Not that anybody asked. It took a lot of attempts but four screws are 0.208" x 0.9 mm at different lengths, a 208"x32tpi (tang) (tapers from 0.230" to 0.208"), and a 0.150"x40tpi . Why? There was speculation that you couldn't run down to the hardware store to replace them. I don't know but these work.

For some reason all the firearm companies seem to use strange screw sizes.

Because gun screws date from a time before standardization, or in other cases, they are proprietary size and Pitch. And since the heads and lengths, and thread lengths are all different, no hardware store would have suitable ones anyway.
At this point, you will have to live with it because it is way too late for the industry and there is zero benefit for them to change.
We used Metric screws for the first 100 years of Military rifle production; remember our first one, the 1795 Musket, was copied from the French Charleville.

quote:

Originally posted by dpcd:
We used Metric screws for the first 100 years of Military rifle production; remember our first one, the 1795 Musket, was copied from the French Charleville.

Can you explain this further? I thought the metric thread was developed in the late 1800's? 1870's or 1880's? I'm not very knowledgeable on early American arms but it sounds interesting.

France adopted the Metric system in 1795. Since our first US made military weapons were copies of the French ones, we copied that too. The French muskets were superior in design over the British ones (Brown Bess), and were 69 caliber, whereas the British was 72. And most notably the French muskets used barrel bands rather than pins, a far stronger method.

This guy should be on a GUNS & AMMO game show!

He would win Millions!!!

Hip

The tang screws on many guns with receiver tangs and separate butt stock was to "push" the stock into the receiver when tightened up. Thus, keeping the stock tight so it wouldn't split in recoil. Old Browning Auto 5's split often because the wood shrinks and the recoil gets taken up by the screw. This wallows out the hole and eventually splits the wood. I think the odd threads and screw shapes were just ways to get after the sale business for replacement and repairs. There's money in parts!

quote:

Originally posted by troutcreeks:
Not that anybody asked. It took a lot of attempts but four screws are 0.208" x 0.9 mm at different lengths, a 208"x32tpi (tang) (tapers from 0.230" to 0.208"), and a 0.150"x40tpi . Why? There was speculation that you couldn't run down to the hardware store to replace them. I don't know but these work.

Hip you have got me laughing more this week than all year!
And I didn't even mention the most salient French design feature; the Double Throated Cock. Much stronger than the British Swan or Goose Cock.

quote:

Originally posted by dpcd:
France adopted the Metric system in 1795. Since our first US made military weapons were copies of the French ones, we copied that too. The French muskets were superior in design over the British ones (Brown Bess), and were 69 caliber, whereas the British was 72. And most notably the French muskets used barrel bands rather than pins, a far stronger method.

That makes sense, I thought you were talking about metric threads which did not appear until nearly 100 years later. It didn't make sense how we could have copied something that did not exist.

Most people do not know the United States has been metric since 1890, but to save their delicate sensibilities I don't belabor the point.

There was a very interesting thesis, I think I posted about it elsewhere, that was published in 2020, titled, The Development, Technology, and application of mechanized manufacture to the Enfield pattern 1853 rifle and the achievement of interchangeability. It is a very interesting read and chock full of primary sources and comparisons with other contemporary arms. I suspect you would find it very interesting.

FYI - I forgot one screw - a 4X40 that holds the loading gate.

quote:

Originally posted by troutcreeks:
FYI - I forgot one screw - a 4X40 that holds the loading gate.

Reminds me of the time a friend brought over is 336 and asked me if I could fix it it wouldn't feed properly.

Tighten the loading gate screw and all was well.

He looked at me and said I wished I thought about that.