Deal wood is a big deal

[bennedose]

I bought a Weihrauch HW 35 in the UK in 1984 and used to do some indoor plinking in bad weather in winter. Soon after I acquired a scope I wanted to try and shoot the head off a matchstick which I set up, and used a 1/2 inch plywood board as backstop. This had always been sufficient for the old and useless mystery brand underlever I had left behind in India. Unsurprisingly my first shot missed the match-head but I was surprised to see that the pellet had gone through the 1/2 inch plywood and had done some minor damage (a depression) to the wall of the room. That made me more conscious of what types of backstop would be effective.

So I was fascinated to read about the deal wood test in which a 12 inch square and 1 inch thick deal wood board is shot at twenty times from a distance of five feet and an air rifle deemed to have passed the test if none of the pellets pass through.

A week ago I decided to subject my own air rifles to the deal wood test. That was when the fun started

Deal wood is a type of pine wood that is light, strong and easy to saw wood that grows in Europe and "north Asia". It is seen most commonly in India as part of packaging for crates. I suspect most deal wood is imported. I was unable to discover if deal wood grows anywhere in India. When I was a boy all packaging material - be it for refrigerators or books or fruit, was made of deal wood. But nowadays deal wood boxes are rarely seen - at least by me. Packaging is almost invariably cardboard with thermocole and other modern, lighter and cheaper material. I see deal wood most often in the market where some fruit are still shipped in deal wood boxes made of strips of deal wood that are 5 mm or 1 cm thick (0.2 to 0.4 inches)

I contacted several wood dealers asking for deal wood. None of them had any.I Googled for dealers who made packaging boxes from wood and found a few but had no success in locating one who had deal wood to sell. In frustration I fell back to the last resort - that is using boxes that were used to package fruit. I managed to get hold of one and documented a few points in photographs which I would like to highlight before I post some comments on the issue.

This is an image of deal wood from a box. As you can see the wood has areas of knots and parts where seams and splits run along the grain.
https://docs.google.com/file/d/0B3JNY4I ... sp=sharing

I was only able to get 5 mm and 10 mm boards and I used duct tape to firmly bind 2 x 10mm and 1 x 5 mm strip to get 25 mm (about 1 inch).
https://docs.google.com/file/d/0B3JNY4I ... sp=sharing

Both my Orion and IHP 35 "passed" this test by failing to penetrate more than halfway through this collection of boards - and I shot the board from just 1 foot (and not 5 feet as stipulated) But I was unable to shoot more than 2 shots from each rifle since the board was not big enough.

Finally I simply strapped together two boards to make a thickness of about 3/4 inch and got the following result (see photo)
1. The IHP pellet caused a split on the other side but did not penetrate
2. The Orion pellet caused a sliver of wood to be sheared off, but the pellet itself remained embedded (see photo) - so the pellet did not go through
Image: view of 3/4 inch deal wood board from the side opposite the face that was shot. Each pellet has cracked or split the wood over a greater distance than its actual depth of penetration and another pellet in the same spot can cause penetration.
https://docs.google.com/file/d/0B3JNY4I ... sp=sharing

These experiences have brought up a lot of questions in my mind
1. Deal wood itself is not freely available and most of it is probably imported. After shooting 20 test shots it has to be discarded.
2. Wood can be of variable quality with knots and seams. There is no scientifically acceptable "standard"
3. The law does not stipulate how far apart each pellet penetration should take place. One pellet could cause a crack/split or weakness in the wood resulting in the next pellet that lands nearby to penetrate the wood causing an unfair fail of deal wood test.
4. In this day and age a chronometer or even a smartphone can be used to calculate pellet energy as long as pellet weight is known. Muzzle velocity is not the issue. It is pellet energy that matters.

I believe the deal wood test as defined in the 1962 law is archaic. In my view the way to define the law precisely is to calculate the pellet energy required to penetrate a 1 inch thick board of deal wood using standard defined pellets of specific weight and shape and by repeating the test 1000 times and taking the average to correct for error, That will require a lot of deal wood boards initially but once defined properly deal wood will not be required any more. Once the pellet energy (of a standard pellet) required to consistently penetrate deal wood of 1 inch thickness is defined, the legal limit can be defined as pellet energy lower than that limit.

[dev]

Good research Bennedose. I would like to add that having chronographed my IHP long ago I found that the .22 would shoot between 500 to 535fps. Having shot the same into a plank of wood which I now realise was deal wood, the pellet just about went in. Even my qb that shoot at a similar velocity of around 535-560 fps in .22 and penetrates about the same amount in the wood.

So I guess if one buys a .22 shooting uptill 550fps, one should be safely inside the legal limit for air rifles. And this velocity is also more than sufficient for dispatching pests if need be. Most of us keep looking for high velocity air rifles without realising what the humble 12 foot pound of power can do. Most of the time this air rifle will be pleasant and accurate to shoot even with Indian pellets, my air rifle is now beginning to show a fondness for mastershot export quality domes. Something that delights me no end as I arrive at my last box of Crosman Premier HP.

Thanks for your test.

Regards,

Dev

[mercury]

interesting Bennedose.......

but what really intrigues me is the rationale behind the deal wood test. if as you point out the law is dated 1962 , it makes it even stranger. I am no air gun historian but I doubt if there were any air rifles that exceeded 9 to 10ft lbs. in that era. so how and on what basis was this 1" penetration from 5ft made ? any type of wood can not be taken as a ' scientific standard" , given that the density of wood will vary at any given point on even a square foot board. the hardness of different brand pellet is also not a constant.

if we use Dev's velocity of an average of 550 fps and the penetration being similar...making it a legal. and if we were to use an average weight pellet of 14 grns, that would work out to around 9.5 ft lbs. that would be muzzle energy and at 5 feet the pellet would retain pretty close to that energy. so , would 12ft lbs penetrate a 1" piece of wood ?? maybe ...may be not.

or does the deal wood test ( with all its faults) put a restriction of 10 ft lbs on air rifles ???

my understanding was that the deal wood test was a "take" on the 12 ft lb. limit and a legacy of the British law. if you date the deal wood test law as of 1962 , it is no legacy. the 12 ft lb. law came into effect in the UK in 1968. ( one interesting reason being the threat that Webley and BSA faced from the US made more powerful pump ups gaining popularity !)

there can be no arguing with "...what the humble 12 foot pounder can do..."

[bennedose]

Mercury that is what intrigues me about this deal wood test. It seems to be an arbitrary hack/jugaad/ready reckoner/guesstimate type of test that has entered the law books. I assume that it is in the law books based on a description of the test on another thread on this fourm.

I have no information but I am certain that most such old laws in India are takes on old British laws and time and again one finds that the British have woken up to modern times and modified their laws to be more rational/scientific/current while the law remains untouched in india.

Specifically, the deal wood test seems to say nothing about FPE or Joules. I would like the same deal wood test to be defined in Joules. I think the standard is fair, but the test is approximate.

Having said that - there is another issue that has been tickling my mind for a while now. I think there must be some kind of legal restriction on the size of piston and cylinder in a springer and this seems to be followed judiciously by gun manufacturers in India This is just a guess. I don't have enough information but the "stroke length" of the piston in Indian springers (to my knowledge) rarely exceeds about 11 cm or so. And with a diameter of 2.5 cm one can be certain that such a piston chamber can never generate the pressures required to get illegal energies no matter what spring is used. Please don't take my word for it - this is a guess and I am trying to get more data to see if I can work out the math. I think that the highest energies can only be squeezed from springers that have a longer stroke length and perpaps a greater diameter. Need to dig for American springer design specs.

[Grumpy]

`Deal` isn`t a species of tree - it can be almost any type of pine/fir but usually Scots Pine.
`Deal` is basically pinewood deemed suitable for building` - the original meaning of the word was `plank`.
The town where I was born used to be a thriving small port but the river that flows through the town was allowed to silt up and eventually only the town dock was deep enough to float a ship. One of the major products imported was `deal pine` for the building trade from Russia and Scandinavia and that continued into the 1970s when eventually shipping ceased.
A power test based upon a non-specific quality/density of wood is pretty well meaningless.

[Grumpy]

By the way, cheap pine off cuts would be suitable - if you go to a carpentry shop ( a place where they make stuff - furniture, stairs, garden furniture, etc ) you often find that they chuck the off-cuts into a skip and are quite happy for you to help yourself ..... it`s politic to ask first though.
You`re right by the way, Deal, IS a big deal for air rifle tests when it isn`t a specified product.

[bennedose]

`Deal` isn`t a species of tree - it can be almost any type of pine/fir but usually Scots Pine.
`Deal` is basically pinewood deemed suitable for building` - the original meaning of the word was `plank`.
.

Brilliant thanks. That is more information I have got about deal wood than I got in two days of asking my uncle, Mr. Google

[airgun_novice]

Dear bennedose - fine testing and finer report. Thank you for your post. regs, A.

[essdee1972]

Bennedose, great test! Kudos to your energy and attention to detail!

Well, most of our laws seem to date back from the times of Warren Hastings or close. Post independence, our honourable lawmakers changed the laws to ensure that nobody went to the British King or Queen for a mercy petition!! Emphasising our independence, as it were! That is why you get post-1947 dates on many of our laws. The thought process remained the same - to keep the common people as "subjects". The close association of our leadership with such great people as Josef Djukashvili aka Stalin, also helped!

[brihacharan]

Dev wrote.......
So I guess if one buys a .22 shooting uptill 550fps, one should be safely inside the legal limit for air rifles. And this velocity is also more than sufficient for dispatching pests if need be. Most of us keep looking for high velocity air rifles without realising what the humble 12 foot pound of power can do. Most of the time this air rifle will be pleasant and accurate to shoot even with Indian pellets, my air rifle is now beginning to show a fondness for mastershot export quality domes. Something that delights me no end as I arrive at my last box of Crosman Premier HP.


Bennedose / Dev / Mercury / Essdee....
> After all there is some "Lopsided" wisdom in pegging ARs to 12 foot-pound limit....
> Moral of the story = Don't compromise 'Shooting Pleasure' for upping velocity
Briha

[dev]

Sir,
My belief is that an air rifle should do what you expect from an air rifle. It should not mimic the performance of a .22lr, I mean the tool should fit the job right?
When I need to do 50m and beyond shooting I reach for my firearm. Otherwise the air rifle loses the fun factor and becomes sinister in nature.

Regards,

Dev

[Basu]

I have observed that upto 9 fpe ARs give a pleasurable feel of shooting. The said power is safe enough to qualify deal wood test .
With 9 fpe at muzzle , I can shoot well upto 30 mts.

Basu

[mercury]

here you go Bennodose.

piston stroke / swept volume can be manipulated if one has the required skills so I doubt if there is any legal restriction on the part of manufacturers to size their pistons and cylinders. slap down your rifle barrel and check the slack. it would in all probability have to do with the perceived tolerance levels of their products.

I would think that Precihole is the only ( from what has been posted here) Indian rifle that has ensured that their product can not be manipulated with.

also a smaller diameter piston can produce more power than a larger diameter piston , given that the stroke length is the same. pls don't ask me for the math , but surface area has a role here. (??????) and of course it is not just the longer stroke that adds to the power....there is more to it.

anyways hope this data helps with your study.

[Grumpy]

`Benjamin Super Steak` ?
Mmmm ..... Tasty. I`ll take mustard with that.

[mercury]

the perils of online ...cut, copy & paste. streak it is. should have added a disclaimer ! I do now.

but yes a Benjamin super steak does sound yummy .... go easy on the mustard... that "crazy power" has me worried !