K31 Reloading help again! Bullets are too big?

[Latigo]

Good moring, Uncle Ray.
Its not meplat position, its the fact that the edge of the meplats are uneven, and that's what can make a difference of 2 to 4 thousandths. If you're indexing on an uneven meplat tip and not indexing on the ogive, you're not going to have the accurate seat depth you're looking for.
Uncle Ray, we seldom use our GP11s. We've equaled and surpassed the GP11s known accuracy and consistency using 175gr Berger VLDs. The VLD is virtually a carbon copy of the GP11 projectile with the same very long nose. Fortunately for me my Dad bought some 5 thousand of them very long ago when the prices were at $17.00 per 100. Those same projectiles are now in the $52.00 to $56.00 per 100! I couldn't afford to do the load data gathering I now do at that price!

This is our projectile prep:

Anything out to 300 we don't necessarily do this, but beyond that range we do.

This is our process. Your's may vary, but this has proven itself for us.

Projectile prep:

We only use Berger VLDs, but Sierra SMKs work really great too. This particular sequence is with a 175 SMK we're loading for a Wilson long range AR10.
Our method is to begin with meplat trimming. We use the Hoover. Buy the sort that indexes on the ogive, not the base of the bullet. That's going to be very important when you cross reference/compare actual seat depth from the ogive to COAL, cartridge to cartridge later.

Untrimmed and uneven meplat



Trimming process.



Trimmed



We then use a Hoover Pointer to reshape and center the hollow point and we taper it down to an opening that's approximately twice the thickness of the jacket wall.

Pointing






Pointed correctly



This is only the beginning of our overall case/projectile prep process.
Thanks for your response, Uncle Ray. My Dad has been in your conutry a number of times in the late 50's when he was still sailing merchant ships.


Latigo

[Bruce_in_Oz]

A timely post.

I am a happy K-11 owner. Last week, a friend picked up a very nice K-31. I made him up some dummy cartridges using Privi brass topped off with projectiles from 7.62 NATO: same recipe as I used for my dummies for my K-11.

Instant jammo!!

Tapped open the bolt and, as you expect, the projectile stayed in the throat. Note that I had used the Lee "Factory Crimp" die to ensure retention of the projectile.

Dropped a cleaning rod fitted with a blunt-ended brass jag down the barrel and out popped the projectile. Sure enough, there were four "grab" marks from the lands about 7mm forward of the cannelure.

What this tells me is that K-31s are throated for a VERY slinky bullet (GPG-11) and the K-11 appears to be set up to accept both the GP-11and the older GP-90/23. This is similar to the situation with SMLEs being throated for the old Mk6 round-nosed cartridge for many years after the Mk7 spitzer came into serice.

I have been using 155gn Palmas in my K-11 for a couple of years now. That is mainly because I use lots of them in .308Win and buy them in bulk packs. As an aside, the deer I put in my freezer two years ago was nailed front-on at 50 yards with a 155 Palma; heart and lungs were very messy. The K-11 sights don't exactly track the Palma trajectory accurately, but for my purposes, they group very nicely. I might give 168 SMKs a whirl soon.

[trooper554877]

for us in Australia,
i use 155 HBC dwyers from the state rifle association but the best is the 155 gn A-max hornady
cheers
NED

[Bruce_in_Oz]

I did a bit more research by loading up a bunch of dummies with the 155 BJD (Dyer) bullet and the Hornady 168 A-Max (with the cute plastic ballistic tip).

Very interesting results.

The A-Maxes were seated out just a few thou short of nominal GP-11 length and the BJDs came up a bit shorter.

The A-Maxes did not engage the lands of the K-31, the BJDs did.

Why?

Ogive differences.

The BJD has a tangent ogive, the A-Max is a secant ogive. Briefly; a tangent ogive is where the ogive blends perfectly at the bearing surface, a secant ogive will show a distinct change from parallel to radiused at an obvious point.

The BJD also appears to have a much smaller radius (not as "pointy") in its ogive than the A-Max.

Guess what? The GP-11 appears to have a secant ogive as well. That seems to explain some of the problems with seating in K-31s.

The next thing it to cook up some loads with the A-Maxes and send them down-range in both the mate's K-31 and my K-11.

The funny thing is that I suspect that the A-maxes will shoot fine in both rifles. The big thing will be the CHANGE in group size, if any, in the K-11. There is quite a bit of bullet jump in the old girl, primarly because it was built when the round-nose was still very much in service and thus it has a long throat.

[Charon]

Or, to bring it all back together for dummies like me, make a round. Stick it in rifle. If it sticks, too long. Shorten it. When it doesn't stick, shoot it.

[Latigo]

By George I think he's got it!! Sorta.

[ptf18]

Heres what I do to find the max ASSEMBLED cartridge lenght of any load for any of my rifles. This measurement does not mean that the cartrige will fit into the magazine and would have to be adjusted accordingly.

I close the bolt on the rifle. I place a cleaning rod down the bore untill it contacts the bolt face. I mark the rod at the muzzle crown.

I remove the bolt. drop whatever bullet I like to use into the chamber and using a wooden dowel push the bullet into contact with the leade of the throat and keep light pressure against the bullet.

I then reinsert my cleaning rod into the barrel and push it into the bore untill it contact the bullet.

I make another mark on the rod and remove the rod. I measure the distance between the 2 marks and that is the MAX lenght of a assembled cartridge with THAT bullet that will chamber into the rifle.

Set yor seating dies accordingly.......

Gee my bad...when I read the entire posting I see others use simalar methods...... Like minds seem to think alike.

[ottoman45]

I found that the easy way to find my OAL for my K31 was to take a fired GP11 brass case and load a bullet in it a bit long. The smaller diameter of the fired GP11 case was the perfect hold for the 308 bullet.

I slowly closed the bolt till it locked.

Opened bolt took measurement and subtracted .010 off it.

This has worked well for 147gr M80 projectiles and both Nosler Custom Comp bullets 155gr and 168gr.

Now once I get it dialed in with IMR4895 I'll be happy shooting the K31 at 1/2 the price of GP11 and Privi

[dvgunner]

You will find that the bore is the right size .308 Really you should check you COL With the cartridge length you have now. The bullet is encroaching in the barrel. Your cartridges are to long. Take recommended COL from your loading manual. Make a dummy round resized brass with no primer. Set the bullet in the case so it doesn't fall out of the case mouth. Then drop it in the chamber and shut the bolt on the round. Then pull back on the bolt retrieve the cartridge from the chamber. Don't let hit the floor. Then check with a mic to get the overall length and then set the bullet back on your reloads .5 .10 or whatever you need for proper feeding and doesen't touch the rifling.

Good Luck
Gunner

[Lone Cypress]

Just picked up my first K31 this week, working on refinishing the beech stock first. Looks like I may be asking a few questions when I start to reload for her. Looks like a ton of useful info. here! Will post pics. when I get her all cleaned up.