38special stroke 357 question about wadding

[kennyc]

my copy of the latest Lyman cast bullet manual reccomends not using fillers as there is a school of thought that believes there is a chance of the filler/wadding compressing ahead of the burning charge leading to elevated pressures and subsequent "ringing" of the chamber.

[Laurie]

If you remember the detailed pistol cartridge handloading articles by Clive Stevens in the old Target Shooter magazine many years back, loo paper was recommended in the 45 Colt as a filler over the standard load of 9gn (I think, speaking from memory) Unique with a 250gn cast lead bullet. In this instance it was said to give much better results than the usual practice of part filling the case. The paper didn't burn or scorch at all, but was blown out of the muzzle shredded making a bit of a mess ahead of the firing line.

Never heard of this being done with or needed for the other popular revolver cartridges.

[Oddbod]

I've loaded many thousands of rounds of both .38spl & .357mag & never used a filler.
4.8gr of 700-X doesn't take up much case volume in the .357, nor does 3.2gr of Red Dot in .38spl & neither load has ever presented a problem out of a Ruger GP100.

[Mattnall]

The "urban myth" used to be that very small charges, i.e. 2.8 gns of Bullseye, could detonate rather than fast burn, (with the detonation doing very bad things to the gun, and possibly your hand) if the charge was laid along the length of the case, so it was all in contact with the primer flash at the same time.
(I do not know of anyone with 1st hand, or even 2nd hand, knowledge of this happening to anyone.)

I have seen this happen twice now with rifle cartridges where a very light charge has caused a detonation and luckily only the bolt jammed on one and the bolt and carrier split on another. It can happen with the slower rifle powders.

With faster pistol powders it might not make much of a difference. I have used 4 - 4.6gn of powder in a big 44mag case since before the pistol ban and have never had a problem with this type of detonation and don't use a wadding or other packing.

[Laurie]

Yes, but pistol powders behave very differently in both a physical and chemical way from rifle grades. The former are designed with small fill-ratios in mind so they usually (but not invariably) are is thin disc form. This sees the primer detonation pick kernels up and throw them into a cloud mixing with the hot primer eject particles and gases producing a very rapid ignition and burn sequence, but without detonation. Secondly, they are designed to burn efficiently and consistently at low pressures compared to rifle cartridges. Just compare SAAMI / CIP MAPs for the older revolver cartridges such as 38 and 44 Special, 45 Colt, 32 S&W Long etc against any rifle cartridge. Even those designed in the early days of smokeless powders such as the .45ACP run at very low pressures compared to rifle cartridges.

For interesting insights into this topic, have a look at

http://www.gmdr.com/lever/lowveldata.htm

and in particular click on the embedded link called 'The use of pistol powders in rifle cartridges'

As a final point, if the idea of very low fill ratios of fast burning flake powders and the so-called 'convective' or flash ignition seems wrong or worrying, perhaps causing sleepless nights over detonation fears, then whatever you do don't shoot a .22LR standard velocity 40gn LRN round in either a rifle or pistol. The LR case was originally designed for a several grain weight charge of black powder but this was reduced to around 1.5gn of smokeless in the old Hercules Bullseye class when smokeless powders were invented. The charge only takes up a small amount of case capacity in the standard velocity loading. (HV and super HV loadings are different with heavier charges of slightly slower burning propellants and much higher, sometimes 100%, fill-ratios.)

Hear of many .22LR detonations?