.22 Rimfire Benchrest Barrel Length

J

John W...ski

Guest
I have a Turbo action on its way and a Shilen 16" twist ratchet HV barrel. The barrel blank measures 28 1/2", so i figure I can get a finished 26" barrel maybe a little more.

Does anyone have any recommendations for the finished barrel length on this build? Please feel free to elaborate with your reasons.

Thanks,

John
 
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John W...ski said:
I have a Turbo action on its way and a Stiller 16" twist ratchet HV barrel. The barrel blank measures 28 1/2", so i figure I can get a finished 26" barrel maybe a little more.

Does anyone have any recommendations for the finished barrel length on this build? Please feel free to elaborate with your reasons.

Thanks,

John
Click to expand...

I strive for a finish length of 26.500". Mainly use .900" straight, 16 twist blanks and have had better success tuning 26 1/2" length barrels. Nothing scientific ... just personal experience and preference.

John

PS: Did you possibly mean "Shilen" 16" twist ratchet?
 
John W...ski said:
I have a Turbo action on its way and a Stiller 16" twist ratchet HV barrel. The barrel blank measures 28 1/2", so i figure I can get a finished 26" barrel maybe a little more.

Does anyone have any recommendations for the finished barrel length on this build? Please feel free to elaborate with your reasons.

Thanks,

John
Click to expand...

John,

I know better than to say this but in an attempt to be helpful I'll do it anyway. Barrels must be crowned at the smallest, roundest place in the barrel. To find that place you will have to slug the barrel many times. (push bullets in, and out of the bore, and measure).

You can't make the barrel any longer than it will let you. Barrel length means very little, if anything to accuracy. But if you don't crown it in the right spot you will not get the best out of the barrel that it has to offer.

TKH
 
center22 said:
I strive for a finish length of 26.500". Mainly use .900" straight, 16 twist blanks and have had better success tuning 26 1/2" length barrels. Nothing scientific ... just personal experience and preference.

John

PS: Did you possibly mean "Shilen" 16" twist ratchet?
Click to expand...

You are absolutely correct, it is a Shilen, I have corrected my post. Thanks
 
tonykharper said:
John,

I know better than to say this but in an attempt to be helpful I'll do it anyway. Barrels must be crowned at the smallest, roundest place in the barrel. To find that place you will have to slug the barrel many times. (push bullets in, and out of the bore, and measure).

You can't make the barrel any longer than it will let you. Barrel length means very little, if anything to accuracy. But if you don't crown it in the right spot you will not get the best out of the barrel that it has to offer.

TKH
Click to expand...

Thanks, that is the kind of reply I am looking for. I have heard and read about slugging the barrel before and agree it makes sense. John
 
Do a search. There is plentiful info as to How/why/where you locate the crown in the location tony has given you.
 
Thanks Guys

I slugged my barrel several times, thought a it over and slugged it several more times. Thought about it some more and read what Bill Calfee had to say about determining barrel length. I then slugged
my barrel several more times and am now confident on where I want to put the crown. Thanks for the input, it was just what I was looking for.

John
 
There must be a learning curve

John W...ski said:
I slugged my barrel several times, thought a it over and slugged it several more times. Thought about it some more and read what Bill Calfee had to say about determining barrel length. I then slugged
my barrel several more times and am now confident on where I want to put the crown. Thanks for the input, it was just what I was looking for.

John
Click to expand...

when it comes to slugging barrels, because I have tried it a number of times and find that I do not posses the ability to feel the tightest spot. With the resistance involved and the pressure required to push the bullet through, I can't tell, really, where the tightest spot is. Perhaps I haven't done it enough but - - -. Perhaps someone will find it in their heart to tell we heavy handed or weaklings how to improve this slugging thing?????

:)

Pete
 
Pete Wass said:
when it comes to slugging barrels, because I have tried it a number of times and find that I do not posses the ability to feel the tightest spot. With the resistance involved and the pressure required to push the bullet through, I can't tell, really, where the tightest spot is. Perhaps I haven't done it enough but - - -. Perhaps someone will find it in their heart to tell we heavy handed or weaklings how to improve this slugging thing?????

:)

Pete
Click to expand...

I didn't do it by feel, I measured the slugs at 1/2" increments. The truth is I measured the first few inches from the breach then started measuring at around 25" from the breach. The barrel I have was still getting smaller in size until nearly 27-1/2" from the breach. I measured the smallest spot and marked the barrel.

Good luck,

John
 
I know nothing about slugging a barrel having never even attempted it. So, take this for what its worth which is absolutely nothin'.
If the muzzle has choke isn't wherever you cut it the tightest spot?? Is .030 shorter or longer gonna make that much difference when we're taking about 1/10ths?

Keith
 
linekin said:
I know nothing about slugging a barrel having never even attempted it. So, take this for what its worth which is absolutely nothin'.
If the muzzle has choke isn't wherever you cut it the tightest spot?? Is .030 shorter or longer gonna make that much difference when we're taking about 1/10ths?

Keith
Click to expand...

I suppose you could refine the measurements down to what ever spacing you wanted, I chose to do measurements at 1" intervals from the breach, I only went the first 3" and found a slight taper already starting to develop. I didn't worry to much about the middle, and started my measurements again at 25" from the breach end and measured at 1/2" intervals, the diameter was slightly smaller and the taper continued, in my mind validating my decision to skip the measurements in the middle of the barrel. at about 27-1/2" from the breach end I measured my smallest diameter, 1/4" further the diameter was .00005 out of round and getting bigger, a further 1/4" and the diameter was still opening up. Depending on what my gunsmith cuts off at the breach end I am expecting a finished barrel that will be between 26" and 27" long, hopefully not as short as 26".

I agree .030 shorter or longer will not affect anything except maybe by luck ending at a better spot that is more aligned with the barrel harmonics. The amount of taper is very small, only .0002" for the whole distance so anywhere shorter than the smallest spot would work.

John
 
Pete Wass said:
when it comes to slugging barrels, because I have tried it a number of times and find that I do not posses the ability to feel the tightest spot. With the resistance involved and the pressure required to push the bullet through, I can't tell, really, where the tightest spot is. Perhaps I haven't done it enough but - - -. Perhaps someone will find it in their heart to tell we heavy handed or weaklings how to improve this slugging thing?????

:)

Pete
Click to expand...

Far be it for me to suggest to the internets leading gun wrangler but perhaps, Pete, you might want to measure the slugs, as in push them partially in....mark the spot......reverse it back out and mic them to see what's actually going on in there.

If you lnduldge in home lapping remedies and state you cannot feel what you're doing and do not measure what you're doing....uh.....how in the hell do you know what you did to the bore ???
 
John W...ski said:
I suppose you could refine the measurements down to what ever spacing you wanted, I chose to do measurements at 1" intervals from the breach, I only went the first 3" and found a slight taper already starting to develop. I didn't worry to much about the middle, and started my measurements again at 25" from the breach end and measured at 1/2" intervals, the diameter was slightly smaller and the taper continued, in my mind validating my decision to skip the measurements in the middle of the barrel. at about 27-1/2" from the breach end I measured my smallest diameter, 1/4" further the diameter was .00005 out of round and getting bigger, a further 1/4" and the diameter was still opening up. Depending on what my gunsmith cuts off at the breach end I am expecting a finished barrel that will be between 26" and 27" long, hopefully not as short as 26".

I agree .030 shorter or longer will not affect anything except maybe by luck ending at a better spot that is more aligned with the barrel harmonics. The amount of taper is very small, only .0002" for the whole distance so anywhere shorter than the smallest spot would work.

John
Click to expand...

While it is by no means common, you'd be advised to reconsider forgetting about the middle of a blank.
More than a few turned up over the years that ended up being big in the middle and, for instance, allowing gas blow by. Now, not real common, why not check it because should you ever get one, nothing near the muzzle will rectify the issues that took place in the middle.
In a perfect world you want a steady, progressive taper, without jumps in dimension.
 
Hey Tim

Tim
Go Back To The Private Message i forwarded to you, That proclaimed to be an expert with a slugging rod and a bore scope. is now asking how to do it.
He that posts BS is just that!!!!!!!!!!.
 
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