Cutting a Barrel Ruins Precision?

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Who has cut a barrel and seen a degradation of precision? And I’m not talking a three shot group, I mean shot some ten shot groups before and after the cut.

I have a 24” barrel that is shooting 10 shot groups of multiple factory ammo types right at an inch and want to cut it to 20”. But I’m scared to mess it all up.

Interested in evidence, not opinion. Thanks!
 

Gargoyle

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Nov 24, 2022
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More than likely get even better precision. Less of the barrel whipping compared to a long pole.
I just cut down a 30" ELR rig barrel to 23.5" oh, MTU profile. Load development with new components is going great with no skip in the precision I got with the 30" version.

Now, the hand loads I developed for the 30" barrel ain't doing so good in the 23.5". Harmonic change, and 130fps less MV. So, I would need to tweak the old load if I wanted to proceed with that bullet for hunting. Probably not though, the Hammer 154HHT and 137HH are F'N bangarang in load development right now.
 
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MTMeatHunter
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Yeah see, that’s what makes me nervous. I’m shooting factory ammo and I can’t tweak the load. Did you shoot some big groups and notice the drop off?
 

RobertLosekamp

Lil-Rokslider
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So long as the crown is done properly after the cut it shouldn't be a problem, worst case you have to test ammo to find what it likes again after the harmonics changed.
 
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I have chopped a bunch of barrels. I can think of only one where I didn’t have to change the load a bit to get it to the same level of accuracy/precision. Most of the time I was able to find something that worked better.

If you are stuck with factory ammo, and it is something that is a bit difficult to find, then you may want to reconsider. If it is something readily available (308, 30-06, 6.5 creed, 6.5PRC, etc) then go for it with the understanding that you will probably have to find a new “best friend” for that rifle.
 

gbflyer

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Who has cut a barrel and seen a degradation of precision? And I’m not talking a three shot group, I mean shot some ten shot groups before and after the cut.

I have a 24” barrel that is shooting 10 shot groups of multiple factory ammo types right at an inch and want to cut it to 20”. But I’m scared to mess it all up.

Interested in evidence, not opinion. Thanks!

Shooting that well, I suggest that you step back 4” and leave it alone.


Sent from my iPhone using Tapatalk
 

Weldor

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Had a.257 bbl. cut, It ruined it. Cut it from 20 to 16.5 to run a can. 3 inch was a good group. tried tweaking loads for awhile ended up scraping it. My Bad.
 
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MTMeatHunter
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Had a.257 bbl. cut, It ruined it. Cut it from 20 to 16.5 to run a can. 3 inch was a good group. tried tweaking loads for awhile ended up scraping it. My Bad.
Alright, that right there convinces me. I guess I’ll be stuck at 30” with the can. It’ll be my open country gun lol.
 

Weldor

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I run 20" and 22.5 on my 6.5 prc's, no issues carrying them. 18" 308 works awesome too. All factory bbl.'s
 

Harvey_NW

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Harmonics don't exist in the context most shooters think they do, lol. Only one of the answers to your question met the request of having a large sample size as evidence to prove so.

Cut rifled, hammer forged, or button? Because that can potentially play a part in the result, but there is also a solution to that.
 

Harvey_NW

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Had a.257 bbl. cut, It ruined it. Cut it from 20 to 16.5 to run a can. 3 inch was a good group. tried tweaking loads for awhile ended up scraping it. My Bad.
Something to note here, if you're talking about something like a 257 wby mag being chopped to 16.5" I confidently bet you were having powder burn issues, and it had nothing to do with cutting the barrel shorter. It was that it was cut too short.
 
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MTMeatHunter
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I wouldn’t be concerned about it at all. Find a good smith and let it rip imo

I wish I could shot you a before cut group but I cut it before I ever shot it.
I wish I’d never shot this rifle before deciding on whether to cut it. It would be easier not to know what it does at 24” :).
 
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