K-31 Ka-boom
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NavyShooter
CGN Ultra frequent flyer
- Location
- XMU Local .303
Bah,
The swiss should go back to watches and chocolate.
They should send all their poorly built rifles to me.
(I have a feeling I'll be waiting for a LONG time for them to arrive...)
NS
The swiss should go back to watches and chocolate.
They should send all their poorly built rifles to me.
(I have a feeling I'll be waiting for a LONG time for them to arrive...)
NS
Perhaps the K31 may not be the best design in the event of a case failure. Given the quality of G11 ammunition this is a non-issue with this ammunition. There are other rifles, many very well known, that do not perform well in the event of cartridge case failure.
I suppose that anytime any rifle is used with handloaded or non-standard ammunition, the shooter must be aware of possibilities.
Fortunately no one suffered serious harm.
Barrel dimensions - bore diameter and groove diameter - is 7.5 Swiss actually a "tight" .30 according to actual measurement? Standard is .300 x .308, what is the Swiss? Of course, throat and leade dimensions are more significant.
I suppose that anytime any rifle is used with handloaded or non-standard ammunition, the shooter must be aware of possibilities.
Fortunately no one suffered serious harm.
Barrel dimensions - bore diameter and groove diameter - is 7.5 Swiss actually a "tight" .30 according to actual measurement? Standard is .300 x .308, what is the Swiss? Of course, throat and leade dimensions are more significant.
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No, only what little gas might escape around the bolt and into the raceways.
Tiriag is right. The K31 is not for fast powders. Ariskas maybe.
But it is great at what is is designed for, jacket bullets, rifle powders, high BC bullets, and decent long range accuracy at reasonable pressures.
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Here is a reply from CDXfire, who has been shooting matches with cast bullets in K31s longer than I've know they existed.
"Depending on what the intended charge of 2400 was, a double charge could likely cause that much damage without any other contributing factors. A double charge with insufficient clearance for the case neck to expand and release the bullet is a sure guarantee for disaster. (hindsight is always 20-20).
When I was a kid, my local dealer had the pieces of a 7x57 Mauser that had self-destructed with a double charge of 2400. It looked like a low-number Sprinfield failure. (Gee, does that mean that I should hang all of my Mausers on the wall and never fire them again??)
The reason(s) that I settled on 15 grains of 2400 behind the Ideal 311291 in 30-06 is that the old Lyman manual that I had at the time listed the maximum charge for that combination as 30 grains; thus I reasoned that a double charge should not damage anything. (And I don't have to move the small poise on the scale arm. I am inherently lazy) The newer Lyman manual shows the maximum charge for that combination as 29.5 grains with a pressure of 43,100 CUP. OTH, if I was loading 20 grains and double charged; 40 grains would probably be a bomb.
My favorite (and very accurate) cast load for the K31 is the Lee C312-155-2R with 14 grains of 2400, bullet sized to .308 or .309, depending on which rifle it is going in. Again, I theorized that a double charge would not do damage, but I am not anxious to test that theory. 2400 is a great powder, but the high nitroglycerine content will push the pressure spikes very high very, very fast near "the top end".
Resp'y,
Bob S.
"Depending on what the intended charge of 2400 was, a double charge could likely cause that much damage without any other contributing factors. A double charge with insufficient clearance for the case neck to expand and release the bullet is a sure guarantee for disaster. (hindsight is always 20-20).
When I was a kid, my local dealer had the pieces of a 7x57 Mauser that had self-destructed with a double charge of 2400. It looked like a low-number Sprinfield failure. (Gee, does that mean that I should hang all of my Mausers on the wall and never fire them again??)
The reason(s) that I settled on 15 grains of 2400 behind the Ideal 311291 in 30-06 is that the old Lyman manual that I had at the time listed the maximum charge for that combination as 30 grains; thus I reasoned that a double charge should not damage anything. (And I don't have to move the small poise on the scale arm. I am inherently lazy) The newer Lyman manual shows the maximum charge for that combination as 29.5 grains with a pressure of 43,100 CUP. OTH, if I was loading 20 grains and double charged; 40 grains would probably be a bomb.
My favorite (and very accurate) cast load for the K31 is the Lee C312-155-2R with 14 grains of 2400, bullet sized to .308 or .309, depending on which rifle it is going in. Again, I theorized that a double charge would not do damage, but I am not anxious to test that theory. 2400 is a great powder, but the high nitroglycerine content will push the pressure spikes very high very, very fast near "the top end".
Resp'y,
Bob S.
Love my k31 but reloading for it always makes me a little nervous due to on how deep I have to seat a bullet into a case for proper chambering. Tight neck and short throat they are. Swiss GP 11 round measures 3.041 OAL. and the bullet dia. neck is .304, a wolf gold 174 gr. round measures 2.997 OAL. and .305 dia. at the neck. Using 168 gr. HORNADY match I had to seat the bullet to a OAL. of 2.850 with bullet DIA. at neck of .306 to make this rifle chamber and make it go bang. Pushing a 168 gr. bullet that far into the case just does not seem proper. (the deeper you seat pressures go up correct ?) My next step is cast bullet try outs with gun in one piece afterwords.
That's one of the reasons why powder charge goes down as bullet weight goes up. Same charge of a powder and bullet weight in .308 and 7.5x55 give higher pressure in the .308 due to less internal volume in the .308.
No big deal
Bullet Ogive is the deciding factor in finding the A.O.L for that caliber and bullet combination.
http://www.larrywillis.com/bullet-shape.html
Nice article about bullet ogive.
Wonder why Bergers bullets are more expensive?
No big deal
Bullet Ogive is the deciding factor in finding the A.O.L for that caliber and bullet combination.
http://www.larrywillis.com/bullet-shape.html
Nice article about bullet ogive.
Wonder why Bergers bullets are more expensive?
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Thanks Slug for parting with the rifle.
It looks like the bolt was not locked up. Stud on operating rod must have sheared off upon closing the action. See how the case seems to have flowed a bit to fill in a gap.
http://news.webshots.com/slideshow/568637838dtAdYb;jsessionid=abckycm6PHBh99p5GLu2r
There is a machined cut-out on the right side of the barrel threads into the raceway for the operating rod.
Venting? Acted that way it seems.
Operating rod is CV, not CN or CM.
Notice heart shape stamp on receiver block close to where front action screw sheared off.
It looks like the bolt was not locked up. Stud on operating rod must have sheared off upon closing the action. See how the case seems to have flowed a bit to fill in a gap.
http://news.webshots.com/slideshow/568637838dtAdYb;jsessionid=abckycm6PHBh99p5GLu2r
There is a machined cut-out on the right side of the barrel threads into the raceway for the operating rod.
Venting? Acted that way it seems.
Operating rod is CV, not CN or CM.
Notice heart shape stamp on receiver block close to where front action screw sheared off.
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aftermidnight
CGN frequent flyer
- Location
- West Kelowna BC
picture link is not working.
maple_leaf_eh
CGN Ultra frequent flyer
And now I understand better why my Parisien Match 7.62x51 to 7.5x54 MAS conversions had such a snap on the ejection cycle. The powder has more room to expand and build up pressure.
