Bartlein break in rounds

Sled

WKR
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How many rounds did your bartlein take to get it up to speed? I have a 6.5 PRC that's about as fast as my factory 6.5 CM but I only have a dozen rounds through it. There are a lot of variables but I'm expecting to at least see another 100-150 fps. I just hope I can get there sooner than later.

Fresh
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After
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"I have a 6.5 PRC that's about as fast as my factory 6.5 CM"

is this apples to apples? same bullet, same barrel length, ect?

are you handloading or shooting factory?
 

BrBa

Lil-Rokslider
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More than 12. How are you cleaning it? Mine started to settle down and tighten up at around the 50 round mark. By 125 +/- speeds have been pretty stable.
 

Dmoua

Lil-Rokslider
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Around 150 rounds with a Dasher. I’m guessing 100 or less for a magnum cartridge.
 
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Sled

Sled

WKR
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More than 12. How are you cleaning it? Mine started to settle down and tighten up at around the 50 round mark. By 125 +/- speeds have been pretty stable.

Just cleaning for copper between a couple shots. I'd be happy if it only takes 50 rounds. I'm just curious how many more I need to get thru it to trust the dope. Id also like to see if it's worth the upgrade from my 6.5cm
 
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Sled

Sled

WKR
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"I have a 6.5 PRC that's about as fast as my factory 6.5 CM"

is this apples to apples? same bullet, same barrel length, ect?

are you handloading or shooting factory?

Barrel is .5" longer on the PRC and the projectile is 12gr heavier. The CM has had factory and hand loads perform similarly. The PRC only has some break in factory 147 eld-m.

I do expect they'll speed up like most barrels do.
 

BrBa

Lil-Rokslider
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Just cleaning for copper between a couple shots. I'd be happy if it only takes 50 rounds. I'm just curious how many more I need to get thru it to trust the dope. Id also like to see if it's worth the upgrade from my 6.5cm
I thought Bartlein recommends only using a solvent for carbon. If there are traces of copper in the bore, it's actually a good thing. And they say skip the brushes as well, if you're using any.
 

huntnful

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You’re looking at 100+ rounds before the throat starts cracking, causing more friction on the bullet and increased pressure to create an increase in speed. It has nothing to do with the bore, or “break in” or cleaning copper between shots.

A 147 ELDM has a long bearing surface that robs a lot of velocity compared to other similar weight bullets. And factory hornady ammo is no speed demon either.

Handload for handload, pressure for pressure it will easily beat the 6.5 CM. You’re just not making an equal comparison at the moment.
 

huntnful

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IMG_1908.png
This cracking at the start of the throat, just in front of the case neck portion of the chamber, is what causes the “speed up”. The bigger the cartridge, and hotter the powder, the fast it happens.

And the speed up is just pressure related. From that cracking grabbing the bullet harder as it enters the barrel. Nothing to do with a bore smoothing out or anything like that.

On a 6.5 PRC, I’d say at least 100 rounds
 
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Sled

Sled

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Agreed, better off leaving the chrono at home and enjoying the gun for a while.

I’d reassess at 100 and 200 rounds.

I have done that before but not when I have Garmin burning a hole in the case. It's so damn easy to use, why not use it and track data points?
 
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Sled

Sled

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Thanks for all the info. My question has been answered and I should have a couple hundred rounds down it before April. I should have left the part out about the creedmoor but I was thinking out loud.
 
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