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Wayne Smith
04-19-2009, 06:22 PM
I have DeltaEnterprises bottom pour mold that almost exactly fits my K31's. I loaded up 50 of them and only about 5 fired. The rest show no primer contact at all. The rifle is all right, I fired Privi Partizan ammo without problem. The bolt was fully closed. I'm aware ofthat problem.

My best guess is that my Hornaday sizing die is set too low and shoved the sholder back, preventing headspace. Obviously the extractor does not hold the cartridge tight enough for it to fire.

Does anyone know of a solution short of pulling these down, annealing the necks. using my 8mm-06 die to upsize the necks and then resizing with the 7.5 die turned up a bit? Yeah, I know I have to do this trial and error with the rifle in my lap.

Anyone else have a problem with Hornaday 7.5 Swiss dies?

I supose I could just reload with a different boolit! Headspace on that.

jhrosier
04-19-2009, 06:44 PM
...

I supose I could just reload with a different boolit! Headspace on that.

Probably the simplest solution.

The usual caveats about checking for bullets left in the bore if ejecting a loaded round apply.

I wonder if anyone makes a cartridge headspace guage for the 7.5 Swiss?

I suppose that it would be easy enough to remove the firing pin and extractor from the bolt and use the gun to check for interference with a resized but unloaded round. Back the die out a full turn and then run it back in 1/6 of a turn at a time until the bolt closes with no resistance.

Funny you should mention though, most people have a problem getting their die adjusted down enough, not too far down.

Jack

oneokie
04-19-2009, 06:49 PM
Depending on a lot of variables, alloy hardness, how hot the load is, how much crimp was applied to the boolits, one could use a kenetic bullet puller to move the boolit out of the case enough that it would engage the rifling hard enough to resist the strike of the firing pin. Thereby fire forming the case.

Or one could use the hoof nipper, linemans plier, sidecutting pliers to partially pull the boolits to where they would engage the rifling. Do a search for that technique.

Another option is to pull the boolits and remove the crimp, re flare the case mouth, load some boolits backwards so as to engage the rifling.

Wayne Smith
04-19-2009, 06:55 PM
The boolit fits in the bore with very light rifling marks. Only the base was kissed by my .308 sizer. I'll need another boolit.

jhrosier
04-19-2009, 07:09 PM
Wayne,
Howsabout rolling the boolit a couple of turns between a couple of files to raise a little knurl on the straight part of the nose.
You might be able to do this without pulling the boolits.

Jack

TAWILDCATT
04-19-2009, 09:21 PM
try crimping the shoulder with vise or plyers very gently you just want to deform it enuf to hold the case against the bolt.not so you cant close it.then fire and see if there is a diference.you can st the sizing die with that.or if you have an empty back of die and try that case.:coffee:[smilie=1:

JSH
04-19-2009, 10:10 PM
Before you get the pliers file or hammer out, go back to basics.
I am no eggspert on these but have been flustered enough by them that I have learned a thing or two. I would almost bet that the lugs are not FULLY locked into place. I take just enough of the bell out of my brass to chamber, then give the die about anoer 1/4 turn. If your brass has not been trimmed, there may be another issue. I trim mine short. If you are not belling and shave lead or a build up of lube and gunk gets right at the mouth, it will cause problems. If you are crimping, you may be putting to much on it and buldging the case
I had a few odd ball 7.5x55 pieces of brass laying around and neck turned them just enough to take the high spots off. This helped a lot but most folks, me included don't want to do that unless as a last resort.

If your range is at all close or handy, I would take the rifle and your loads out. Load one round in the magzine. Slam the bolt home with a good hard shove. Then with the heel of your hand give it a couple of good hard thumps. I bet it will fire.
I don't know what kind of findings folks have found with the Hornady 7.5x55 dies. I have a set of lee and RCBS. Both are for the early 1911 rather than the K31, they work the **** out of the brass. I did a little looking and thinking the 30-284 is a fairly popular wildcat........I ran across a full set of 30-284 Lee dies, not my first choice, but cheap enough to give them a try, as i had been advised they wouldn't work. Well they work fine, better than the ones labled for the 7.5x55 by some. If I FL size cam over on the shell holder, it will just kiss the shoulder and barely hits anything at the web.
These rifles can be a headache at times, but the return way more than overcomes that.
If you want, pm me and I will call you if that would help you out.
jeff

Rockydog
04-19-2009, 10:33 PM
Try pulling a bullet out of the Privi Partizan and use that to set your sizing die. You'll have to smoke the case, insert the case in the die and turn it down until it contacts the neck, as the neck will be stretched slightly from the bullet being seated. Then back the case out and turn the die in about 1/8th of a turn and, running the case up in the die, check the marks on the smoked neck. Keep going 1/8th at a time until the die hits the shoulder. Lock it down at the point it just kisses the shoulder. Now your ammo should match the privi and fire in your gun. RD

jh45gun
04-19-2009, 11:05 PM
"I am no eggspert on these but have been flustered enough by them that I have learned a thing or two. I would almost bet that the lugs are not FULLY locked into place."

I agree to set up the dies according to parashooter at the swiss site you have to set up your press so the shell holder touches the die when there is a shell in the press. If you do not the shell will not chamber as you do not have the shoulder set back far enough.

This was the info he gave about resizing 284 brass and he has said the same about other brass too when using the press.

Altering the tools is seldom necessary. What is necessary with the tough .284 brass is good lube and adjusting the die to compensate for press spring under load. If there is any gap between shellholder and sizer when actually sizing a case, the die must be screwed farther in until there is no gap under load.

Most folks never look at the junction of shellholder and die. Cases formed with a gap like this aren't going to chamber.


http://telecom.hartford.edu/images/diespring.jpg

leadman
04-20-2009, 12:08 AM
Did you resize any Prizi fired cases with your dies? Might want to compare unfired Prizi to a resized.
Due to variances in tolerances and wear when the die touches the shell holder this could be too much sizing.
You said you were aware of the bolt being fully locked. Did you look at the plate the rear of the reciever on the bolt assembly? Is it touching the receiver?
I've got 2 K31s and anything keeping that plate from touching the receiver will cause them to not fire. If your boolits are engaging the rifling when the bolt closes you may want to seat them a little deeper.
Midway sells a very inexpensive kit to use with a cleaning rod to determine overall length with different bullets, cast or jacketed. This has made an amazing difference in the reliability and accuracy of my reloads. The same thing can be done with tape and a cleaning rod.
Also, my K31s don't like boolits more than .001" over bore diameter. My best loads have boolits sized to .3085".

VintageRifle
04-20-2009, 12:31 AM
Your die set could also be put together wrong from the factory. Stamped one cartridge but actually another. I have heard of and seen sizing dies with the wrong internals before.

Another thing, check to make sure you bolt is assembled correctly and there are not damaged parts.

There is also the possibility that the bolt appears to be closed, but is not. It looks closed, but the cam follower is not fully forward (Serial Number can still look like it is at top dead center). Check this before you fire the rifle. If the cam follower is not flush with the back of the bolt, it will not fire.

Wayne Smith
04-20-2009, 10:52 AM
Unfortunately the range is just under an hour away and other responsibilities keep me home many weekends. In the meantime I can pull some boolits, make some changes, and see if the primer fires.

atr
04-20-2009, 11:51 AM
Wayne,,,
if there is oil buildup on the shoulder when you formed the brass in the die, then that thin film of oil will act to push the shoulder back just enough (in some chambers) so that the headspace will be affected and the case will be off just enough that the firing pin will not strike the primer properly.

Maven
04-20-2009, 12:13 PM
"I agree to set up the dies according to parashooter at the swiss site you have to set up your press so the shell holder touches the die when there is a shell in the press. If you do not the shell will not chamber as you do not have the shoulder set back far enough. This was the info he gave about resizing 284 brass and he has said the same about other brass too when using the press."

jh45gun, Parashooter's advice is correct when forming .284Win. brass into 7.5 x 55mm brass for the K-31. However, after they are formed and fire-formed, you can back off the FL sizing die enough to leave ~1/16" shoulder at the neck-shoulder junction of the [fired] case. I do this with all K-31 brass as well as others that I don't neck size and have never had a problem chambering them, especially in both of my K-31's.

725
04-20-2009, 02:30 PM
Probably one of the most common problems with the K-31. Size the brass enough and check the bolt when closed to ensure it's in battery.

Wayne Smith
04-28-2009, 03:07 PM
I pulled one of the boolits and tried to pop the primer, no luck. Just for grins I tried the same cartridge in my other K31 - POW!

I think I have a rifle problem, I need to pull that bolt down.