Suppressors anyone shooting suppressed sub sonic 6.5 cm?

[SB545]

i'm toying with the idea of some sub sonics that i can shoot behind the house. i shoot regular loads there but at certain times it'd be nice to keep the neighbors happy. i have national forest out the back door and have steel hung at 200 and 450 that i'd like to plink on for practice. i thought about a sub .223 but that is in a different platform and it'd be nice to stick with my hunting rifle for the reps. with the 6.5's i'd be using it on i have a tikka t3x and kimber hunter that would be my hunting guns. i was thinking about getting something with a flat base and heavy for caliber to be pushed by a slow powder, maybe imr 7828 since i have plenty left. would this put my suppressor at risk in any way that a super sonic load wouldn't?

 

[loveha]

See no way it would hurt it. Subsonic is subsonic, it does not matter in the slightest what caliber and size bullet.
Just make sure your load is stable before you put it through your can.

 

[biffj]

Unless you're planning on running subsonic 70gr bullets in your rifle you could have issues. The twist rate in most of the 6.5's is about 1-8 which is way too slow for the heavier and more useful bullets. If you run the really light bullets that won't tumble and trash your suppressor you get little out of them for energy that you couldn't get out of a 22LR. The last problem is a big one too. The case capacity is huge compared to the volume you need for running subsonics so your choice is to use a powder like trailboss which isn't proving to be very accurate or using some sort of filler which can damage your barrel.
All in all the benefits don't outweigh the liabilities as far as I can see. It is possible but its not reasonable.
If you really feel you need to run subsonic 6.5 bullets a setup using the necked up 223 case in a bolt rifle with a fast twist barrel like a 1-6 or faster would make a lot more sense.

Frank

 

[SB545]

that's good info and why i asked. i think it might be best to figure another option out. maybe it's time to buy a 223 tikka. i'll just need to do a little math to see what type of distance i can get out of it. for the cost and lack of reloading time, it may even be be worth searching for a tikka 22lr and 20moa rail.

 

[SmithM21]

I hunt with a Remington 783 suppressed, cal. 6.5 CM, in Pa. The suppressor is a OSS HX-QD 762 Ti.

 

[Gustav7]

Unless you're planning on running subsonic 70gr bullets in your rifle you could have issues. The twist rate in most of the 6.5's is about 1-8 which is way too slow for the heavier and more useful bullets. If you run the really light bullets that won't tumble and trash your suppressor you get little out of them for energy that you couldn't get out of a 22LR. The last problem is a big one too. The case capacity is huge compared to the volume you need for running subsonics so your choice is to use a powder like trailboss which isn't proving to be very accurate or using some sort of filler which can damage your barrel.
All in all the benefits don't outweigh the liabilities as far as I can see. It is possible but its not reasonable.
If you really feel you need to run subsonic 6.5 bullets a setup using the necked up 223 case in a bolt rifle with a fast twist barrel like a 1-6 or faster would make a lot more sense.

Frank

So running the big 140-156gr wouldn't work mainly due to powder selection/case capacity?

I wonder if anyone has tried some of the powders specifically for .300blk? Theres gotta be a slow pistol powder that would work with low case capacity with a magnum primer.

Not that Titegroup would work in this situation, but I do use it in my .38spl light loads. I've gone down to 3.0gr, which is barely enough in the case to even see it, and I still get good ignition with regular primers, magnum makes it more consistent though.

 

[biffj]

Running the 140-150 grain bullets wouldn't work due to the tumbling bullet effect you get from having a twist rate way too slow for the length of bullet you're shooting. Powder capacity and selection is more a problem for accuracy or ignition. I'm sure you could find a powder to run those heavy bullets subsonic but at those speeds the bullets just don't spin fast enough to stabilize.

The powder issue will become worse as your bullets get lighter because it takes less powder to get the same speed. When you have your case fill at about 10% of capacity its anyone's guess where its sitting when the primer goes off. You may ignite the whole charge at one time or you may not be able to ignite it at all.

One of the main requirements for any sort of accuracy is consistency. You need the powder charge to sit in the same spot for each round fired and you need it to ignite the same way every time. When your charge is very small in relation to the volume of the case the charge can move around and spread out in ways that make consistent ignition basically impossible. What is normally done for subsonics is to use cases that have low capacity to start with.

The 300 blackout is pretty successful and it is because its possible to shoot subs accurately. With a 220gr bullet and a 10gr charge of AA1680 the case fill is about 85%. With a 308 case and the same bullet your case fill is about 10%. Using super donuts (Trailboss powder) you can get the case fill up to about 50-60% which is an improvement but the accuracy is still not there and unless your twist rate is 1-8 or faster you are likely going to trash your can with wobbly or tumbling bullets. Most guys shooting 308 subs use lighter bullets to prevent damage due to a lack of stabilization. When you use the light bullets you lose the main advantage of the subsonics which is to maintain a higher energy downrange while avoiding the supersonic crack of the bullet that makes so much noise. Check some of the energy calculators on the various ballistic table sites and you'll see what I mean.

If all you're after is quiet and you don't care whether the bullets even hit the target, much less disable it than you can run what used to be called "cat sneeze" loads. Back in the old days guys would run really really light bullets with tiny charges to shoot indoors or just to keep the noise down. A friend told me he used to run 80gr 32 auto bullets in his 30-06 cases using a few grains of bullseye so he could shoot in the backyard without his neighbors knowing. At that time he was happy with minute of truck accuracy. His intent was just to shoot.

So I suppose the shooters intent is the deciding factor. Shooting a deer with subsonics means you need energy but shooting paper means you don't need so much. Just make sure your bullets are suitable for the twist rate you've got in order to avoid damage to your suppressor.

hope all that makes sense

Frank

 

[SmithM21]

I will be reloading for my suppressed hunting rifle in 6.5 CM in the very near future. I will not be loading for sub sonic rounds. My son's and I hunt with suppressors because the deer never seem to figure out your exact location allowing a second shot.

I would never hunt with subsonic rifle ammunition.