Steel carts - reload plus LP/HP

[HantsRob]

Evening!

 

What's the difference between low perfornance and high performance steel cartridges?
Also on my gamebore steel carts, the box says you can't reload them. Is there a reason for this?

:)

[mellors]

9 hours ago, HantsRob said:

Evening!

 

What's the difference between low perfornance and high performance steel cartridges?
Also on my gamebore steel carts, the box says you can't reload them. Is there a reason for this?

As far as I'm aware its the speed and pressure difference. I've never gone into it as i only reload standard steel loads for pigeon. 

I've reloaded hundreds of 20g kent/gamebore steel cases doesn’t say anything on the box. 

[TIGHTCHOKE]

9 hours ago, HantsRob said:

Also on my gamebore steel carts, the box says you can't reload them. Is there a reason for this?

Might be worth ringing Gamebore and asking.

[rbrowning2]

9 hours ago, HantsRob said:

Evening!

 

What's the difference between low perfornance and high performance steel cartridges?
Also on my gamebore steel carts, the box says you can't reload them. Is there a reason for this?

Low performance can in theory be used in any modern gun, high performance must in theory only be used in a steel proofed gun. Then certain choke restrictions also apply, but other will be along to tell you more.

 

as for gamebore saying can’t reload them, as do in general others, just a backside covering exercise plus discouraging reloading.

 

[Dave at kelton]

The difference is about pressures/velocities with increased pressure in the HP loads. Look at the BASC information sheet on line via google.

I reload cases with steel for wildfowling so can’t see what the issue is if the case is in good condition and resized.

[bigroomboy]

56 minutes ago, Dave at kelton said:

The difference is about pressures/velocities with increased pressure in the HP loads. Look at the BASC information sheet on line via google.

I reload cases with steel for wildfowling so can’t see what the issue is if the case is in good condition and resized.

Just to add to this its also about mass/shot size. Hence why larger shot sizes are generally HP. Pressure for steel proof and CIP S are the same  but steep proof considered the energy of the pellet as it goes through the choke restriction.

[Guest cookoff013]

Yup.

[Dave at kelton]

7 hours ago, bigroomboy said:

Just to add to this its also about mass/shot size. Hence why larger shot sizes are generally HP. Pressure for steel proof and CIP S are the same  but steep proof considered the energy of the pellet as it goes through the choke restriction.

Yep can’t remember if it changes around Size 4?

[HantsRob]

Inside the box. I haven’t emailed gamebore to ask why

[Guest cookoff013]

Hp loads are a little faster than the limits of standard proof. The pressure limits are 740bar to 1050bar. That extra pressure for 30-60fps? It kinda makes sense. Manufacturers use pressure very wisely. And 1050bar can be achieved with faster powder at the expense of high pressure.

Dont be scared of hp shells. Use an appropriate gun and have fun.

[Smudger687]

iirc CIP has decided that a cartridge is deemed to be high performance if:

1) The velocity exceeds a certain value (I think its 395 m/s) 

2) The momentum exceeds a certain value. (Can't remember, think it works out to a maximum load of around 32g)

3) The pellet size is larger than 3.25mm (steel size 4)

If any of the three are exceeded then the cartridge is deemed to be high performance, and a maximum of half choke is to be used with any pellet size larger than 4mm (1 and larger).

High performance cartridges have their own limits - maximum of 1050 bar chamber pressure, 430 m/s velocity limit and 19 Ns momentum for 89mm chamber guns in 12 gauge. 

In my opinion though, even if loaded to maximum allowable CIP specs (and many commercial offerings aren't even close to it) it's still pretty anaemic compared to what the Americans can get hold of. 

I suspect that gamebore is just covering its **** when it states not to reload - if some dipstick puts too much powder in a home load and injures themselves it could open them up to a liability claim if the injury was blamed on some sort of case failure. 

Don't believe the received wisdom that steel patterns best with 1/2 choke - one only needs to check some of the steel shot patterns from the 12 gauge Muller UFO choke (~43 thou constriction) and the 10 gauge .720 and .705 terror chokes (55 and 70 thou constriction respectively) to know that the rule is frequently violated. Randy Wakeman has a more cynical explanation- that shotgun manufacturers make poor quality chokes which can't stand up to steel when tightly constricted. 

[Guest cookoff013]

17 hours ago, Smudger687 said:

iirc CIP has decided that a cartridge is deemed to be high performance if:

1) The velocity exceeds a certain value (I think its 395 m/s) 

2) The momentum exceeds a certain value. (Can't remember, think it works out to a maximum load of around 32g)

3) The pellet size is larger than 3.25mm (steel size 4)

If any of the three are exceeded then the cartridge is deemed to be high performance, and a maximum of half choke is to be used with any pellet size larger than 4mm (1 and larger).

High performance cartridges have their own limits - maximum of 1050 bar chamber pressure, 430 m/s velocity limit and 19 Ns momentum for 89mm chamber guns in 12 gauge. 

In my opinion though, even if loaded to maximum allowable CIP specs (and many commercial offerings aren't even close to it) it's still pretty anaemic compared to what the Americans can get hold of. 

I suspect that gamebore is just covering its **** when it states not to reload - if some dipstick puts too much powder in a home load and injures themselves it could open them up to a liability claim if the injury was blamed on some sort of case failure. 

Don't believe the received wisdom that steel patterns best with 1/2 choke - one only needs to check some of the steel shot patterns from the 12 gauge Muller UFO choke (~43 thou constriction) and the 10 gauge .720 and .705 terror chokes (55 and 70 thou constriction respectively) to know that the rule is frequently violated. Randy Wakeman has a more cynical explanation- that shotgun manufacturers make poor quality chokes which can't stand up to steel when tightly constricted. 

great post.

also 'merican manufacturers have inhouse designed wads for extreme performance wads. Hypersonics etc. Homeloaders already use excess powder. I have seen some finland data. It scares me. It scares me alot.