Deal Wood test is a penetration test, not a power test

[bennedose]

Folks on a hunch I thought I would test a hypothesis that the Deal Wood test is a test of penetration ability and not one of power. I got the idea after reading somewhere that some bullets need to have about 59 fpe energy to penetrate deal wood. You must not and cannot translate deal wood penetration into Joules or Her Majesty's fpe for some very important reasons that I will list below.

But first the test.

I obtained a special steel needle and modified it so that it could be shot from my IHP 35. I will not say what or how - IFGians are welcome to reach their own conclusions.

I then shot three needles into a 1 inch thick block of deal wood as advised in the test. Unfortunately the needle bent every time from the weight of the hub but the needle penetrated more than 3 cm into wood. That means that if the needle had gone straight in it would have passed through the block of deal wood.

Now for some calculation. The needles each weighed 0.32 grams (Her majesty's 5 grains). Velocity from IHP 35 was 228 m/sec (750 fps). That works out to 8.3 Joules or 6.1 fpe

Here is an image of how far the needle penetrated (in an oblique direction so it did not emerge from the other side)

deal-needle.jpg

Here is some theory. I challenge anyone to penetrate a 1 inch thick block of deal wood using a cricket ball. Cricket balls weight about 160 grams . You can hit a deal wood board with a power of 15 fpe (20 Joules) if you throw the ball at the board at 57 kmph (35 mph). This is slower than most spin bowlers and anyone should be able to throw a cricket ball to hit a deal wood board at 57 kmph or 15 fpe power. It will not penetrate the wood. Recall that balls hitting bats at greater than 140 kmph does not "penetrate" them.

What does this mean for us shooters in India?

1. Because 0.177 pellets have a slimmer "face" - i.e they are "sharper" they will penetrate deal wood at lower power. Even then I suspect that velocities of greater than 800 fps will be required

2. For 0.22 shooters I am certain that guns that develop even 14-15 fpe (maybe more) will pass the deal wood test because they are "blunt" and offer a greater area for absorpion of energy before penetration.

I only wish some academic engineering dept in some engineering college would take this up as a study - so that we can have our own standards and need not shiver in our dhotis unnecessarily about illegal power weapons. If an academic study establishes the fps neede for penetrating deal wood for 0.177 and 0.22, our air gun makers can then wake up and start making guns to match reality and Indian laws rather than simply sitting on their backsides blindly using someone else's standards and lulling us into the unthinking state of ignorance that we continue to exist in.

[goodboy_mentor]

On the surface, the deal wood test appears to be only a penetration test. But indirectly it is also a power test. The penetration of projectile depends on mainly four factors:

1. projectile impact velocity
2. projectile mass
3. projectile shape like its sectional density/ ballistic coefficient
4. projectile hardness

In the example of cricket ball that you have given, projectile mass, shape and hardness are constant. Its impact velocity is the variable. If its impact velocity is somehow raised sufficiently so that it possesses sufficient force/energy/power to perforate or break the board, it will fail the deal wood test. Similarly some airguns can also fail the deal wood test, provided the pellets possess sufficient force/energy/power to perforate or break the board.

[bennedose]

On the surface, the deal wood test appears to be only a penetration test. But indirectly it is also a power test. The penetration of projectile depends on mainly four factors:

The important point is that projectile shape and hardness can cause failure or pass of the deal wood test.

A sharp hard projectile will fail the deal wood test at lower power ratings than a blunt soft one

This is a crucial fact - apart from the fact that it is our law. If we must folow the law we must have guns that pass teh test.

I am saying that 0.22 will need higher power ratings to fail the test than 0.177 simply because the area over which the power is transmitted to the wood. Unless this is experimentally verified we cannot assume that there is some uniform power value at which the deal wood test will fail. You have yourself pointed out the following list of factors:

1. projectile impact velocity
2. projectile mass
3. projectile shape like its sectional density/ ballistic coefficient
4. projectile hardness

Of these only 1 and 2 are related to power. 3 and 4 modify the effects of that power in ways that no one in India has bothered to verify. Non Indians will not give a damn because their laws do not involve the Deal wood test. The verification and testing has to be done by Indians who are interested.

[Harish Asnani]

@goodboymentor & Bennedose- Very good explanation from two very experienced individuals, I have learnt a lot from this conversation and from my little knowledge I feel projectile mass/shape and velocity of impact is crucial for deal wood test ( I'm just a novice )

[Suyash]

@ Benne

“There is much reason in your saying”
I think that there is need of a better way to 'officially' test the ‘power’ . but looking at the positive side we can enjoy more ‘powerful’ .22 air rifles of pickling.

[goodboy_mentor]

Surely we cannot assume that there is some uniform power value at which the deal wood test will fail for all or even same caliber because of four variables i.e. projectile impact velocity, mass, shape and hardness. The fifth variable i.e. the hardness of deal wood also comes into play. The deal wood that has more moisture or of low density, will make the test fail at lower projectile energy or power.

Regardless of the fact whether the gun fails or passes the deal wood test, whenever any commercial Indian manufacturer or seller is giving in writing that air gun is exempt from Arms Act, the cops or the law is not going to bother you. They might bother the manufacturer or seller. The reasons are many, like before issuing license for commercial manufacture and sale of air guns, the government fully satisfies itself that the deal wood test is satisfied. Also when the commercial manufacturer or seller is giving in writing that the gun is exempt from Arms Act, the buyer is buying it in good faith. Anything done in good faith does not attract Arms Act.

[dr.jayakumar]

penetration is related to speed(velocity).lots of physics innvolved here.whatever test it is,it is used less.
regards
dr.jk

[ckkalyan]

Very interesting and a no brainer test - however if it is to the advantage of the importers - more power to such inane tests.

Mods, please note that we have now three different posts on the dealwood test - request to merge.

http://indiansforguns.com/viewtopic.php?f=2&t=23177

http://indiansforguns.com/viewtopic.php?f=2&t=23168

http://indiansforguns.com/viewtopic.php?f=2&t=20940

I have an idea that RK Narayan and RK Laxman could have come up with a brilliant cartoon re this test. Goes somewhat like this...you'll have to imagine the images - I am a lousy sketcher / cartoonist.

Importer (Aam Admi): Here is my .22 Cl air rifle Saar; can I offer you with the dealwood and pellets for the test, saves some time and effort?

Customs Official: Thank you, yes, certainly very thoughtful.

Importer (Aam Admi): Here is the piece of wood (super hardwood) and here are the pellets (custom 'muzzle loading', huge-headed top-heavy, flat-head pellets).

Customs Official: Thank you. But hey, the head of the pellet won't fit into the breech!?

Importer (Aam Admi): Ah - you see saar, these pellets are for muzzle loading air rifles...and hence the skirt has to be inserted from the muzzle.

Customs Official: Ah I see, OK lets try from 5 feet away; I load the pellet into the muzzle and fire... (Phhhtt...pellet drops on the floor at 4 feet from the muzzle). Okay your rifle has passed the test you may take it home! Congratulations!

Importer (Aam Admi): Thank you very much Saar! Would you like to keep this piece of wood and some 50 pellets in case you need it for future importers?

Customs Official: That is a very good idea my friend, thank you; saves me a lot of trouble looking for these things when I really need them!

[ibalajis]

Very interesting and a no brainer test - however if it is to the advantage of the importers - more power to such inane tests. [emoji38]

Mods, please note that we have now three different posts on the dealwood test - request to merge.

http://indiansforguns.com/viewtopic.php?f=2&t=23177

http://indiansforguns.com/viewtopic.php?f=2&t=23168

http://indiansforguns.com/viewtopic.php?f=2&t=20940

I have an idea that RK Narayan and RK Laxman could have come up with a brilliant cartoon re this test. Goes somewhat like this...you'll have to imagine the images - I am a lousy sketcher / cartoonist.

Importer (Aam Admi): Here is my .22 Cl air rifle Saar; can I offer you with the dealwood and pellets for the test, saves some time and effort?

Customs Official: Thank you, yes, certainly very thoughtful.

Importer (Aam Admi): Here is the piece of wood (super hardwood) and here are the pellets (custom 'muzzle loading', huge-headed top-heavy, flat-head pellets).

Customs Official: Thank you. But hey, the head of the pellet won't fit into the breech!?

Importer (Aam Admi): Ah - you see saar, these pellets are for muzzle loading air rifles...and hence the skirt has to be inserted from the muzzle.

Customs Official: Ah I see, OK lets try from 5 feet away; I load the pellet into the muzzle and fire... (Phhhtt...pellet drops on the floor at 4 feet from the muzzle). Okay your rifle has passed the test you may take it home! Congratulations!

Importer (Aam Admi): Thank you very much Saar! Would you like to keep this piece of wood and some 50 pellets in case you need it for future importers?

Customs Official: That is a very good idea my friend, thank you; saves me a lot of trouble looking for these things when I really need them!

Super ROFL

[Harish Asnani]

@ ckkalyan- Hilarious ....I wonder whether we have an custom official in our midst and what will be their reaction....

[ckkalyan]

@ ckkalyan- Hilarious ....I wonder whether we have an custom official in our midst and what will be their reaction....

Ouch - I guess I did put my foot in my mouth eh?

However, maybe the official will have a good laugh and also encourage his colleagues to go easy on airgun imports - sort of Humour in Uniform (Ref. Readers Digest) - what do you think??

[Harish Asnani]

@ckkalyan- Yes for sure I wish our officials get time to read readers digest after all they do/go through in a day..ahhmmm...

[goodboy_mentor]

Regardless of the fact whether the gun fails or passes the deal wood test, whenever any commercial Indian manufacturer or seller is giving in writing that air gun is exempt from Arms Act, the cops or the law is not going to bother you. They might bother the manufacturer or seller. The reasons are many, like before issuing license for commercial manufacture and sale of air guns, the government fully satisfies itself that the deal wood test is satisfied. Also when the commercial manufacturer or seller is giving in writing that the gun is exempt from Arms Act, the buyer is buying it in good faith. Anything done in good faith does not attract Arms Act.

Matters appear very similar when air guns are imported. It is only when the customs are satisfied that the air gun does not require license, only then the air gun is handed over without asking for license. Needless to say regardless whether airgun is purchased from local manufacturer or imported, it appears one should keep all the paper work safely with oneself.