Page Index Toggle Pages: 1 [2]  Send TopicPrint
 25 Krag Bore Size Question (Read 5780 times)
Texas10
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 71
Location: Austin,
Joined: Aug 4th, 2015
Gender: Male
Re: Krag Bore Size Question
Reply #15 - Dec 24th, 2019 at 4:39pm
Print Post  
You may be right. I used the method described above using a 00 buckshot. I lubed the shot with Hobo Oil and wiped the excess off before driving into the muzzle. I was surprised as to how easy it was to push out after it was about 4 inches down the barrel.

I performed this twice. The first time the shot came out distorted, so I tossed it and tried again.

I'll try it again and select a better looking, less distorted shot I've pulled from a 12 ga shell. I have the exact same micrometer pictured, and have standards I've check accuracy with.

May do a few other barrels too.
  
Back to top
 
IP Logged
 
Texas10
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 71
Location: Austin,
Joined: Aug 4th, 2015
Gender: Male
Re: Krag Bore Size Question
Reply #16 - Dec 26th, 2019 at 7:15pm
Print Post  
I repeated the slugging process and confirmed that the bore is .300 and grooves are .306 to .3065

If it is supposed to be .308 I guess this would explain my first observation that a jag and patch combination that worked well in my 308, but does not fit into the krag, is due to the bore being slightly smaller.
  
Back to top
 
IP Logged
 
Whig
KCA Official Member
***
Offline


Krag Enthusiast!

Posts: 1324
Location: Balt MD
Joined: Sep 24th, 2016
Gender: Male
Re: Krag Bore Size Question
Reply #17 - Dec 26th, 2019 at 8:16pm
Print Post  
Unless it's been answered and I missed it, I'll ask again. Are you sure that this is an original barrel on your Krag? Many have been changed. You can't always tell from the front sight base.
  
Back to top
 
IP Logged
 
madsenshooter
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 1079
Joined: Sep 10th, 2009
Re: Krag Bore Size Question
Reply #18 - Dec 26th, 2019 at 9:04pm
Print Post  
Nothing wrong with a smaller groove diameter, if indeed that's what you have.  I very regularly shoot .308 bullets out of my Swiss K31.  It has a .294" bore and .3055" groove diameter and is perhaps the most accurate milsurp rifle I have.  The bullets will swage down to the diameter they need to, once the pressure starts rising.  I generally anchor the push out rod to the floor and hit the rod I'm pushing the ball in with so that the ball is smushed out into the grooves, making sure you get the full diameter.  You ought to be getting the full diameter with the .33" OO.
  
Back to top
 
IP Logged
 
Texas10
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 71
Location: Austin,
Joined: Aug 4th, 2015
Gender: Male
Re: Krag Bore Size Question
Reply #19 - Dec 27th, 2019 at 8:51pm
Print Post  
@Whig,

Although I have no reason to suspect an aftermarket barrel was fitted at one time, because it's been sporterized there remains the possibility that it has. What I can tell you is that the blued barrel is 22 inches long, and a Pacific front sight soldered on. Bluing was removed for that work and was not replaced. The sight is clocked slightly to port.

There are two holes, drilled and tapped on the top of the barrel, and a dove tail machined into the barrel for an iron sight, but has been filled with lead.

There are stamped marks on the breech consistent with what I've read.

I shot it today at 100 yds using handloads consisting of new Winchester brass, CCI 200 primers, 40 grs of IMR 4350 and 220 gr Hornaday round nose, and it shot well putting 5 in the 10 ring once I got used to the peep sight.
« Last Edit: Dec 27th, 2019 at 11:17pm by Texas10 »  
Back to top
 
IP Logged
 
Texas10
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 71
Location: Austin,
Joined: Aug 4th, 2015
Gender: Male
Re: Krag Bore Size Question
Reply #20 - Dec 27th, 2019 at 8:59pm
Print Post  
@Madsenshooter,

The 00 buckshot ball got shaved a bit being forced into the muzzle, with a ring of lead hanging off the rear as it was tapped down 3 inches or so. Wise to the issue of rotation now, I made sure it was driven out carefully, which by the way, was quite easy to do. Easy push with a hardwood dowel.

Barrel was clean and oiled for the test.

Cleaning today after range time, I once again found differences in patch/jag size compared to my 308 barrels, but finding a good patch combination to produce a tight fit was not a problem.

Cleaning with Ed's Red first, to be followed with a borescope examination for copper.

  
Back to top
 
IP Logged
 
Whig
KCA Official Member
***
Offline


Krag Enthusiast!

Posts: 1324
Location: Balt MD
Joined: Sep 24th, 2016
Gender: Male
Re: Krag Bore Size Question
Reply #21 - Dec 28th, 2019 at 12:13am
Print Post  
Thanks for the info and pictures. I have never seen those markings on a Springfield Armory barrel- the numbers on the chamber face of the barrel. It also looks to have an old dovetail cut behind the rear sight screw holes. I suspect it is not an arsenal barrel and may have been made with slightly different bore rifling cuts. That could answer the unusual measurements you got.

It's great to hear, though, that you are getting it to shoot well. Lots of fun with a Krag in almost any condition!

Keep up the good work.
  
Back to top
 
IP Logged
 
Texas10
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 71
Location: Austin,
Joined: Aug 4th, 2015
Gender: Male
Re: Krag Bore Size Question
Reply #22 - Dec 28th, 2019 at 4:39am
Print Post  
Almost forgot to post pic of target. IF there's no pic, it didn't happen. Wink

This shot closest to center of bull was from previous 3 rounds while I adjusted windage on the Peep.
  
Back to top
 
IP Logged
 
butlersrangers
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 6330
Location: Michigan Bi-Peninsular&Proud
Joined: Oct 7th, 2009
Re: Krag Bore Size Question
Reply #23 - Dec 28th, 2019 at 5:11am
Print Post  
Promising group! Now go shoot more of them and stop 'futzing' like a Bench Rest Shooter.

FWIW - An original Krag barrel will have an 'index mark' at the "9 O'clock" position and a "P" (proof) mark.
  
Back to top
 
IP Logged
 
Texas10
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 71
Location: Austin,
Joined: Aug 4th, 2015
Gender: Male
Re: Krag Bore Size Question
Reply #24 - Dec 28th, 2019 at 10:36pm
Print Post  
I pulled the action from the stock to look for any proof stamp, but did not fine one.
  
Back to top
 
IP Logged
 
Texas10
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 71
Location: Austin,
Joined: Aug 4th, 2015
Gender: Male
Re: Krag Bore Size Question
Reply #25 - Dec 28th, 2019 at 10:37pm
Print Post  
Here is what I did find, a letter I and an O.
  
Back to top
 
IP Logged
 
Texas10
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 71
Location: Austin,
Joined: Aug 4th, 2015
Gender: Male
Re: Krag Bore Size Question
Reply #26 - Dec 28th, 2019 at 10:38pm
Print Post  
I am also including a pic of the inspector stamps on the action
  
Back to top
 
IP Logged
 
butlersrangers
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 6330
Location: Michigan Bi-Peninsular&Proud
Joined: Oct 7th, 2009
Re: Krag Bore Size Question
Reply #27 - Dec 29th, 2019 at 5:04am
Print Post  
Texas10:

FWIW - I believe your barrel is an original Krag barrel, (with some alterations - shortened, commercial front-sight, and 'dovetailed' at one time for a commercial rear-sight).

I think the "I", on your barrel, may actually be a poorly stamped "P". Your action and barrel reveal armory index marks.

I played a bit with you photos:
« Last Edit: Dec 29th, 2019 at 6:14am by butlersrangers »  
Back to top
 
IP Logged
 
madsenshooter
KCA Forum Member
*
Offline


Krag Enthusiast!

Posts: 1079
Joined: Sep 10th, 2009
Re: Krag Bore Size Question
Reply #28 - Dec 29th, 2019 at 2:46pm
Print Post  
Looks original to me, that's for sure a poorly struck P.
  
Back to top
 
IP Logged
 
Page Index Toggle Pages: 1 [2] 
Send TopicPrint