BP cartridges weight vs volume

[MosinMan13]

I recently picked up some Bertram 41 LC brass, and after a small hiccup I got to loading a few today. It’s immediately apparent next to my Starline brass that the Bertram holds considerably less powder by volume. I’m using a 1.3cc dipper (gives me about 19gr of fffg Schuetzen) and with all my other brass (starline, Rem and Western) I get perfect compression, with the Bertram I’m getting roughly 1/8” from the rim after pouring, which is too much to properly seat the bullet.

I found with a 1cc scoop (gives me about 16g of fffg Schuetzen) gives me the minimal amount of space in the case to seat my 200gr HB bullets with proper compression.

I do not use a drop tube as of yet.

My question is since the Bertram brass won’t hold the amount of powder I need, can I reduce the weight of the charge as long as I maintain proper compression, or am I asking for trouble? I know with smokeless reducing charges can be dangerous but I can’t find a strait answer on this.

Or will a drop tube make a difference for a charge this small?

 

[Snider shooter]

Doesn’t matter how much powder you put in. As long as your case is full. Different cases have a different internal volume so adjust your load to suit. The small difference in amount of BP isn’t going to make much difference.

 

[Janeau]

No air space under bullet.
You can reduce powder charge by adding a wad. I use a sandwich of cardboard wad - a 3/8 felt wad and topped by cardboard with great success in my 45-70/ 45-75 and 45-60. Pistol cartridge such as 44-40 and .45 colt - a case full that allow seating the bullet is not too much.

 

[Re3iever]

Not sure if it will work for a handgun cartridge but I use a "compression die" on my 45-70 and 45-120 cartridges with black powder loads in order to seat the projectile to the desired depth. For example with 45-70 , for 70g ffG black powder even after using a drop tube I still need to use a compression die in order to include a cardboard wad and seat the standard 405g bullet to a normal depth.

Retreever

 

[MC One Shot]

Those lee powder scoops are designed for smokeless powders. Black powder volumetric powder measures are different. There may be some discrepancies when using volumetric powder measures if not poured from you horn or flask the same each time. Height of the powder pour make the most common error.

Weighing your powder will be consistent each time. Practical for loading cases or powder vials in your reloading room, impractical elsewhere.

When BP volumetric measures are filled properly there should only be a very minor difference beteen weight and volume.

 

[MosinMan13]

Not sure if it will work for a handgun cartridge but I use a "compression die" on my 45-70 and 45-120 cartridges with black powder loads in order to seat the projectile to the desired depth. For example with 45-70 , for 70g ffG black powder even after using a drop tube I still need to use a compression die in order to include a cardboard wad and seat the standard 405g bullet to a normal depth.

Retreever

Interesting I may have to look into that, I’ll be getting into 45-70 next but I haven’t needed a drop tube or compression die for 41LC yet, just these Bertram brass are a little out of spec, by volume they hold about 3gr less than any other brass I have, and they measure slightly smaller in diameter with thicker sidewalls. I’m wondering if because they’re new they’ll fire-form out to spec because from the bag my sizing die doesn’t touch it, and the expander nearly distorts the entire case. The crimp barely touches the case at full setting either.

To circle back to my question, will having 3gr less charge creat any dangers? It doesn’t need a filler or wad because it’s still compressed a proper amount, also it’s a hollow base. The problem is I can’t fit anymore powder in these particular cases, compressed or not.

 

[MC One Shot]

Just looked up my reload data; 20 grains FFG or FFFG by weight. Have on occasion reduced the FFFG to 18 grains. I do not use any wads as I found did not make any appreciable difference in performance here. Just saved time and money. I do not do a compression phase with pistol cartridges as with rifle cartridges since the bullets are smaller and less susceptible to deformation so I use the the bullet to compress the powder during the seating stage. Make sure you size the bullet to your case to fit your case so when seated the cartridge fits the chamber.

 

[Dmay]

To circle back to my question, will having 3gr less charge creat any dangers?

No it will not, so long as it's compressed, which yours is. I would suggest using a drop tibe, you will likely get a slightly larger charge in then.

 

[Re3iever]

Interesting I may have to look into that, I’ll be getting into 45-70 next but I haven’t needed a drop tube or compression die for 41LC yet, just these Bertram brass are a little out of spec, by volume they hold about 3gr less than any other brass I have, and they measure slightly smaller in diameter with thicker sidewalls. I’m wondering if because they’re new they’ll fire-form out to spec because from the bag my sizing die doesn’t touch it, and the expander nearly distorts the entire case. The crimp barely touches the case at full setting either.

To circle back to my question, will having 3gr less charge creat any dangers? It doesn’t need a filler or wad because it’s still compressed a proper amount, also it’s a hollow base. The problem is I can’t fit anymore powder in these particular cases, compressed or not.

Sorry but I am not qualified to answer the question about reduced load but I don't see why it would create a problem.

Retreever

 

[vagrantviking]

It's certainly safe.
Hopefully they will fire-form decently so that they load like the other brass but you aren't likely to gain a full 3gr capacity.
Different brass has different interior dimensions and some are more extreme than others. The thicker cases might even be a bit of a benefit to case life and betting those aren't real easy to come by.

It's possible that the point of impact will be a bit different but probably not hugely so keep the different headstamps separate and just use one type for each target or range session. It is a bit of a pain to have different loads went at the reloading bench but sometimes that's just how it goes.

Maybe you can find someone else out there that has the same trouble and would like to trade so you each have more of the same brand? Don't know how much Bertram brass there would be around though.

 

[MosinMan13]

It's certainly safe.
Hopefully they will fire-form decently so that they load like the other brass but you aren't likely to gain a full 3gr capacity.
Different brass has different interior dimensions and some are more extreme than others. The thicker cases might even be a bit of a benefit to case life and betting those aren't real easy to come by.

It's possible that the point of impact will be a bit different but probably not hugely so keep the different headstamps separate and just use one type for each target or range session. It is a bit of a pain to have different loads went at the reloading bench but sometimes that's just how it goes.

Maybe you can find someone else out there that has the same trouble and would like to trade so you each have more of the same brand? Don't know how much Bertram brass there would be around though.

Thanks all for the advice. I went out the other day and came back with my hand attached, no pressure signs and relatively acceptable results, for a weekend warrior like myself.



I did have two fliers but only one from the smaller charge, I took 6 of the Bertram 15.5 gr charge and 6 in Starline brass 20gr charge, (turned out to be 5, either dropped one somewhere or miscounted when I grabbed my belt) I should have photographed separately but surprisingly the two keyhole came from the larger charge rounds. That said the lighter rounds couldn’t push the 200gr projectile through the other side of the barrel like the hotter loads do, which is fine for plinking, especially if I’m saving powder at no cost of accuracy.

The only real disappointment is the Bertram brass didn’t fire form like I had hoped, it did enough to take the distortion out from the projectile but not enough to add any volume of charge, which I assume means the case is just thicker and tapers in more?

I may look into a compression die and drop tube. Do I need caliber specific or do they come in generalized sizes? Any recommendations on where to find such tools?

 

[MC One Shot]

Mosinman13, Have you annealed your brass?

 

[MosinMan13]

Mosinman13, Have you annealed your brass?

No actually I haven’t and that’s an interesting thought. I guess I never put much thought to annealing pistol cartridges, and I probably assumed (wrongly) that factory brass came annealed. Maybe worth a shot?

 

[vagrantviking]

Normally I don't worry about annealing pistol brass as most is cheap and used in big volumes but as the cost goes up that might change for some.

The low pressure black powder rounds can really benefit from having soft necks to get a better gas seal and more of the cases for bp guns are getting into that $1/cases territory too. People are having real trouble finding 44-40 and the like.

Many bp cartridges were originally made with copper and brass foil which illustrates how dead soft a case works well for low pressure.

My experience is that new brass often comes a little hard for use with bp but it varies. If I see blow-by or worry about the life of the brass I will anneal every 3 or 4 firings.

I use some all brass Magtech shotgun shells that have never seen a sizing die and I find they get harder after a few firings so they get annealed regularly also.