K31 7.5x55 question

[offthepaper]

I just got back from the range to shoot my 1st reloads, 7.5x55 Swiss for my K31. I used Privi Brass (once fired), 41gr of H4895, using a 150gr Honady FMJBT, cci 200 primers.
This was my 1st attempt at reloading, so as you can imagine I was more than a little disappointed when my rds failed to fire, no marks on the primer at all. They seemed to chamber in the rifle fine, but the FP doesn't seem to be reaching them. I had a couple of rds of GP11 with me that fired fine, so it's not a question of malfunction with the rifle.
What do you guys think?

 

[NCsmitty]

You may have set your shoulder back with your die, creating too much headspace on the cartridge. Compare the fired GP11 cases to the reloads for case dimensions.

NCsmitty

 

[lonniemike]

More likely the cases weren't resized enough and/or the cartridge OAL is to long. Pull a projectile and see if just the cartridge case will go into full battery(no bullet or powder). ?They seemed to chamber fine? You did slam the operating rod fully forward and did check for no space left in the operating rod slot, or verify that the bolt's serial numbers were straight up in the 12 o'clock position before you pulled the trigger, right. Even a really oversized case should not fail to fire assuming the 31's cartridge OAL will allow the bolt to close completely. best-o-luck

 

[R.W.Dale]

More likely the cases weren't resized enough and/or the cartridge OAL is to long. Pull a projectile and see if just the cartridge case will go into full battery(no bullet or powder). ?They seemed to chamber fine? You did slam the operating rod fully forward and did check for no space left in the operating rod slot, or verify that the bolt's serial numbers were straight up in the 12 o'clock position before you pulled the trigger, right. Even a really oversized case should not fail to fire assuming the 31's cartridge OAL will allow the bolt to close completely. best-o-luck

This is most likely the correct answer, especially in light of the firearm used. In both rifles I owned when using Lee dies if the FL die wasn't screwed in HARD against the shellholder I would end up with the results you mention.

 

[mccook8]

Redding FL sizing dies are the ONLY ones designed to match the K31 chamber.

I've sized them too much before, and ended up with weird-looking shoulders.

I've had rounds that failed to fire the first time, but did fire when I reseated them in the chamber.

Check your cartridge OAL.

Take a gander at this page:

http://www.swissrifles.com/ammo/reload1.htm

 

[NuJudge]

If, when the bolt is in the forward position, the serial number is not visible on top of the bolt, your bolt is not fully closed. The case, or the bullet, or both, can cause this. If the bolt is not fully closed, the energy of the striker falling will first be used to attempt to close the bolt all the way, before the firing pin is allowed to contact the primer.

When people here say your cartridge OAL may be too long, they are referring to the fact that on most barrels the rifling comes right back to the case neck, and if the bullet does not taper immediately ahead of the cannelure it will be jammed into the rifling, resisting bolt closure. This can be cured by seating bullets deeper, or using a more tapered bullet.

The K31 rifles have tight and loose chamber dimensions at the same time. The dimension from boltface-to-cartridge shoulder (headspace) is really tight, but the side-to-side dimension is really loose (everything is different on the 1911 and earlier rifles).

Screw your sizer die down until it contacts the ram, then screw it down another 1/4 turn. This causes the press to go slightly beyond Top Dead Center, spoken of as "camming over."

Assemble a dummy cartridge without primer and powder before assembling a lot of live rounds. Insert it into the magazine, and feed it into the chamber. If the bolt's Serial number is not on top, you know you have a problem.

CDD