6 MM Bbl.life ?

[Old Corps 8541]

Just thinking ahead, and knowing the lead time might be up to 6+ Mo. I'm using the "7 P" principle , so, I'll be needing to replace the 6 CM bbl. and wondering what other 6 MM users are seeing as usable Bbl. life of the smaller 6 MM cases ie; 6BRA , 6 Dasher, and the 6GT using 105 the 115 gn bullets
As I see it, I've already got $$$ dies and a good supply of new 6 CM brass and should have close to 1500 rounds on the present Criterion Bbl. this time next year.

 

[John Glidewell]

It depends on how hard you run them. I ran mine with 109s at 3050ish and they all went around 1700 to 2k.

 

[RegionRat]

Agree with John.
The idea is simple when put into terms like pressure, velocity, and heat. The wear equations have exponents on them, and the ones for velocity are higher than the ones for pressure, and the ones for heat are higher than those. In so many words, the same barrel goes longer when you don't get it hot with all other things being equal.... shot cadence matters.

 

[lte82]

Acceptable accuracy is different for different people. For a guy that wants 1 moa at 100 yards, a Dasher barrel may go 5000+ rounds if loaded light. If you expect .2's at 600 yards, then you may only get 1500 rounds. Maybe your barrel won't even do .2's at 600 yards even when brand new, so maybe your barrel life is literally 0 rounds. That said most 6BR/Dasher barrels will go 50-100% longer than a 6 creedmoor, all things considered equal.

 

[Matt_3479]

My current bra barrel has a touch over 2600 rounds still shooting great!

 

[Old Corps 8541]

OUTSTANDING info Thank you'll

 

[4O6shootist]

Well I've seen dasher go 2200-2500. My old 6gt has 2400ish on a mod400 bartlein still shoots small. Br/bra id say 3k should be good. This is all holding sub half moa as a standard. It depends on how hard you run them. My 6bra has about 800 rounds on it and has only. 006 throat erosion. Still shoots original load in the 2s and threes consistently, a bad group is in the 4s. Probably needs cleaned or tuned on seating depth.

 

[Supersubes]

As stated, how hard you push with regard to loads and firing tempo will greatly affect barrel life.

My personal creed was a special project just to test life when the internet lore said the 6cm was a barrel torching monster. Im at almost 800 rounds with no measurable wear with slow fire and conservative loads. Its gonna live to thousands of rounds I think.

 

[High Desert duck]

I’m at 1700 rounds on my 1st barrel. I use it for club matches. The 1st 1200 rounds were 110 atips at 3060. The last 500 or so rounds have been 108s at 3000. Erosion has been steady at about .005 per 100 rounds. Still shoots like it did at 200 rounds, .5-.6. Haven’t seen the speed drop off either. My big match barrel is at 800 rounds. Again A-tips at 3070. Same erosion as the 1st. I have also stopped chasing the lands. Groups are hanging tight.
Barrels are bartlien heavy varmint 28” using 40 grains of 4451

 

[LR1845]

I had a 6CM barrel go at 800 rounds with over .050 burnt outta the throat...we wont talk about load or speed. most other 6CM barrels went around 1200-1700.

A buddy of mine just pulled a BRA barrel with 3800 rounds through it and would still shoot 3/4-1" pretty consistently but was throwing odd fliers.
my personal best was 3200 through a BRA but i tend to run on the higher side.

 

[Longtrain]

My Dasher generally shot 108 Berger’s @2960 fps. My first Shilen barrel went 2400, my first Brux barrel started to show accuracy issues and more copper at 2000. Just spun Brux #2 on, we’ll see how that one does.

 

[Old Corps 8541]

longtrain , not much difference between 2000 & 2400 , but why did you go with a Brux instead of a Shilen ? Availability ?

 

[Longtrain]

longtrain , not much difference between 2000 & 2400 , but why did you go with a Brux instead of a Shilen ? Availability ?

Yeah, when I built the Dasher, a buddy had an extra Shilen sitting on his shelf, as far as the Brux goes, I heard good things and testimonies from a few fellow shooters. Bore scoping them, they are beautiful inside, a really good barrel.

I’ve shot Hart, Shilen, Brux and Kreiger in my bolt guns, 223, 223AI, 6BR, Dasher and 308. They all shot well, but the best was the Kreiger in 6BR, whether it was the cartridge, the barrel or both, it was an absolute tack driver.

Lately, a lot of guys are shooting Bartlein, I’ll need to give them a look at some point.

 

[Lightning8]

I just switched from 6XC to a 6 Dasher in my primary rifle and my backup rifle is wearing a new 6BRA barrel. Load 105 Hybrids at 2919 in Dasher and 105 MBs at 2820 in 6BRA. Several experienced shooters who are mentoring me in my PRS journey suggested setting aside 2000 projectiles from same lot for each rifle and once those 2000 rounds are consumed I should assume it is barrel change time

 

[CK1.0]

6CM, Proof SS prefit 1 in 7.5T, 112gr Match Burners, 41gn StaBall, ~2900fps, jumping .100"... 2300rds - throat/lands only lost/eroded less than 10 thou over its whole life. It shot the same (great) over its whole life until it suddenly lost over 100fps and fell off a cliff (dead).

The throat/lands eroded so little that I thought something was wrong with how I was measuring (nope), but once I noticed it I stepped my game up at measuring and became excellent at it so I could keep better track of it for my next barrel...

...and I'm ~1600rds into the second one, loading the same way (100 thou off, ~2900fps), measured the lands at ~1500rds and I have only lost a thou or so (yep, you read that correctly)...

 

[CK1.0]

once those 2000 rounds are consumed I should assume it is barrel change time

^^^ I think ~2000 is a safe bet for just about any 6mm. Some may go longer, or shorter... depending on which 6 you're shooting and what you are feeding it.

 

[Longtrain]

On my new Dasher barrel, for fun I’m going a different route to see if it makes a difference in its’ life span.

Not finding Varget or Norma 203B, which I used for my previous barrels, I’ve tested and switched to VV N140, a single base powder which has a little “cooler” burn then some others. Also, I’ve gone back to coating my bullets with Tungsten Disulfide, WS2, which worked really well when I was shooting F-T/R a few years back.
The barrel life calculators say it should matter, we’ll see how it plays out. Here’s some Peterson Dasher brass I loaded this week with WS2 coated bullets.

 

[4O6shootist]

On my new Dasher barrel, for fun I’m going a different route to see if it makes a difference in its’ life span.

Not finding Varget or Norma 203B, which I used for my previous barrels, I’ve tested and switched to VV N140, a single base powder which has a little “cooler” burn then some others. Also, I’ve gone back to coating my bullets with Tungsten Disulfide, WS2, which worked really well when I was shooting F-T/R a few years back.
The barrel life calculators say it should matter, we’ll see how it plays out. Here’s some Peterson Dasher brass I loaded this week with WS2 coated bullets.View attachment 8039753

One my fellow match shooters run N150 exclusively in lapua 6 dahser brass with 105s going 2880 and it hammers. Ran varget last two barrels with 2200-2500 life. He's experimenting as well. I have a bunch of N150 as well, tempted to try it in the GT, my H4350 load just shoots so well.

 

[Longtrain]

N150 is supposed to be good for velocity, N140, accuracy. I’m always looking for accuracy and legit velocity, and since that was what I could buy, N140 is it. So far, it’s been great.

 

[Matt_3479]

N150 is supposed to be good for velocity, N140, accuracy. I’m always looking for accuracy and legit velocity, and since that was what I could buy, N140 is it. So far, it’s been great.

I’ve ran both in my bra. Both powders performed excellent. I’ll be curious what you think

 

[Longtrain]

I’ve ran both in my bra. Both powders performed excellent. I’ll be curious what you think

Once Spring shows up, I’ll post my chrono and target results. Thx.

 

[4O6shootist]

My friends dahser consistently shoots in 2s/3s at 100y, and half moa at distance with N150. I don't know if a guy could ask for more than that unless you're a competitive benchrest shooter.

 

[Longtrain]

I don’t usually save “wallet targets”, but this one was stupid good. It’s a 223 test for seating depth, 1.970” is the LTO, 73 grain Berger’s, 23 grains of N140 and BR4 primers. 5 shots at 100 yds.

 

[Longtrain]

Well it took a while, but I think I’ve got the Dasher on the right road. I have been loading N140 under WS2 coated 105 Berger BT’s.

After breaking in the barrel, I started them just off at the rifling. Charge weights started at 30 grs and moved up in .3 grain increments. This was done with only BR4 primers and took awhile, but I was able to check for velocity, pressure, accuracy, SD and ES signs.

At my chosen load I substituted a variety of primers and tested again.

All in all the worse groups at my chosen load were just under 3/4 MOA, the best just under 1/2 MOA. Rem 7 1/2’s were one of the best loads, SD’s were 7, mostly under 1/2 MOA.

Tried again moving the bullet in by .010”, nothing consistent over 30 rounds. Changed to Tula 556M primers, .010 off, bingo. 100 yd grouped in the mid .1’s. and even a little better at 200 yds. SD was 6.4. Here’s the 100 yd target, 5 shots. They were running 2934 fps out of a 28” barrel.

Next week a 300 yd FClass match, we’ll see how it goes. If ok, we’ll use the load for a 800, 900, 1K match at the end of the month.