Suppressors 6.5CM vs 308 pressure levels inside a can

[MosesTheTank]

In deciding which can to get for a 24" barreled 6.5CM I was told that 6.5CM generates much higher pressure levels than a 308 and I should maybe get a 300WM rated can. Supposedly the higher pressures will cause a 308 can to develop a bulge. At first I was thinking of getting the AAC Cyclone, but a 300WM can will put me into a much higher $$ bracket. I can't find any data at all about pressure at the muzzle end. Anyone know about such things?

 

[TGagnon]

Re: 6.5CM vs 308 pressure levels inside a can

If you can give me some loads you will be running I can run them through QuickLoad and tell you the muzzle presure from that. I just need some basic load data. I will run it compared to maximum load data for the 175MK as listed on sierra's page once I get your 6.5CM data you plan to run.

 

[Remnar]

Re: 6.5CM vs 308 pressure levels inside a can

I have a 308 can incoming for my 260. I contacted AAC prior to purchase and they said it would be fine. I realize a 260 isn't a creedmoor but it is pretty close.

 

[MosesTheTank]

Re: 6.5CM vs 308 pressure levels inside a can

I will be running the factory Hornady 129 SSTs (2950fps), 140 A-Max (2710fps), and the Copper Creek 142 SMK at 2710fps. My barrel is 24". I don't have anything more specific such as powder and primer data. Thank you

 

[dvdt]

Re: 6.5CM vs 308 pressure levels inside a can

Just to provide a data point that might help.

My bolt gun has a 24" bbl chambered in 6.5CM.

139gr scenar running @ ~2800 my friend calculated to be 57.2k PSI in quickload. I'm using H4350. I have no idea or reference if that's accurate or should raise an eyebrow of concern.

I've shot it thru a Shark which to my knowledge is only 308 rated. It was maybe 30-40 rounds on an already warm can.

I ordered a 30P-1 for this rifle. The 30P-1 is 300winmag rated and I wanted to "future proof" my gun buying habits

Hope this helps a bit.

 

[earthquake]

Re: 6.5CM vs 308 pressure levels inside a can

This is timely. I'm building a CM rifle now and have a .308 too. I was wanting one can to switch between the two, 30P-1 or Arbiter.

 

[MosesTheTank]

Re: 6.5CM vs 308 pressure levels inside a can

I decided on, and plopped down a check for, the AAC MK13-SD. The $ was a bit of a stretch, but you only live once. Thanks guys. Now the wait...

 

[Twitch2120]

Re: 6.5CM vs 308 pressure levels inside a can

Went from the thread on cyclone to qd mk13. Why not the 300tm?

 

[MosesTheTank]

Re: 6.5CM vs 308 pressure levels inside a can

I wanted a 300TM but none were available. AAC said it was a 6month wait and my dealer searched high and low. Otherwise, that is what I would have bought. The idea crossed my mind to buy one anyway. Do you think the screw on is a better choice for precision rifle?

 

[MosesTheTank]

Re: 6.5CM vs 308 pressure levels inside a can

Once I came to terms with the fact that I had to spend the extra $ for a 300WM can I wanted one that could also serve my 5.56 AR and the soon to be ordered GAP10. I also wanted to get the NFA process underway ASAP. I am wincing just a little bit in that I need 3 91T ratchet mounts. But if I become convinced that a screw on gives some advantage for accuracy I will buy one. When hearing that the 300TM had a long wait I called TBAC about the 30P-1 and they said it would be a wait to get a serial number out. So, I have the MK13 sitting in my dealers safe. Some 3 or 4 paychecks from now I will order the GAP10, and after that I will be making a choice on another suppressor as funds come available. which one is the question.

 

[KYS]

Re: 6.5CM vs 308 pressure levels inside a can

When it comes to MULTIPLE platforms for one suppressor to service. Get the QD can, you will be happy that you did. The MK13 is an awesome can but just remember that Ti cans dont like high heat, so you will have to go at a slow pace on the semi autos.

TBAC 30BA would be a good choice.

 

[TGagnon]

Re: 6.5CM vs 308 pressure levels inside a can

Adjusting a 140 Amax to get 2710fps with 42.1grn of H4350 out of a 24 inch barrel I get a muzzle pressure of 9369psi and 98.63 percentage burned. That is plenty low enough for any 308 can out there. Also the 6.5CM has less case capacity than the 260 as well as operating at a lower pressure as it was designed for semi auto platform rifles.