P-47 Thunderbolt gun mounts

[spaters]

I am interested in the differences in wingmounts on WW2 fighters. It appears to me that the gun mounts on the P-47 fighter is different from most other fighters. Most that I have seen have vented sleeves on the 50 cal. Browning barrels while the P-47 has a tube mounting. Can anyone explain why this is? Thanks.

[PHN]

I have read that the barrels of the P-47's guns had "thermal sleeves." I am unsure what the function of these sleeves was. There is a forum at www.quarry.nildram.co.uk that has excellent information on automatic guns, including aircraft-mountings.

[FLYBOYJ]

These sleeves probably kept the barrels cool and also kept them from warping.

[DAVIDICUS]

Interesting topic. I don't know how these sleeves could have aided in cooling a hot barrel. You want maximum surface area exposed to the cooling medium, which is air. A sleeve over the barrel would act as an insulator, no?

I wonder if the reason is because the guns are configured parallel to the ground as opposed to being centered in the wing. The sleeves may be additional "guides" for proper gun barrel placement.

[FLYBOYJ]

If its a dissimilar metal, the sleeve will draw the heat away from the barrel. You could only shoot the guns for a few quick seconds at a time, fighter pilots would do this in "squirts." Prolonged firing of the guns will definitely warp the barrels.

I don't think alignment has anything to do with this as the guns and gun sight are calibrated to converge at a specific distance during a process called bore sighting. I know an old WWII an Korean war armorer, the next time I see him I'll ask him.

[the lancaster kicks ass]

wow i never realised the guns were mounted parallel to the ground like that..............

[DAVIDICUS]

I am going to "re-post" this question on the Aviation forum where it will receive more review and consideration.

[spaters]

Thanks everybody, I appreciate the input. This is a question my father, an avid WW2 aviation buff, has wondered about for many years. We have asked a number of people at various museums over the years this question, and have never found anybody that could explain this difference. I'll keep watching the post. Once again, thanks.