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20mm Burney recoilless?

T

Tony Williams

Well-Known Member
I have just been sent this message by a correspondent:

I was just reading "Men Against Tanks" by John Weeks. In it he mentions that Sir Dennis Burney actually made a 20mm recoilless that had a muzzle velocity of 2,850 fps. This was in 1942, and in light of Sir Dennis' comments about the Swedish m/42 in your excellent article, I've become very curious about this matter.
Is it possible that the gun John Weeks is referring to is actually the m/42 that Sir Dennis tested? Or was it really one of Sir Dennis' own designs? Is there a surviving specimen or pic of the gun or ammo?
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This doesn't really match up with the info I have included in my article on the m/42 here: http://www.quarry.nildram.co.uk/gustav.htm which is as follows:

A 1943 assessment of factory drawings by no less than Dennis Burney of the Broadway Trust Company (designer of the recoilless Burney guns) estimated a muzzle velocity of 800-820m/s, but it appears that he was assuming a heavier projectile, as most 20mm AT weapons had bullet weights of 130-150g. In fact, the m/42's projectile weight was 108g and the muzzle velocity around 950m/s. The AP shot had a tracer and was known as the slpprj m/42; unusually for an ATR, there was also an impact-fuzed HE projectile known as the sgr m/43.

Burney had some interesting technical comments to make, comparing the design with his own very similar 3.45" recoilless gun. He estimated that the size and shape of the exhaust jet in the breech would limit the recoil absorption to about 80% but that it was capable of improvement and was basically a satisfactory design. Interestingly, he suggests that its main use could be as a sniping weapon.
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My info comes from a letter actually written by Burney, dated 25th November 1943; note that he only refers to seeing drawings, not testing a gun. If he had been working on a 20mm, surely he would have mentioned it then when writing about the m/42. So is Weeks completely wrong about this?
 
Tony,

I have a copy of "British and American Artillery of WW2" by Ian Hogg.

on page 231 he describes Sir Dennis Burney's early guns.

The first was a modified 4 bore shotgun

The second was a 20mm single shot gun weighing 50lb and firing a standard Oerlikon shell at 3,500ft/sec. development was not proceeded with.

There are no pictures or drawings in the book.

I am trying to find any Burney Cases or Projectiles. I have a 95mm HE shell in my collection.

Will.
 
Burney 20mm

I can confirm from documentation I have Hogg is correct. Burney did build a 20mm shoulder fired RCL gun and it weighed 50lbs. Velocity is quoted at 3,500 fps. with a standard service projectile.

Regards
tonyE
 
It seems the Americans were playing around with 20mm recoilless guns in the early 1970's when someone came up with the idea of a recoilless version of the M55 round. Apparently the muzzle velocity would have been between 1500 and 1800 fps.
Apologies for the quality of the reproduction.
Dave.
 

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SG500 said:
It seems the Americans were playing around with 20mm recoilless guns in the early 1970's when someone came up with the idea of a recoilless version of the M55 round. Apparently the muzzle velocity would have been between 1500 and 1800 fps.
Apologies for the quality of the reproduction.
Dave.
Click to expand...
Interesting - I hadn't heard about that one.
 
Tony Williams said:
I have just been sent this message by a correspondent:



This doesn't really match up with the info I have included in my article on the m/42 here: http://www.quarry.nildram.co.uk/gustav.htm which is as follows:



My info comes from a letter actually written by Burney, dated 25th November 1943; note that he only refers to seeing drawings, not testing a gun. If he had been working on a 20mm, surely he would have mentioned it then when writing about the m/42. So is Weeks completely wrong about this?
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Tony I'm fairly sure Bill W has several expt 20mm Burney rounds in his collection, it may be worth you asking him.
Dave.
 
20mm Burney

I shall be down at Bill's in two weeks, so I will check and take photos of anything he has.

I have pictures and details of the Burney 20mm.

Regards
tonyE
 
TonyE said:
I shall be down at Bill's in two weeks, so I will check and take photos of anything he has.

I have pictures and details of the Burney 20mm.

Regards
tonyE
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Tony did you manage to get photos of the Burney 20mm rounds?
I'm just curious to see what they look like.
Dave.
 
Burney

Unfortunately, thanks to the BA cabin crew strike I never made it to Tucson but met Bill in St.Louis for the SLICS show.

I still intend to get to Bill's soon, perhaps in November, so will pursue the 20mm Burney rounds.

I have drawings of the 20mm round and pictures of the Burney gun.

Regards
TonyE
 
Burney

According to a 1944 report on the Burney experiments the following had been mnufactured and tested. 20mm, 3.45 shoulder Gun, 95mm and 7.2. Under design 3.7, 3.7 AA Duplex projectile, 8'' RCL and modified 3.45 shoulder gun.

Ammunition actually fire 20mm, 3.45, 95mm, WB projectile, 35lb HE, 7.2 WB.

The 20mm fired an Oerlikon projectile at 3500fps.

Regards
 
Burney

Thanks Sandy

I used to have a mint 3.45 dummy round, the conical type without a bottleneck, but it got lost in circumstances beyond my control!

Have you ever seen a 20mm example?

Regards
TonyE
 
20mm

Tony,
Never seen a 20mm but the report has drawings and pictures of many of the rounds/guns including the 20mm.
My Burney pics.

Sandy

PS. The term shoulder fired has a new meaning with the size and weight of some of these weapons!
 

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Apologies for the quality, I was in a rush.

Regards

TimG
 

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20mm Burney

That is a slightly better quality picture than my scan, Tim. Do you have the whole manual on Burney weapons?

Also, there is a .303 perforated case that is mentioned in the documentation but I am not sure where it fits into the overall schame of things.

Regards
TonyE
 
Burney article

Tony - I have just about finished an article on Burney and the Broadway Trust Company for the IAA Journal with a lot more details and pictures. You may want to put some details from that in the ECRA Bulletin. I am sure Chris will not mind.

Regards
TonyE
 
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