5/8-24 Muzzel thread

Talk about the AR15 style rifles chambered in 450 Bushmaster.

Moderator: MudBug

5/8-24 Muzzel thread

Postby Specter23 » Tue May 17, 2016 7:56 pm

Hello,
Is there a good reason not to have my 450B barrel re-threaded from 11/16-24 to 5/8-24? I know 458 SOCOM is not the same round, but does share some similarities and the 458 barrels seem to be threaded in 11/16-24 and 5/8-24. I understand the 11/16-24 threads give the barrel some more beef between the threads and the bore, but would 5/8-24 take too much away for the 450B?

Thanks for any thoughts or experience on this topic.

- BTW - I hope to use a SiCo Hybrid to suppress my 450B. The Hybrid unfortunately currently has 5/8-24 as the largest direct thread adapter. (Not interested in being talked into a separate suppressor)
Specter23
 
Posts: 33
Joined: Sat Oct 25, 2014 8:28 pm

Re: 5/8-24 Muzzel thread

Postby Colohunter » Tue May 17, 2016 9:27 pm

I couldn't find the e-mail, but I believe Silencerco announced that they would be offering additional thread patterns for the Hybrid, I'm not sure if that means the threaded mounts or the ASR muzzle devices.

The main issue that I could see is that the majority of 5/8X24 flash suppressors or brakes will have an internal bore diameter designed for 308 projectiles. Make sure you don't shoot the Bushmaster through a 308 hole!
User avatar
Colohunter
 
Posts: 407
Joined: Mon Nov 23, 2009 7:58 pm
Location: Colorado

Re: 5/8-24 Muzzel thread

Postby Specter23 » Wed May 18, 2016 3:03 pm

Colohunter wrote:I couldn't find the e-mail, but I believe Silencerco announced that they would be offering additional thread patterns for the Hybrid, I'm not sure if that means the threaded mounts or the ASR muzzle devices.

The main issue that I could see is that the majority of 5/8X24 flash suppressors or brakes will have an internal bore diameter designed for 308 projectiles. Make sure you don't shoot the Bushmaster through a 308 hole!



Defiantly no desire to shoot 450 through a .308. I don't use any sort of flash hider or break so I'm not too concerned about that.

I guess I will have to call SiCo and see what's new if anything.
Specter23
 
Posts: 33
Joined: Sat Oct 25, 2014 8:28 pm

Re: 5/8-24 Muzzel thread

Postby plant_one » Wed May 18, 2016 9:42 pm

i'd just be nervous about the sidewall getting to thin and your muzzle doing some serious belling if not worse.


regarding belling in 30 caliber barrels with 5/8x24 threading.
http://bulletin.accurateshooter.com/201 ... uch-steel/
User avatar
plant_one
 
Posts: 1109
Joined: Sat Mar 19, 2016 8:58 pm
Location: Oakland County, MI

Re: 5/8-24 Muzzel thread

Postby Al in Mi » Thu May 19, 2016 5:29 am

plant_one wrote:i'd just be nervous about the sidewall getting to thin and your muzzle doing some serious belling if not worse.


regarding belling in 30 caliber barrels with 5/8x24 threading.
http://bulletin.accurateshooter.com/201 ... uch-steel/


Regarding the article, I take the barrels were never fired, so would tend to agree with some of the comments about relieving some stress after threading. What would have been nice to know is what the pin tolerance was used to check the bore past the threading as you could be talking as little as .0003 in pin sizes. (for reference a typ sheet of paper is about .004 thick so we're talking about 1/10th the thickness here)

Personally, I'm not good enough with a AR platform, or even a bolt platform for that matter, to test the theory as to how much it would affect measurable accuracy.
User avatar
Al in Mi
 
Posts: 1982
Joined: Sat Jun 20, 2009 8:24 am

Re: 5/8-24 Muzzel thread

Postby Hoot » Thu May 19, 2016 6:16 am

I shoot rimfire BR also. The other end of the spectrum from the 450b. A game where precision is everything. Successful barrels have a small degree of choke near the muzzle that you can barely feel when pushing a patch through. A barrel that gets wider near the muzzle is a tomato stake.

As Al said, the impact that would have upon a caliber like the 450b, disappears in the noise floor long before other more critical aspects of precision factor in. This is not a precision caliber for many reasons. It can shoot very well, but you're never going to see precision 5 or 10 shot groups and by that I mean ones that are measured in tenths of an inch at 100 yds.

Turning the muzzle for 5/8 inch threads is not going to produce a blunderbuss. Don't lose sight of the fact that having a muzzle device screwed on over that reduced diameter, increases it's effective diameter back out.

Hoot
In Theory, there is no difference between theory and practice. In Practice, there is.
User avatar
Hoot
 
Posts: 5083
Joined: Tue Feb 09, 2010 9:34 am
Location: Minnesota

Re: 5/8-24 Muzzel thread

Postby Specter23 » Thu May 19, 2016 6:54 am

Thanks Hoot, that was the type of reasoning I was lookin for. It will always have a suppressor or thread protector on it, and although accurate - I don't expect sub 1/2 MOA groups like with some of my other guns.
Specter23
 
Posts: 33
Joined: Sat Oct 25, 2014 8:28 pm


Return to AR15 Style Rifles

Who is online

Users browsing this forum: No registered users and 21 guests