The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

Very interesting series of posts. I have to hold my hands up to 'Stiff Bolts' a few years ago when as a new reloader I started chasing velocity. Those of us who shoot classic rifles must also remember that many of these are approaching, or are over 100 years old, and we should not be running maximum loads. The practice of using pistol powder 'downloads' as seen on some forums is in my opinion downright dangerous. Never 'Try it to see what happens' which one club member was guilty of in the old pistol shooting days when he required a new barrel for his 9mm Browning high power. When he got it he loaded up again with some of his reloads until gently asked 'Colin can you remember why you needed a new barrel?' At that point he saw sense and his shooting improved as he was not fighting mega recoil all the time.
Above all take your time at each stage of the reloading process especially when checking cases during cleaning and don't forget to check case length and the need to trim cases. I know of one case where a Krag was blown up by sloppy reloading practices and using the wrong powder. It all sounds so obvious but do we do it ALL the time or do we allow ourselves to get rushed by having to reload in a hurry for a shoot tomorrow?

Robert303 wrote: The practice of using pistol powder 'downloads' as seen on some forums is in my opinion downright dangerous.

Why do you see this as dangerous when there is good data and statistical precedent for it?

Surely it is no more dangerous than using any other data when used with good handloading practice.

I am curious to know why you think this is dangerous.

Sorry if I overgeneralised on pistol powders, but there is the problem of volume and the powder lying along the case which with some powders, I was reliably informed by an Army Ammunition Technical Officer, could lead to detonation as opposed to burn. He stated that the shock wave from this was more liable to produce shattering or brisance* than bursting. Should you have access to printed data or manufacturers online data on using pistol powders in .303 / 6.5 x 55 Swedish I would appreciate it if you could let me have the link or reference. I'm always willing to learn ;-)
* https://en.wikipedia.org/wiki/Brisance

SEE has been statistically proved to happen with less than 60% case fill of medium to slow rifle powders have a partial ignition driving the bullet into the rifling, the powder then ignites fully and the bullet has become an obstruction sending pressure through the roof. "Firearms Pressure Factors" by L E Brownell PhD.

The detonation effect you refer to has never been proved with fast powders even although many have tried to replicate it. I would like to see the reference where this relates to and has been replicated in medium sized cases and fast burning powders.

As to data Mattern and Harris are the primary sources backed by decades of statistical data from this country and abroad, this data has been robust enough for gaining range insurance for such loadings.

Thanks for that I'll go and do some more reading.

Perhaps the most likely pitfall with fast/pistol powders for "down-loading" rifle ammunition is the possibility of double-charging a case due to the small volume of powder.

Of course, good reloading practices should identify this eventuality. Should...

That is about the procedure of reloading nothing to do with the actual use of fast pistol powders in medium calibre rifle cases.

Also this can happen in other loading situations and is not just a risk when using small loads rifle cases, the same risk can be there when loading other calibres.

Double charging, under charging, bridged charges, excessive seating depth, using the wrong powder, misreading the data etc. etc. are all risks about the process of handloading not about the load itself.

For those that load low pressure cartridges, you may exceed max pressures long before you see any signs of "overpressure warnings". The "max" pressure loads we see listed for the 44-40, for example, can more than double before pressures signs might can be seen. Winchester manufactured 44 "High Velocity" loads only to be used in the Winchester Model 92' and other strong action rifles. It produced up to 22,000 cup. "Max" published and normal loads only produced 13,000 cup or less. Some handloads in older 1930's manuals, well know and reputable to handloaders at the time, have 44-40 loads that top out at 30,000 cup....which could be catastrophic effects on revolvers or weak action rifles.

Lot's of good information under this topic!

Thank you so much for the detailed explanation...

Really informative!