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  • Hi Guest - just to let you know that we performed some work on the forums recently. You may use this thread report any issues you encounter.

Measuring question - would appreciate input.

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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fuzz

Hawaiian transplant...
Sep 9, 2002
995
73
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After seeing a couple threads regardinglength questions of euroguns, I was going to measure all of mine to get a good comparison between barrel and overall length.

How do you think I should measure overall length? For my Rob Allens, the muzzle to butt is a certain length, but the bottom of the grip sticks out a few centimeters more. Likewise - for the Beuchat, the loading pad sticks out a certain distance, but on 2 of them, I took off th e loading pad so it's the same as the RA's.

Should I go with consistency & measure as if there were no pad? Should I stick to whatever length it comes out to? Should I include the grip when there is no loading pad?

Really picky, but I'm anal & I have too much time on my hands ;)
 
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Murat

Promethian
Jun 21, 2002
2,982
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In my opinion, measure from the top, tip of the muzzle to the end of handle. No need to include loading pad since it is removable part of the gun. If handle extends more a bit you can include it also. Basically most of the euro gun's handle extends if you neglect loading pad.
 

jodyfreedive

New Member
Sep 25, 2003
51
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0
Personally I think to compare guns you should measure from band attachment on muzzle to loading tab/cut on spear when spear is loaded. This is the measurement that determines the band stretch and power. Then you don’t have to consider where the sheer is in relationship to the handle, loading pad, how bands are attached to the muzzle, etc..
Jody
 

Dogmatrix

Deeper Blues pet
Jun 4, 2002
210
19
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Generally I just measure the barrel... eg 1.3M gun has a 1.3M barrel.. ignor muzzle and trigger.

I would guess that working on band streth could give an idea of power... but am not sure this relates to the "size of a gun" i guess it just depends how you quantify it.

It's no wonder different manufacturers use different sizings.

Rob
 

fuzz

Hawaiian transplant...
Sep 9, 2002
995
73
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I was going to post a chart for overall length vs. measured length(i.e. 1.3m) as part as a beginning freediver FAQ

I thought this might help people who are confused between the difference between a 50" Riffe & a 110cm euro. My 110 RA is roughly 128cm long from butt to tip of muzzle... a couple centimeters long when taking the handle into consideration. A 50" Riffe is 127cm. By this, we can see that a 110 is actually a bit longer overall then a 50" Riffe, whereas if we went by barrel length, it'd be reflected as quite a bit shorter.

My basic point of this post was to find your opinions to use a consistent measuring system - especially if anyone else wished to measure there guns at home & help out with data :D
 

Memo

New Member
Sep 1, 2003
1,237
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the proper lenght should be measured like this...
 

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Iyadiver

Mr. Long Post
Apr 22, 2002
998
72
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Good idea Fuzz, measure overall length and some barrel info length, this way we know what to expect from the mentioned data by different manufacturers. If you can measure the length of shaft given and its overhang, that will be 100% complete.

In terms of power, 15 cm exra overall gun length can mean extra 3 feet of shooting distance with some models.....this is a lot. Swinging matters a lot too even at extra 15cm, this data is important to people who wants to learn about those guns and not having access to the real thing to inspect and feel.

If I can help let me know.

IYA
 

fuzz

Hawaiian transplant...
Sep 9, 2002
995
73
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Memo... :( Please re-read my posts - you seemed to have missed my point ;)

Iya, thank you. If anyone would understand my idea, I knew it'd be you :D The overhang idea was one I was contemplating as well as band stretch.

Band stretch would be another interesting one. Not only for calculations between lumber style guns & euros, but also between different types of euro gun styles. For example: if you took the distance the band stretches on a typical euro-gun, then subtract the plastic screw section on both ends as well as the wishbones to get a true stretch distance. On my impromptu measurements, a 90cm Rob Allen had more true stretch than a 100cm Beuchat!

:hmm

*the diagram below shows how band stretch differs between a typical Euro gun and a SA-styled Euro-gun
 

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shaneshac

FIN TRASHER
Oct 8, 2002
1,874
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Fuzz, are both bands the same length to start with. The euro bands usually take into consioderation the fact that the length of the caps is "lost band length" and therefore compensate for this by offering shorter bands in the first place.

You would need to calculate the percentage of the original band length (I.E by how many times has the band stretched)

I hope you understand what I mean.
 

fuzz

Hawaiian transplant...
Sep 9, 2002
995
73
0
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Shane, I understand what you mean.

I was trying to evaluate the band stretch of the guns & not the bands themselves. Basically - for a given gun length, how much is allocated to band stretch.

Shortening of euro-bands is not the most efficient manner of overcoming the difference.
 

shaneshac

FIN TRASHER
Oct 8, 2002
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DO you think that the longer the band stretch the more power the gun has? The amount allocated to band stretch in euro guns is calculated on loading effort as well as explosive properties of the bands. A 20mm band of one manufacturer might take 80cm fo stretch to get the shaft to 30 metres per second and another might take 100cm. The 100cm would make a smoother shot but the shaft speed of them both would be the same.

There are a lot of factors to take into consideration.
 

fuzz

Hawaiian transplant...
Sep 9, 2002
995
73
0
43
To answer your question - I think that with other factors constant & using similar materials, length of band stretch does directly affects power. Consider the following case:

You have similar 16mm band material on the same length gun

#1 has to stretch from 30 to 90cm to power the gun.
#2 has to stretch from 35 to 105cm to power the same gun.

They both stretch to 3 times their original size to be loaded. With equal stretching, we can roughly assume that they now carry the same power per cm of pull length(variable X). So despite being a bit longer, #2 now has an overall advantage in total power (105x vs. 90x)

This is a very crude example and I didn't take out resting length, but I believe the fundamental logic is sound. This is similar to the logic behind Rollergun experiments which attempt to maximize the stretch amount of one's slings and not only minimize the dead area's of overall sling length, but extend it past the physical limit of the gun length.

:hmm
 

Iyadiver

Mr. Long Post
Apr 22, 2002
998
72
0
YES !!!! Band stretch, very important. Thank you. I notice the Riffe-s have different percentage of strecth for the shorter ones and the longer ones.

I am ready anytime you need info. For the Riffe-s, those model that comes with the hawaiian shaft has different overall overhang and so is a shaft with Ice Pick or normal screw on spearhead. I have almost all the data for the Riffe, I can get info on the Collins too.

This will be something good for everyone, I don't think there is such complete data ever published yet......:p .....ur the man Fuzz.

Do you want to put shooting range too ? This is going to be a tough one because there is no reference to what is considered as effective shooting range.....:head and then come multiple band....hhhmmmm lots of work but sure fun.
 

fuzz

Hawaiian transplant...
Sep 9, 2002
995
73
0
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Originally posted by Iyadiver
YES !!!! Band stretch, very important. Thank you. I notice the Riffe-s have different percentage of strecth for the shorter ones and the longer ones.

I am ready anytime you need info. For the Riffe-s, those model that comes with the hawaiian shaft has different overall overhang and so is a shaft with Ice Pick or normal screw on spearhead. I have almost all the data for the Riffe, I can get info on the Collins too.

This will be something good for everyone, I don't think there is such complete data ever published yet......:p .....ur the man Fuzz.

Do you want to put shooting range too ? This is going to be a tough one because there is no reference to what is considered as effective shooting range.....:head and then come multiple band....hhhmmmm lots of work but sure fun.

Thank you for the validation Iya ;)

I'll put together a spreadsheet to lay out what fields I should take into consideration, then ask you for the data later. :) Thank you for your willingness to help.

As far as range, that's a real tough one as it's very subjective. Effective range is really based on other factors like weight of shaft, velocity, momentum, head-size, flopper protuberance, inertia, etc.

I tried to do accuracy & got some good results(and realized my aim sucks), but realized that to be really fair, I'd have to buy all brand new spearguns since they'd all have to be stock - brand new bands, shafts, etc. Otherwise it'd be an unfair representation of a gun's potential if another shaft or fatigued bands were used.

Oh well, back to the drawing board :head
 
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