Throat Erosion on my 6 creed

[LC 6.5 Shooter]

Current barrel is a proof ss 7tw heavy palma. Ive got 443 rounds running 115dtacs with 41.3g h4350 @3050f/s.

Did my first check on throat erosion at 443 rounds. Throat erosion is 0.038”. The barrel use has been a mix of range shooting on a bench for the most part and 1 80 rounds PRS local.

2 questions

1. is that normal erosion for the information i provided.

2. Is throat wear proportional. Say 0.019” per 200 rounds at the current erosion rate.

 

[jhunter]

1. This is excessive. If you are measuring with a bullet and OAL gauge could it be a different lot of bullets?
2. not at all each barrel wears differently

Pressure creates erosion. I shot 105s at 3140 forever out of the Creedmoor. I found that if you back the charge down by about a .5 grains then you get twice the barrel life. To me that makes the extra 50 fps not worth it

 

[just browsing]

Worrying about throat erosion in a 6 Creed is like rearranging deck chairs on the Titanic.

Put the bore cam down and shoot until it doesn’t.

 

[Newbie2020]

Thanks @jhunter. I don’t load but switched from the Hornady Match ammo to the Black 105s to save cost and throat life.

I’ve read posts on here about the 6cm being a “bbl burner, and other posts saying they’re in the thousands of rounds, but now I’m thinking it’s the load, not the cartridge....

 

[Steel head]

That’s pretty substantial wear.
As long as it shoots it doesn’t matter.
If you want more life back the load down a bit.

 

[Supersubes]

Op, you didn’t say what your barrel length is. You’re .8 gr over hodgdon’s max charge, and you’re 150 faster than they were. They listed their max pressure was 59k psi. Fair to say you’re pushing the load well over max pressure.

As a point of comparison, my 6creed, which I’m intentionally loading soft in a 27” barrel, goes 2900 with 37.5 Gr of RL16(identical to H4350 in burn rate). Last time I checked the throat I had zero erosion at just under 500 rounds. You can have speed or you can have barrel life, not both.

 

[6brshooter]

But gardener said 3150fps and 2500+ rds barrel life,lol

 

[Steel head]

But gardener said 3150fps and 2500+ rds barrel life,lol

6.5 saum is still laughing.

 

[6brshooter]

6.5 saum is still laughing.

Pepperidge farms remembers...

 

[LC 6.5 Shooter]

Op, you didn’t say what your barrel length is. You’re .8 gr over hodgdon’s max charge, and you’re 150 faster than they were. They listed their max pressure was 59k psi. Fair to say you’re pushing the load well over max pressure.

As a point of comparison, my 6creed, which I’m intentionally loading soft in a 27” barrel, goes 2900 with 37.5 Gr of RL16(identical to H4350 in burn rate). Last time I checked the throat I had zero erosion at just under 500 rounds. You can have speed or you can have barrel life, not both.

26” barrel. Pressure signs not showing. No primer backflow. No sticky bolt etc.

First real dip into the 6mm world. Was 6.5 creed previously. Have never checked erosion before and heard 6creed being known as “burners”. So I checked out of curiosity. Not overly concerned as Ill shoot it till it craps. Dont really feel like backing off and doing more load development. Just wanted to see if what Im seeing was as excessive as I thought. I did load development in the 60’s and have shot this load in the low 90’s with no pressure issues. Ill keep rocking just trying to gain knowledge. Next barrel Ill look for something a little slower and probably go 109 bergers or 108 elds too.

 

[6brshooter]

I say screw it, if I want 2900fps 6mm, ill run a br or bra. I run my 6 creed at 3180, 26" .236 bore, 41.4gr rl16 and 105hybrids.

 

[LC 6.5 Shooter]

I say screw it, if I want 2900fps 6mm, ill run a br or bra. I run my 6 creed at 3180, 26" .236 bore, 41.4gr rl16 and 105hybrids.

Great point brother. I did go creed for speed and if I decide to go a little slower and more tame Ill probably jump on the dasher train.

Another reason for me going 6 creed was just incase I didnt feel like loading I could get some great match grade ammo.

 

[whatsupdoc]

Although not impossible I believe you may be measuring incorrectly. Make sure you clean the chamber before you take measurements.
I am running two 6mm creeds and my erosion is way less. You are not using any abrasive cleaners?


Running 41.0 H4350 105 at 3040FPS

Rounds Erosion
2.192____ 0
2.195____260___ 0.003
2.202____660___0.010
2.208____ 915___0.016
2.212___1032___0.020

 

[6brshooter]

Great point brother. I did go creed for speed and if I decide to go a little slower and more tame Ill probably jump on the dasher train.

Another reason for me going 6 creed was just incase I didnt feel like loading I could get some great match grade ammo.

Also, if you wanted to try a 6mm at 2900-2950, but not plunge into a br case(added dies&brass), you can run h4831sc/h4831 in 6creed. Fills the case and should be around 2950+/-.

 

[LC 6.5 Shooter]

Although not impossible I believe you may be measuring incorrectly. Make sure you clean the chamber before you take measurements.
I am running two 6mm creeds and my erosion is way less. You are not using any abrasive cleaners?


Running 41.0 H4350 105 at 3040FPS

Rounds Erosion
2.192____ 0
2.195____260___ 0.003
2.202____660___0.010
2.208____ 915___0.016
2.212___1032___0.020

I used the wheeler method with a bullet from the same lot. I use butchs bore shine for cleaning. And I did clean it just prior to rechecking CBTO distance.

 

[King_beardsly]

I didn’t know you could push 115 dtacs that fast, but pressure torches barrels and you need a lot of pressure for that speed. I’ve been pushing 105 hybrids over 41.8 of H4350 and getting 3150. Now will this combo kill my throat quickly, most likely but I didn’t get a 6creed for the barrel life.

 

[b6graham]

I didn’t know you could push 115 dtacs that fast, but pressure torches barrels and you need a lot of pressure for that speed. I’ve been pushing 105 hybrids over 41.8 of H4350 and getting 3150. Now will this combo kill my throat quickly, most likely but I didn’t get a 6creed for the barrel life.

don't ask Lombardi what he pushes his from a 6XC then baha

pretty sure Tubb has shot DTACS at 3250 before from a 6XC. 3050 is very doable with 40gr or so of powder from an XC

whats it shooting? still good? small groups?

 

[King_beardsly]

don't ask Lombardi what he pushes his from a 6XC then baha

pretty sure Tubb has shot DTACS at 3250 before from a 6XC. 3050 is very doable with 40gr or so of powder from an XC

whats it shooting? still good? small groups?

Well Mike is a mad man and that might explain what his setup is absolute laser beam.
If I do my part from a bench it’s like .4 as of lately, I tweaked my case prep a little so it’s more consistent.

 

[Carlos Danger]

I found accuracy at a lower node so I'm sticking with it for now.....but I dont do any long long range shooting. I'd rather extend the barrel life if I can.

 

[b6graham]

Well Mike is a mad man and that might explain what his setup is absolute laser beam.
If I do my part from a bench it’s like .4 as of lately, I tweaked my case prep a little so it’s more consistent.

i meant the OP for groups etc.

but yeah its a laser...until you see my 22LRV light off haha

 

[King_beardsly]

i meant the OP for groups etc.

but yeah its a laser...until you see my 22LRV light off haha

22LRV... you’ve got my attention

 

[LC 6.5 Shooter]

Sho

don't ask Lombardi what he pushes his from a 6XC then baha

pretty sure Tubb has shot DTACS at 3250 before from a 6XC. 3050 is very doable with 40gr or so of powder from an XC

whats it shooting? still good? small groups?

Shooting just fine. More of an educational question. Thx

 

[b6graham]

Sho


Shooting just fine. More of an educational question. Thx

then just keep shooting it. if it gets bad push the bullets a little further out and call it a day

 

[Milo 2.5]

Current barrel is a proof ss 7tw heavy palma. Ive got 443 rounds running 115dtacs with 41.3g h4350 @3050f/s.

Did my first check on throat erosion at 443 rounds. Throat erosion is 0.038”. The barrel use has been a mix of range shooting on a bench for the most part and 1 80 rounds PRS local.

2 questions

1. is that normal erosion for the information i provided.

2. Is throat wear proportional. Say 0.019” per 200 rounds at the current erosion rate.

38 thou erosion in 443 rds is substantial. Comparing erosion amongst a group like this is unfair, you could buy 3 barrels from brand x and shoot the same load in all 3 and have different results. Throw in 6-8 different barrel brands, now your results spread even greater.
Not implying you did anything wrong here, but a guy really needs to fire some initial rds before deciding just what the measurement to the lands are. A miniscule burr in the throat area can give false numbers.
I am at .040" erosion on a dasher, less than 1K rds and wondering where or how that happened.
Some barrels do fine with a lot of erosion, I had one that hit the trash pile with ..027" total, no bringing it back either.

 

[redneckbmxer24]

That’s a crap load of erosion. How/when was your first measurement done? If it was done on a fresh chamber with the hornady/Stoney point type tool I’d say you had a nice burr that you were measuring too and throwing your measurement off.

 

[Steel head]

That’s a crap load of erosion. How/when was your first measurement done? If it was done on a fresh chamber with the hornady/Stoney point type tool I’d say you had a nice burr that you were measuring too and throwing your measurement off.

I’m less than that with my current 7 saum barrel with a bit over 1200 rounds through it.

 

[King_beardsly]

Also, if you wanted to try a 6mm at 2900-2950, but not plunge into a br case(added dies&brass), you can run h4831sc/h4831 in 6creed. Fills the case and should be around 2950+/-.

Oh man, you mean I didn’t need a dasher to get great barrel life pushing 105’s at just shy of 3000.

LC 6.5 Shooter In all seriousness just shoot it till an issues arises weather it been speed or accuracy, and maybe look at keeping a spare barrel lined up in case the current one just falls off unexpectedly. I also know that the freebore on the proof stuff is rather long to accommodate stuff like the ELD-M’s so that could cause a little premature erosion and is the reason I personally went with a short freebore designed for the 105 Hybrids and Dtacs to extend service life when I’ve got to start chasing the lands.

 

[RMerillat]

I'll chime in with my 6mm Creedmoor experience. I just replaced my Brux 8 twist barrel at 1300 rds. The throat had moved forward .060 inch. Throughout it's life, I used 42 gr. of H4350 with a Berger 105 hybrid; velocity early on was 3070 fps. It still seemed to shoot well in terms of groups at 100 yards, but seemed inconsistent at extended range. (It now has a new Bartlein barrel chembered in 6 GT by GAP.)

 

[LC 6.5 Shooter]

So 265 rounds later another 0.032” throat erosion. Ive never shot a barrel out before but accuracy isnt as good now (3/4-1/2moa where it was a consistent .3” or better at 100) And velocity was a little low and more es that usual yesterday. Im right at 750 rounds now. Has anyone ever shot a barrel out that fast in 6creed. What are some other signs the barrel is toast.

 

[Petrov]

Man things changed, before all this fancy technology and gadgets we just shot rifles and didnt look at the throat untill there was some problem.
Strange how all these issues are popping up now that every one has a bore cam.

 

[Steel head]

My Smith and I started keeping logs of throat erosion. There's a decent sized group of us that shoot PRS, NRL, and field matches that he does barrels for. His shop is right across the street from the range we run monthly PRS club matches on. Guy's swing by and he measures their throats and takes notes in his log. 3-4 thou per hundred is average for BRs and Dashers. And his sandbagged 30" XC going 2900. 5-7 thou per hundo is what we're seeing on the bigger Creed's, SLR, and hard run 6's.

It’s interesting that my 7 saum barrel is about 3-4 thou per 100, same as BR and dashers.
I really would expect 6 creed levels.

 

[IPoutdoors]

It’s interesting that my 7 saum barrel is about 3-4 thou per 100, same as BR and dashers.
I really would expect 6 creed levels.

interesting. Thanks for sharing. Do you think different powders have Something to do with erosion numbers?

 

[Steel head]

interesting. Thanks for sharing. Do you think different powders have Something to do with erosion numbers?

 

[LC 6.5 Shooter]

It’s interesting that my 7 saum barrel is about 3-4 thou per 100, same as BR and dashers.
I really would expect 6 creed levels.

Im way beyond those numbers. Wtf

 

[Steel head]

Makes you wonder if people know how to measure their lands repeatabley

I use the wheeler method along with a dedicated case and bullet.
The Hornandy Tool gives the same numbers.
I’ll measure again tomorrow as I’ll be at a bit over 1500 rounds.

 

[trophyhunter]

Again as stated it’s real hard to measure accurately. A carbon ring or deposit can fudge measurements. It’s all off “feel” just a slight touch could be .010-.020” jammed so your numbers are off.

I say just run it till you notice speed drop, then run it some more.

if you’re gonna compare throat erosion against another totally different barrel and person measuring...good luck

 

[trophyhunter]

I use the wheeler method along with a dedicated case and bullet.
The Hornandy Tool gives the same numbers.
I’ll measure again tomorrow as I’ll be at a bit over 1500 rounds.

Do you scope the barrel for any carbon prior to measuring now and at first measurement?

 

[Steel head]

Do you scope the barrel for any carbon prior to measuring now and at first measurement?

True.
I also have a brand new barrel with same reamer That I compared to my current barrel measurements when new and as it sits now.

 

[trophyhunter]

True.
I also have a brand new barrel with same reamer That I compared to my current barrel measurements when new and as it sits now.

Interesting bit, so we chambered for a customer 6XC, 2 barrels, same brand, same everything specs, with the same lathe, and same reamer. So the customer did load work up for one and said “I’ll use this load in both”. Then a few days later decided to swap barrels to start to season it. Ammo wouldn’t fit, he called worried that maybe we set the wrong headspace as he was having issues. Originally wanted to use brass for both. After checking headspace was identical....but throat on 1 (the 2nd barrel) was .080” shorter. So when he was using ammo from the 1st barrel it was to long and sticking.
Barrels do weird things

 

[Steel head]

Interesting bit, so we chambered for a customer 6XC, 2 barrels, same brand, same everything specs, with the same lathe, and same reamer. So the customer did load work up for one and said “I’ll use this load in both”. Then a few days later decided to swap barrels to start to season it. Ammo wouldn’t fit, he called worried that maybe we set the wrong headspace as he was having issues. Originally wanted to use brass for both. After checking headspace was identical....but throat on 1 (the 2nd barrel) was .080” shorter. So when he was using ammo from the 1st barrel it was to long and sticking.
Barrels do weird things

.08 with the same reamer(if it was still in good shape) is a huge variance.
My current when new and new barrel thankfully are far far closer, like within a few thou.

 

[trophyhunter]

.08 with the same reamer(if it was still in good shape) is a huge variance.
My current when new and new barrel thankfully are far far closer, like within a few thou.

Had only had those 2 chambers on it

did a 3rd barrel later and it matched 1st barrel

we figured it might’ve been something with bore that was just tighter. Both shot great so never worried about it. Ended up throating 1st barrel to match.

 

[Steel head]

Had only had those 2 chambers on it

did a 3rd barrel later and it matched 1st barrel

we figured it might’ve been something with bore that was just tighter. Both shot great so never worried about it. Ended up throating 1st barrel to match.

tighter bore kinda makes sense.

 

[nickw]

I'll chime in with my 6mm Creedmoor experience. I just replaced my Brux 8 twist barrel at 1300 rds. The throat had moved forward .060 inch. Throughout it's life, I used 42 gr. of H4350 with a Berger 105 hybrid; velocity early on was 3070 fps. It still seemed to shoot well in terms of groups at 100 yards, but seemed inconsistent at extended range. (It now has a new Bartlein barrel chembered in 6 GT by GAP.)

This was my 6Creed load and out of my Bartlein GAP spun barrel, I got 850 rnds before it went south. Also had .060 of erosion when I pulled it. Velocity dropped 50fps and groups opened considerably. Had the bbl scoped and throat was toast. There was fire cracking 6” up the bore. I switched to 6XC and 115 DTACs @ 2920 in an attempt to get better bbl life and got 1400rnds before bbl went south in the middle of a major match. Love 6mm but there is a price to pay running one at high velocities. No free lunch.

 

[samb300]

Fast load + PRS rates of fire + potentially soft steel + jump sensitive bullet = fun times!

 

[Dthomas3523]

This is why I don’t measure chambers. It’ll screw with your head.

Every 300 rounds or so, load your current length. .003, .006, and .009 longer. 3 shot groups. Shoot them and see which seating depths your rifle currently likes. Sometimes even with erosion it will still like the current depth.