Round count to settle barrel down

badthirtyone

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My 2 cents worth,

Depending on the quality of the barrel, stock/factory vs. custom/match grade/aftermarket (which are often hand-lapped and muuuch smoother) the round count to "settle" a bore can vary a good amount - but usually I'd say in the range of 60 to 100 total break in shots to get everything consistent.

I'm generally happy at around that 100 round mark.
 

Rick Richard

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My 2 cents worth,

Depending on the quality of the barrel, stock/factory vs. custom/match grade/aftermarket (which are often hand-lapped and muuuch smoother) the round count to "settle" a bore can vary a good amount - but usually I'd say in the range of 60 to 100 total break in shots to get everything consistent.

I'm generally happy at around that 100 round mark.
About the same for me too.
 

highdrum

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Nov 30, 2008
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Proof barrels are a different animal since they come with such a smooth lap. I personally feel they're over lapped to a mirror like finish. All 3 my bartleins have been done speeding up by 120 rounds. The few benchmarks and rocks were done by 100. The few proofs I've had have taken considerably longer 180 on one, 210 the other. Larger overbore cartridges seem so speed up the process. My friends 6.5x47 lapua on a proof carbon never fully stabilized till 240.
 

MagnumManiac

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Feb 25, 2008
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I had my last 3 Bartlein barrels all speed up after 80 rounds, and it was progressive over about 20 or so shots.
My old Hart barrels didn’t speed up until 120 or so shots.
My custom 338-416 Rigby Improved barrel, CM 32” long 9” twist is hand lapped and it only shoots HBN coated bullets and it sped up at 90 shots, like someone turned on a light switch.
It also took a lot of burnishing with the HBN before it would even settle on a powder node, it was a roller coaster journey for those 90 rounds.
Barrel steel hardness, how the barrel is stress relieved and what machining tools are used all affect how it burnishes.
My latest barrel is being cryo’d, have tried nitrided and melonite in the past. Nitriding is thin and wears off in my experience after only a couple thousand rounds.

Cheers.
 

340PR

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Nov 18, 2018
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Average breaking in to max velocity using Kreiger, Broughton, and Brux has been 75-125 rounds. However, the last Brux I got is lights out after the first shot. Still pinching myself to understand how this could be true. Now 600rounds in and still 3/8MOA or better (when I show up..) Velocity increase 25fps from new. living in a huge node.. Full disclosure: I changed gunsmiths for the latest barrel. Have a 6BRA coming up for replacement, will see what happens.
 

2ndson

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May 14, 2020
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OK
Every barrel is different. I have had barrels continue to speed up past 200 rounds. I have had barrels speed up over 100f.p.s. til they settled in. I have had them barely speed up at all. But I would say the "average", if there is such a thing, would be a speed up of about 40-70f.p.s. and settle in about 150 rounds.
 
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