Du-lite, a popular finish of the era.  Applied to an unpolished surface, it comes out black.  Brownell's Oxpho blue creates a finish most similar to the original.  Indeed, with a thin coat of Cosmoline to fill the pores, it actually gets a greenish hue.

[Rifleman1 0]

roverboy,.. My original barrel was shot-out, as in, no rifling left at all, and the head spacing was far beyond of what was acceptable. The bolt would easily close on the no-go gauge ... I did shoot it a couple of times, but noticed that the ejected cartridges had bulged..  Always up for a challenge, I decided to make a new barrel. After practicing on several different 30-06 barrels, like the 1903 and a Remington take-off, I came across a "large ring" Mauser barrel new 30-06 that had pretty much the right contour, so I wouldn't have to do extensive full barrel turning on my little hobby lathe... Still I had to make all kinds of jigs and tool holders, but it was a great learning experience and I would do this again...

Brian, I remember reading as well that Joseph Scott had looked into the original finishing on a JSAR and thanks for the tip on Brownell's Oxpho Blue,  I will look into that.  Thanks to everyone for their valuable input and tips, especially Joseph Scott, who gave me all the pointers on the dimensions and turning it on the lathe,.. Brian, ArtR, Ed Johnson, M48Tanker and everyone else I was in contact with about this project.   Later, I will post pictures of the end-result with bayonet lug and front sight attached.

Bill

 

[roverboy 0]

Hope to see pics soon. Have a good one.

[Rifleman1 0]

Hi all,

I have finished my barrel project, and am very pleased with the result..  see pictures..  For a finish, I decided to use bluing solution rather than parkerize it..  tried to create that elusive green hue by coating it with grease.. but in the end it kinda stayed dark.. I’m okay with that.. just happy that I have a good and safe shooter...

Bill

 

[ArtR 0]

Hi Rifleman

Regardless of the "finish", you have your original barrel for "show" and the new barrel to shoot. A win-win for sure. Enjoy.

ArtR

[M48TANKER 0]

Congratulations on the completion of your new barrel. It does look great. There is such satisfaction in doing it yourself, not to mention the cost savings...er....that is if you don't count the time you invested in the project!