410 from 303 HELP

[Jeffery8mm]

I recently bought a new H&R 410.. I have 25 303 brass cases that I want to make into 410 brass shells. I loaded one up tonight with 5gr of unique and topped with cream of wheat for fireforming. No wad/cards on top or over the powder. The resulting "fireformed" case was bulged at the neck. What is the proper way to acheive this??
Thanks
Jeff

[onesonek]

Got any pic's?,,,might be helpful to see exactly what you got going on. You will likely need to anneal the upper 1/3 of the body and neck. But I would also put a wad of tp over the cow. I haven't heard of the .303 being use for this,,,,it's a tad small in the web area. I know others have been using the .444 Marlin brass.

[JeffinNZ]

I would say you were a bit conservative. I fire form my .38-303 brass I load 15gr Green Dot topped with corn meal and let fly. Works great.

[Jeffery8mm]

I would say you were a bit conservative. I fire form my .38-303 brass I load 15gr Green Dot topped with corn meal and let fly. Works great.

I wondered about that too.
Jeff

[hk33ka1]

I did it with .303 brass and Unique with TP and Grits on top. Even loaded them with some shot after that. They were a terrible shape and I could never get them to blow out to straight walled. The neck was bigger than the base/centre . It was my first try at annealing and most of them split.

I have a .444 shell now and will try with it.

[Reg]

Tried this several years ago and just didn't have much luck with the 303 cases. The did finially fill out but didn't have the rim dia. needed. Used 444 Marlin cases and had MUCH better luck.
Now use them in 4 different shotguns in many different loads and all work well.
Get some 444 cases and your life will get much easyer.

:drinks:

[303Guy]

Yup - done that. I made a die for the purpose (just a trial with a 41 cal rifle conversion in mind). I'm behind with my promises to make stuff and do stuff for people (JeffinNZ is one - sorry Jeff, divorce and all that pooh!) otherwise I would offer to make you a set of expander dies. They work.

http://i388.photobucket.com/albums/oo327/303Guy/pictures023.jpg

The case stuck on the expander is 41. The other long one is 38-303 - 375/303 if you like.

I expanded one case up to 38/303 and back down to 303 then back up ... and so on several times. The case did need trimming in the end to square it up.

The 38-303 is the 303 Brit case with the neck expanded to the body diameter at the shoulder. The 41 makes the case parallel leaving the web a little bit indersize but can be done with the area just in front of the web on size and symmetrical - not super critical on a shotshell but looks nicer.

Point is, very do-able. Very much so with annealing the front bit of the case. For interest, the 303 Brit case is a necked down brass 410! The case goes through a '410' stage during it's making. The Indians chambered some SMLE's in 410 using the Brit case (riot control or something). It's available on the net.

Quoting from Wikipedia;

"RFI in India and SAF Lithgow in Australia both produced single-shot conversions of the SMLE chambered for a .410 shotgun cartridge. The .410 conversions made by Ishapore were generally used as riot shotguns for crowd control in India, and were originally chambered for a 2" British .410 brass shotshell,[74] basically a blown out .303 British cartridge."

[Jeffery8mm]

I did not anneal mine. Will do that before I try again. Also, I read about a couple of wraps of masking tape arount the rim portion of the brass. Will try that also!!
Thanks
JEff

[Mk42gunner]

I tried annealing the .303 brass and fireforming with 231 and COW. I still got wasp waisted cases.

I then tried expanding the case with a .40-65 neck expander, it worked, as far as it went. I need to make a longer expander to reach deeper inside the case.

I have since found a box of .444 Marlin brass, it is easier to use, but shorter. No more than i shoot a .410, twenty rounds will last me a while.

When I get my lathe going the first project will be to turn a piece of 1/2-20 down to .410" forexpanding the rest of the .303 cases.

Robert

[eagle27]

The thread heading pricked my ears up thinking it was about converting an SMLE to a 410 shotgun. Done plenty of those making a strong light shotty for bunnys etc. Not sure I get the gist on wanting to use brass 303s for loading 410, what have I missed?

[303Guy]

Two reasons come to mind - fun and shortage of 410 reloadable cases (I nearly said brass!)

Make that expander in several stages - I did mension that the case on my expander is stuck there!:roll: Also, the final expander will need to closely accomodate the internal case shape - but then you already knew that.