6.5 CM throat erosion and rebarrel

[FourT6and2]

How much erosion is typical for 6.5 Creedmoor over lifespan of barrel?

EDIT:
Finally got around to measuring throat erosion. When new, estimated jump with factory 140gr ELD-M was 0.030". 600 rounds: 0.032", 1000 rounds: 0.0398", and currently at 0.042". Still shoots pretty good. Exact round count is unknown but probably around 3,500. Total erosion over life of barrel so far is 0.012". What is typical for a 6.5 Creed?

 

[Digetydog]

Is the scope ok?

 

[Rob01]

Haven't shot the rifle in 2 years and it's off a few tenths but shoots like that and that's a problem? LOL Stop bragging and shoot the rifle.

I'd start getting a barrel ready if it does have 3500 rounds through it though.

 

[spife7980]

3500 on a creed? Yes, I dont need targets to tell me that

 

[FourT6and2]

Is the scope ok?

I hope so. I haven't had the energy to really suss it out. But I probably should.

 

[FourT6and2]

Haven't shot the rifle in 2 years and it's off a few tenths but shoots like that and that's a problem? LOL Stop bragging and shoot the rifle.

I'd start getting a barrel ready if it does have 3500 rounds through it though.

Haha noted

Yeah I've got a barrel here but my smith is booked about 6-months out and has an injury currently preventing him from working until it's healed.

 

[Supersubes]

Its lived a good life

 

[kthomas]

Not enough data to determine if the barrel is toast.

However, 3500 rounds on a 6.5 Creedmoor is a lot. If it's not at the end of it's life now, it certainly will be soon.

If you need a barrel fast, TS Customs can spin you up a barrel in a couple of weeks.

 

[FourT6and2]

Finally got around to measuring throat erosion. When new, estimated jump with factory 140gr ELD-M was 0.030". 600 rounds: 0.032", 1000 rounds: 0.0398", and currently at 0.042". Still shoots pretty good. Exact round count is unknown. But total erosion over life of barrel so far is 0.012". What is typical for a 6.5 Creed?

 

[Sogan]

What kind of flex is this?

 

[Supersubes]

Finally got around to measuring throat erosion. When new, estimated jump with factory 140gr ELD-M was 0.030". 600 rounds: 0.032", 1000 rounds: 0.0398", and currently at 0.042". Still shoots pretty good. Exact round count is unknown. But total erosion over life of barrel so far is 0.012". What is typical for a 6.5 Creed?

Id estimate most people are seeing that much erosion per thousand rounds, if not more.

 

[crispy]

those groups ... at those distances ... shooting unsupported, kneeling

 

[IDbound]

Okay I will bite. Where are the images of the groups the OP is to have shot?

 

[crispy]

must've deleted them ... no idea why, because one was a 10 round group basically one hole than the size sandwich pickle

 

[crispy]

*smaller

 

[IDbound]

Okay that makes sense.

 

[trophyhunter]

I don’t know the group size or distance shot , but if it’s at 100yds or 200, velocity won’t change much to make it a bad group.

The better indicator of life would be measuring velocity with the same items, load. Let’s say for numbers your 41.6gr when newer netted you 2750fps, and now with same powder load you are at 2625. Well it’s obvious you hit the steps of velocity loss. Hence making your barrel toast as if you are at a match, and it drops another step, you’d need to adjust if you can spot your shots for the next drop. Most creeds on traditional barrels I’ve seen them start to wander velocity after 1500-2000rds. But they will still shoot great groups at 100yds. Good for hunting and range days, not so much for a major match that you’ll shoot 200rds over the weekend.

Like your bullets, primers and powder…your barrel is a spendable item with each use, don’t fall in love with them.

 

[FourT6and2]

I don’t know the group size or distance shot , but if it’s at 100yds or 200, velocity won’t change much to make it a bad group.

The better indicator of life would be measuring velocity with the same items, load. Let’s say for numbers your 41.6gr when newer netted you 2750fps, and now with same powder load you are at 2625. Well it’s obvious you hit the steps of velocity loss. Hence making your barrel toast as if you are at a match, and it drops another step, you’d need to adjust if you can spot your shots for the next drop. Most creeds on traditional barrels I’ve seen them start to wander velocity after 1500-2000rds. But they will still shoot great groups at 100yds. Good for hunting and range days, not so much for a major match that you’ll shoot 200rds over the weekend.

Like your bullets, primers and powder…your barrel is a spendable item with each use, don’t fall in love with them.

When new, velocity was 2834 fps. Now it's 2790. This is with factory ammo though. I don't hand load.

 

[trophyhunter]

Same lot of factory ammo or just random lots of whatever you pick up at the store?

So you’re already seeing a velocity drop, but since factory ammo you can’t gauge if it’s the ammo or barrel velocity drop.

 

[FourT6and2]

Same lot of factory ammo or just random lots of whatever you pick up at the store?

So you’re already seeing a velocity drop, but since factory ammo you can’t gauge if it’s the ammo or barrel velocity drop.

I have 1,000-round lots. When I move to a new lot, I re-chrono and re-zero and get new DOPE out to 1,000 yards. I know there's some variation from lot to lot. I've found that it isn't really any different from the variations I see within the same lot of ammo. But sure... it's hard to keep every variable the exact same using factory ammo.

I do suspect the first 1,000-round lot I used was different. Hornady had just released the ELD-M. Tip color was different. Charge was probably different as I was seeing some pressure signs from that lot of ammo (flattened primer). But the next few lots had lower velocities and no more pressure signs. Tip color also changed. But holy crap... that first 1,000 rounds shot better than anything I've ever seen. Could have been the ammo. Could have been the fresh barrel. Could have been both. But I was absolutely nailing every shot at all distances. None of the other lots of ammo I have shoot as good as that first lot before Hornady made those changes.

But a drop of 44fps over 3,000 rounds doesn't seem like a lot to me?

 

[Baron23]

Finally got around to measuring throat erosion. When new, estimated jump with factory 140gr ELD-M was 0.030". 600 rounds: 0.032", 1000 rounds: 0.0398", and currently at 0.042". Still shoots pretty good. Exact round count is unknown. But total erosion over life of barrel so far is 0.012". What is typical for a 6.5 Creed?

Wait...are you saying over 3,500 rounds you only had 12 thousandths of erosion? Wow??? Not to be insulting, but I wonder how consistent your measurement technique is.

I really like Cal's Precision Rifle Blog because he's very objective, analytical, and just data driven without any BS.

Check out these blog entries...he's talking in the recent blog about 6CM which should erode faster than 6.5....right???.....but certainly not an order of magnitude faster.

Precison rifle blog throat errosion - Google Search

 

[FourT6and2]

Wait...are you saying over 3,500 rounds you only had 12 thousandths of erosion? Wow??? Not to be insulting, but I wonder how consistent your measurement technique is.

I really like Cal's Precision Rifle Blog because he's very objective, analytical, and just data driven without any BS.

Check out these blog entries...he's talking in the recent blog about 6CM which should erode faster than 6.5....but certainly not an order of magnitude faster.

Precison rifle blog throat errosion - Google Search

I've read that. I know about that site; great info.

And yes, apparently 0.012" of erosion. I use a Mitutoyo caliper, Hornady OAL guage, and take a series measurements and record the mean, median, and mode each time. That's about as accurate as I can get. Unfired round (same one I've used since day one) measures 2.1960" BTO. Distance to lands mean: 2.23612", median: 2.2380", mode: 2.2385" = current jump of 0.042" as best number. When new, barrel had 0.030" jump. That's 0.012" erosion. Seems very small to me, but the numbers aren't lying.

When I get a rebarrel, I'll have my smith cross section the current one and I'll take a peek.

 

[Pete B]

Mate, stating only 12 thousands wear has occured indicates your measuring is flawed. No offence meant, but you don't seem to realise this......

 

[spife7980]

Ive not seen obscene erosion rates either myself on the handful Ive measured via wheeler method.
Im inclined to believe him. Im sure parts have eroded more but relationship between that bullets bearing surface and ogive and the leade may not indicate much when measured.

 

[FourT6and2]

Mate, stating only 12 thousands wear has occured indicates your measuring is flawed. No offence meant, but you don't seem to realise this......

Ok thanks.

I suppose it's possible my round count is off and I'm at 2,000 and change and not 3,000. If I forecast the erosion rate on paper, it would make sense that I'm at 0.042" jump at 2,500 rounds. Buuuut... it's a bit hard to misplace 1,000 rounds of ammo lol

 

[FourT6and2]

Ive not seen obscene erosion rates either myself on the handful Ive measured via wheeler method.
Im inclined to believe him. Im sure parts have eroded more but relationship between that bullets bearing surface and ogive and the leade may not indicate much when measured.

What's the wheeler method?

 

[moosemeat]

Have you cleaned the bejebus out of the barrel to make sure your not measuring on hard carbon deposits in the throat?

 

[Baron23]

What's the wheeler method?

Video is half way down on this page of his site

Videos | wheeleraccuracy

www.wheeleraccuracy.com

 

[FourT6and2]

Have you cleaned the bejebus out of the barrel to make sure your not measuring on hard carbon deposits in the throat?

I have a borescope on the way, so I'll take a look.

 

[FourT6and2]

Video is half way down on this page of his site

Videos | wheeleraccuracy

www.wheeleraccuracy.com

Ah yes I know of that method. I don't hand load, so I don't have dies or seating tools, etc.

Another method I could try is the locktite one. Gently chamber a case with bullet seated long and some thread locker in neck and let rifling push bullet into case neck and wait for thread lock to set.

 

[trophyhunter]

If the barrel shoots, keep winning matches.

But a 6.5 creed with 2500 or 3500rds is worn out. Mr Green a well known person that makes barrels has tested this in the factory a few times. They have a new material that from what I understand will up the barrel life.

But as I said before, don’t worry about it, shoot the crap out of it. If it’s eroded .012” or .120” it don’t matter if it’s a competitive barrel. But just know that barrels are like a tires, eventually they run out and need to be replaced.

 

[FourT6and2]

If the barrel shoots, keep winning matches.

But a 6.5 creed with 2500 or 3500rds is worn out. Mr Green a well known person that makes barrels has tested this in the factory a few times. They have a new material that from what I understand will up the barrel life.

But as I said before, don’t worry about it, shoot the crap out of it. If it’s eroded .012” or .120” it don’t matter if it’s a competitive barrel. But just know that barrels are like a tires, eventually they run out and need to be replaced.

Yeah that's my plan and I have a new blank ready to go already. This is all just for my own curiosity.

 

[Baron23]

Ah yes I know of that method. I don't hand load, so I don't have dies or seating tools, etc.

Another method I could try is the locktite one. Gently chamber a case with bullet seated long and some thread locker in neck and let rifling push bullet into case neck and wait for thread lock to set.

I think that this ^^ will get you into the lands a bit but I'm FAR from an expert and have no estimate of how far off that would put you from actual. Many others here.....like @spife7980 ...are indeed highly knowledgeable and experienced. I'd look to them for advise.

I do use a Hornady OAL and have found...like yourself...that if I take a series of measurements most of them are within a couple of thousandths...with a bit of practice I've gotten pretty consistent results.... and its pretty clear which ones are outliers from poor technique. But I've never had a great deal of confidence in it.

BUT my two 6.5 CM rifles have SAAMI chambers and I've found when loading Berger .264 Hybrid Targets in a 6.5 CM case that I'm limited by mag lengthy (using MDT mags with the binder plate) and believe that the closest I can get to the lands is about .060" off.

If I do get a more customized chamber in a future barrel (with less freebore, right), I'd probably do the Wheeler method. @orkan also has a video doing the same technique.



Question, if you don't reload and only shoot factory ammo....why do you care about any of this...well, other than just an interest in the hobby? Just look for dropping muzzle velocity and group size opening up as to tell when the barrel is going tits up.

@spife7980 - am I making sense, my friend, or am I completely out to lunch and leading this guy (and me) down the primrose path?

P.S. - I see you responded that its for curiosities sake and yeah....its just an interesting part of the hobby, right?

 

[FourT6and2]

I do use a Hornady OAL and have found...like yourself...that if I take a series of measurements most of them are within a couple of thousandths...with a bit of practice I've gotten pretty consistent results.... and its pretty clear which ones are outliers from poor technique. But I've never had a great deal of confidence in it.

Yep, I did 10 measurements with 5 bullets. Kept getting the same number 3, 4, 5 times in a row and figured that's good enough after 50 measurements.

BUT my two 6.5 CM rifles have SAAMI chambers and I've found when loading Berger .264 Hybrid Targets in a 6.5 CM case that I'm limited by mag lengthy (using MDT mags with the binder plate) and believe that the closest I can get to the lands is about .060" off.

I only shoot Hornady 140gr ELD-M and in a fresh SAAMI chamber, the lots I have typically jump 0.030". I calculated this a few different ways and kept getting the same number. Hornady says they should jump 0.098". But that's much farther than what I'm seeing.

Someone on another forum even suggested I try this (and I did) and I got 0.030" exactly.

"Throat datum for a new 6.5 CM SAAMI chamber is .262" X 2.187" from the bolt face. Mark your Hornady round with a sharpie at the bullet cylinder/ogive junction. Lock a micrometer (not calipers) to .262" and use the carbide anvils to lightly scribe a fine line on the bullet at .262". Measure with a caliper from the base to your line. You can get scary close by eyeball if you pay attention. Subtract your measurement from the datum number, in this case its 2.187", the sum is your jump. You can also track your throat erosion by making a three fingered collet from a case, mark your bullet, and breech seat it in the chamber. 6's and 6.5's move forward pretty quick. Measuring from a datum .002" under groove diameter is more reliable that OAL. The distance from tip to the datum point varies greatly even on similar types and weights of match bullets."

Question, if you don't reload and only shoot factory ammo....why do you care about any of this...well, other than just an interest in the hobby? Just look for dropping muzzle velocity and group size opening up as to tell when the barrel is going tits up.

Just curiosity and to learn.

P.S. - I see you responded that its for curiosities sake and yeah....its just an interesting part of the hobby, right?

Yeah

 

[spife7980]

Question, if you don't reload and only shoot factory ammo....why do you care about any of this...well, other than just an interest in the hobby? Just look for dropping muzzle velocity and group size opening up as to tell when the barrel is going tits up.

@spife7980 - am I making sense, my friend, or am I completely out to lunch and leading this guy (and me) down the primrose path?

Make sense to me. When I first got into loading for "precision" a few years back I measured my barrel like every 100 rounds watching the erosion. I never found much of anything egregious, I never had .1 of growth, the .012 was more like what I saw.

A few more barrels of less frequent measuring but still never tenths of an inch or anything crazy.

Id then do a test with that new length in growth trying to chase the throats and bracketing on each side for margins of error and then test to see what was happening as it moved and refencing it back to the original load. What I found was that it still shot best where it originally was before usually.
Now I take a throat measurement when new just to find where Im touching and test going backwards from there. I dont measure anymore except for maybe once every 1k rounds and thats just for curiosities sake, I let the actual testing steer my decisions. I havent been surprised by extreme growth, maybe .030 after its life.

 

[Rob01]

Yep, I did 10 measurements with 5 bullets. Kept getting the same number 3, 4, 5 times in a row and figured that's good enough after 50 measurements.


I only shoot Hornady 140gr ELD-M and in a fresh SAAMI chamber, the lots I have typically jump 0.030". I calculated this a few different ways and kept getting the same number. Hornady says they should jump 0.098". But that's much farther than what I'm seeing.

Someone on another forum even suggested I try this (and I did) and I got 0.030" exactly.

"Throat datum for a new 6.5 CM SAAMI chamber is .262" X 2.187" from the bolt face. Mark your Hornady round with a sharpie at the bullet cylinder/ogive junction. Lock a micrometer (not calipers) to .262" and use the carbide anvils to lightly scribe a fine line on the bullet at .262". Measure with a caliper from the base to your line. You can get scary close by eyeball if you pay attention. Subtract your measurement from the datum number, in this case its 2.187", the sum is your jump. You can also track your throat erosion by making a three fingered collet from a case, mark your bullet, and breech seat it in the chamber. 6's and 6.5's move forward pretty quick. Measuring from a datum .002" under groove diameter is more reliable that OAL. The distance from tip to the datum point varies greatly even on similar types and weights of match bullets."

Just curiosity and to learn.


Yeah

It’s because you don’t have a SAAMI chamber. Can say it over and over but it’s not if only .030” to lands with a factory round. Just not happening with a .199 freebore in the SAAMI.

 

[FourT6and2]

It’s because you don’t have a SAAMI chamber. Can say it over and over but it’s not if only .030” to lands with a factory round. Just not happening with a .199 freebore in the SAAMI.

Do you disagree with the procedure outlined in my post?

 

[Rob01]

Do you disagree with the procedure outlined in my post?

Not about procedure but result.

 

[FourT6and2]

Not about procedure but result.

What about the other member here who said he chambered a barrel using SAAMI reamer and measured with this ammo and also got ~0.030"?

Throat length on 6.5 Creedmoor chamber

Hello, Have a #2 Hawk Hill getting done and it is going on a Rem 700 adl with factory mag box. The smith can throat it at .150 throat length so that the 147 eld will touch the lands at 2.808 or so. Thinking the saami throat is around .198. Thinking there would be no downside to going shorter...

www.snipershide.com

Throat length on 6.5 Creedmoor chamber

The 140 ELD, like the other ELDs, don't mind a jump. Shooting factory ammo and jumping .070" it shoots great in my rifle. Used a tuner to tune harmonics and got it to 1 hole 5 shot group so the bullet jump is not an issue. Most load to the .030-.010" as they can and like being closer. I load...

www.snipershide.com

 

[Rob01]

Honestly don't care but you are just running under the assumption you have SAAMI and from someone who has had many SAAMI chambered Creedmoors I can tell you that if you have .030" jump with factory ammo that is not a SAAMI chamber. Again you need to find out what reamer your smith used as in you posts you said even he wasn't sure but just used the same one so doesn't mean the same is SAAMI.

 

[FourT6and2]

Honestly don't care but you are just running under the assumption you have SAAMI and from someone who has had many SAAMI chambered Creedmoors I can tell you that if you have .030" jump with factory ammo that is not a SAAMI chamber. Again you need to find out what reamer your smith used as in you posts you said even he wasn't sure but just used the same one so doesn't mean the same is SAAMI.

No, I never said he wasn't sure. I said he told me every 6.5 Creedmoor job he does gets the same spec. But you're right, he wasn't forthcoming about what the actual spec was.

 

[DellaDog]

.012 erosion after 3500 rounds just ain’t right - probably closer to .120 than .012

 

[Rob01]

No, I never said he wasn't sure. I said he told me every 6.5 Creedmoor job he does gets the same spec. But you're right, he wasn't forthcoming about what the actual spec was.

And the assumption it's SAAMI is the problem when your numbers are not near what mine in multiple barrels were. I just don't want anyone doing some research and looking for info down the road to come across this and assume it's SAAMI and .030" off with factory is normal. There is a disconnect somewhere.

 

[FourT6and2]

And the assumption it's SAAMI is the problem when your numbers are not near what mine in multiple barrels were. I just don't want anyone doing some research and looking for info down the road to come across this and assume it's SAAMI and .030" off with factory is normal. There is a disconnect somewhere.

Yes, there is a disconnect somewhere. That said, in the other thread @Supersubes said he chambered a barrel with a SAAMI reamer and measured 0.032" jump with this specific ammo. See links I posted above.

And following the other procedure outlined above, I also measured 0.030" jump comparing this Hornady ammo to SAAMI reamer spec using a micrometer to scribe line on bullet.

The link I posted in the other thread to the experiment comparing three different freebores, including SAAMI, showed 0.055" jump using SAAMI reamer.

Hornady claims 0.098" jump, though. And that's much different.

You stated 0.05 - 0.07" jump in the other thread.

Could the disconnect be the ammo? Because Hornady did change this ammo over time. When it first came out, it had a different color tip, different charge, and bullets might have been seated at different length. My lots of ammo are from when Hornady first released the ELD-M...

 

[Rob01]

Yes, there is a disconnect somewhere. That said, in the other thread @Supersubes said he chambered a barrel with a SAAMI reamer and measured 0.032" jump with this specific ammo. See links I posted above.

And following the other procedure outlined above, I also measured 0.030" jump comparing this Hornady ammo to SAAMI reamer spec using a micrometer to scribe line on bullet.

The link I posted in the other thread to the experiment comparing three different freebores, including SAAMI, showed 0.055" jump using SAAMI reamer.

Hornady claims 0.098" jump, though. And that's much different.

You stated 0.05 - 0.07" jump in the other thread.


Could the disconnect be the ammo? Because Hornady did change their ammo over time. When it first came out, it had a different color tip, different charge, and bullets were seated at different length. So... maybe jump differs because the way Hornady seated bullets changed over time? My lots of ammo are from when Hornady first released the ELD-M...

The OAL of factory ammo can vary and does. I have 140 ELD lots that range from 2.800 to 2.820" OAL to that is the variable that is there for you being a person only using factory ammo. I have at least 8-10 lots of it I checked. I had the first lot of 140 ELDs factory ammo and bullets to hit the market also. They vary in lots. I am not new to the cartridge or factory ammo for it.

Also as I mentioned taking measurements with the Hornady OAL guage and 140 ELDs I am getting .070" to the lands from the closest 2.800" as a baseline with multiple barrels that I know for a fact are SAAMI .199 freebore. If it's loaded to 2.820" then it will be around .050". So take that for what you want but anyone else reading in the future take that into account also.

 

[FourT6and2]

The OAL of factory ammo can vary and does. I have 140 ELD lots that range from 2.800 to 2.820" OAL to that is the variable that is there for you being a person only using factory ammo. I have at least 8-10 lots of it I checked. I had the first lot of 140 ELDs factory ammo and bullets to hit the market also. They vary in lots. I am not new to the cartridge or factory ammo for it.

Also as I mentioned taking measurements with the Hornady OAL guage and 140 ELDs I am getting .070" to the lands from the closest 2.800" as a baseline with multiple barrels that I know for a fact are SAAMI .199 freebore. If it's loaded to 2.820" then it will be around .050". So take that for what you want but anyone else reading in the future take that into account also.

My current lot measures, on average, 2.8056" OAL.

 

[whatsupdoc]

How much erosion is typical for 6.5 Creedmoor over lifespan of barrel?

EDIT:
Finally got around to measuring throat erosion. When new, estimated jump with factory 140gr ELD-M was 0.030". 600 rounds: 0.032", 1000 rounds: 0.0398", and currently at 0.042". Still shoots pretty good. Exact round count is unknown but probably around 3,500. Total erosion over life of barrel so far is 0.012". What is typical for a 6.5 Creed?

Like the others have stated something in your measurements is not correct, .012 throat erosion in 3500 rounds is not possible.

Here is one barrel in 6.5 Creed, while my measuring method cannot be construed as "precise" it does give a reasonable representation of throat erosion using the same hornady 140 ELD.

New 2.185
327 2.188
754 2.194
1009 2.194
1304 2.204
1485 2.210
2137 2.236


Different barrel 140 Berger

449 2.142
645 2.144
1046 2.153

 

[FourT6and2]

Like the others have stated something in your measurements is not correct, .012 throat erosion in 3500 rounds is not possible.

Here is one barrel in 6.5 Creed, while my measuring method cannot be construed as "precise" it does give a reasonable representation of throat erosion using the same hornady 140 ELD.

New 2.185
327 2.188
754 2.194
1009 2.194
1304 2.204
1485 2.210
2137 2.236

Ok so in 2,000 rounds, you've seen 0.051" of erosion. My current jump isn't even that much (0.042"). So I would have been jammed into the lands when new based on that info.

You measured 2.185" BTO when new? Just making sure I understand what you're saying. What are you measuring your ammo's BTO as to calculate jump? I know it's hard to compare because we might be using different methods/tools. But my factory ammo measures 2.196 BTO. That would mean when new, my ammo in your rifle would have had a 0.011" jump...

BTW, my current average measurement matches yours: 2.236" = 0.04" jump.

 

[whatsupdoc]

The Jump is irrelevant in my measurements, my measurements are simply the point that the bullet is stopped by the throat. Yes 2.185 BTO new (after firing 20 rounds)

My ammo is handloads.

 

[FourT6and2]

The Jump is irrelevant in my measurements, my measurements are simply the point that the bullet is stopped by the throat. Yes 2.185 BTO new (after firing 20 rounds)

My ammo is handloads.

Got it. So yeah, you've seen 0.051" erosion in 2,000 rounds. I thought you said you were shooting the same ammo. But you meant same bullet.