410 Case Forming from 303 Brit for round ball or slug use

[Blackwater]

Don't know if they're available in your area, but I believe it's Mag Tec that's making brass cases for shotgun shells now. I have some for 32 ga., which is essentially just a .50 cal. They seem to be worth the cost, at about $1 ea. They're set up for priming with LP primers, of whatever make you have. They ought to do really well for you if you can find some - always a question these days, it seems.

And FWIW, when my son was very young, I got a break action .410 and took some 3" factory loads, opened them up, and put 4 .380" lead balls for cap n' ball pistols, and filled the rest up with corn meal. The primers indicated some extra pressure, but nothing I was worried about with all the metal around the breech and barrel. It was built on a 12 ga. frame. Those loads printed all 4 pellets in a space I could cover with my hand at 40 yds., which really made my eyebrows hit my hairline. I took him and that little gun with me (cut bbl. to 19" so it's balance and swing better for him then, and cut stock to fit also) deer hunting on some deer drives I went on just for him, and he was surprisingly good with that little gun. Threw some clays for him at close range with bird shot, and he hit most of them. The young will really listen if you approach them right! The little .410 lends itself to specialized ammo, I think, more than most guages do. I have no doubt that 4-ball load would have killed the biggest deer in my state! And his accuracy with it was surprising, too!

[Outpost75]

My duty .410 traveler is a pre-WW2 H&R .44/.410/11mm, originally a 2-1/2" chamber in which I split the muzzle shooting roundballs out of it as a kid. Cut it off behind the split choke at 20", leaving a cylinder bore at .425" diameter, and rechambered for 3" shells. Loves the S-B 5-pellet 00 buck, or four .390 cast balls with 15.4 grs. of #2400 in expanded up 9.3x74R brass.

[LAGS]

To answer your question about the length of the .303 cases in a 3" chamber.
I had No issues with round ball, buck shot or shot loads.
My loads used either a Plastic or a home made Paper shot cup.
I cant find my loading data, and I think I gave it away with the .410 /22 OU when I sold it.
The shorter cases didnt always want to feed in a .410 pump action that I had.
But they fired great
And Yes, You may have to thin down the rim on the .303 to get your action to close.
But one single shot H&R I had worked fine without having to thin the .303 rim.

[303Guy]

Thank you all for your input.

Ok so it seems my first step is to go with the expanded 303 cases and see what happens. I don't have a source of balls yet nor the slugs. I have the feeling that the wadded slug might be the better option but taking into consideration that this gun is choked, any slug I choose would need to be of soft lead and ribbed whereas a round ball only needs to be supported in a cup. The cup could be tricky though, I should think.

I do want to keep the barrel at full length if I can although I am tempted to remove the choke. What I like about the long barrel is the balance and lower muzzle blast (I think it's lower with more expansion volume and further away from the ears).

The rim thickness is actually about the same - its the shape of the rim that differs so all that is required is giving the breach side of the rim an angle. A file and holding the case in the lathe chuck at low speed was all it took.

[LAGS]

I a pinch, you can cast slugs in a hole drilled into a piece of wood.
And if you get the size right, those little slugs of lead can be pounded into a semi round ball, them placed in a rotary tumbled and let tumble till they are round.
You aint talking about trying to get Olympic Accuracy or perfection.
Play with what you can do , while waiting to find what you need.
The balls dont have to be perfect, as you are using a wad or shot cup to get the size right.
Roll paper around a dowel the size you need and glue it like a tube.
Then glue a plug in the end to form a shot cup.
The sides can then be split if you use them for shot so they open up.

[HABCAN]

Why not just buy some brass .410 SHOTSHELL cases from Magtech?? Expensive, but............?? (I got some, for 'speriments.)

[LAGS]

The OP is in New Zealand.
Sometimes they can not get the material that we can or they are cost prohibitive or even restricted.
But there are ways to Make Due till the proper materials can be found.
I started off playing with the reformed .303 cases because the .410 ammo was so expensive for Specialty Rounds that I wanted to shoot , or have a back up plan if ammo ever became more restrictive over here.

[Reverend Al]

I've gone both routes and fire-formed .303 British cases into straight cases, but they are to use in my Lee Enfield .410 Musket which used in-formed (straight) .303 basic cases and the British military loaded them with a .410 round ball in rifles that had been bored to .410 smooth bore single shots. (They were used for native troops and prison guards in India.)

https://www.youtube.com/watch?v=ZzWrMhDYL3M

I also managed to source a bunch of once fired Norma 9.3x74R cases at a reasonable price and have successfully fire-formed them into straight 3" brass cases for my Marlin Ballard No. 5 Pacific in .40-90 Ballard straight and I also formed some for my .410 O&U shotgun. Hornady is listing 9.3x74R brass for sale, but it is pricey ...

[303Guy]

I did a quick Google search - Magtec cases are indeed available here. Nz$85 including shipping. This is for 25 cases and they are 2 1/2". I'll stay with modifying 303 cases until longer brass can be found.

[LAGS]

Are you going to modify Berdan, or Boxer primed cases ?
You can Modify the Primer pockets on the Brass Berdan Surplus ammo to take Large Rifle or Large pistol Primers.
Those cases may be found in your area already fired, and for Free.
Or , in your part of the world, can you get the Berdan Primers.

[Reg]

The modified 303 cases will work and give a good service life. Have made up a bunch. I think the brass itself in the 303 is thicker and tougher than the 410 brass shells you can buy.
Only problem I have noticed is that the rim is a bit smaller in dia and also the head dimension too is smaller but will fire form out leaving a small but not too serious bulge in the head area just above the rim. The bulging is never equal all around but rather tends to settle to one side. The bulging itself due to the pressures you are working with are not anything to worry about but
because of that slight bulging effect you will note the rim will tend to hold itself off a bit to one side. This being offset a bit and a bit smaller to begin with will sometimes create a bit of a extraction problem in that the extractor might over ride the rim. If you have a very tight chamber, it might not be a problem, if you have chambers that are on the loose side-- it can be a problem. If the bulge pushes the rim to the extractor, you will not have a problem, if it pushed the rim away from the extractor, you could. Etc.
As a thought. I have heard this mentioned but have never tried it myself. Take it for what it is worth.
When fire forming cases that you know will bulge out a bit, wrap a layer or two of scotch tape around the head before firing, Will hold everything central and prevent off center bulging.
Like I said, have never tried it myself but will with the next batch of cases I blow out of the 303.

[303Guy]

I plan on using only boxer cases. I have one modified berdan PMP case that does work. I have enough odd cases for the gun for now. If I do come across a supply of berdan cases then I will modify them.

Reg, that is a valid consideration. I was thinking of expanding the cases far enough down the body to centralize the case but the tape trick sounds much simpler. With the expander one still has to somehow centralize the case. Thanks for that tip.

[bstone5]

The 444 Marlin brass is for me the best choice. A over powder wad is required beneath the plastic shot wad. Shot these a lot in a H&R single shot and a S&W Governor revolver. My 9 year old grandson shots the break open shot gun a lot. Have used the same 50 pieces of brass for several years with lots of reloads. Star Line is making the 444 Marlin brass may need to get some of this brass.

[JeffinNZ]

I did a quick Google search - Magtec cases are indeed available here. Nz$85 including shipping. This is for 25 cases and they are 2 1/2". I'll stay with modifying 303 cases until longer brass can be found.

Robbie Tiffen at Gunworks has them Pete.

Why not just use plastic .410 hulls?

[LAGS]

The taping trick does work for Fire Forming the cases.
All my cases were done with hand Mandrals to expand them.
Then I pounded them into a homemade sizing die made out of a 1" thick Bar of steel with a bole drilled in it
Heating the Unprimed .303 cases worked to help them stretch out the necks easier.
My primer converted cases worked really good.
Good luck on your reloading.
Once you build up a stock of the converted .303 cases for your .410, then it will lessen the firing of the hard to find .410 factory or reloaded plastic cases.
Besides, you will have built the skills to provide yourself with needed ammo when things are too expensive or impossible to find.
Home made Cases, Home Made wads ,shot cups and even Foster style swedged slugs.
What could be better.
And you can do it with simple hand tools and a little knowledge, and help from your friends.
Why Buy, When you can Build

[RoyEllis]

I plan on using only boxer cases. I have on modified berdan PMP case that does work. I have enough odd cases for the gun for now. If I do come across a supply of berdan cases then I will modify them.

Reg, that is a valid consideration. I was thinking of expanding the cases far enough down the body to centralize the case but the tape trick sounds much simpler. With the expander one still has to somehow centralize the case. Thanks for that tip.

Hey 303guy, if you can get 209 primers easily there, think about modding berdan cases for those. I have about 25 or 30 I converted to 209's, over the past 4 yrs the grandsons have shot them a BUNCH....probably going on close to 100 reloads per case now. Not enough pressure to wear on them, they seem to keep going & going like 38 spec target brass does. All you gotta do is drill for the body then a countersink for the primer rim so it seats flush. BTW, 30/40 krag brass works too, comes out almost 3" but that brass is kinda hard to come by now.

[Tackleberry41]

9.3x74r are by far the best 410 shells. I have done 303, they get that funky backwards bottle neck due to the thickness at the base. 444 doesnt do much better.

[Ballistics in Scotland]

9.3x74r are by far the best 410 shells. I have done 303, they get that funky backwards bottle neck due to the thickness at the base. 444 doesnt do much better.

I'm quite sure you are right about 9.3x74R, especially for a 3in. chamber. They won't be cheap, and probably still leave the OP with the problem of getting them from overseas. From Europe, where they are certainly made, might now be easier than the US.

[303Guy]

I'm quite sure you are right about 9.3x74R, especially for a 3in. chamber. They won't be cheap, and probably still leave the OP with the problem of getting them from overseas. From Europe, where they are certainly made, might now be easier than the US.

I happen to have a nephew who lives in Germany ......
He's here visiting right now. I'll ask him to send me some if he can get. Maybe even some Brenecke slugs.

Thanks for the shotshell primer conversion tip, Roy. I have already bought the 209 primers to reload my plastic hulls.

Jeff, those plastic hulls are always an option but I would need to buy more to make it a proposition. Or find some spent ones. I would think that the larger case would lower pressure somewhat, depending on how they are loaded? Longer plastic case life maybe?

[kenyerian]

http://www.endtimesreport.com/410reloading.html Interesting article on 410 reloading using different brass.