P-40 live fire at Wanaka video

Taigh Ramey · **Posted:** Wed Mar 26, 2008 11:18 am

Sorry that I didn't post this in the base theatre but it is too cool not to post on the front page!

There are two videos that have been posted on youtube of the live fire demo of the P-40 at Wanaka. I was told yesterday that the shells were collected, signed and sold to raise funds for the show or charity. I would think that the rain of brass and links would be more spectacular than the guns firing themselves.

Six guns at 10 to 12 rounds a second that’s 120 shells and links dropping out of the wing every second!

http://www.youtube.com/watch?v=w3T5QkFg6cw

Awesome!

Warbird Kid · **Posted:** Wed Mar 26, 2008 12:57 pm

Demos like that have to happen more in the States! Or at least rig up more of those gas pipe line guns that the Tora team and a few other Warbirds have been equipped with.

Elroy13 · **Posted:** Wed Mar 26, 2008 1:14 pm

Now thats cool!! You can see the muzzle flashes before you hear them go off!

gsheff · **Posted:** Wed Mar 26, 2008 1:36 pm

Is that live ammo, blanks, or one of those fake gas operated guns. This is so cool. Please tell me these are atleast blanks!

Mike · **Joined:** Tue May 04, 2004 8:54 am **Posts:** 3333

There are photos around on the web showing the empty cases being ejected under the wings on the firing passes, so I think you can safely assume they're not gas-operated!

Taigh Ramey · **Posted:** Wed Mar 26, 2008 1:58 pm

Those are real blanks fired through six full auto live machine guns.

Old SAR pilot · **Posted:** Wed Mar 26, 2008 2:39 pm

Taigh noted:

Quote:

Six guns at 10 to 12 rounds a second that’s 120 shells and links dropping out of the wing every second!

...And at current prices for the blanks and links in the US, that's about $250/sec! :shock:

Nice effect, though! :wink:

Richard W. · **Posted:** Wed Mar 26, 2008 4:42 pm

I'm curious to know how they've adapted those .50's to fire the blanks.

Some device to restrict the gas flow is required at the muzzle end in order to cycle the action with blanks.

Anyone know how they have them rigged?

Taigh Ramey · **Posted:** Wed Mar 26, 2008 5:25 pm

The aircraft 50 cal (ANM-2 Aircraft Basic) is the simplest 50 to adapt for blank firing. Two blank adapters are needed; one on the muzzle and one in the feedway. The 50 heavy barrel or ground version is not as simple as it requires a big ugly external adapter that goes from the receiver (main body of the gun) to the muzzle. Some folks have made special heavy barrels strictly for blank firing.

The 50 Browning is a gas operated gun, so to speak, as it requires forces acting to push the barrel toward the rear during operation. These forces move the whole bolt and barrel extension until the breech lock is retracted to allow the bolt to continue aft and cycle. These forces are generally created by the pressure developing behind the bullet as it travels through the barrel. As the bullet exits the muzzle, pressure is also pushing on the front face of the barrel.

When you shoot a blank there is not enough pressure in the barrel to move the bolt and barrel extension and the gun will not cycle. The blank adapter replaces the front barrel bearing in the cooling jacket (perforated barrel shroud) and makes a cap around the muzzle of the barrel. This cap has a smaller opening to act as a restriction to maintain higher pressures inside the barrel and to put pressure on the front face of the barrel when the gun is being fired. This pressure helps the bolt and barrel extension move to the rear and cycle the gun.

The other adapter is the feedway adapter which is simply a block that keeps the shorter blank ammunition positioned properly in the feedway. If the ammunition slips a little forward in the feedway then the gun will not pick up the next round and will stop firing.

I understand that they did have problems with jams and feeding with the P-40. I hope to talk to the person whose guns were used to see what kind of problems they had. I would like to share information as we have come across similar problems with the different types of blanks and adapters. Different blanks may have different powder loads and will cause problems with a given orifice size on the blank adapter.

Awesome undertaking and I can’t wait to see better video.

Old SAR pilot · **Posted:** Wed Mar 26, 2008 5:26 pm

If they did a mod as was done to the waist guns used in Memphis Belle, an adaptor was probably fitted to the accelerator cap on the barrel jacket. This restriction would allow the gun to build sufficient pressure in the barrel to function. But the Kiwis prolly have their own devices for that...

Django · **Posted:** Wed Mar 26, 2008 5:41 pm

Here's another one... :lol:

The roll on this pass is excellent. Plus a surprise.

http://www.youtube.com/watch?v=_GFH5faZtSk&NR=1

Richard W. · **Posted:** Wed Mar 26, 2008 6:07 pm

Taigh- Thanks for your explanation.

Yeah, I was thinking of those clumsy blank firing adapters we used to have on our ground model M2's when I was in the Army. I did not know that the aircraft model had a different requirement.

warbird1 · **Joined:** Fri Sep 21, 2007 6:25 pm **Posts:** 2760

Awesome video, Taigh! I can hardly wait to buy the Wanaka DVD, so I can see it up close.

Do you know if they plan on firing the blanks again during any performances in the future or was that a one-time special occasion deal? Did they have to get any kind of waivers from the New Zealand civil aviation authority?

Old SAR pilot · **Posted:** Sun Mar 30, 2008 2:55 pm

An answer to the "How'd they do that?" re: blank-firing .50s.....

Email'd Graham at Classic Wings on it, and this was the reply:

Quote:

Hi Bob,

That was a good question. You got me curious too, so I asked Garth Hogan and he replied as follows.....

The guns were modified to fire blanks by the fitting of a Blank Firing Adaptor (BFA) to the end of each barrel. This is a machined piece of steel with a small hole in it that acts as a "choke" and is screwed on to the end of each barrel. Keeping in mind that a machine gun, when fired, relies on the back pressure in the barrel behind the projectile to re-cock and load the next round. With a blank of course there is no projectile to create the back pressure and hence not enough pressure in the barrel to re-cock and re-load the gun. With a BFA the hole is significantly smaller than the bore in the barrel (which of course is .50") and this increases the pressure in the barrel. We spent sometime test firing the guns and gradually reducing the size of the hole in the BFA until there was enough back pressure in the barrel to re-cock the guns but still a big enough hole to allow the gas (and of course the Flame and smoke) to get out. Hope this answers your question. Best part about firing the guns is that it turns someone 60 years old , albeit temporarily, in to an 18 year old. Marvellous experience!

What a neat thing to be able to allow and airshow crowd to see and hear!

Cheers for now,
Graham

Django · **Posted:** Thu Nov 13, 2008 6:07 pm

We're here for WARBIRDS, right?!

This never gets old...

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P-40 live fire at Wanaka video

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