Mle. 1874 Gras bullet paper patch thickness


#1

Gentlemen,

Requiring the exact thickness (service dimensions) of the original paper patch of the Gras cartouche Modele 1874 and 1879 for research.

In anticipation,

Guy and Leonard A-R-West


#2

Goog evening Gentlemen,
If you read my book: cartridges of the Gras system published by Armory Publications , you will see that the patch paper has a thickness of 55/100 mm and is cut in diamond of 67 by 121 mm.
Regards
Phil12


#3

Guy & Leonard–Do you have the book “Les Cartouches du Systeme Gras” (Translated into English)? It has VERY detailed information on the original arsenal instructions on making Gras cartridges.

Concerning the paper patch of the Model 1874 cartridge, it says (Page 11) “Paper Patch: of a thickness of 55/100 and cut in diamonds of 67 mm by 121 mm, it must be white, smooth, parchment lie, resistant and extensible, and must wrap easily around the bullet and stay there”. On Page 9 it says “The paper patch covers 19mm of the bullet length (the seam of the patch has a 35 degree angle)”

Changes to the Model 1879 include the following"

(Page 30) “The height of the paper on the bullet is 18mm and the seam has an inclination of 50 degrees”

Hope this helps. I can provide detailed information on the bullet if needed.


#4

jp.sedent.free.fr/CALEPINER%20LE … 20GRAS.htm


#5

Am I correct in understanding that .55 mm is the thickness of the completed paper patch and not the thickness of the sheet of paper from which it was produced? I think that’s what Pierre-Jean’s link says, but my French isn’t quite up to this task. JG


#6

JG

I had the same question. .55mm is .0215", almost a light cardboard. I have made and shot PP bullets and I use paper that is .001" to .003" thick. With two complete wraps it makes the diameter over the patch .004" to .012" bigger than the slug diameter. Using paper .55mm thick would make the bullet diameter over the patch much too large. I think they mean .055mm thick.

Something doesn’t compute.

Ray


#7

[quote=“Ray Meketa”]Something doesn’t compute.

[/quote]

That’ll be me then.


#8

In addition to my previous post , as 55/100 seems to pose problems the paper thickness is 0.055 millimeter . Include an official dwg from the “Table de constructionde la cartouche 1879” which doesnt appear in my book
Any other question welcome !
phil
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#9

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This is a better version


#10

phil

.055mm is 55/1000 which converts to .0022" and makes more sense , to me at least.

On a related subject :

It’s only a coincidence but Ron M. and I were talking about paper patching bullets just this past week. I am making one for him and looking for a suitable paper. Originally, patches were made from a linen or cotton based paper, what was called “banknote” paper in the olden days. As far as I know paper today is made primarily from wood based pulp and it doesn’t always work as it should when making PP bullets.

So, my question. Can anyone who reads French tell me if that text in the link by JP says anything about the type of paper used.

And, maybe more important, does anyone know where I might get a sheet or two of linen or cotton based paper in .002" to .003" thickness?

Ray


#11

On the web site relating to Gras reloading , they use the thin sometimes colored paper formerly used to make copies with type writing machines . It seems that it works well !
phil


#12

I think that the paper used to make “homemade cigarettes” could be used too


#13

Gentlemen,

Thank you all for assisting in clarifying the question of the patch thickness which has puzzled us for years. From what can be deduced from the attachment sent in by Phillippe Mention co-author of the excellent Cartridges of the Gras System that the thickness ranges from 0.053 - 0.057 mm which translates into 0.0020 - 0.0022", which we have been using for our ballistic experimentation all along.

From the angle of the patch of 50 degrees it must be from the Balle M/79, the M/74 had a more acute angle of 35 degrees. Is the patch from the M/74 the same thickness?

Phillippe, please may we have permission to use the attachment for our project on this subject and an acknowledgement shall be included in the conclusion. Slightly off subject, but still on the Gras theme and important to our research, we are trying to find out where on the Mle. 1866-74 Transforme, the ‘T’ was stamped? Apparently it was not evident on all of the transformations, our examples are void of such a mark. If anyone has evidence of such a marking we would be grateful for an attachment.

We would like to thank Greg for the dimensions of the Lorenz bullet. Now we are in the process of getting a bullet mould made for our ballistic evaluation. We did send Greg an e-mail and are not sure as to whether he has received it.

On a related subject, for anyone who is interested, we are now in the process of shooting the M/67 Carcano needle ignition with a cartridge duplicating the original which has proved to be a very satisfying experience. We intend demonstrating the M/67 at Bisley at the HBSA 35th Anniversary.

With thanks and in anticipation,

Guy and Leonard A-R-West