How is 6.8SPC different from 6.8SPC Spec II?
- Thread starter thevolkp
- Start date
Squeeze
New member
The original chamber has pressure issues with combat powered
loads. The SPEC II chamber helped a bit, and further testing
with different twist rate seem to have settled on something
in the 1:11 to 1:12 range for the smaller weight bullets
typical for this cartridge.
Today the best choices for the 6.8 SPC have settled on
the SPEC II, or DMR, chamber and a 1:11 or slower twist,
to get the most muzzle velocity out of this intermediate
sized case.
Squeeze
bluealtered
New member
You can type in 6.8spc and get tons of history on the 6.8 or you can try demigodllc.com and type in 6.8spc there and get the complete history.
There were a lot of problems in the first models simply because remington wasn't given the right specs. this has been corrected with the spec2 and the results are a very good mid range rifle. blue
There were a lot of problems in the first models simply because remington wasn't given the right specs. this has been corrected with the spec2 and the results are a very good mid range rifle. blue
coyote6974
New member
The SPCII chamber has slightly more free space which results in lower chamber pressures. This allows for the safe use of ammunition loaded to achieve higher velocities. It is no different than a .223 Remington chamber compared to a 5.56 NATO chamber.
im not sure if my 6.8 upper is SPC or SPCII. i have always shot normal SPC rounds and it has worked fine with an occasional jam here and there (i think due to crappy mags). i have a box of SPCII that i have not shot yet. is it ok to try it out in the gun? i guess im asking if 6.8 SPC uppers can shoot both cartridges?
Brandon Sneed
New member
jackh:
What do you mean by spc and spcii ammo?! There's no such thing. Commercial ammo is typically safe for shooting out of the spc and spcII chambers.
For your upper, if it's not marked on the barrel, then most likely a SPC chamber (original SAAMI chambering produced by Remington and the like). Where did you get the barrel/upper from?
Additionally, the upper, if it is a SPC chamber, will not be safe for shooting "Tactical" loads from SSA, or handloaded to max levels. Obviously, if you do reload start at the minimum, and work up until swipes start appearing, or other pressure signs start becoming apparent.
WHat is the box of "SpcII" ammo you're talking about?
What do you mean by spc and spcii ammo?! There's no such thing. Commercial ammo is typically safe for shooting out of the spc and spcII chambers.
For your upper, if it's not marked on the barrel, then most likely a SPC chamber (original SAAMI chambering produced by Remington and the like). Where did you get the barrel/upper from?
Additionally, the upper, if it is a SPC chamber, will not be safe for shooting "Tactical" loads from SSA, or handloaded to max levels. Obviously, if you do reload start at the minimum, and work up until swipes start appearing, or other pressure signs start becoming apparent.
WHat is the box of "SpcII" ammo you're talking about?
brandon-i was under the impression that there was an SPC and SPCII round. i was also under the impression that depending on what your gun was chambered for, you could shoot one, but possibly not the other.
kind of like .223 and 5.56. i cant ever remember which it is, but if your chambered for .223 you can shoot both, but if your chambered for 5.56 you can only shoot 5.56.
is this not correct?
kind of like .223 and 5.56. i cant ever remember which it is, but if your chambered for .223 you can shoot both, but if your chambered for 5.56 you can only shoot 5.56.
is this not correct?
Originally Posted By: jackhbrandon-
....kind of like .223 and 5.56. i cant ever remember which it is, but if your chambered for .223 you can shoot both, but if your chambered for 5.56 you can only shoot 5.56.
is this not correct?
Actually, it is the other way around. The 5.56 NATO chamber is cut with a bit more freebore than the 223REM. So you can shoot 223REM in a 5.56 NATO chamber but it is not a good idea to shoot 5.56 NATO in a 223REM chamber.
320pf
....kind of like .223 and 5.56. i cant ever remember which it is, but if your chambered for .223 you can shoot both, but if your chambered for 5.56 you can only shoot 5.56.
is this not correct?
Actually, it is the other way around. The 5.56 NATO chamber is cut with a bit more freebore than the 223REM. So you can shoot 223REM in a 5.56 NATO chamber but it is not a good idea to shoot 5.56 NATO in a 223REM chamber.
320pf
Brandon Sneed
New member
Originally Posted By: jackhbrandon-i was under the impression that there was an SPC and SPCII round. i was also under the impression that depending on what your gun was chambered for, you could shoot one, but possibly not the other.
kind of like .223 and 5.56. i cant ever remember which it is, but if your chambered for .223 you can shoot both, but if your chambered for 5.56 you can only shoot 5.56.
is this not correct?
As has been stated, no, the .223 is the first Remington chamber. 5.56 is the freebore chamber, which means that it has a longer leade than the .223, allowing for increased pressures. 5.56 brass is also thicker than .223, so the brass can withstand the additional pressure as well. This allows for the use of .223 and 5.56 out of the 5.56 chamber, but not the other way around. Applying that to 6.8, the first 6.8SPC SAAMI chamber brought out by remington was the "223" of the 68 world. The new SPC or x43 chambering (which is all the same, but technically not, which is a can of worms all in itself) is the "556" of the 68 world. The SPCII or x43 denotation will provide a longer leade and offer increased pressure potential out of shooting in the chamber.
For 6.8, there is no commercial vendors, excluding SSA (SILVER STATE ARMORY) that produces a "SPC and a SPCII" ammo. That's just the denotation of the barrel/chambers. THe ammo you buy from Hornady, Remington, Corbon, are all commercial loads. This means that if I shoot with a SPC chamber, that they are safe, unless otherwise noted.
For SSA, Commercial are safe for these types of chambers as well. Unless you shoot the "Tactical" loads from SSA, then you are required to sign off on any liability, and declare you are indeed shooting with a SPCII chamber.
Handloading is also a caveat here. You can load up to max, or even further than some reloading manual's max (as they're based on SPC chambered guns), and for that gun, run ammo that would generally pressure swipe in a SPC chambered gun, but be fine in the SPCII chambered gun.
This I'm sure is even more confusing if you do not know what gun you have!... as I mentioned before, what upper assembly do you have (Is it a complete upper from a manufacturer) and does it have any markings on the barrel?
kind of like .223 and 5.56. i cant ever remember which it is, but if your chambered for .223 you can shoot both, but if your chambered for 5.56 you can only shoot 5.56.
is this not correct?
As has been stated, no, the .223 is the first Remington chamber. 5.56 is the freebore chamber, which means that it has a longer leade than the .223, allowing for increased pressures. 5.56 brass is also thicker than .223, so the brass can withstand the additional pressure as well. This allows for the use of .223 and 5.56 out of the 5.56 chamber, but not the other way around. Applying that to 6.8, the first 6.8SPC SAAMI chamber brought out by remington was the "223" of the 68 world. The new SPC or x43 chambering (which is all the same, but technically not, which is a can of worms all in itself) is the "556" of the 68 world. The SPCII or x43 denotation will provide a longer leade and offer increased pressure potential out of shooting in the chamber.
For 6.8, there is no commercial vendors, excluding SSA (SILVER STATE ARMORY) that produces a "SPC and a SPCII" ammo. That's just the denotation of the barrel/chambers. THe ammo you buy from Hornady, Remington, Corbon, are all commercial loads. This means that if I shoot with a SPC chamber, that they are safe, unless otherwise noted.
For SSA, Commercial are safe for these types of chambers as well. Unless you shoot the "Tactical" loads from SSA, then you are required to sign off on any liability, and declare you are indeed shooting with a SPCII chamber.
Handloading is also a caveat here. You can load up to max, or even further than some reloading manual's max (as they're based on SPC chambered guns), and for that gun, run ammo that would generally pressure swipe in a SPC chambered gun, but be fine in the SPCII chambered gun.
This I'm sure is even more confusing if you do not know what gun you have!... as I mentioned before, what upper assembly do you have (Is it a complete upper from a manufacturer) and does it have any markings on the barrel?
Last edited:
Brandon Sneed
New member
Originally Posted By: 320pfOriginally Posted By: jackhbrandon-
....kind of like .223 and 5.56. i cant ever remember which it is, but if your chambered for .223 you can shoot both, but if your chambered for 5.56 you can only shoot 5.56.
is this not correct?
Actually, it is the other way around. The 5.56 NATO chamber is cut with a bit more freebore than the 223REM. So you can shoot 223REM in a 5.56 NATO chamber but it is not a good idea to shoot 5.56 NATO in a 223REM chamber.
320pf
Hey 320... I didn't even recognize the comment until I looked back and saw it was you. I've been following the .25/223 saga for a while, and liking the looks of it. Thanks for posting here as well as on quarterbore. Will be keeping tabs of updates. Really appreciate you signing up here and offering up info as well!
....kind of like .223 and 5.56. i cant ever remember which it is, but if your chambered for .223 you can shoot both, but if your chambered for 5.56 you can only shoot 5.56.
is this not correct?
Actually, it is the other way around. The 5.56 NATO chamber is cut with a bit more freebore than the 223REM. So you can shoot 223REM in a 5.56 NATO chamber but it is not a good idea to shoot 5.56 NATO in a 223REM chamber.
320pf
Hey 320... I didn't even recognize the comment until I looked back and saw it was you. I've been following the .25/223 saga for a while, and liking the looks of it. Thanks for posting here as well as on quarterbore. Will be keeping tabs of updates. Really appreciate you signing up here and offering up info as well!