• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Lightloading high capacity cases

boltgunluvr

Sergeant
Full Member
Minuteman
Apr 11, 2012
389
2
54
Jxn, MO
I've read a few posts that discuss people utilizing a little faster powder to save some $$. I'm hoping that people come to understand this can be dangerous with cases that have a higher capacity. Example: light loading a 243 Win (which is an overbore) is dangerous.
 
Re: Lightloading high capacity cases

hmm i guess i see what you are getting at there definitely could be dangers,

but you are going to sacrifice velocity in most cartridges that have the case capacity especially when doing it safely and most shooters don't take to kindly to lower velocities

I didn't buy a .300 rum to push 180grs at the same speeds as a .308 win.

JMO
 
Re: Lightloading high capacity cases

boltgunluvr...Please explain the reasons you believe that light loads of faster powders can be dangerous. This has been done for years by the military and others...usually called "gallery loads". It isn't the most efficient, nor maybe the most powerful or accurate, but reduced loads have their place. JMHO
 
Re: Lightloading high capacity cases

Are you referring to reduced power loads or loads of fast powders utilizing less than complete case capacity in order to achieve similar MV?

I don't think most people do it to save $$, I think they do it because the faster powder loses less MV when cutting down to shorter barrels. How much they consider the fact that it does this via a greater initial pressure spike probably varies from loader to loader.
 
Re: Lightloading high capacity cases

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">boltgunluvr...Please explain the reasons you believe that light loads of faster powders can be dangerous. This has been done for years by the military and others...usually called "gallery loads". It isn't the most efficient, nor maybe the most powerful or accurate, but reduced loads have their place. JMHO </div></div>

Lightloading relative to high capacity case, especially overbores...I've seen a rifle go kaboom. The man lightloaded. Basically, the ignition from the primer must have gone over the top of the powder inside the case and detonated....lightload. Hence, the importance of selecting a powder that fills the case better OR understanding there are certain powders that may be better to use for lightloading certain cartridges.
 
Re: Lightloading high capacity cases

I understand the concept, but that is, as I understand, limited to using light loads of SLOW burning powder, not reduced loads of fast burners. Technical term I think I remember is "deflagration to detonation". I would personally not shrink from using a light load of 4198 or 3031 in a .243...but I wouldn't use a 30 or 40 percent reduced load of 4831 or such. JMHO
 
Re: Lightloading high capacity cases

I read a theory a while back that not only talked about flash over it also talked about the primer explosion fluidizing the powder (swirling air born) while simultaneously igniting it.
Whatever goes on inside the case it is a very real phenomena that is also very powder specific.

The best way to approach this is to find a source for pressure tested reduced loads (such as Lyman) and stick to their recommendations.
A 243 is a pretty small case for this phenomenon....I can't see it happening, but I suppose it might.

In messing with cases like the 505 Gibbs I ran into all kinds of weird reduced load combinations...Duplex powder loads, case stuffing, you name it.
 
Re: Lightloading high capacity cases

I understand the point being made. Perhaps what was meant is a caution against casual load reductions because there is plenty of data indicating that strange, if not dangerous results can happen. The fact that the services may use reduced loads for a special purpose is a little different and I assume, carefully approached?

Small cases "could" be a concern, if the rumor I heard a while back is truth; that being, the most frequent Model 700 failure is 17Remington. For <span style="text-decoration: underline">various reasons</span>, of course, but pressure is pressure. BB
 
Re: Lightloading high capacity cases

If H4895 is an applicable powder, you may safely load down to 60% of the book load.

Google Hodgdon H4895 60% rule. This is straight from Hodgdon.
 
Re: Lightloading high capacity cases

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">If H4895 is an applicable powder, you may safely load down to 60% of the book load.

Google Hodgdon H4895 60% rule. This is straight from Hodgdon. </div></div>

Very true. H4895 is very stable and helps to avoid the undesirable kaboom.