You have to laugh

[10x]

I had a chance to mold up a few lead heads over the weekend.
I'm using the NOE 316299 mold, they have dropped out at .3155.
Below is one that I've used to slug the bore with.
This weekends task is to make some ammo up.

10X your idea of using the case trimmer as a pilot is golden.
You're on the money with that plan, cheers.

Thank you.
There was a time when I asked my boss why he gave me the worst, most complicated jobs that we ran into. His reply "When I see a difficult job I give it to the laziest man on the crew. He will figure out the fastest and easiest way to do it." And I am proud of that...

[Pup]

I went down to the range yesterday, full of hopes.
I had loaded a variety of charges for the largest head that I can mold.
This is a .3155 from the NOE mold 316299.
The range of powders that was used is TU2000, Reloader 7 and GM3.
I had high hopes for the larger head with a larger TU2000 charge.
As you can see from the cards below, no change.
I fired off the first group of 5 and thought that I should have another go at the crown.
Thanks to 10x, this is now easily done at the range with a manual cutter.
After a quick re-cut and clean, I had another go.
As you can see, they all consistently tumble in a group, so this gave me some form of hope.
Anyway, I went through the TU2000 loads then the Reloader 7, with the same results.
My last hope of a good grouping was with the GM3, this is a much faster burning powder, so I didn't expect a lot from a rifle.
But, as you can see from the last card, I have a "no tumbling" grouping.
RESULT.

At least I have a starting point for a future load.

I would like to thank everyone for their comments and advice.
You have provided some good ideas and yes, I will still save the paper patching for the future, if needed.


Pup

[10x]

Check the diameter of the rifling at the muzzle.
My Mk III Martini with a 303 barrel had to be turned back almost 3/8" before I reached rifling that was not washed out (worn) by over a hundred years of cleaning rods.

If you can, get some 0.318 bullets and shoot them as cast.

Did you slug your bore? If so what is the diameter.
Slug the chamber mouth as well, and slug the portion of the bore at the muzzle if you can to make sure the rifling is not washed out by a cleaning rod.
These guns can be made to shoot cast bullets extremely accurately with 2" or less groups if you get the loads right.

The fact that a powder change stopped the tumbling is interesting. I suspect this lower pressure at the muzzle and you have some issue with the rifling in the last 1/4" or so.
measure that last 1/2 inch of rifling carefully. If it shows any sign of the lands getting larger to the muzzle then that may cause the tumbling with higher pressure loads.

Also I start testing every cast bullet with Unique powder at minimum pressures - it is the most forgiving of the powders. As a load is worked up with Unique, if problems develop or accuracy goes west (or south) I know it isn't the powder and solve that problem.

[frkelly74]

Use the fattest boolit that will chamber without undue effort. If your .313 boolits tumble, they must be too small.

[I'll Make Mine]

I agree with the above; the faster powder is helping because it's upsetting the boolit enough to fill the rifling, and the pressure is dropping before the boolit reaches the worn out portion at the muzzle.

I still think a counterbore would do more good than just recrowning; the difference is that you can counterbore an inch or two inches without having to do anything to the front sight. That will get you past the cleaning rod wear in the muzzle rifling and let a boolit sized to groove + .002" or so shoot well with normal rifle speed powders.

[Pup]

10x, I've just tried to slug the bore again.
Below is a picture of the result.
A friend gave me some 310 cadet heads.

Just my luck, the battery on my vernia is dead, I'll measure the size in work tomorrow and get back to you.

[brotherdarrell]

Just an observation - In post #40 you posted a pic of a 316299 that you used to slug your barrel and it appears that this is the boolit you are shooting. One thing that appears to be missing, to me anyway, are any marks on the nose of the boolit from the rifling. Could it be that the nose of the 316299 is unsupported and be a possible cause of the tumbling issue?

If I am off-base here just throw a rock at me and I will go away.

brotherdarrell

[Plinkster]

If I had a rifle that could tumble 'em that consistently I don't think I'd touch a thing. There are companies that have spent millions getting their bullets to do just that trick, albeit after they hit the target. Anyway I think it gives the rifle great character but good luck getting it to shoot, it looks like you have a good start.

[Pup]

10x/ I'll make mine, the slug that I used recently was for a 310 cadet.
It started its life as a .323 head, it has now ended up, after going thought my rifle at .3135.
Having put a lot of thought into it, I've counter bored the muzzel.
I've reached a depth of .191, I know this does not sound a lot, but, to start this project, I filed the end of the muzzle flat and then cleaned up the crown. So you can add another 4mm onto that figure.
Anyway, if it doesn't work I can always go deeper. I am mindful that I can't add metal.
I've taken a putty mold of the rifling at the end of the bore, a picture is below along with the counterbore.


Brotherdarrell- no stones being throw from my side of the pond.
If this was a perfect bore(unfired), it should be sized at .303.
I know it's not that good as the pilot that I used for the counterbore measured .304.
The molded head comes in at .302 on the head and .3155 across the drive bands/grease grooves.
Would this have an effect, I don't know.


Plinkster- it does make a good grouping, even if they don't fly correctly.
But, I'd still like it to work, in a fashion.

[10x]

It looks like you are down to good lands and grooves with the counter bore.
I would also check to see how much there is between the lands and the nose of the bullet.
you just may have to get a bullet where the nose fits the bore exactly.
I would try with a different bullet as well if your counterbore does not work to solve tumbling from some loads.


What is really interesting is that they are all in the same state of tumble when they go through the target.
That indicates consistency in the cause of the tumble, ie. all tumbing at the same rate of tumble.
and that suggests one factor that is causing the tumble.
It would be interesting to see if 2 grains more/less of powder changes the rate of tumble.

[Plinkster]

They do seem to be flying like throwing knives, I'm curious to see another group now though. And if they do continue to tumble (which I rather doubt) the increased or decreased charge test would be interesting to see also. Good work!

[I'll Make Mine]

Aaaah. I bet that'll slay it. Even if the nose is unsupported, you'd expect a big group, not a complete tumble like you've been getting. That new crown (at the bottom of the counterbore) looks much better, now, and the putty mold seems as if you're got good rifling at the crown.

If you find you've gotten rid of the tumble but can't get groups any better than the tumblers gave, the next step might be to lap the nose (only) of your mold so the bore riding portion is about .001" larger than bore diameter, and make sure you're sizing the driving bands to about .002" larger than groove. From what you posted just above, your .315-.316 sized diameter should be just right, but you need to enlarge the nose by a thousandth or a thou and a half. Then, find the right seating depth (so the boolit just touches the lands, but doesn't engrave enough to pull out of an uncrimped case), and you'll be in the realm where a little testing of different powders and charge weights ought to make that rifle into a shooter.

[10x]

Aaaah. I bet that'll slay it. Even if the nose is unsupported, you'd expect a big group, not a complete tumble like you've been getting. That new crown (at the bottom of the counterbore) looks much better, now, and the putty mold seems as if you're got good rifling at the crown.

If you find you've gotten rid of the tumble but can't get groups any better than the tumblers gave, the next step might be to lap the nose (only) of your mold so the bore riding portion is about .001" larger than bore diameter, and make sure you're sizing the driving bands to about .002" larger than groove. From what you posted just above, your .315-.316 sized diameter should be just right, but you need to enlarge the nose by a thousandth or a thou and a half. Then, find the right seating depth (so the boolit just touches the lands, but doesn't engrave enough to pull out of an uncrimped case), and you'll be in the realm where a little testing of different powders and charge weights ought to make that rifle into a shooter.

Excellent advice...
Those old Martinis can do very well.
I would advise you try a lee Collet neck sizing die as well. There will be the advantage of longer case life, less trimming, and other perks.
Much depends on your budget.

[nekshot]

maybe a martial arts fella had the gun and trained it to kick box(or kick boolits). I must admit it is kinda cute in a funny way!

[curator]

Pup,

Your bullet is under size for your bore. And/or your bore is wider at the muzzle than at the breech. Sometimes something as simple as a "balistic filler" can solve this problem. Read this article about shooting cast bullets in the Lee Enfield which will also apply to Martini Enfields in .303 British (believe me on this) Check it out: http://www.303british.com/id37.html

[Pup]

I had some spare time over the weekend and made up my next range offerings.
From the advice on the forum and the curator, I read the 303 page on fillers.
So, I loaded up a range of bullets with different charges and powders and now fillers.
I used the GM3 load as the test marker, to see if I was anywhere near the target.
I then went to the range on Wednesday and fired for effect.
I was not looking for a grouping, just to see how the heads impacted the target.
As you can see from the below pictures, the GiM3 load works fine.
Reloader 7 still tumbles, TU2000 is good and everything with a filler is good.
The fillers that I used on this occasion were semolina and kapok.

10x, I do have the neck sizing dies and use them all the time.

On card 1 is five shots from just TU2000 and two of the Reloader 7. 2 shots are under the V-bull tumbler.
On card 2 is the different powder charges with the semolina filler.
On card 3 is the same charges with Kapok used as the filler.

From the consistency of the shots, I'll be looking to work a load with Kapok as the filler or just TU2000.

I would like to thank everyone for their posts, without you, I wouldn't have been able to acheive my results today

Thanks loads,

Pup


Sorry the scans aren't the best.