Home Forums Hunting & Shooting Gunsmithing barrel threading question

Does a Remington Model 7 (.243 or .260) barrel have enough material for it to be threaded for suppressor use?

It is marginal at best for 5/8" threads. Might have to resort to 1/2" threads and run an adapter if you have a 5/8" compensator.

That was my thought, but wanted to get an opinion from someone's who may have done one. Thanks. Was thinking about a model 7 for the kids, but want to be able to put the Omega on it when they start shooting.

The model 7 in .300 blk that comes threaded from the factory must have thicker profile barrel

Yes, the 300 BO model has a different profile barrel.

Yes, Kp321 has it right.

Thanks guys.

On a similar note, has anyone seen one of the new model 700 TB models that comes with a threaded barrel? Is the barrel profile any thicker than a standard 700 barrel?

I'm wanting to get or put together a fairly light weight .243 for my kids. They, like their old man, are fairly small. Want the threaded barrel to screw my Omega on to take the boom out of the equation.

Most hunting rifle barrels are too small for 5/8-24 threads, but 9/16-24 is the standard for thinner barrels in calibers bigger than 22; better to not go down to 1/2" if you don't have to.

Redleg, what is the muzzle diameter of the rifles you want to have threaded? If you'll measure and report back, I can tell you what thread will be most appropriate.

Also, will you be using a muzzle device with that Omega, or just direct thread?

Just out of curiosity, why is 1/2" thread bad for 30 cal barrels??

Yondering,

Don't have a set barrel yet, just exploring options at this point. It will be 2 years till the kids can hunt, so I'm not in a big hurry. Was debating on if a youth 700 ADL/SPS could be threaded 5/8 for running an Omega via direct thread. What I'll probably end up doing is buying an action and having a barrel put on it. Something thick enough to thread and than maybe have it fluted to try to take the weight back down to closer to the Model 7 weight.

The root of the 1/2-28 thread is about .450", that leaves .071 barrel wall thickness for that length. Typically .100" wall thickness is considered minimum and most re-borer's won't go less than .125". There is more of a chance for the bore to open up at the muzzle (like a blunderbuss)and that does nothing good for accuracy. If incorrect nose radius is used on the threading tool, you could have a stress crack form in the thin section.

Yes, all of that. It's like having a very thin muzzle, only worse.

How would you feel about a sporter barrel that tapers to .450" at the muzzle?

Makes sense.
I think my 300 Whisper upper is 1/2-28, but I'm not sure. Never ran a can on it.

1/2-28 works just fine for a brake on a .30 caliber bore. Hanging the weight of a suppressor on it could get a little sporty.

It "works", as far as that goes, but it's not ideal. Removing that much steel often allows the bore to open up slightly, which is not good for accuracy. You may or may not be able to tell a difference, depending on a lot of things, but it's never helpful.

Of the many hundreds of small barrels I have installed brakes on, I have never seen a bore "open slightly". I call Bullshit. What method would a smarter gunsmith than me use to attach a brake to a small diameter barrel, Knower of all, seer of much?

It's true....too many barrel makers have reported on it not to be.
http://bulletin.accurateshooter.com/2015/04/muzzle-threading-dont-remove-too-much-steel/

What you see typically....
.22 - 1/2x28
6.5 - 9/16x24 (or 5/8x24)
.30 - 5/8x24

Precision builders avoid muzzle threading altogether and here is a comment by Whitley...

By Robert Whitley
In truth, the 5/8” x 24 tpi threading never came out of any accuracy-based think tank or set-up, it’s a military .30-Cal threading for barrels that someone has to carry around (they needed to keep the barrel weight down so it was smaller in diameter and the threading had to work with that situation). People have somehow assumed because the military uses that threading for certain things that it must mean that it’s also fine for a highly accurate rifle too, but that’s not really correct.

Besides what Direct Drive posted above, it's a known fact in machining steel that removing material around the OD of a hole allows the ID to grow slightly. The amount of change is generally small, but it is predictable, and proportional to the amount of material remaining around the hole.

You can often see it in the bore fouling pattern near the muzzle. By your sarcastic remarks, you must think if you've never seen it, it must not happen, right?

A "better gunsmith than yourself" would avoid small diameter thread profiles where possible. Using a larger thread diameter and registering against the muzzle instead of the shoulder is often a good option, if that can work with the device being attached to the muzzle. Easy to do with brakes and flash hiders, or thread adapters for suppressor mounting.

A pure lead, lubed slug pushed through the bore will reveal tight and loose spots that measure in the tenths. A loose muzzle is pretty easily determined and quantified. Quantifying an enclosed defect further in the bore would probably require an air-gage, but the slug will tell you it isn't consistent.

Removing metal around a properly stress relieved cut rifled barrel will not promote growth in the bore. I call BS on that. I have braked a few 300 Weatherbys with #1 contour barrels with 1/2"-28 and they were accurate and durable. They were just louder than I can stand so none of mine have brakes any more. There isn't near the pressure at the muzzle as there is at the breech. I think some are over thinking this. I do suggest that you use the largest practical diameter for any given barrel.

I have no idea how a can would fare on a 1/2-28 30 caliber. I don't think it would matter that much what the thread size was as long as it was fitted right.

I thread everything I can to 5/8, even .22s. I do have a couple of thin barrel guns in .30 that are 1/2, and have yet to see an issue.