K31 Reloading help again! Bullets are too big?

[Latigo]

I certainly appreciate your 50 years, knowledge and awards, but in the case of any hollowpoint projectile that method leaves a lot to be desired unless you're meplat trimming and pointing every projectile.
Meplats are seldom the same and mostly always irregular by more than a couple of thous.
There's certainly a faster, better method. I'm betting you already know what that is.
Indexing on the ogive is critical for long range shooting. The cartridge OAL means nothing to me at all.

Latigo

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[Patrick Chadwick]

The cartridge OAL means nothing to me at all.

Well it will if you can't get the cartridge into the magazine

Seriously, neither Uncle Ray's Q&D method not my SbP method will give the answer to the last thou, and I have seen myself how meplats vary. I already pointed out that even with the excellent Lapua Scenars the OAL varies with a spread of about 4 thou - for that very reason - the RCBS competition seater is indeed indexing on the ogive, as do most (I'm not going to bet on all ) top punches (odd name, one doesn't punch with it). However, we all refer to OAL, and you are right to point out that that is not what we really mean (or ought to mean?).

But these methods put you quite close for a good first approximation. When I have made such a measurement, I seat the very same bullet in an empty case with the top punch screwed right out, and then by trial and error screw down the top punch and re-seat it until the OAL is about 20 thou longer than the SbP measurement. I then "paint" a black ring around the bullet with a felt marker pen, let it dry, and then reload the case in the rifle. When the cartridge is removed, the forcing cone, lead, transition, throat or whatever you like to call it will have made tiny marks at the contact points. Again, reseat a couple of thou deeper, paint and repeat, until no marks are produced. At this point the seating of THAT bullet is such that it is just off the lands.

As already remarked, since every mechanical item has tolerances, I like to take that setting and back off 8-10 thou (.2 - .25mm) for the final setting. For BPCRs I make that 20 thou, because of the fouling that builds up in a competition where you cannot thoroughly clean the rifle between shots.

If you like, you can go for 5 thou or even less. It depends how much confidence you have in your equipment. But on simple mechanical considerations, a seating clearance that varies from say 8 to 12 thou is going to cause less shot-to-shot pressure variation than one that varies from +2 (i.e. just free) to -2 (i.e. cammed into the lands).

Patrick

[Latigo]

Yup. Mostly what I do.

Latigo

[Patrick Chadwick]

... is the head space. Or, to be more precise, the head clearance, i.e. the end play or "slop" of the loaded cartridge. Let us say you have a real service rife, not a bench rest construction. It will have a head clearance of say, 6-8 thou. So what happens when you fire that cartridge?

The firing pin rams the cartridge right up the chamber until it stops, and then continues to detonate the primer.
- So your bullet just got 6-8 thou closer to the lands.
Now the prime ignites the powder, the case expands to grip the wall, the base moves back, causing the cartridge stretch that bothers head-space worriers in the first place.

But what happened to your "just 3 thou off the lands" seating.
It went to zero, that's what. And your bullets were jammed into the thoat before the powder was properly ignited.

And now you know why I seat my bullets in a fashion that some may consider over-conservative.
And why I only use neck-sized cartridges that have been fired in the same rifle.

Feel free to comment, disagree, and correct. But reasoned argument please!

Patrick

[Latigo]

Patty, me boyo........ Are you talking about a k31?

Latigo

[Uncle Ray]

Well, I can't disagree with either Patrick's of Latigo's approach for a different reason. Yes; I'm aware that there is a variation in meplat location.But give what I wrote some thought; I AM indexing the projectile on the meplat. If the bullet cannot proceed any further into the bore, then what is stopping it?.

My next step is to set up a dummy round in the bullet seating die, and using the same projectile placed loosely in the sized case. I gradually wind down the seating screw, checking the overall cartridge length until the O/A length corresponds with what was measured, minus two thou.for the straight-pull. This gives me my O/A length for that particular profiled bullet.

My local range is limited to 300 metres, and when shooting at this range on the old ISU Olympic target with a 10cm (3.94") "10" ring, the projectiles I use on this target are batched for uniform weight, and meplat location (yes, even the Lapua scenars vary), and of late I have been using the 155gn HBC-BJD (Dyer MKII) projectile produced in Darwin, Australia, due to this bullet's greater uniformity AND accuracy over the other match projectiles. This is my choice for use in my K.31, and other 30.cal. rifles, and yes; it has a hollow point.

Here I should clarify one thing. All of my competitive shooting is single-shot; no magazine-loading. Because of the short distance I shoot, I don't worry about closing the hollow point; that's not critical in my situation. As I previously said, the "Stick and Pencil" method is all I need. If you are shooting 1,000yds or more, that is a different story, for other reasons.

But while we are mentioning hollow-points, let's think about this. Is every K.31 or earlier model shooter on this forum endeavouring to go to all this trouble if all he wants to do is shoot occasionally at 100 or 200 yards? If he belongs to a Military Rifle Club which requires him to shoot rapid as well as slow-fire, he does not really need to go to the effort as described above, including Latigo's & Patrick's suggestions. I am aware that some military rifle clubs will only allow FMJ projectiles. The Prvi Serbian 174gn is one we use in Australia, being the cheapest.

The critical things to remember (as previously mentioned) is (1) not to jam the bullet into the rifling, and (2) make sure that when loading the bullet into the case, the die is properly set up to ensure that a slight bulge does not occur on the case at the junction of the shoulder with the wall of the case.
Now these comments are not mentioned to draw a rebuff from either Latigo or Patrick, who are both experienced reloaders, but Newbie's to this game need to be eased into reloading for the K.31 at ground level, that means starting off with cheap SP bullets, or 30 cal. military projectiles, then working their way up if they want to go further.

We could confuse them at this stage by introducing meplats, G1 BC's V's G7 ballistic co-efficients, VLG's, "transonic" velocities, and so on. That is the best way to put a new shooter off reloading. The K.31 will group very well with the Remington 180gn round-nose, soft point, flat-based garden-variety projectile out to 200+ yds; ideal for a newbie to start off with, and cheap, too; as is the Serbian .30 cal. military projectile.

In 1960 a British .303" No.4 properly bedded target rifle fitted with an aperture sight, and shot from a rest was considered excellent if it could put 10 shots into one and a half inches with military ammunition at 100 yards. We have come a long way since then with projectiles, and powder. This led to hand-loading producing for the price, a better alternative to factory ammunition - which in itself is OK for the casual shooter.

My K.31-as issued, made in 1941 will put 10 shots into one and a half inches, bench-rest,when loaded with the 180gn Rem. Do we need to spend a fortune on projectiles only to shoot at 100 or 200 yds? The answer is NO. Powder load and seating depth is more important for shooting at the short ranges.

In Australia we have never been blessed with military-issue GP11, hence our handloads. Latigo; you are lucky that you are down to your last 3,000 rounds. Don't shoot 'em all off at once!

[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.