6.8SPC AR15 Owners-Lurkers-On the fence? Urgent info update.

[BLACK LION]

I am posting this just in case there are any 6.8spc owners out there or people who were contempltating buying one or building one.

I did not make the mistake that many did when purchasing a 6.8spc and that mistake is buying an out of spec barrel... the original SAMMI specs of a 1-10 twist and 6 grooves is not optimal and not a viable set up for the cartridge. These are not the specs originally provided by Holland and co and are actually an abomination caused by remington. Some places even sell a 1-9.5 twist barrel wich is asking for trouble... these specs lead to many problems and poor performance mostly becuase of overpressure... this is similar to the .223 / 5.56 chamber issue...

The minimum acceptable specs are the SAMMI SPEC II chamber and a 1-11 twist with 6 grooves which many companies that were in the dark or just stubborn are changing to... Ideal would be a 1-12twist 3 groove and some have even tested 1-13 twist barrels for this cartridge... 6.8 Ammo manufacturers have had to download thier cartridges becuase of this and instead of getting close to 3000 fps we are getting 2500 or less...

I dont want to get into a long winded post on this matter becuase there is so much corrected info that is not circulating and I will be here all day and night trying to put it down...

Bottom line, if you have a 6.8spc barrel with a 1-10/ 1-9.5 twist 6 groove barrel with the SAMMI SPCI chamber then please either demand it be replaced by the manufacturer or demand they ream it to SAMMI SPEC II... or buy one with a 1-11 twist at the least and preferrably 4 grooves which many manufacturers are switching to...
If you have not purchased one yet... I suggest you go to 68forums.com and get all the info you need or contact arperformance.com or titanarmory.com and they can square you away with a life-long shooter...

I have a 1-11 twist 6 groove ss barrel that has been fire lapped and its a shooter that rarely needs cleaning... My next upper is a more combat oriented upper from Tim @ Titan Armory which is a 1-11.5 twist 4 groove chrome lined barrel... the right stuff is out there and its plentiful...

thanks for reading

 

[jetboatdeath]

the original SAMMI specs of a 1-10 twist and 6 grooves is not optimal and not a viable set up for the cartridge.

Not optimal for what factory loads?

Some places even sell a 1-9.5 twist barrel wich is asking for trouble

Again maybe for factory ammo but some barrels are not for factory ammo,this would be a great barrel to toss some light fast bullets.

 

[BLACK LION]

It may be ok with factory loads. It could still be overgassed or overpressured.... the original specs that were released thru remington were wrong. I wouldnt expect stellar performance from it and it will never show the potential of the cartridge. The SAMI SPC I is the wrong chamber and 1.9-5 and 1-10 are too fast. It at least needs to be reamed to the SAMMI SPEC 2 chamber... or just ditch the barrel and get one that has the spec 2 chamber and is no faster than a 1-11 twist...

 

[BLACK LION]

Actually with the 6.8spc its the slower 1-12 twist barrels that increase the muzzle velocity to the tune of an 85gr v-max @ 3300 fps and 100gr ner 3000fps

 

[jetboatdeath]

Yea my bad 1-12 twist is slower than 1-9.5

 

[BLACK LION]

Remington and SAMI royally screwed the 6.8spc when the released it with the improper specs... but becuase of the dilligence and tireless work of those dedicated to it, it has recovered loos ground and gained so much more.