john.loann@gmail.com
john.loann@gmail....
1 post
Joined May 2020

Extruded powder small mouth cases

I’ve identified two issues when trying to reload small mouth cartridges, e.g. 223 Rem, with extruded powders. Dillon Customer Service simply says there are too many good Ball™ powders or spherical powders that work well. Just use them. OK. I get their point but I really like N 140 and Varget. Additionally, I have a lot of IMR 4895. All of them work very well in 223.
The first issue is powder charge weight variations depending on the powder used. That problem hasn’t changed since the first extruded powders were dropped by a powder measure. Yes, greater weight variations occur with extruded powders than Ball powders.
The second and more important issue is extruded powders frequently jam or “bridge” in the Dillon powder funnel. This is a very dangerous situation. It causes one squib load followed immediately by an over-charged case, hopefully with powder spillage on the ram
CAUTION: If you ever detect loose powder on top of the ram, STOP, inspect and analyze. Hopefully, a case just doesn’t have a primer. However, if the case just loaded is overfilled, the previous round with a bullet already seated is almost certainly a squib load.
Now it’s easy to understand why Dillon Customer Service just says don’t use extruded powders with small mouth cases. I don’t blame them due to the safety issues. However, I’m unwilling to hand weigh every load. I can’t even use the Dillon powder system to throw an initial charge of extruded powder reliably. I DO want to reload .223 with extruded powders.
This is what I did to eliminate bridging in the powder funnel. I’ve tested my resulting modified powder funnel by throwing over 500 charges each of N140, IMR 4895, Varget and IMR 4198 without a single instance of bridging. Before modification, N140 would bridge, on average, 1 in 15 loads. The other powder extrusions are longer than N140.
I found that in every instance, bridging occurs at the intersection of the bottom of the funnel and the top of the drop tube. By grinding a small amount of steel away from that intersection in a small portion of the diameter of the circle, it changes that interface from a perfect circle into an asymmetrical oval shape. By making that interface asymmetrical, the even pressure caused by powder at the top of the funnel causes a differential pressure on the asymmetrical bottom causing granules to “pooch out” into the drop tube. All my testing shows this to have solved the bridging problem.
Time and tools needed:
½ hour
Dremel drill or equivalent
Dremel silicon carbide conical grinding stone or equivalent size aluminum oxide conical grinding stone with about 0.010” at tip
Rubbing compound - your choice
Polishing compound - your choice
Cotton bore crushes for smoothing and polishing
Brake cleaner or cleaner of your choice

Using the grinding stone, grind some of the sharp-edged funnel-drop tube junction away. It only takes an area about the diameter of the tip of the grinding stone or about 45 degrees of the 360 degree junction. Be careful not to allow the tip of the stone to contact the drop tube wall on the side opposite of the grinding.

Use the rubbing compound to smooth the area that was ground.
Repeat using the polishing compound.
I also polished the drop tube to remove all friction points but am not convinced it is necessary because I never found an instance of bridging in the tube.

Usage notes:
I was a little bit concerned that since the powder funnel has no keying feature to keep the powder funnel from rotating during use, that bridging might occur depending on the angle of rotation. When I tested 500+ charges of each of the four powders listed, I started with the powder funnel in each of the four 90 degree coordinates. It doesn’t seem to matter. I had no bridges in the 2000+ loads.

Of the 2000+ charges, I weighed of 250 of the N140 charges just to get a good statistical sample of the weight variation. I also weighed at least 30 each charges of the other 3 powders. While I had 0 bridges occurrences in the funnel, the extruded powder bridged in the neck of the casing while dropping powder onto my scale. All I had to do was shake the casing just a little to break the bridge loose.

Disclaimer: Like everything to do with reloading, safety is in the hands of the operator. Even with this modification, it is up to you to be safe and recognize potentially hazardous situations. This modification worked for me but I’m not guaranteeing it will work for you. STOP and analyze if you see the tell-tale sign of loose powder on top of the ram.

A safe reloader will analyze the impact of charge weight variation caused by extruded powder and back away from reloading book’s listed max charge. For N140, using my press with modified funnel (which doesn’t impact charge weight), I had to back away from book max by 0.2 grains creating a new personal max. Your methods may differ. Statistical evaluation of a large sample size should be performed.

Even if you decide to weigh every extruded charge, at least you can use the Dillon powder system to throw the initial charge then weigh and trickle, Just eliminating the bridging will make it worthwhile to do the modification because you won’t need to stop to clean up spilled powder.
I hope this helps.