6XC Barrel life.. What are you really getting?

[Petey]

My first 6XC was chambered about this time last year and I immediately fell in love with this little round. Took me no time to find a load that shoots teeny-tiny groups out to 1000. I ended up putting about 1100 rounds down it in 2015. I'm in the processes of building another as we speak, b/c I love the round so much.. but to my question, for those of you that's gone through barrels, what are you truly getting out of it?

To paint the picture, I'm talking MTU/HV Krieger contours 29-30 barrels in 1000 yard benchrest conditions. Actually VBR - matches consist of ~55-60 rounds with sighters.
I know a lot has to cleaning, powder, etc... But to give me a ball park here

Me, I'm using H4350 (39.8 Gr) shooting bare 107 SMK around 3075. Not really hot rodding it, but shoot 5-8 rounds in 3-5min span for each relay and bank of targets. 4 groove, .236 bore

What's your barrel, What's your powder, What's your bullet, How fast you running it, How often are you cleaning? I've read so many things from 1800-2500+. By the end of the year this barrel should have another 500-600 down it which would put it in the 18-1900 range. Is now the time to set back (if there's merit to it)? What should I expect to see?.. If it's 2K I'm good.. if it's 1.8K I may consider. Hard to even consider doing that since this barrel is OUTSTANDING at the moment. I really don't want to ruin a good thing.. Oh yeah and if you're asking what's accurate.. last group at 500 it mic'd at 1 3/4", 5 shots. I don't want to turn an outstanding barrel into a good or even great barrel. Not having actually going through a full barrel's life yet with this round, I'm at a bit of a loss on knowledge here.

Thanks!

 

[TAJ45]

My first 6XC was chambered about this time last year and I immediately fell in love with this little round. Took me no time to find a load that shoots teeny-tiny groups out to 1000. I ended up putting about 1100 rounds down it in 2015. I'm in the processes of building another as we speak, b/c I love the round so much.. but to my question, for those of you that's gone through barrels, what are you truly getting out of it?

To paint the picture, I'm talking MTU/HV Krieger contours 29-30 barrels in 1000 yard benchrest conditions. Actually VBR - matches consist of ~55-60 rounds with sighters.
I know a lot has to cleaning, powder, etc... But to give me a ball park here

Me, I'm using H4350 (39.8 Gr) shooting bare 107 SMK around 3075. Not really hot rodding it, but shoot 5-8 rounds in 3-5min span for each relay and bank of targets. 4 groove, .236 bore

What's your barrel, What's your powder, What's your bullet, How fast you running it, How often are you cleaning? I've read so many things from 1800-2500+. By the end of the year this barrel should have another 500-600 down it which would put it in the 18-1900 range. Is now the time to set back (if there's merit to it)? What should I expect to see?.. If it's 2K I'm good.. if it's 1.8K I may consider. Hard to even consider doing that since this barrel is OUTSTANDING at the moment. I really don't want to ruin a good thing.. Oh yeah and if you're asking what's accurate.. last group at 500 it mic'd at 1 3/4", 5 shots. I don't want to turn an outstanding barrel into a good or even great barrel. Not having actually going through a full barrel's life yet with this round, I'm at a bit of a loss on knowledge here.

Thanks!

 

[TAJ45]

I have looked at a meloniting process to maximise a truly outstanding pipe. How much measured erosion do you have now?
It seems they recommend trtmnt aft a hundred or so rounds.
A well seasoned colony and BR competitor Bud has noticed a distinct advantage for the 6mm RemAI over the 243 AI in bbl life, all multiple quality bbls thru the years. Counter intuitive with the extra pwdr cap of the 6Rem.

 

[TAJ45]

I have looked at a meloniting process to maximise a truly outstanding pipe. How much measured erosion do you have now?
It seems they recommend trtmnt after a hundred or so rounds.
A well seasoned colony and BR competitor Bud has noticed a distinct advantage for the 6mm RemAI over the 243 AI in bbl life, all multiple quality bbls thru the years. Counter intuitive with the extra pwdr cap of the 6Rem.

. ##%@# phat fingers on the new phone......continued:

We are collaborating on a 6XC Long Neck. A .400 neck (6mmRem = .350). An idea I had last Fall and it is coming together. He has spoken with enough excellent shooters/reloaders to feel there is a node to be had for the heavies North of 3200fps. B/C of his experience w/ the 6Rem, we think burying the turbulence point another .050" on an already long neck design could only help with throat erosion. I like the option of being able to seat lighter, shorter bullets into the lands with sufficient neck gription. Just throat .060 or more shorter.
He also likes warmish loads - with a careful and measured approach. This is our reason for choosing the small primered brass - Lapua Palma .308.
The Pbike257 30* shoulder pushing/necking dies were invaluable for bringing the brass to XC spec.
My Bud's wildcat experience and depth of shooting knowledge has carried this idea to the range test stage on one of his 8 tw bbls. I' ll be offering a virgin 7.5tw 5R Krieger straight pipe finishing over 30" for testing this Spring.
He has spoken with enough long time XC shooters to feel confident in the " next level" of velocity being safely achievable and is awaiting weather concessions for testing of the 95% BE, wad and filler formed brass. NF and S III will be the scopes used. Stay tuned for results. A torture test of pocket/expansion #of reloads is next on his agenda.

Looking fwd to reading others' results with the XC. We are optimistic on increased bbl life at near max loads - d on accuracy of course.

 

[Petey]

Well here's the kicker and I'll bet 90% of the people on here will say I'm a liar, but I was very meticulous about measuring and documenting out of the gate, b/c this particular round was all new to me.

I checked last night 10 times all repeatable (only one time was it .001) off and I'm only seeing .006" erosion. (yes 6 thousandths not 60)

Don't get me wrong I'm not complaining but it doesn't make sense from what everybody else is seeing in the 30 to 40 thousandths range after 1100 rounds.

So you'll ask how am I checking erosion? Well I'm using a Hornady OAL gauge with a modified case that I drilled and tapped from a fired round from this chamber. I'm also using the exact bullet that I used from day one, which was marked and set aside, plus the Sinclair Hex/Ogive Nut. A year ago I checked 10 times, all repeatable before highly documenting it. I checked it throughout season never really seeing much if any erosion affects. I need to look back down it with my hawkeye, which I did at the end of season. From what I recall I could easily see the lands, with minimal wear.


So I'll throw some numbers out here see if any of this makes sense, or if I just happen to have a SUPER barrel or something. lol

First off the chamber was cut with a .274 nk, .090 Freebore and 3/4 lead. I'm thinking the freebore and lead are my "helping" factors on minimal erosion here, but that's up for argument.

I'm shooting 107 SMK's which most people use at least a .098 if not a .110 freebore for those 105-107 class bullets. With the .090 freebore it does put my boat-tail very close to the neck-shoulder junction.

So 1 year ago maybe 15 rounds down, my tool gave me with 107 smk

3.086" for a CBTO measurement on top of nut or rather a true CBTO of 2.086". Base of case to at least where my Hex nut hits the bullet of .24 (maybe not true Ogive but repeatable measurement on same bullet)

My load was a CBTO of
Top of nut : 3.094"
Bottom: 2.094"

for a jammed load of +.008"

Checked through each match, never saw much if any erosion using same methods. Gun won last match (which my son won with)with same load and seating depth as first match (which it won). I may have moved my moved my seating depth +.002 throughout the year, but not .020 or .030 or .040 as some would have to.

Last night, same bullet used from day one and all season long as my "gauge"

3.092" to Lands (top nut)
2.092" (bottom of nut)

So 1100 documented rounds:
Before 2.086 to touching lands
After 2.092 touching lands

am I sure it touches? Well yes b/c in every scenario my bullet actually is left in the throat when I pull my tool out, giving minimal pressure.

So is there something to this "short" freebore 3/4 lead and jamming from day one, oh and only using H4350 and never hot rodding it? OR have I screwed up somewhere and I'm not measuring what I think I am? (which I don't believe to be the case from my observations of physically looking at it with the bore scope)

Sorry this is all so lengthy but I'm scratching my head. Why is everyone else seeing .030-.040 and I'm only seeing .006? Is it because of the good steal, the chamber and how it was cut, the load, powder and jam combination or am I just imagining all of this with a barrel that is like any I've seen before for accuracy.

Oh also, I didn't mention this but I came from burning up two different 6.5x284 barrels the year before using the same methods chasing erosion every match.

 

[WyleWD]

I've been shooting an XC since 2007. I pulled the original 26" barrel (Kreiger) with almost 1900 rounds through it in 2014 and replaced it. When I pulled it, my gunsmith told me there was no reason to set it back as there was no fire cracking and not enough throat erosion to worry about. Mine is a 1-9 twist which I have used H4350, IMR4350, and R-15 in it, shooting 95gr uncoated bullets. So, I use the barrel I took off for load development and "small" matches now a days. It still shoots well, as I still can't out shoot that barrel.

Like you, I was just thinking of it getting towards the end of its life and with the long lead times of barrels and gunsmiths, I didn't want to find out in the middle of a season that I should have rebarreled it before the season started. The way this turned out for me is that I now have a very competitive spare.

I shoot mostly varmint matches with a fire rate of up to 13 rounds in 15 minutes and clean after every 35-40 rounds with Boretech eliminator. Hope it helps you some. JME. WD

 

[Petey]

Well this is a Krieger as well... #10 MTU, 30" 1-8, .236 bore

My second gun getting chambered as we speak is the exact same make barrel. Maybe these guys getting massive erosion are firing coated bullets like DTACS, Hot rodding them with RL17/15. No clue, other than I'm not seeing it.

Of course I'm not shooting 115 bullets either. I'm shooting 107's with a shorter than designed freebore

I'm glad you posted your history. It makes me feel like I'm not Bat shit crazy!

 

[TAJ45]

Well this is a Krieger as well... #10 MTU, 30" 1-8, .236 bore

My second gun getting chambered as we speak is the exact same make barrel. Maybe these guys getting massive erosion are firing coated bullets like DTACS, Hot rodding them with RL17/15. No clue, other than I'm not seeing it.

Of course I'm not shooting 115 bullets either. I'm shooting 107's with a shorter than designed freebore

I'm glad you posted your history. It makes me feel like I'm not Bat shit crazy!

Very, very interesting Petey. I really like taking information that is well presented and filing it away for further cogitations.

The bud who sent me this post, which prompted me to make mine, is the one doing 99% of the R&D on the Long Neck. When talking with him y'day evening, we were talking about having a reamer made to his specs and discussing the leade angle. The shallower angle will increase the OAL to reach lands, something to obviously consider. The other thing was the "combustion volume/chamber" (I don't remember) as it's been over 12 hours ()......But I'd read of the Theory that if a bullet was jumped quite a bit such as a factory Wby chambering, the initial nanoseconds of bullet movement w/o resistance of rifling to slow it would extend the burning powder further into the bbl leading to possibly more firecracking, wear etc. I'd just read that concept a bit earlier but he knew of it and labeled it.

Saying that - your shorter freebore just seems to fly in the face of that "theory".......with your bbl.
Not taking any issue whatsoever, I believe your methodology and the results you posted. I'm just, by anecdotal mention, saying that there has to be a whole lot going on that is yet to be corralled in my pea brain and your experience gives me another question that may/may not be answered before I leave this world. The list is getting longer by the week.

All in all, a very informative thread and looking for more input. Thanks for starting it.

 

[Gina1]

Here is the "inside" scoop on barrel life for the 6XC.....
I'm nearing the end of the life of my 3rd 6xc barrel. I know this from a bore scope of the chamber and several inches down the pipe. What i'm seeing is a flatting of the lands and some fire cracking.
My 1st barrel (unknown manufacture) I shot maybe 1800 rounds, Way past it's usable life (not knowing it was why my group was going to crap) Took it to the gunsmith for a look and was told it was shot.

My 2nd barrel was a Bartlein, from Bullets.com (1.25-1.00) 7.5 twist 5R. Lasted a year, with 1,400 rounds (group opening up)
All my loads were average, not over loaded, bullet seating depth was correct, nothing out of the ordinary. Powder was IMR 4350

Wondering what it really looked like inside the barrel, I cut it open with a band saw (OH WHAT SACRILEGE)
The following pictures tell the story.

Picture 1 was taken at the muzzle, of barrel #2. This is what rifling should look like.

Picture 2 was taken a small distance from the chamber of barrel #2
Notice the start of fire cracking, and that the land is flatting out (that broad white streak)

Picture 3 is the 1st barrel. Lands are totally gone, and severe fire cracking.

 

[Gina1]

gina 1 here.

Sorry that was my first post under the new software. Guess I got thing screwed up a bit.
Hope my post helps. BTW the picture of the muzzle end, shows some copper in the rifling and lands. Not normal for me, Just didn't clean it out before cutting it open.
Oh, by the way, my 3rd barrel is Barlein also and has about 1,300 rounds down the pike, also from Bullets.com, same as the 2nd.

Gina

 

[TAJ45]

gina 1 here.

Sorry that was my first post under the new software. Guess I got thing screwed up a bit.
Hope my post helps. BTW the picture of the muzzle end, shows some copper in the rifling and lands. Not normal for me, Just didn't clean it out before cutting it open.

Gina

gina 1 here.

Sorry that was my first post under the new software. Guess I got thing screwed up a bit.
Hope my post helps. BTW the picture of the muzzle end, shows some copper in the rifling and lands. Not normal for me, Just didn't clean it out before cutting it open.

Gina

Numbers, visuals: What's not to like - thanks for posting. Good thread, eh?

 

[AckleymanII]

Gina, How much would you have to cut off to get rid of the fire cracking, and how far down the barrel does the fire cracking go?

 

[Gina1]

In each case I cut off about 3 inch's The first barrel, the worst, I guess you could cut it down to make a nice high caliber pistol.
The 2nd one, I started to get lands I could feel with my finger nail at about 2 1/2 inch's
The question is, would it be worth re-chambering ? Starting off as a 28" barrel, removing 3 inches, then makes it a 25" used barrel. IMHO, I would go with a new barrel. Especially for competition.

 

[Frankr]

Gina 1 from what I see in the picture does not look that bad..looks like fine checking. I have see a few barrels with a bore scope look real bad and still shoot GREAT but they did powder foul quickly. then groups would suffer..All I am saying is the pictures do not look that bad to me..I have seen fire cracking that was deep and long.
I cant find the insert. But daily bulletin October 31 2014 is a good article.

 

[Gina1]

Each to their own, I guess. When my group opens up, no matter how I load my rounds. (this is a barrel that shot 5 rounds, 1/8 MOA 100 yards), something is going on. Having lands that are almost flat or gone, will I'm sure does not bode well for accuracy.
You know we are "perfectionists" when it come to shooting. Turning necks, just the right amount of powder to the kirnel, seating depth, etc, etc. Do you think a competition shooter would use or accept a barrel like that ?
IMHO

 

[Petey]

Let me offer this up for discussion as well.. We seem to have two separate Krieger bbls with little to no erosion (myself and WyleWD) with 1100 and 1900 rounds respectively

My barrel is conventional rifling, I would ask WyleWD if that barrel was also conventional.

Not implying better steel of Krieger over Bartlien whatsoever... Maybe, Maybe not. But one could argue 5R vs conventional on erosion amounts as well. I only have one Bartlien in 5R but that's in a fire breathing barrel burning 6.5x284. I've burnt through Kostyshyn and Kriegers in that round, but have yet to even shoot the Bartlien so I have no input.

Anyone ever compare conventional rifling vs 5R in regards to erosion? maybe it's not Krieger vs Bartlien in this instance but rather 5R vs conventional.

If WyleWD is not conventional, I suppose that may put the nail in the coffin to this question/theory/argument.. If there is one? Lol

Also gina1... Were your barrels .236 or .237 bore? Could you provide any info on your above chamber specs? I.e freebore, lead, etc.. And I assume you're shooting 115's but you never said. Coated or bare.. All good stuff to help compare what's happening. Whatever you're doing definitely seems repeatable

 

[Raptor]

I had a Kreiger conventional 4 grove that was chambered in the 6XC. I put just a tad over 1800rds through it(38grs of H4350 with old original heavy 6XC brass and 107MKs) and decided I needed more HP to push the 115DTACs so I took it to my smith to see if I could re chamber to a 6SLR or I needed to get a new barrel. He bore scoped it and said it looked great and was just showing some wear in the throat area and didn't see any fire cracking.

He re chambered it to a 6SLR and after another 1000+ rounds I pulled the barrel and tried the BRX but didn't like the little cases and was going to have it re chambered to the 6SLR again. He said I should put my old barrel back on and finish it out since it still looked good. I said are you sure?? It has close to 2800rds on it!! He said he would "clean" up the throat since it was going on a different action and sent it back to me. I shot it until it had over 3500rds on the barrel and it was still shooting .5 MOA at 600 but I was getting fliers at longer ranges. I do believe that shooting H1000 for over half the barrels life also helps with the long barrel life. I also only shot a couple of matches with this one. Still that is a lot of rounds on a 6MM barrel....

 

[savagedasher]

Barrel life depend on how the load is and how you shoot. Mild loads and longer shooting time between shots . Will increase barrel life.
Larry

 

[Petey]

Well put Larry!

I guess what I was hoping to get was the real world tales of each shooter's load, how they shoot it, etc so we can compile a "go to" guide on this round.

For instance, Raptor's post really warmed my heart (as well as WyleWD's) seeing as how the load is very close, same powder, same bullet, same barrel maker, same rifling... Both state 18-1900 rounds with no ill effects. Me, I'm sitting at 1100 so I can pretty much conclude (maybe not difinatively) that I'll get that or even better. From my observations I should be more in the neighborhood of 2500, but who knows until I reach that point.

Gina1 has a different story to tell.

This is all to your point above.

Hopefully at the end of this, maybe one can determine using X-brand of barrel, rifling, chamber specs, powder choice, charge amount and bullet specs... One can expect to see X amount of rounds.

Or maybe we can determine that one shooting 107smk's should expect to see 56% more barrel life than someone shooting 115DTAC's at comparable velocities based off bearing surface of bullet alone. Oh how to dream!... But just maybe it could be that simple lol

The route mine is on, looks to be positive for sure

 

[Raptor]

Petey. your on the right track. I do believe you will get more barrel life out of a rifle with 107s than you will with the 115s. Larry is absolutely correct. Your barrel life "WILL" depend on how you use or abuse the rifle. When I was shooting tactical matches with my 260s they were toast at 2200 to 2400rds. The rifling would be black 8"s up the barrel and look like a dried up lake bed. My last 260 went to 3000 rds. But I never shot it in a match and never got it very hot when shooting it.

The reason that I went to the SLR was because I could use the "Cooler" burning powders and still get good velocity because of the bigger case. With the 6XC or 6x47 lapua your stuck with the faster burning powders and they generate more barrel heat. When I shoot the 6SLR with a load of H4350 the barrel gets hot faster than when I shoot a load of H1000. As we all know HEAT is the killer of barrels. Good discussion....