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6pr 7cwt case

Brew_Up

Active Member
Ive have this 6pr 7cwt case, going by the crimp what sort of round would this case have held? Currently got a relic APCBC round stuffed in there. Also would anyone have dimensions of the nose cone for that round. Thanks

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You need to hold the projectile alongside the case, with the bottom of the driving band level with the top of the case and see if the cannelure and crimp rings match up. If one is higher or lower than the other it is not the right case. To me it looks like a HE case with the cannelure that low down. But basically, they are pretty much all the same cases...excepting the APDS case.
 
You need to hold the projectile alongside the case, with the bottom of the driving band level with the top of the case and see if the cannelure and crimp rings match up. If one is higher or lower than the other it is not the right case. To me it looks like a HE case with the cannelure that low down. But basically, they are pretty much all the same cases...excepting the APDS case.

Ive just held the round alongside the case and the base of it only just reaches the crimp. There is a recess in the portion of the round that sits inside the case which I assume is meant to match up to the crimp on the case which in this instance it doesn't. I guess a HE round would sit deeper in the case? I'm under the belief the 6pr HE round wasn't very effective, hence swapping to the 75mm on churchills and cromwell.
 
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My HE round has the cannelure at the same height as my other projos, AP, APC and APCBC. The only one that is different is the APDS with its top crimp.
The ballistic cap on mine is 90mm overall with a 7mm tip radius. I couldn't easily measure the crh of the cap but it is likely listed somewhere.
 
My HE round has the cannelure at the same height as my other projos, AP, APC and APCBC. The only one that is different is the APDS with its top crimp.
The ballistic cap on mine is 90mm overall with a 7mm tip radius. I couldn't easily measure the crh of the cap but it is likely listed somewhere.

Thanks tankbarrel, I can get on restoring the round now. Ive also got a AP round to do too with a beaten up drive band.
 
My HE round has the cannelure at the same height as my other projos, AP, APC and APCBC. The only one that is different is the APDS with its top crimp.
The ballistic cap on mine is 90mm overall with a 7mm tip radius. I couldn't easily measure the crh of the cap but it is likely listed somewhere.

No the cannelure for the cases with He projectiles is lower than for the cases with AP ,APC and APCBC projectiles.
 
No the cannelure for the cases with He projectiles is lower than for the cases with AP ,APC and APCBC projectiles.
Mine aren't. My HE projo has the groove in exactly the same place as my various AP projos and I also have two HE cases with original base stencils and they also have the crimp in the same place as AP cases.
 
Just a thought, I wonder if the different types of HE projectiles have different crimping positions?
 
I can see from that my case must have been for the long HE shell. I wonder why there was 2 types of HE?

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Make sense. Are the HE cases less common? A bit dissapointed its not for an AP round but still a nice case to have in the collection.

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Make sense. Are the HE cases less common? A bit dissapointed its not for an AP round but still a nice case to have in the collection.

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Based on my assumption that your case is for the longer HE projectile (I base that assumption purely on the link I posted above that seems to show the lower crimp on the HE projectile) then your case is scarce and if I were you I'd be happy with it. The longer HE rounds (and hence cases with lower crimping) are very difficult to come by.
I'm sure you'll pick up case with the much more common crimping used on the short HE, AP, APC,APCBC and proof easily enough, they frequently crop up in boot sales, on line and militaria fairs.
Dave.
 
Based on my assumption that your case is for the longer HE projectile (I base that assumption purely on the link I posted above that seems to show the lower crimp on the HE projectile) then your case is scarce and if I were you I'd be happy with it. The longer HE rounds (and hence cases with lower crimping) are very difficult to come by.
I'm sure you'll pick up case with the much more common crimping used on the short HE, AP, APC,APCBC and proof easily enough, they frequently crop up in boot sales, on line and militaria fairs.
Dave.
I bought the case from earni on here, great guy to deal with, im only dissapointed in the fact that id not done my reasearch before hand and just not realised what i had got. Im happy with the case, its a mint, like you say i will keep an eye out for the correct case for the rounds i have got. I bet finding a long HE round will be unlikely then.

So quite by accident ive end up with something more interesting for a change, im too impaitant sometimes and rush to buy the first thing i see then regret it after, not this time though

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I bet finding a long HE round will be unlikely then.

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I've had 2 of the long HE rounds in 25 years of collecting, now traded out of the collection long ago, they're certainly out there.

Dave.
 
Early in WWII there was not much call for 6Pr 7cwt HE shell, kinetic energy AP shot and upgrades were much more in demand. The Mk1 HE was in existence but nobody used it much because it was not very good, being rather small.
Later on when we got into urban warfare in Italy, then after D Day, there was a need for the infantry to have HE shell for their own anti tank guns, rather than rely on tanks who might be off doing their own thing. However, there was a 6Pr 7cwt shell production capacity shortage, but there was capacity for producing slightly modified 6Pr cartridge cases and the navy did not have a pressing need for 6Pr 10cwt HE.
So the 6Pr 7cwt Mk1M case was produced to suit the naval shell.

The original Mk 1 army shell was fitted with an external tracer, was the same full length diameter, had a driving band 0.77" wide, and was slightly humped about two thirds up from the base end. It was also 1 and a quarter inches shorter than the Mark 10.
The diameters of both Mk 7 and 10 shell were reduced, below the driving band by 0.022", which led to the corresponding increase in the internal diameter of the Mk 1M cartridge case. The Mk 10 was fitted with an external tracer, but the Mk 7 was not.
The driving bands of both these marks were 0.812" wide, but the Mk 10 was plain, whereas the Mk 7 had two rebates. Both were flatter in appearance than the Mk 1.
These two complete rounds were referred to as hybrids.
The Mk 1 case was also used with APCBC and APDS shot.
Plug FH 1.6" No 1 was used, but not often as the rounds were held fuzed.
 
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