Subsonic 6.5 PRC loads?

lupis

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Apr 24, 2012
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I just purchased a suppressor for my 6.5prc. I am interested in experimenting with some subsonic loads. I'm not having much success in finding any data for subsonic loads. Has anyone tried this, or know of any place that I can get some load data?
 
300blk is the best subsonic host in standard size. 8.6 blackout if you wanna step up
Agreed. These cartridges are designed around subsonic use and loads. I am by no means a subsonic expert, but when I've loaded for my 300 BO subs, It's very similar to loading for a pistol cartridge…which makes sense as you're pushing a heavy bullet at slow speeds…like a pistol.

I've been interested in the folks running subs through a .308 win. It seems like you would need to set up the rifle just for subs though to be able to shoot heavies at low speeds? Meaning you need a fast twist barrel like a 1:7? At that point, I'd stick with the 300 BO as it works in a normal AR frame, uses very little powder to shoot around that 1050 mark, and is still pushing a .30 cal projectile. I'd rather use the .308 for medium range work. But that me…
 
The only bolt gun I have for subs OTHER THAN 300 BLK is a custom built 308.
It's 16" with an 8 twist and long throated to shoot 230gr bullets.
Its a fun gun to hang on to because it can do everything 300 blk can do...and more. That said...I wouldn't do it again.

Subs are fun, but a dedicated cartridge and system for them is where it's at...and a PRC is NOT it.

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The only bolt gun I have for subs OTHER THAN 300 BLK is a custom built 308.
It's 16" with an 8 twist and long throated to shoot 230gr bullets.
Its a fun gun to hang on to because it can do everything 300 blk can do...and more. That said...I wouldn't do it again.

Subs are fun, but a dedicated cartridge and system for them is where it's at...and a PRC is NOT it.

View attachment 607110
What powder and charge are you using for your 308 load?
 
Your going to be using a lot of powder for a sub-sonic in the 6.5 PRC....compared to smaller case capacity ones....
Sub-sonic loads work the best with smaller cases.....unless you can find a powder that fills the case close to 90%.....plus finding a good bullet for a 6.5 that will work for hunting might be a hard one....

A good round is the 308 and using TrailBoss close to a full case using 220 gr. bullets....only problem is TrailBoss is no long being made and I don't know when its going to be made again....

Remember smaller cases will be quiter than a larger one shooting sub-sonic....300 BO is one of the best also 8.6 BO is also tops.....
 
Your going to be using a lot of powder for a sub-sonic in the 6.5 PRC....compared to smaller case capacity ones....
Sub-sonic loads work the best with smaller cases.....unless you can find a powder that fills the case close to 90%.....plus finding a good bullet for a 6.5 that will work for hunting might be a hard one....

A good round is the 308 and using TrailBoss close to a full case using 220 gr. bullets....only problem is TrailBoss is no long being made and I don't know when its going to be made again....

Remember smaller cases will be quiter than a larger one shooting sub-sonic....300 BO is one of the best also 8.6 BO is also tops.....
Thanks for all the input! Everything y'all said is spot on… that being said , back in the day, loading reduced (what they were called then) loads were fairly common place. I was just checking to see if anyone still did this.. thanks again!
 
338fed is another option of a good sub load. Almost every bullet weight in 338fed is worth subbing? 300gr 33cals aren't cheap! However a 358fed wildcat would be cheaper.
 
The other challenge and for me a good reason to say no to trying subs in this cartridge is that the best subsonic rounds have very heavy for caliber offerings that actually eat up a good bit of pressure accelerating. The 6.5 does t really have those offerings. You might find a 162-165 grain offering, compared to a case capacity in the 56-60 grain capacity. If you do the math, on ratio of case capacity to bullet weight it is pretty easy to see what makes it tough to build subs on. Also, there is significant risk of a 'double pressure' situation if the case isn't significantly filled with powder. If yiu haven't already decided against it, I think it might be time toove in that direction..
 
I'm sure if you really want to, you can do it--- what would be your reason? Hunting? Or just for fun---- problem with hunting is you are going to have a very reduced hunting distance if you can't find a bullet designed for subsonic expansion in 6.5 cal

In 308, there are heavy bullets designed to expand down to 6-700 fps so anything in .308 can be done subsonic ( I've seen 300wm subs before even)

For a standard 308w with 1:10 twist, lots of guys are using trailboss, but it can be done with fast pistol/shotgun powders as long as you are careful ( I have a 200gr 308 sub load that uses green dot powder)

I highly doubt you'll find any data online as I'm not sure anyone is doing it, so you would have to be the guinea pig to try. If you do, make sure you post your results

If you can find trailboss, start with a full case and then slowly work down till you are happy with the speeds.....if you use pistol/shotgun powder -- be careful not to overcharge as they build pressure quick
 

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