Hulls and pressure

[eye shot]

How much more pressure will a brass hull withstand over a plastic hull?
Thanks

[Johnch]

IMO in many cases the shotgun will start to be damaged soon after you exceed the recomended Max

Dad ruined a Winchester Model 12 3" Heavy duck back in his day with over pressure loads

Not 1 load , but a lot of them
The loads trashed the bolt and the barrel

John

[UNIQUEDOT]

How much more pressure will a brass hull withstand over a plastic hull?
Thanks

Ummm... I'm pretty sure the correct answer is... no more than the plastic hull.

[turbo1889]

For the thin walled Mag-Tech type brass cases ~ Very little if any extra pressure beyond what a plastic hull will withstand although they do have the advantage of stretching in the base area (at normal pressure levels) rather then separating from the base like some plastic hulls will do in an oversize loose chamber as is commonly found on 45-Colt/410-shot combination guns.

Now the heavy walled RMC type brass cases will take as much or more pressure then your gun can handle even if it is built to withstand rifle pressure levels (very few are) since they are built even tougher then most rifle brass with thicker heavier walls.

[Reload3006]

In a shotgun it is not so much how much pressure can your hull stand its how much pressure can your guns chamber stand. Do not think that because you have a brass shell you can load hotter. You may not live through the experiment.

[turbo1889]

In a shotgun it is not so much how much pressure can your hull stand its how much pressure can your guns chamber stand. Do not think that because you have a brass shell you can load hotter. You may not live through the experiment.

+1

But for those who do have a gun that is built to handle full on rifle level pressure levels go with RMC brass if you want to hotrod it above about 20-K (most plastic shells won't take much more then 20-K pressure levels).

BUT YOU STILL NEED TO BE CAREFUL. And you had better be right about having a strong enough gun and its going to kick like a mule straight out of the pit of hell itself.

[eye shot]

Thats what I wanted to know- plastic 20k. I have made a .410 slug gun out of a .444 Marlin single shot rifle that I know is good for at least 42k. I'm using a slow burn rifle powder at 60% of .444m max load- a youth load. I can only use plastic in this state for deer and didn't know how far I could push the plastic hull. These youth loads haven't hurt the hulls. I will go higher untill the hull shows singes of failling. Thanks

[turbo1889]

An important note is that usually with plastic hulls that fail due to high pressure is that the failure will occur at the base of the plastic where it attaches to the metal head and failure may not be immediately noticeable until the hull is reloaded a second time and then it will completely separate upon firing.

After firing take the spent hull and grab the plastic tube with one hand and the metal head with the other and try to pull them apart. Pull hard; if they separate then it is a good thing you caught that one and didn't reload it since it wouldn't have held for the second loading.

20-K isn't a hard fast rule, just what I have observed in practice. All the one-piece compression formed hulls that don't have a separate base-wad but the tube and base-wad are one continues piece of plastic like the Remington STS hulls and the old Winchester AA compression formed hulls in 12ga. & 20ga. will hold up to the most and will take quite a bit more then 20-K before they fail in some other way but those kind of one-piece compression formed hulls are kind of a rarity in the 410-bore size although Winchester did make a few of them years ago. But all the hulls with separate base-wads either plastic or cellulose fiber will usually fail at the base and the base will separate from the plastic tube body. Remington's seem to be slightly stronger then the others and the Fiocchi seem slightly weaker then others with the exception of the Fiocchi 3-1/2" hulls which use a different base-wad and are built like a tank but those are only in 12ga. & 10ga. so that is only a foot note to someone asking about 410-bore hulls.

Interesting 410-bore build what is the action style? Bolt, lever, break open ??? Did you change out the barrel to a 41-cal or are you using the original 0.430" barrel and just stuffing the larger diameter boolit into the plastic hull? Reason I ask is because several years ago I built a 410-bore rifled barrel slug gun for my brother because he is a bean pole, tall skinny and light weight and even my 20ga. knocked him around more then he was willing to tolerate which pretty much left him SOL for hunting in the shotgun only areas so I found an old beat up 303-brit army rifle that was big chunky and heavy and pulled the barrel and had a 405-Win barrel blank threaded to fit and then cut the chamber for 2-1/2" 410-bore shells and took a dremel to the box mag so that it would fit and feet the 410 shells (303-brit bolt face fits 410-bore shells almost perfectly) left the original military ghost ring sight on the rear and just put a fresh blade on the end of the barrel. Loaded it with 41-mag boolits from an old RCBS mold that dropped large to begin with that I beagled and used them "as cast" so they would just fit the barrel which was about 0.415" in the grooves. IMR-4227 and R-7 loads with nitro cards between the powder and the slug worked great he still uses it to this day to hunt those areas although he has had his gun examined more then once by a game warden who though he was hunting those areas with a high powered rifle.

[eye shot]

Turbo
I'm using a new CVA Elite Stalker break open 24" heavy barrel, 1/20 twist in .444M. It took me about 10min. to convert it to a .410 rifled slug gun. The only thing done to the gun is ream it out alittle for the larger .410 rim. The chamber it self and bore are left original. There is more work to the hull than the gun. I run the .410 hull in a .444 die and then cut it down to.444 length. Take a 7/16 drill bit in drill press and ream inside of plastic hull deep enough to seat bullet. I'm thinking a 7/16 tree bur may work best .I don't use a crimp. I've shot some old 225jhp and 300gr cast and no plastic hull to head leeks. I have some 355gr LWN GC. coming this week. I'm looking to get 1500-1700fps out of the 355's and that would be deadly on deer. I will chrony when weather permits. Oh I do have to restamp the barrel .410. Thanks