Che
Not all flask have a top that can be unscrewed for filling. Does the outside edge of the top have a cannular design on it and does it over lap the top edge by a small amount. If not then the top does not unscrew. My 2nd generation Colt flask does not so I have a small funnel that I made to fill it with. I unscrew the spout and open the gate, insert the funnel and pour in the powder. You need to premeasure the amount of powder you want to put into the flask otherwise you'll spill excess powder.
Dan

 

What Dan said...

 

I also agree with Dan. A picture or two would probably help.

As an aside, I wrap old bicycle inner tube around what I am trying to loosen if I want to make sure I don’t damage the threads.

Bob

 

Easiest way.

Amazon.com : TDC Flask Filling Funnel : Sports & Outdoors

Amazon.com : TDC Flask Filling Funnel : Sports & Outdoors

www.amazon.com

 

One of the older flasks I had 40 years ago had small grub screws securing the top to the body. For lack of a funnel that wouldn’t clog, I removed the screws and slipped the flask apart. That was still a PIA. I eventually opened and tapped the holes for a larger sized screw with a head I didn’t need jewelers tools.
Wasn’t pretty but I was young and dumb and it worked on my budget.
I bought higher quality flasks after that. Even then not ‘High Quality”, just better quality.
Tubular brass with a selection of spouts. I still need to maintain the gates to prevent sticking. (When I remember)

 

Sorry on original post I did not add photos. Phones now added on original post.

Thanks

 

Update:
On the flask pictured with the 1860 Army reproduction, I was able to remove the three "tiny" (and I mean tiny) screws. Upon doing that I was able to pull the top off. What a PITA (especially with my fat fingers and late 60s eyes!.! The flask was definitely designed for presentation, although once filled with powder they are usable.

The other flask there are no screws, but it there are 3 brass pins (once again very tiny). I betting if I push the the pins through (and they would have to fall inside the flask) the top would come off. Unlike the other flask they do not unscrew like one would think, but the screws and the pins are solely there to keep the top section from coming off during use.

So what I learned, on the powder flasks I have- there is no good way to add powder. :O(

 

I unscrew the spout, undo the curved spring,[just pop it up], and used either a funnel shaped piece of good paper or a small funnel. If you can't get the funnel off just undo the spring and pour it down the spout. I sometimes have to tap the flask to get the powder moving again.

 

First couple times I messed around removing the top, since then I roll a paper cone and scotch tape it, unscrew the measure nozzle tube and funnel in powder with the stop lever rubber banded open, stick flast in a sneaker to hold upright.
A 3.5 handed job done w 2.

 

I have an old (35 years) CVA powder measure. All brass except the spring and hold down screw. Both the top and bottoms screw off. Came with 3 spouts and darned if I can remember what each one allowed what powder charge. It shows up when I least expect it. Used the smallest spout to load BP charges into my little BP cannon. Probably 20 grains or so. Frank

 

I agree with GUNBB, For years (50+), I have used a small funnel put on top of the spout and poured powder into it while holding the spring open. Never had any problems at all. When the body is full you will have powder in the small spout. Then simply use a larger funnel to dump the excess back into the original can.