Making 410 out of 303 brass

[boingk]

Pretty much what the title says - making 410 shotshells out of 303 brass. I've recently picked up a basic little Boito 410 side-by-side with the view of getting into some slightly unconventional reloading using existing equipment and components. I've got 303 brass, I've got suitable powders and primers... why not?

To fire-form the cases I'm giving them a shot with 10gn of Trailboss with a cotton wad and a wax plug. Should work but we'll see.

Ultimately I'll see if I can run my own shot. I'll see if it works and post the details if anyone's interested. I'm aiming for around the #4 size or so.

[Oldbloke]

What a great project. I'd really like to see how you go making the shot. Do you intend making the shot maker?

[straightshooter]

Fireforming the brass the way you describe would be a very risky proposition in your Boito.
The working pressure for the 410 is well under 15,000 psi and to get the case to blow out you would need pressures in the region of 25 to 30,000 psi.
Thus your project might come to an abrupt, unforeseen end.
I would suggest a different method.
Anneal the brass with a flame and then use Hornady style elliptical expander balls to get to a straight walled case. Repeated annealing and incremental expansion may be necessary.
A suitable method might be to drill a hole in a piece of steel sized so that it holds the case rim down in a shallow container of water. The water level should be about 6 mm above the solid web of the case. Heat evenly with a propane torch with a diffused flame (not pinpoint) until the case reaches an even dull red in a fairly dark room.
Now expand when cool. A light lubricant might help.
A slow process I know, but you will only have to do it once.
Good luck with your project.

[bigpete]

Fireforming the brass the way you describe would be a very risky proposition in your Boito.
The working pressure for the 410 is well under 15,000 psi and to get the case to blow out you would need pressures in the region of 25 to 30,000 psi.
Thus your project might come to an abrupt, unforeseen end.
I would suggest a different method.
Anneal the brass with a flame and then use Hornady style elliptical expander balls to get to a straight walled case. Repeated annealing and incremental expansion may be necessary.
A suitable method might be to drill a hole in a piece of steel sized so that it holds the case rim down in a shallow container of water. The water level should be about 6 mm above the solid web of the case. Heat evenly with a propane torch with a diffused flame (not pinpoint) until the case reaches an even dull red in a fairly dark room.
Now expand when cool. A light lubricant might help.
A slow process I know, but you will only have to do it once.
Good luck with your project.

I agree with annealing the brass,however,this method of fireforming 303 into 410 has been done thousands of times before with zero issue. Its actually reasonably common

[bladeracer]

https://youtu.be/wupF-N5vqzI

[bigpete]

https://youtu.be/wupF-N5vqzI

Ha ha,not sure if I'd want to try that! One way to fireform though lol

[Oldbloke]

Shot making.

https://youtu.be/fGWiVEBYAf0

[Noisydad]

Pretty much exactly what I did to feed my 1950s Mossberg bolt action .410. Those fire formed cases cycle from the mag perfectly and work great.

[bladeracer]

https://youtu.be/wupF-N5vqzI

Ha ha,not sure if I'd want to try that! One way to fireform though lol

I subscribed to him for a long time, and recalled him doing this
But his American "patriotism" and "religion" eventually got to be too much for me.

[bigpete]

Oh god,I can imagine !

[boingk]

Thanks for the advice guys.

Straight shooter, I understand that with annealed cases and non-metallic projectiles the process should be fairly safe. I'm using waxed cotton wadding on top of 10gn (2.1cc dipper) of Trailboss with a pistol primer. As I understand it this will generate very low pressures but should be enough to form the cases - it may well need two firings from what I've heard.

I saw the Magma shot maker! Very cool piece of kit. I'm thinking more along the lines of a tin with a small hole in it over a bucket of water... very basic but the same process has been used for hundred of years in shot towers and small commercial casters.

Hopefully I can get to the range Tuesday after work.

- boingk

[boingk]

Also check this out. 30-30, 444 Marlin and 454 Casul from a little old 410 single barrel.

https://youtu.be/wAnbDvLIAac

[bigpete]

Thanks for the advice guys.

Straight shooter, I understand that with annealed cases and non-metallic projectiles the process should be fairly safe. I'm using waxed cotton wadding on top of 10gn (2.1cc dipper) of Trailboss with a pistol primer. As I understand it this will generate very low pressures but should be enough to form the cases - it may well need two firings from what I've heard.

I saw the Magma shot maker! Very cool piece of kit. I'm thinking more along the lines of a tin with a small hole in it over a bucket of water... very basic but the same process has been used for hundred of years in shot towers and small commercial casters.

Hopefully I can get to the range Tuesday after work.

- boingk

Been there,done that re trying to make shot. Did not work well at all for me. But give it a try. You may have better luck than I. In fact I might try again but with a lot smaller holes,I used a sink sieve with about 5mm holes to try and make mine. I think 1mm holes might work better.

[straightshooter]

Dear bladeracer and boingk
I am sure everybody is grateful for the videos you refer to from youtube university but they miss a salient point.
The original post was talking about fireforming in a Boito side by side of unknown robustness.
Both videos utilise single shot actions of the type also used to make break open centerfire rifles inherently having a known margin of safety.
Over the years I have possessed a #4 and a Martini both converted to 410 and I would have no hesitation in recommending either of those for fireforming.

boingk,
If you want to carry on regardless then at least consider replicating a 410 recipe from a published reliable source as best you can.
Starting with annealed cases will definitely help the process.
There are additional things that can be done to facilitate the fireforming but they can be trickey or dangerous where a choke is involved.

[duncan61]

I am with straight shooter on this.I would have a good look at how well made your side by side is.You can always set it up and pull by string.I ordered a H and R Handirifle that was interchangeable 410/22 Hornet barrels.The Hornet barrel was the same as the 45/70 and 30/06 just drilled smaller so I had no trouble experimenting with subsonic loadings before I had even heard of trailboss.I managed to develop a subsonic round using 80gn matchkings but they went through the paper sideways.I like what you are going to do and years ago I would of been all over it.Now reloading is a chore

[bladeracer]

The specific firearm should at least be proofed to normal shotgun pressures though, meaning it is certainly sufficiently robust to withstand the very low pressures of firing either a .303 cartridge or a paper wad with zero problems.

Dear bladeracer and boingk
I am sure everybody is grateful for the videos you refer to from youtube university but they miss a salient point.
The original post was talking about fireforming in a Boito side by side of unknown robustness.
Both videos utilise single shot actions of the type also used to make break open centerfire rifles inherently having a known margin of safety.
Over the years I have possessed a #4 and a Martini both converted to 410 and I would have no hesitation in recommending either of those for fireforming.

boingk,
If you want to carry on regardless then at least consider replicating a 410 recipe from a published reliable source as best you can.
Starting with annealed cases will definitely help the process.
There are additional things that can be done to facilitate the fireforming but they can be trickey or dangerous where a choke is involved.

[boingk]

Afternoon all.

I understand the issues involved and have fully stripped, cleaned and inspected the gun in question. It looks like an earlier production Boito with signs of use, but not much wear. Both barrels came up bright and unmarred with a quick brush, oil and patch. External cleaning has shown no rust evident.

The action itself is typical - very basic, rough machine marking on the mating break surfaces and silversolder evident on the hidden underside components in some places where too much was flowed into the joints where not visible and unaffecting the visual appeal.

I'd say overall it's in good-to-excellent mechanical condition and fair-to-good cosmetically.

While I hear the concerns of the process I've outlined for fire-forming, it appears that everything I can see lists ariund "10gn of fast burning pistol or shot powder" as a fairly consistent base loading. Some recommend cream of wheat for a plug, some recommend beeswax, some recommend a light load of shot over a card, others a combination of similar materials. Sealing is either wax, glued card, or other similar substitutes.

What I'm attempting to do not only seems widely replicated but also quite safe.

Straightshooter, I'm not trying to downplay your response at all. I'm appreciative that there is a measured voice of reason giving sound and safe advice. For anyone looking to do this I'd strongly recommend you conduct your own reading on the matter so you properly understand the procedure.

FWIW, the gun will obviously be test fired with standard commercial loadings before I go on to fireform loads.

- boingk

[Oldbloke]

There will only be a fraction of the weight of a normal shot load on top of the charge. Pressures will therefore be very low. It will be fine.

[boingk]

There will only be a fraction of the weight of a normal shot load on top of the charge. Pressures will therefore be very low. It will be fine.

Bingo. Pressure in a constricted volume is expansion and resistance. Lower the resistance and you lower the pressure proportionally.

[Oldbloke]

There will only be a fraction of the weight of a normal shot load on top of the charge. Pressures will therefore be very low. It will be fine.

Bingo. Pressure in a constricted volume is expansion and resistance. Lower the resistance and you lower the pressure proportionally.

Yep, too much mis information out there on YouTube and faceache. Most don't fully understand basic physics of firearms, let alone chemistry of explosives.

It will be fine. Just don't compress trailboss if that is used.

[in2anity]

Nothing but a good bit of “pushing the boundaries” to get the blood flowing, I know the feeling too well… waiting with baited breath to see the outcome of this. Keep us posted boingk.

[boingk]

Baited breath hey?

It worked just fine. I put a half dozen 303's through the gun without issue. They formed, but only partially, so I'll re-anneal and reload with something that's got a bit more pressure. I'm thinking powder, tufted cotton filler, then a 78gn hardcast .314" projectile. That should give enough go to blow the neck out properly without creating excessive pressures.

- boingk

[in2anity]

Death breath in the mornings.

Glad to hear it worked out. I had a .410 as a kid and it has a special place in my heart. I also have tones of 303 brass from service. I might just revisit it again one day.

[boingk]

Give it a try. I've got much the same feeling from taking snakes and rabbits in the farmhouse orchard and near the chicken coop. Currently chasing a nice little poachers gun, the folding SxS hammered type, just to complete the memory.

- boingk

[bigpete]

Baited breath hey?

It worked just fine. I put a half dozen 303's through the gun without issue. They formed, but only partially, so I'll re-anneal and reload with something that's got a bit more pressure. I'm thinking powder, tufted cotton filler, then a 78gn hardcast .314" projectile. That should give enough go to blow the neck out properly without creating excessive pressures.

- boingk

That was my same experience using 303 for 44 mag shotshells.

[boingk]

Alrighty.

My experiment with this has come to an end. The 303 brass did form, at least some of it anyway. The lower portions need either more pressure or more annealing or both and I'm not keen on doing that. What I've ended up with is a few cases that look good until you turn them in your fingers and realise they aren't concentric in the lower portions. The primers are also not consistent - the gun does not seem to like pistol or rifle primers and will fail 1 in 10.

Usable, but not ideal.

What I am getting into now, though, is shotshell reloading. I didn't realise you can do it fairly easily without a press, or even with a basic home made unit. Either way I've got some CCI 209 primers (100% strike rate), some used hulls, an improvised primer punch and a few different measures for shot and powder made from brass and copper. I'm waiting on wad cutters (leather punch set - check ebay) but for now I"m just hand cutting corrugated cardboard discs.

I'll grab some pics when I can.

Cheers - boingk

[bigpete]

Yep,loading shotshells is easy peasy

[bladeracer]

Never anneal the lower part of the case.
Try chamber your hulls before you load them to confirm they chamber okay, otherwise you'll want to resize the bases.

Alrighty.

My experiment with this has come to an end. The 303 brass did form, at least some of it anyway. The lower portions need either more pressure or more annealing or both and I'm not keen on doing that. What I've ended up with is a few cases that look good until you turn them in your fingers and realise they aren't concentric in the lower portions. The primers are also not consistent - the gun does not seem to like pistol or rifle primers and will fail 1 in 10.

Usable, but not ideal.

What I am getting into now, though, is shotshell reloading. I didn't realise you can do it fairly easily without a press, or even with a basic home made unit. Either way I've got some CCI 209 primers (100% strike rate), some used hulls, an improvised primer punch and a few different measures for shot and powder made from brass and copper. I'm waiting on wad cutters (leather punch set - check ebay) but for now I"m just hand cutting corrugated cardboard discs.

I'll grab some pics when I can.

Cheers - boingk

[boingk]

Never anneal the lower part of the case.
Try chamber your hulls before you load them to confirm they chamber okay, otherwise you'll want to resize the bases.

Yup. For anyone following along and thinking 'why?' the case head and lower portion of the case shouldn't be annealed as you will be likely to have extraction problems or even case head / web integrity failure... otherwise known as a facefull of hot gas or even a 'bang' at the wrong end of the gun.

[northdude]

would forming them hydraulically with water work