.455 tumbling

[BobH]

As this is the nearest to a section 7.3 area on the forum I thought I would just share some of the details of last night at the Historic/Heritage Small Arms meeting at the Leicester Shooting Centre.
Although I only fired 40 rounds in total the shooting was very enjoyable.
The two firearms I used were my 1916 S&W Mk2 Hand Ejector in .455 and my 1903 Husqvarna (Nagant) Model 1897 revolver in 7.5mm.
Both guns worked like a dream and the only problem came with two of the .455 rounds tumbling. I’m not sure if it is the ammunition or the gun as I don’t seem to get the same problem with my Webley Mk VI’s but I do with my Colt New Service.
Anyone got any ideas?

[dromia]

That is usually a sign of undersized boolits.

Have you measured your chamber mouths, forcing cone and bore/groove diameters?

Were you using flat base or hollow base boolits?

Were the bought or home cast?

What were the boolit diameters? If home cast did you size them?

What alloy/hardness?

Were all the case mouths expanded the same as a tight case can resize down soft boolits?

Two rounds out of how many?

Were the tumbling rounds from the same cylinder load?

[Watcher]

I used to have problems with a Webly Mk VI which was due to that fact that it had a mismatch cylinder which was properly indexed. Difference was that this was a problem for every round - but maybe worth considering.

[BobH]

That is usually a sign of undersized boolits.

Have you measured your chamber mouths, forcing cone and bore/groove diameters?

Were you using flat base or hollow base boolits?

Were the bought or home cast?

What were the boolit diameters? If home cast did you size them?

What alloy/hardness?

Were all the case mouths expanded the same as a tight case can resize down soft boolits?

Two rounds out of how many?

Were the tumbling rounds from the same cylinder load?

Thanks for the reply.
The rounds were purchased from LSC as I am only authorised to possess them at the club. They are cast on site using a RCBS single mould i.e hollow based with three grooves exactly reproducing the Eley original. Factory loads are non existent. They were sized to .452 although the design allows for a wide variance because the base flares.
The case mouths were all expanded the same amount and the tumbling rounds were not from the same cylinder.
I'm not sure of the alloy/hardness but I will check next time I speak to Steve.

The two rounds were from twenty I shot last night.

[dromia]

Was there any sign of spitting from between the cylinder and the forcing cone?

[BobH]

Was there any sign of spitting from between the cylinder and the forcing cone?

Not that I noticed mate.
I have spoken to other members with S&W's and they tell me they get a few tumblers. I'm the only one there with a Colt so I've nothing to compare it with. Both my Webley MkVI revolvers shoot this ammunition without a problem so I'm beginning to think that it is something about the US cylinder/barrel/groove of the guns made for the non US .455 cal round.

[FredB]

I have owned and shot competetively two New Service .455s, one S&W Triplelock and four Webleys. Never had a bullet tumble. I used .452 bullets in my Colts and in the S&W. I had a Webley WG Army which needed .458 bullets or it was inaccurate, but even that didn't tumble. Are your bullets very hard? Sorry not to have more suggestions,
Fred

[BobH]

I have owned and shot competetively two New Service .455s, one S&W Triplelock and four Webleys. Never had a bullet tumble. I used .452 bullets in my Colts and in the S&W. I had a Webley WG Army which needed .458 bullets or it was inaccurate, but even that didn't tumble. Are your bullets very hard? Sorry not to have more suggestions,
Fred

Not hard, not soft, sort of medium I suppose although I do not have a lead hardness tester. As I don't cast them it is difficult to be 100%. Next time I use the S&W I'll do some proper testing/comparisons against the Webley and let you all know what happens.

Could be a few weeks before I get to do it, the ammo is blo*dy expensive now

By that time I should have some ammo ready for my Nagant 1895 "Gas Seal" so I'll have something else to test as well.

It's all good fun :shakeshout:

[rufrdr]

If you can find these in the UK, they work really well in my MkVI. They are aa .455 hollow base bullet with a rounded flat nose for paper punching. I get them from a guy in Pennsylvania and he casts them using a Lyman mold from what I understand. Perhaps your S&W has a couple chambers that are not sized properly compared to the other chambers which allows the .452 bullets to enter the throat off kilter which gets them down the bore not set up properly?