French Gras question

[Patrick Chadwick]

Hallo Aragorn243!

I'm in Kiwiland at the moment, so what follows is out of the top of my head, as I cannot check with my books.
Your Mle 66/74/80 appears to be in excellent condition, with strong rifling right to the muzzle. I had one of these, before I found an original Chassepot, so I am wiring from experience. The trouble is ammo! Basically, you are either very rich or get creative with Win 348 cases. See this link:

http://jp.sedent.free.fr/UNE%20CARTO...SIL%20GRAS.htm

and the associated articles by Mr. Sedent.

The snag is that you do not have an "as built" Gras rifle, but a Chassepot (Mle 66) converted to take Gras center-fire cartridges (Mle 66/74). This was done by inserting a sleeved element in the Chassepot system, with a resulting "squeeze" section just in front of the Gras-sized chamber. The /80 modification was the pressure-relief groove milled out behind the chamber to handle burst cases in those early days of brass-drawing technology. The link above is worth studying to understand this, even if it it requires a bit of patience and a good dictionary!

The squeeze means that the nominally 11 point something mm bullets are squeezed down to 10 point something mm and then bump up (we hope!) to fill the bore. This means that YOU MUST ONLY USE SOFT LEAD BULLETS !!!!. (max 3% tin). Harder lead will fail to bump up and will produce lousy results. As for jacketed bullets - your life insurance would advise against it! DO NOT EVEN TRY JACKETED BULLETS.

P.S. Your bayonet is the Gras bayonet. The orginal Chassepot bayonet was a yatagan type.