6XC ground truth as of Jan 2020?

[CLance]

I too have been having the same issue as Hoot. We have basically the same barrel brass set up. Most the things he has tried I have also. I just came back from trying it headspaced off sized brass that had been suggested to me. No help. I have seen some folks that run this combo with no issue. I am going to try to contact CBI this week. If they cant/won't help then I guess I have the same choices as Hoot.
If I go the Tubbs reamer route what would my odds be of being able to "touch-up" the chamber by hand? Would I be better off to have a Smith shorten the barrel by say 1/2 inch and rechamber? Is there anyone who rents a Tubbs spec reamer?
I really want to stay with this caliber and Peterson brass just hope to not have fortune into it.

 

[Lone Hunter]

Just a follow up to a follow up: Dave, you win the kewpie doll! We finally got some acceptable weather today for a range visit, other than still trekking through ankle deep snow in most places, mud in the others. I had a test load ready to go, waiting for this day.
New Peterson brass. Neck turned from .00140-.00150, down to .0014 +0 -,0005. Mainly just the high spots cleaned off. IE barely smaller than they were. Using a pin gauge, I expanded the mouths this time to .2415. The resultant neck tension was less than I personally have ever gone but they held firm. I seated the bullets at 2.138 (bullet comparator and calipers) which is where they run into the rifling. Previous outings with the 108 ELD-M grouped best with them loaded to the start of the rifling. Powder was H4350 again and CCI 450 primers. I began my foulers at 37.8 gr which yielded an average velocity of 2850. Far less than members running 115 DTAC's at or above 3k fps. From the first shot until I gave up, I had heavy bolt lift. The empties bind in the chamber again, right where the case wall meets the shoulder transition as far as I could see. I had also included some bullets plated with HBN but that didn't help, though I skipped expanding the necks beyond how they came from the factory since with the HBN plating, the seating resistance felt close to ideal. No ring around the noses like I used to get with unexpanded necks and bare bullets, from the force needed to seat them.

I accept that this apparent high pressure is not the result of any neck tension issue. I had loaded up a brief ladder test but stopped at 38.2gr of H4350 because bolt lift just kept getting heavier the higher I went. This is daunting as I'm not running anywhere near what others successfully run without heavy bolt lift. FWIW, primers showed no sign of even beginning to flatten but then they didn't all last summer as I was wrestling with this issue. I have not tried changing to powders with a history of lower pressure for similar velocities, though I have some on hand, as that's treating the symptom and not the cause. Plenty of folks successfully use H4350 in this caliber. I'd like to get back to ~2975 fps as the resultant 5-shot, 100 yd groups really were awe inspiring at that point. I have not tried Nosler brass, nor resized 22-250. I do have some R-P .22-250 brass but jeez Louise, I came to this caliber when I chose to re-barrel my shot out 6mm Rem, after reading it was "second to the .308 in ease of tuning". I have a .308 and it truly is easy peezy to produce many great shooting loads with it. What's next? Kiss the chamber up with a 6XC-II reamer or walk away and swallow the loss? I really like the quality of Peterson brass. It runs great in my .260 and I'd like to stay with it.

Frustrated Hoot

P.S. I'm not the only person running a 6XC Criterion barrel with this issue.

I just received a 6XC Criterion barrel. I bought 200 rounds of Tubb brass. I have a brand new Redding Type S die. I will not be able to do any load work up for a little while due to shoulder surgery . I hope I will not have problems but from reading this thread it looks like I will. Will be watching this thread with interest . Thanks for the information .

 

[Hoot]

Have you contacted Criterion about this? What do they have to say about it? If there's more than one with the same issue, maybe they're reamer is junk. I'd give them a call if you haven't already.

Given my barrel is approaching 2 years old (I'm slow to concede defeat) I doubted they would do much for me. About a year ago, I emailed them with a question regarding the reamer they use. Never got a reply and that kinda turned me off to their customer support philosophy FWIW, its not just the 108 ELD-M. Other bullet weights I've tried, do the same thing.

Some additional metrics I may not have reported: With the .375 comparator zeroed on the headspace GO gauge I set my barrel to, the fired cases shrunk back -.0015. I would have been surprised to find out otherwise but the bottom line is that's not locking them in. Case head growth went from unfired new cases of .4672 to 1-fired .4683. This leads me to suspect that the chamber is cut at that point to the "PTG reamer for CBI" spec of .470. That spec document is from back in 2004 FWIW. Fired necks despite being turned down .0005 still measured .274 and untumbled, new bullets drop down into them without any help. The CCI 450 primers showed soe minor cratering, I'd wager from my recollection of the Rem 7 1/2's I was using, the same amount. Not as severs as some I've seen images of. Not worried at this point enough to get s bush job. I really don't want to throw any more money at this caliber, short of renting a 6XC-II reamer, than I can avoid, in an effort to cut my losses in the event that I cut and run. In case anyone is wondering, last summen I did try seating these bullets with a jump, to no avail.

If anyone can think of any additional dimensions I can take that would be germane to thius issue, please chime in.

Thanks in advance,

Hoot

 

[Dave Marshall]

I wouldn’t be too quick to start running 6xcII reamers into your chambers. I tried that and am having issues finding dies that will resize properly. I now have too much oversized brass and oversized chambers to go back. I believe I have a solution, but haven’t tried it yet. I’d try a Tubb reamer first if I suspected an overly tight chamber.

If rounds are chambering easily, you could try applying Dykem to the case and firing some. It should show the tight spot I’ve never tried this, but it’s worth a try. Sharpie ink might do it too.

 

[Hoot]

I wouldn’t be too quick to start running 6xcII reamers into your chambers. I tried that and am having issues finding dies that will resize properly. I now have too much oversized brass and oversized chambers to go back. I believe I have a solution, but haven’t tried it yet. I’d try a Tubb reamer first if I suspected an overly tight chamber.

If rounds are chambering easily, you could try applying Dykem to the case and firing some. It should show the tight spot I’ve never tried this, but it’s worth a try. Sharpie ink might do it too.

Thanks Dave. When I said 6XC-II, I meant the Tubbs reamer as well as I thought they pretty similar. By "too much oversized" I assume you mean that you need a die that doesn't size them down as far as they go, to avoid over working the brass given the roomier chamber?

This is the second day in a row since last October that is excellent for a quick trip (10 minutes away) to the range. I'll try marking up some loaded rounds I have left with Dykem and see where the bind occurs. Earlier this winter I marked up some fired cases that bound when I tried putting them back in the rifle and the bind was at as I said, at the corner where the case wall transitions to the shoulder. Though not as pronounced, not unlike where a 22-250 case "mushrooms" when you try forming it into 6XC without rounding the shoulder first in a .308 die, before running it into the 6XC die but I digress. I'll mark some up and pop over to the range.

Hoot

 

[Hoot]

...snip...
you could try applying Dykem to the case and firing some. It should show the tight spot I’ve never tried this, but it’s worth a try. Sharpie ink might do it too.

Back from aroma therapy in the great outdoors. Here's what I learned. Coating your rounds with sharpie ink reduces hard bolt lift.
Must have some lubricating property. Notice I didn't say eliminates unfortunately.
After careful insertion and extraction, the only place where it was disturbed was right at the case body to shoulder transition area. Not sure what to makes from these tea leaves. Probably most impressed with the fact that the ink was totally undisturbed up and down the case after such a violent reaction. Three shots at an abandoned target (not a bad group for elbow shooting) and all three looked like this:

I only coated it up into the shoulder area. The color is a little washed out after cropping, shrinking and hosting. The bare spots are much more shiny and brilliant.

Hoot

 

[CLance]

Was this 22-250 cases?

 

[Dave Marshall]

Looks like a poorly cut chamber or perhaps it was done with a worn reamer. I’d be calling Critireon

 

[Hoot]

Was this 22-250 cases?

No, life got in the way and its spokesperson reminded me about chores I had to do.

Those cases were new old stock Peterson. I mention that because I haven't yet tried the ones I got a short while ago from Tubb, My mind's eye tells me they won't be any different judging by the measurements I took but hope springs eternal. You can't see hardness. That'll probably be my next test before considering other solutions.

Dave, I don't expect my almost two year old barrel to be received very well at Criterion, as having a manufacturing issue. Now I may be able to ride the coat tails of the more recent customers, if and when they make a case. I'm just used to fixing my problems myself but I'll gladly take Criterion taking ownership of this issue.

Hoot

 

[CLance]

My barrel was bought this year but may have been finished by them anytime and just sitting on n the shelf

 

[spclark]

Interesting thread this’n.

It was 62F here today, sunny. Range I can get to most easily was a sea of mud, folks driving their vehicles off the gravel roadway to get closer to firing lines make a mess....

I have Peterson & Alpha brass, all my barrels are Henriksen chambers, pretty much the only option back when 6XC appeared. Once things warm a bit more I want to try these new cases with H4350 & Berger 105Hybrids, see what happens.

They’ve all worked fine before with my Palma-brass based cases and 105VLD’s.

 

[Dave Marshall]

Interesting thread this’n.

It was 62F here today, sunny. Range I can get to most easily was a sea of mud, folks driving their vehicles off the gravel roadway to get closer to firing lines make a mess....

I have Peterson & Alpha brass, all my barrels are Henriksen chambers, pretty much the only option back when 6XC appeared. Once things warm a bit more I want to try these new cases with H4350 & Berger 105Hybrids, see what happens.

They’ve all worked fine before with my Palma-brass based cases and 105VLD’s.

Expect sticky bolt lift. The early chambers were based on .22-250 brass and are tighter. Start low and work up carefully. Both Petersen and Alpha are based on .308 cases.

I had two pieces of Alpha 6xc brass rupture in two different 6xc barrels on T2k rifles chambered in 6xcII. I’ll never put another piece of their brass in my rifles.

 

[Hoot]

To that end I was fortunate to be sitting next to a shooting position at the range this weekend with a member shooting both R-P and Hornady .22-250, who doesn't reload and he gave me his empties. They are tumbled and annealed as I write this. I'm going to load a few of each up with my pet load, (other than SRP's) that causes the heavy lift and try them after work in the next few days. Temps have risen into the low 40's in the afternoons. Will report back what I totally expect to happen, besides loading my shoes up with mud.

I don't want to spend the rest of my interest in this caliber re-forming .22-250's however. Just more of a curiosity satisfier.

Hoot

 

[kolar55]

Looks like a poorly cut chamber or perhaps it was done with a worn reamer. I’d be calling Critireon

+1

 

[luckyshot52]

The case shoulder junction looks like a clambering problem. Should not have that look.
If Criterion chambered I'd complain.
Peterson brass is not the problem. I tested some of the proto brass and use the new in a 6cc. I have seen 3030 without any pressure signs.
Shoots great accuracy at 2990.

 

[spclark]

...use the new in a 6cc.

uh, can you fill in some details about this variant please?

 

[Hoot]

The case shoulder junction looks like a clambering problem. Should not have that look.
If Criterion chambered I'd complain.
Peterson brass is not the problem. I tested some of the proto brass and use the new in a 6cc. I have seen 3030 without any pressure signs.
Shoots great accuracy at 2990.

For point of clarification. Putting marking compound on brass that traveled by surface carrier, all packed together in a plastic bag, tends to amplify the individual dings they incur along the way. The marked up case image I posted earlier is no different. I took a look at two of them under the stereo microscope at work with the marking compound removed and they are indicative of 1-fired Peterson brass I have seen countless times before from this chamber. Unfortunately, someone else had the scope camera checked out and I was forced to capture this image with a smart phone.

While you do not have the benefit of a stereo view's perspective, it should be apparent that what appeared to be a secondary ring at the shoulder corner or a rough engraving, was the result of a poor choice of images.

While it is true that my empties bind in the chamber at that junction and you can kinda see the shined spots left behind when they are extracted against their will, (look where the two shoulders touch), I don't believe that binding is the result of surface imperfection in the chamber. Close study of it with a borescope shows a fairly clean and shiny job at the corner where the straight wall meets the shoulder. Keep in mind that I've only put about 150 rounds through it so any polishing of the chamber wall from the cases having to be yanked free at the bind spot (steel vs brass) is not readily apparent yet. Actually the entire chamber looks like you could comb your hair in its reflection. Makes it hard to assess with the borescope light reflecting back in my eye but I'm just not seeing any irregularities in the cut job there.

I have formed Hornady .22-250 cases into 6XC, which I personally believe the 2004 reamer design used on it was designed for and will likely get to the range in the next few days to see if my pet (Peterson) recipe for small groups cause these .22-250 cases to also experience a hard bolt lift. Looking at the resultant formed cases, there appears to be some room for expansion, which will no doubt ease the pressure at ignition a little bit when filling out and possibly give a false impression, so I may have to reload them again to see if the bolt lift remains the same as the first pass fireforming. Time will tell. Thanks to all the participants in this thread for tolerating me making my problem take up so much space.

Hoot

 

[Hoot]

Update: I annealed and formed fresh Hornady .22-250 cases. The tip about breaking the shoulder with a .30-06 die, did the trick. No mushrooming. Formed quite easily, slathered up with Imperial Wax actually. I enlarged the necks with a regular 6mm Rem decapping button, then lubed and ran them through a neck bushing to get them down to .241 ID. Concentritity wasn't perfect but good enough for a pressure test. Interestingly, it took a .267 bushing where the Petersons took a .270 to hit .241 ID. Anyway, Primed them with Federal GM210M's. Charged them with 38.6gr H4350, just like my 108 ELD-M pet load and seated Berger 105 Hybrids at 2.76 COL which is .010 back from engaging the rifling..

At the range in a biting mid to upper 30's wind near local sunset, their POI was 1 inch higher than the 108 ELD-M's at 100 yds, though I wasn't there for the groups. They extracted with the same force needed to cock the firing pin on an empty chamber! Jubilation T. Corn Pone! Forgot what that felt like.

Back in the shop. Deprimed the spent cases and wiped them down. Spent primers pushed out pretty easy compares to the Peterson SRP's so I'm wagering the case life would be less. First stop was reinserting them into the chamber with the firing pin assembly and ejector removed from the bolt. The bolt handle fell all the way down with its own weight! No binding! Forgot what that felt like as well. Checking the springback , it was -.002 from GO gauge. Necks wound up at .273 OD, down from .274 using the Petersons. Brass looked pretty nice after fire forming. Nice defined shoulder corners. It would be hard to tell them from actual 6XC brass once tumbled without looking at the headstamp.

Experiment concluded.

Hoot

 

[J.d. Popkes]

Update: I annealed and formed fresh Hornady .22-250 cases. The tip about breaking the shoulder with a .30-06 die, did the trick. No mushrooming. Formed quite easily, slathered up with Imperial Wax actually. I enlarged the necks with a regular 6mm Rem decapping button, then lubed and ran them through a neck bushing to get them down to .241 ID. Concentritity wasn't perfect but good enough for a pressure test. Interestingly, it took a .267 bushing where the Petersons took a .270 to hit .241 ID. Anyway, Primed them with Federal GM210M's. Charged them with 38.6gr H4350, just like my 108 ELD-M pet load and seated Berger 105 Hybrids at 2.76 COL which is .010 back from engaging the rifling..

At the range in a biting mid to upper 30's wind near local sunset, their POI was 1 inch higher than the 108 ELD-M's at 100 yds, though I wasn't there for the groups. They extracted with the same force needed to cock the firing pin on an empty chamber! Jubilation T. Corn Pone! Forgot what that felt like.

Back in the shop. Deprimed the spent cases and wiped them down. Spent primers pushed out pretty easy compares to the Peterson SRP's so I'm wagering the case life would be less. First stop was reinserting them into the chamber with the firing pin assembly and ejector removed from the bolt. The bolt handle fell all the way down with its own weight! No binding! Forgot what that felt like as well. Checking the springback , it was -.002 from GO gauge. Necks wound up at .273 OD, down from .274 using the Petersons. Brass looked pretty nice after fire forming. Nice defined shoulder corners. It would be hard to tell them from actual 6XC brass once tumbled without looking at the headstamp.

Experiment concluded.

Hoot

Gonna sell all your Peterson brass?

 

[Kimber.204]

@Hoot
Thanks for the summary and follow up. I'm glad you resolved your issues.