6XC "Rev. D" reamer specs?

[Basher]

Anybody know anything about this? I picked up a few barrels (one Krieger, one Gradous/OTM chambered by Dave Tooley) from the PX, and this is supposed to be the reamer that was used on the Keieger. I can find very little about it. I shot Krieger an email and they stated they don't make AIAT barrels, so they doubt they chambered it. They say they've used a 6XC Rev. D reamer in the past, but that the reamer manufacturer is the only one able to release dimensions. I'll be dropping Dave a message shortly to try and get reamer specs for the reamer most likely used by him.

I got a good deal on the barrels, but trying to figure out what brass to use, freebore, etc. is proving to be a bit of a pain in the rear! I'll probably look into having the chambers of both barrels cast to get exact measurements if I can't find anything else out. Thanks!

 

[spife7980]

Never heard of Rev D. I assume thats an in house fourth design. Not sure if it would be a 6xci vs a 6xcii which is what I would really be concerned with (though I guess you are already aware since youre wondering what brass to use)

http://www.6mmar.com/6XC_II.php

"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."

 

[spife7980]

@DAVETOOLEY

 

[Basher]

Thanks, Spife. I've read the article on the 6XC II, but have never heard of a 6XC Rev. D either, hence my asking. Go figure.

The prior owner was using Norma brass, so my guess is that I'll be alright, but spending time learning about and loading up a bunch of ammo only to run into sticky bolt lift issues would suck, hence my looking around to see what I can find.

 

[Supersubes]

Did they tell you who made their rev d reamer? No reason you can’t do all your normal setup(sizing/seating depth) and shoot a few.

 

[Supersubes]

Here’s a reference to the rev d reamer.

http://6mmbr.websitetoolbox.com/post/6xc-re17-and-115-dtac-3306044

 

[Basher]

Did they tell you who made their rev d reamer? No reason you can’t do all your normal setup(sizing/seating depth) and shoot a few.

Here's what they said:

"We have chambered bolt guns in 6XC Rev D in the past (And currently, RPR barrels), but we use a minimum SAAMI spec reamer from JGS."

I also received an invoice for the barrel from the prior owner, and sent that to them as well. Apparently, they don't do AT barrels, but this one was a "one off" Krieger used to see if they wanted to do AI prefits. So we'll see what they reply with, and I'll look into contacting JGS.

 

[Basher]

Also, I should clarify an earlier statement about brass. The prior owner was using Norma brass out of the Gradous barrel. The Krieger is, as yet, unfired.

How difficult is it to recut the chamber on an already chambered barrel? Perhaps it makes more sense in the long run for me to purchase my own 6XC II reamer and just get this one recut. Then I'd just send it with new barrels when I get them chambered. That way, I'll have known dimensions in every barrel I get cut going forward, reducing my work load between barrel swaps. Bit of an investment, but not unbearable, especially since I'll be replacing a barrel every 2,000 rounds or so (every few years at this point, but I anticipate higher round counts as time goes on and I get the family settled some)...

 

[Supersubes]

Basher, I don’t understand your concern here. The XC is and always was an across the course cartridge. Of all the XC prints I’ve ever looked at, there are only very slight differences between them, and mostly due to leade angles, which tubb and some others seemed inclined to play with. The base dimension issues were sorted out early. What are The chances dave chambered a fast twist AT barrel with a short throat varmint chamber? I think that would be a serious unicorn if he did. You’re planning on using Norma brass, so that won’t be an issue. Take a seating depth measurement. If a heavy bullet sits properly in the neck (not jammed down into the case), load them and shoot. I see no reason you should be concerned about this chamber at all.

With regards to buying your own reamer, not a bad idea if your gonna stay with this cartridge for some time, but don’t do it to “fix” this barrel.

 

[Supersubes]

Here’s another reference to the rev D reamers. It states it was designed to correct the small base diameter issue of the earlier reamers.

http://forum.accurateshooter.com/threads/6xc-brass-question.3779418/

 

[Basher]

Ah, that's a thread I hadn't read yet, and it cleared things up a good bit for me. Thank you! My primary concern was that it was a form of the earlier reamer, and that I'd have to deal with a sticking bolt, but that doesn't appear to be the case. As such, it looks like I should be good to go, even with the Alpha brass I'm actually going with. I appreciate the help, @Supersubes and @spife7980 !

 

[Robert Gradous]

Why not shoot it first

 

[Basher]

Why not shoot it first

At this point, that's the plan I intend to follow. However, I'm a relative noob to reloading, so it may be a bit before I have any ammo loaded for it, haha. Your barrel, the Gradous/OTM that was chambered by Tooley, has 1400 rounds on it, so not much life left, but it ran like a champ for the prior owner.

I was able to obtain some more info on things, however. At 0.200" off the bolt face, the reamer used on the Krieger barrel is 0.4700", and Alpha recommends 0.4705 - 0.4714". So Alpha brass may run a hair tight, though hopefully not tight enough to cause problems. Again, I'll need to get some ammo loaded for it and try it out, but I still need to acquire some stuff to make that happen (dies and projectiles, mainly). I have enough information now to potentially get custom resizing dies made, if I felt like going that way, but if it cycles reliably without serious sticking, I may just shoot this one out and go with a full 6XC II on the next barrel.

I was also told the throat was pretty short, and if memory serves the original owner, it's set up for 105s. Bummer, as I was thinking of running 115 DTACs, but Berger 105 Hybrids get rave reviews from most folks as well. I have a WTB ad listed for various projectiles in the hopes of trying them out. I may just jump at a full box on some of them to have plenty on hand.

Anyway, at this point, the process of gathering dies and loading components has begun, and I'll try to remember to report back with my findings. If anyone has anything else to share or other info, however, I'm all ears!