The 6XC II Chamber works perfectly with the Norma 6XC brass and resolves the “sticky bolt lift” issue.
The original 6XC chambering was designed based off the usage of 22-250 brass which typically has a web diameter in the range of .461″-.463″. The area of the chamber just forward of the web on the original 6XC chambering was .4695″ which left plenty of clearance.
When Norma 6XC brass became available Norma appears to have developed the base of the case from the .308 Winchester line of cases which have a larger web diameter. The web diameter of the Norma brass typically measures right around .4685″ which leaves almost no diameter clearance.
As shooters would use Norma 6XC brass in an original 6XC chamber they typically would experience “sticky bolt lift” due to the lack of clearance and the fact that the large web diameter of the brass prohibited the re-size dies (no matter how small the base diameter was) from squeezing the brass down enough to create sufficient clearance.
The 6XC II chamber resolves this issue and 6XC II re-size dies are available that are compatible with this re-designed chambering.
The 6XC II Chamber
The 6XC II chamber and re-size die:
– Resolves the “sticky bolt lift” problem shooters experienced using the Norma 6XC Brass in the original 6XC chambers.
– Chamber accepts all 6XC brass or ammo with no modification. Take your existing 6XC brass or ammo and use it without issues.
– Works well with existing Norma 6XC brass, or 6XC brass made from re-formed Winchester and Remington 22-250 brass.
– 6XC II Sizing dies and die sets are available and in stock.
– 6XC II Sizing dies are designed to work perfectly with the 6XC II chamber.
– Chamber Reamer drawings are available for you to use (see below) to have your favorite reamer maker or gunsmith obtain a reamer.
Die Sets Readily Available – Contact 6mmAR.com To Order
Reamer Prints Below (two different prints)
The 6XC II-ST reamer just below is shorter throated and was set up for 108gr and lighter bullets.
Shorter Throated Reamer Above
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Long Range Reamer Below (Throated long for 105-115 gr. bullets)
The 6XC II-LT reamer below is throated long and is ideal for loads keeping the full bearing surface of 115 gr. bullets forward of the neck/shoulder junction of the case.
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Max Case and Trim Length for 6XC II Brass Cases is the same as the original 6XC.
There is no formal established max case or trim lengths for the 6XC or the 6XC II brass. The author suggests the following for guidelines:
Max Case Length: 1.900″
Trim Length: 1.890″
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Pictures showing web diameters:
Written by Robert Whitley for 6mmar.com, but subsequently removed, we feel this information is so helpful that we posted it for future reference and archive purposes. Contact Robert at www.6mmar.com for info and purchase enquiries.
AJ Deysel is a competitive rifle shooter in the PRS and NRL Hunter series, a lifelong hunter, and a recognized ballistics specialist whose load development expertise has been featured by industry leaders like Hornady. He is the founder and lead editor of LoadDevelopment.com. Read more about AJ or view our Editorial & Testing Guidelines.
