Barrel contours and suppressors

[OmegaRed]

I'm building a light switch barrel hunting gun and am to the point of deciding on barrel contours and corresponding barrel channel.

I see most builds that are similar to what I'll be doing ending up in the 7.5lb - 8lb range use the following in a non-CF barrel:

• Bart 3b
• Brux/Lilja/Kreiger #5

All of these contours finish below the recommended .750 diameter for threading 5/8x24. Is my line of thinking correct in that my only options are either bumping up to a #6 contour to get the muzzle dia and then fluting to reduce weight to one contour below, or going to a CF barrel? Or paying for a custom contour and doing something like swelling the muzzle end out to a .750 dia.

I'd don't really want to do a CF barrel, but this would give me the option (barrel channel wise) to use beyond benchrest shot count barrels that I have for my BAT B which are a heavy varmint.

 

[Kurz]

Two thoughts for your consideration:

Look at the Bartlein #4 bull Sporter:



Or you can order/buy several styles of muzzle brakes with a 9/16-24 or 9/16-28 thread pattern.

 

[jdh47]

Light and suppressor is an oxymoron. From my experience you need a fairly heavy contour to keep from having too much POI change suppressed. Suppressors add weight soo. If you want less weight and recoil then a MB is the answer. You can use the Rem. Varmint contour and shorten the barrel but it's still going to be muzzle heavy. opinions vary.

 

[XTR]

First talk to the gunsmith that is doing to do the work. I'm not certain where the .75 number is coming from, that's giving him about .125 to remove to thread it. I'm not a machinist, so ask one if that is really needed.

The 24" #4 on my 7-08 is 0.71 at the muzzle. (It's not threaded)

You don't say how long you want your barrel. If you really need the .75 consider shortening. The 24" 7-08 barrel I referenced above is .750 at 20". If you are really going to be shooting most of the time with a can knocking off a few inches might make you happier.

You could always go with a light Palma.

 

[Coonman300]

I have a couple of “pencil” barrels that are 1//2 threads. I got an adapter from forum member john1187 that screws on and will then accept the 5/8 threaded suppressor.

 

[thestoicmarcusaurelius]

Some suppressor companies like TBAC and others offer 9-16/24 muzzle devices which allows you to go with a smaller barrel without using an adaptor.

I went with a carbon fiber barrel when making this choice because I wanted a 26" barrel to keep the speeds up with 308.

Another option is cutting it shorter if you're okay with some velocity loss. I did this on a 18" 7RM that I'm really happy with for a 500 yard and under handy hunting rifle.

 

[Rook 6]

First talk to the gunsmith that is doing to do the work. I'm not certain where the .75 number is coming from, that's giving him about .125 to remove to thread it. I'm not a machinist, so ask one if that is really needed.

The 24" #4 on my 7-08 is 0.71 at the muzzle. (It's not threaded)

You don't say how long you want your barrel. If you really need the .75 consider shortening. The 24" 7-08 barrel I referenced above is .750 at 20". If you are really going to be shooting most of the time with a can knocking off a few inches might make you happier.

You could always go with a light Palma.

Yep. Shorter would be thicker. The Bart #4 listed in the table above would theoretically finish at .7744 at the muzzle for a 24 inch barrel. I wouldn’t want to go longer personally if I had to carry a rifle with a can on it.

 

[WSMNUT]

Most of my hunting rifles are #5 Brux or #5 Lilja's and I threaded all of them 5/8-24 for my suppressor. I blend thread protectors for each of them.

 

[OmegaRed]

Appreciate the replies ya'll!

 

[DangerRanger]

On my #4 rock we went to 21” specifically for this. It got mr to .730 and tbac recommended a min of .725.

With a standard non adjustable mcmillan it nailed 7.5lbs if I remember correctly. Imo the weight is perfect for a magnum hunting rifle. It also handles like it’s on rails being slightly shorter, super handy.

 

[Eagle1899]

I don't see a caliber specified. Thread size is very dependent on caliber and barrel length.

Suppressors don't need be heavy either. A Trash Panda by Q is only 13.7oz with the mount. A Half Nelson direct mount is only 12.2oz. Both are 30 cal.

 

[Oso]

I have a 6.5 Grendel with a .735" OD at muzzle threaded 5/8x24tpi. This is the bare minimum diameter. It is just barely thick enough to have a shoulder and the thread protector cap is half as thick as any of my other rifles. When I rebarrel this rifle, I will go to a slightly heavier profile (.750" at muzzle).

I am assuming you are in a .30 cal or something larger than .224... hence 5/8 x 24tpi. Thinner barrels heats up faster and greater potential for POI shift... Both the cartridge size (powder volume) and number of shots fired will impact POI shift. Thinner barrels heat up faster and more prone to POI... fluted heavier profile barrel is potential offset. Based on your cartridge and planned shooting distance(s), have you determined a required barrel length to achieve a specific velocity/performance?

You have ability to achieve a desired barrel weight by any combination of the following:
1) Profile of barrel
2) Length of barrel - a lighter profile cut shorter may meet the required muzzle diameter for threading
3) Barrel material (steel, Carbon Wrapped, Titanium)... cost increase as you go across list
4) Fluting

For majority of shooting you don't need anything beyond 24", and vast majority of hunting applications 20".
In Excel (spreadsheet program) you can do a simple linear equation to determine the taper of the barrel from the chamber to the muzzle of the blank and determine at what length it meets your .750" diameter. Do this between the different profiles you are thinking about and select the lightest profile that meets your velocity goal (barrel length) and has muzzle thickness for threading.

If you can't find this then go heavier and flute for weight reduction or pony up for a carbon wrapped barrel... check your stock's barrel recess for any restrictions on barrel diameter. If carbon wrapped then take a look at Bartlein (introduced this product a couples of years ago)... I'm dying to get user feedback (guinea pig)!!!
https://www.gaprecision.net/30-cal-bartlein-carbon-fiber-blank.html/?SID=nk7f72ircg97oj64t1u80uvk26

OmegaRed - Send me a PM with your email and I'll forward you my Excel worksheet that I use to decide/compare barrel contours and muzzle thickness at different cut lengths. Nothing fancy but it help visualize...