Blank Barrel Revisited - Sectioned To See Damage

[reconbob]

OK - The size of the hole in the blank adaptor that was fitted to

the barrel in the photos is 0.187", i.e. 3/16". This blank adaptor

with Swanson blanks must have been a violent combination. The

bolt must have recoiled at high speed and the blanks must have

been blown out of the gun - not merely ejected, accounting for

the flattened and split crimps. Again for reference

purposes a 0.246" orfice works a semi with Swanson blanks and a Phila Ord

10.5" blank firing barrel (which has a smaller bore volume than the .45

cal. barrel in the photos) and 29 lb recoil springs.

This barrel has a smaller orfice, and maybe 1/3 the power recoil spring

and the same very powerful blank.

 

Bob

[Blanksguy]

When we make .45 ACP SMG Blanks......we don't load them as "Hot" as Joe-Swanson does. The BFA Hole-Size with our .45 ACP SMG Blanks is about .152"-.166" (NOTE: We've been making Blanks for reenactors for over 20-years). The BFA Hole-Size will differ from gun-to-gun and with different models and/or barrel-lengths.

 

Guys need to realize that "Movie-Blanks" are puposely made to not only make more noise, but to have a higher "flash" for effect. That excess powder being burned (over-and-over-again) will create excess heat in short-order at that point of initial expansion. (IE: As the pressure of the burning powder inside the shell case builds up enough to open the crimped-case-mouth.....this excess higher-pressure will act like a small "blow-torch-effect" at the case-mouth.).

 

I had a Board-Member send me his barrel that was used for Swanson's Blanks to view the "ring" in front of the chamber/lead for my opinion.

My observations brought more questions than answers.....without more test equipment to see exactly the "makeup" of the rigs material......

 

1: Is it possible that the initial "blast" from the opening crimped-case is of a higher-pressure and allows the barrel-steel at that "ring" area to build up enough heat with Swanson's "loading" to infuze carbon from the fired powder (?).

 

2: Are their other "flash-additives" added to Swanson's loading in this .45 ACP Blank that would cause additional heat and/or metal build-up....such as aluminum or other metal (?).

 

3: Are the guns fired in excess of the number of normal FMJ cartridges just because they are "Blanks".......such as a reenactment where several magazines were fired in rapid order building up heat .

 

4: As I have never heard reports of this happening with other calibers when using Blanks such as 9x19mm (9mmLuger)......is this Swanson-Blank just a bad-loading in .45 ACP SMG for use by reenactors (?).

 

I have heard many times that Swanson-Blanks are "too-hot" by many of the reenactors that I come into contact with and post on many of the Reenactor web-pages.

Regards, RichardS in MI.

US Army, Retired

Blanksguy2001@chartermi.net

[Z3BigDaddy]

I would much rather see a few ruined barrels than have them turned into safe queens...

 

 

I don't mind seeing them shot with live rounds but I have seen too many full autos and semi autos screwed up by reenactors tapping the barrels, firing blanks that are too hot for the setup they have and damaging the firearm because they wanted the noise to be louder. Operating the firearms as they were designed to be operated rarely damages them but as in the case of this thread you see what firing blanks in a Thompson barrel can do.

 

One more recent episode I saw was a clod who blank adapted a very nice all matching zero series P38 and on the first blank being fired he destroyed the pistol. He was clueless to how back pressure from a blank can reach a point of being too much and how tapping threads in a collectable firearm ruins its collector value. He was lucky he was not hurt when the pistol blew up.

 

Given the choice between a ruined / destroyed firearm and a safe queen I will vote for the safe queen every time.

Obviously the same can be said of anyone firing any ammo, blank or otherwise. Can't fix stupid... I'll take a blown up shooter over a safe queen personally...

[wwiifirearms]

Just for the record, the gun that had the barrel that started this thread is a Pearl Mfg. M1A1. It was built on a GI parts kit but it wasn't a C&R gun. The guy I bought it from was a reenactor and he told me he wanted a shooter that wouldn't be seriously devalued by use. He knew that simply threading it for the BFA would destroy the barrel, so he bought an extra NOS barrel when the BFA was installed.

 

I'd say if you really want a full auto for shooting blanks then you aren't committing any crimes against history if you do it to a WH or a Pearl.

-wwiifirearms

Edited November 29, 2010 by wwiifirearms

[RoscoeTurner]

I'll take a blown up shooter over a safe queen personally...

 

 

Sounds about par for the course.

[EMEDiva]

Looks like an extreme case of Gas Erosion.

[buzz]

yeah, that looks sort of like the cutting of the top strap that occurs on a magnum revolver at the cylinder gap

 

the jet of high pressure gas cuts the top strap like a tiny blowtorch

 

maybe the blank crimps are directing a jet of gas onto the barrel

[Roland the Thompsongunner]

I have never fired blanks from my Thompson, but have fired a lot through other guns. I have put well over 10,000 rounds of surplus crimped blanks in my ppsh and the barrel still looks the same as it did when i bought it. I also have put thousands of rounds through my m1 garand both crimped and 1909 paper tip type with no barrel damage. Blanks are a lot harder on a gun than live ammo because you are forcing a lot of gas and dirt back into the receiver instead of expelling it out the barrel. The right orifice opening is key to not beating the gun up. I run mine just small enough to make the action work correctly. My ppsh41 runs slower with the blanks because of this but it will run all day long with a bit of cleaning here and there. Nothing wrong with firing blanks and having some fun with your guns. Just have to care for them. I would not do it with just any gun but i like to shoot all my stuff. I get bored very quick with things i cant use . Dan

[RoscoeTurner]

I had a BAR barrel that came to me on the BAR I currently own that had to be replaced due to blanks being used. The throat was eroded to the point the handle on the throat erosion gauge was about all that was keeping it from sliding completely through.

[Merry Ploughboy]

Any chance that the sectioned barrel was just left dirty and in a humid environment which then caused rust corrosion? Up from the chamber there seems to to be some pitting as is typical of older guns left dirty for extended periods in non-controlled environments.

[reconbob]

Blanks damage guns. OK, if you are shooting them out of a Springfield and the

barrel never gets hot - no problem, The M1903 Springfield was the service rifle when

the M1909 blank was adopted. Machine guns and automatic rifles did not exist yet.

If you have managed not to damage the barrel of your PPsH-41 its most likely because

the barrel is chrome lined.

There are two factors at work which make blanks so destructive - the fast burning powder

and the heat. M1909 blanks were loaded with PETN - this is the same high explosive that

was used in hand grenades.

Semi-automatic and automatic weapons maximize the destructive effect of blanks

because the adaptors trap the fast burning powder in the barrel and gas system, and

because you can easily get the barrel hot enough that it gets damaged by oxygen. If

you get steel close to 1200 degrees - red hot - the mere presence of air will erode

the steel by chemical reaction. This is how oxy-acetylene cutting torches work. You

heat the steel red hot with the torch then turn on the oxygen and the steel flows like

water.

When you fire a blank a lot of the powder charge is blown down the barrel until

it hits the adaptor and burns there. If you recall the Danish M-1 Garands sold by the

CMP just about all of them had no rifling left for the front 2-3 inches of the bore

because of shooting blanks.

Many of today blanks use a fairly large powder charge - the case is almost full,

But with those old M1909 blanks the PETN is so powerful that the case is not even

half full.

I also wrecked a BAR barrel by shooting perhaps 400 M1909 blanks in a spirited

encounter during troop training. After shooting the blanks the gun short recoiled and

it turn out that the barrel - which was almost new had been eroded along where the

gas port is. The extra hot gases would hit the blank adaptor and a lot of if would to go

thru the gas port. When you shot ball ammo the bore was now oversized and the

bullet no longer tightly sealed the bore resulting in short recoil.

You can easily over heat an M16 by shooting off one mag, But the barrel is chrome

lined and protected from oxygen corrosion so its not as bad as it could be.

The moral of the story is that blanks are destructive to guns if you shoot the old

M1909 and/or if you overheat the barrel which is very easy to do.

 

My $0.02

 

Bob

[thirtyround]

A few questions. I am not familiar with this blank cartridge, but I very much understand the principles.

 

-What are the Swanson blanks made from, formally used brass?.

 

-Are Swanson blank cartridges reused/reloaded again multiple times for reuse? If so the material is losing integrity and is becoming brittle.

 

A possible explanation; In my opinion, several here are close to being on it with one aspect missing.

 

- In Pic / post 1, second photo, we see splattered and gouged steel in ring formation.

 

- In post 7 and 12 we have the image of the brass cartridge expanded, and ring detail.

 

- I will expand upon post 9 / post 10 / post 24 and post 32. If these are indeed blank cartridges "as hot as it gets, we know blanks in general generate a massive amount of contained heat and pressure. In my opinion the out focused crimp fold is indeed acting as a focused and funneled energy venturi. Where not only extreme heat and gases are colliding into the barrel at one focal point, super heating it, but it is also striping micro particles off the cartridge case crimp fold and pounding them into the steal. After the barrel excessively heats to a certain point, the particles are displacing the steal.

 

-My two cents worth is humbly submitted

[Roland the Thompsongunner]

Thanks very much Reconbob for that info. I have been told that the 1909 blank powder was very Explosive. I recently opened one up and it only has about 12 grains of powder per round. I think maybe I just got lucky with my ppsh because of the blanks i use. They are not that hot and are just enough to cycle the gun. I have all the other parts swapped out to aviod damage to them. I agree that blanks are much harder on a gun than live ammo.

What is your opinion on firing blanks from a browning 30 cal since there is no gas system to deal with? If i were to use a shot out barrel do you think it would cause damage to anything besides the barrel and the blank adapter?

Thanks for all the information you shared. Dan

[reconbob]

Swanson blanks are made from virgin brass cases - they are not reloaded or made

from remanufactured brass. The Swanson.45 ACP blank is very powerful and loud.

I have not used a decibel meter but it certainly seems that the report from the Swanson

blank is much louder than the report from firing ball ammo. But a lot of re-enactors like

and want a loud BANG.

I had forgotten about this post and the unusual corrosion/deformation of the bore

just ahead of the blank which, with the ragged and bumpy edges looks like it was hammered

on with a punch as opposed to being the result of firing and powder gases. I have no idea

what causes this.

Shooting blanks in a M1919A4 would be no problem. The Browning does not use a gas

system - its recoil operated with a muzzle booster. There is no recoil with a blank but the

powder gases hit the blank adaptor and the front face of the barrel acts as a piston which

operates the action. You will probably burn out the rifling, but the mechanism does not rely

on a tight fit of bullet-to-bore to keep the pressure up for the gas system so there is nothing

else to damage. So use one barrel for blanks, and use different barrels for shooting ball

ammo.

 

Bob

Edited October 23, 2015 by reconbob

[Roland the Thompsongunner]

Thanks for the reply about the browning. I just got it all set up to use blanks and just didnt want to overlook something that could damage it. I have a junker barrel so no issue there.

Swanson blanks are super loud. A friend shoots them in a carbine and they are way louder than live ammo. The 45 cal rounds are the same way out of a thompson.

[Mk VII]

You cannot reload crimped blanks as the metal is too tortured to stand it. It is possible to reload the M1909 rolled turnover blanks (crimped this time), and I have done many hundreds in the past.

[reconbob]

The M1909 blank was manufactured using brass that was rejected for

loading cartridges using a projectile. I remember reading in an American

Rifleman magazine from the 1950"s where someone asked if it was safe

to load or reload brass from M1909 blanks. The answer from the technical

staff was not to use the brass because it had been rejected. I always wondered

about this because the brass certainly looks good, but if the reason for

rejection was thin walls, improper annealing, soft heads, etc. then I guess

it was good advice...

 

Bob

[full auto 45]

If someone a barrel that has been cut in half and wants to get rid of it, I would like to have one. PM me.

[Embalmer]

These are swanson blanks being tested in my bar. After reading this thread, probably going to readjust for less powerful blanks. Can see the amount of gas ect coming out of gas tube and flash hider. Orifice is .0172 I believe.

 

[reconbob]

You should make an adaptor with a bigger hole. The gun is over-powered

and the empty cases are being ejected much farther than regular ball ammo.

(At least a full auto BAR) You want the minimum amount of power that will

work the gun. My BAR ejects the cases a few feet and it looks like these

cases would easily eject 20 ft. or more depending on the angle you hold

the gun.

 

Bob

[Embalmer]

Actually were about 10 ft to my right. Talked to joe before. He admits they are hot, and warned not to put these bar tuned ones in a garand cause it will blow them up. I believe there's some black powder mixed in with the other propellants, due to the slight egg smell when cleaning. My flash hider is the blank adapter, has a set screw inside that's interchangable, and I drilled out the largest of the 4 or 5 that came with it to Joes recommendations. I have some less powerful ones from Atlantic wall I'll be toying with. I know with current setup it hardly moves the bolt.