2008, 6.8SPC PERFORMANCE TEST- follow up report now posted

[Tim_W]

No doubt but what I think they are speaking of in terms of dirt is what ends up back in the chamber. The piston stop all of it from the gas tube and only leaves backwash from the barrel. The self regulating nature of them reduces this as well by bleeding off some of the pressure at the port. With DI guns becasue of the increase volume of gas the suppressors create plus the very nature of introducing gas into the upper and chamber area on purpose causes them to have dirtier chamber sooner. Since cleaning the chambers reduced the pressure in the DI guns its stands to reason the Piston guns will good longer before the same issue arises just as they go much longer before dirty operation causes function issues. They all are centered around crap in the chamber upper receiver area.

Tim

[HTR]

Tim,

Thank you very much for taking the time to help get the pictures uploaded here. You're right, I spent about 20 hours on the total report, picture editing and formatting....I was dreading doing it twice, but I definitely wanted it posted here for the 68 forums members.

My hat is off to you, sir,...I owe you one

[Tim_W]

I knew that is what happened and you are more then welcome. I appreciate the time you have taken and the resources you have used to get us this info. I understood exactly how you felt. After "I did the 6.8 facts page whihc was toll story long I just about started crying when I saw I had to redo all the formatting when I copied it over to here.

It was the least I could do.

Tim

[HTR]

Harrison has mentioned that some of you were interested in Hog hunts. I have already talked to JAdams and I know he's coming soon (we are still baiting them as we speak, HAHA).

For those of you that are interested, please feel free to IM me for the details regarding lodging, meals and fees for guided weekend hunts. We can accommodate air travelers, as we have an airport in Victoria, which is only 30 minutes from the ranch, and if you fly into Houston, you can simply drive from there....about 2 hours to the ranch.

Of course,. if you come to TX for a guided Hog hunt, bringing your 6.8 SPC is mandatory, HAHAH :lol:

BTW, we also may use suppressors in TX to shoot hogs. Since I am a courteous neighbor, I definitely welcome suppressors for the purposes of reducing noise pollution... :twisted:

[Tim_W]

Victoria??

That is only about what a 1 hour to 1.5 hour from Shiner? The nest town over is Moulton and back out of there is where our family place is. I thought you were closer to Corpus.

Tim

[paulosantos]

Chris or Constructor. I noticed that the velocities from the SSA Combat loads that you guys tested were very high. Were these Combat Loads the standard Combat Loads that SSA sells, or are they some special loads that Art cooked up for the testing?

[Tim_W]

Your right those rounds are certainly at the top end of the combat line. Not what we have been see lately. I wonder if they mixed up the suppressed and unsuppressed numbers? It seem about right. 50-100 FPS jump.

Tim

[constructor]

They were standard Combat loads of the earlier type in the blue boxes. Chris did not fire any through the chrono with the can on.

The first small primered cases had a plain case head with the writing only, A later headstamp included cresent lines between the words and those are the cases we had so they weren't the very first loads but they weren't
the latest in the black boxes.

[Bubba FAL]

Very interesting and confirms the testing I've performed since replacing my 1:10 SAAMI barrel with a 1:11 SPCII barrel. The old blue box SSA match loads would self destruct in the 1:10 barrel (pre-separation rings inside the brass after first firing) and the 1:11 digests them without issue (2611f/s avg from 18" bbl). Really wakes up the 6.8!

Since chamber condition (i.e., cleanliness) is now proven to be an issue when it comes to pressure - is someone finally gonna come out with a properly sized chamber brush for the 6.8? The standard 5.56 brush just doesn't cut it, and a 7.62 is too big.

[Mark21]

Dewey offer a 6.8SPC chamber brush:

http://www.deweyrods.com/cgi-bin/ccp5/c ... :BRUSH_MOP

It's the last one on the list.