Trapdoor ........... perhaps

[John Bly]

It's a 50/70. The barrel serial number matches the action. I've got faith that the bore will be good. I've bought from this auction house before and everything has been better than described. If the stock has been chewed on by beavers or is otherwise terrible I'll patch it up with Bondo and put it on my duplicating machine and make a new one. I'm looking forward to getting it. I've got brass, dies and bullet molds.

[mdeland]

Well , as Fred Flintstone used to say "Yubba- Dubba- Dooo, guess what showed up today! Doesn't take much to make me happy!
I ran a slug gauge down bore after wiping and .450 slides snuggly to about 3 incbes shy of the muzzle and stops. I've got some choke it looks like.
Eight lands and grooves with a groove diameter of .458. Unturned blank is 31.5 inches long and 1.200 in diameter. It still has the normalizing (annealing) scale on the exterior which will be turned to the profile of the original barrel.

[mdeland]

It will be interesting to run the slug gauges down bore after it is turned to final profile to see if the bore opens any. It shouldn't if properly annealed between button passes but we will see.
Been looking a three styles of set triggers that came on the various trapdoor models and have figured out pretty well what the hidden parts should look like from assembled photos. It gave me something to do while having the tires rotated on my work truck today.

[Clark Badgett]

I just received my trapdoor receiver yesterday. It's in really good shape. It's a late 499k numbered example. Just ordered the trapdoor and latch parts. The ejector seems to be sold out everywhere I've looked. Now to find a 1 1/16" tapered octagon barrel in .45 that's available. Still debating if I want this to be a Gemmer style or just a sporter style that I make up. I have plenty of deciding time with a possible relocation on the horizon.

[alfajim]

I just received my trapdoor receiver yesterday. It's in really good shape. It's a late 499k numbered example. Just ordered the trapdoor and latch parts. The ejector seems to be sold out everywhere I've looked. Now to find a 1 1/16" tapered octagon barrel in .45 that's available. Still debating if I want this to be a Gemmer style or just a sporter style that I make up. I have plenty of deciding time with a possible relocation on the horizon.

Clark there is a extractor spring and plunger on ebay right now for a fair price.

Jim O

[alfajim]

I just received my trapdoor receiver yesterday. It's in really good shape. It's a late 499k numbered example. Just ordered the trapdoor and latch parts. The ejector seems to be sold out everywhere I've looked. Now to find a 1 1/16" tapered octagon barrel in .45 that's available. Still debating if I want this to be a Gemmer style or just a sporter style that I make up. I have plenty of deciding time with a possible relocation on the horizon.

Clark there is a extractor spring and plunger on ebay right now for a fair price.

Jim O

Al Frasca has two 45 cal extractors one early one late plus one 50 cal extractor all showing un-sold plus some springs and plungers.

Jim O

[mdeland]

I'll get going on this new barrel here pretty quick with some pictures, soon as I get a 7mag set back and rechambered. Guess it will need a thread for a muzzle break as well but that should not take to long.
I think the part about the integral front sight lug should be interesting cause I've not done it before.

[mdeland]

Well I got the other project completed yesterday and it's time to get going on the Springfield barrel. I'm going to turn and thread the shank today, fit to receiver , cut the extractor slot and chamber. That will give me the actual length to be tapered which is plugged into the set over equation so I can calculate the tail stock set over.
First order of business is to turn two brass center plug bearings for each end of the barrel to run the taper on. They wear and are self correcting into the hard steel centers on the lathe that are out of alignment at tail stock set over.
I will do the barrel taper in two sections with a steady rest mid barrel to remove the flex that screws up the taper line and induces chatter.
A full diameter barrel ring will be left where the sight lug is to be machined integral with the barrel. I'm a bit nervous with this part having not actually machined one before but it seams straight forward at least in theory.
Once the taper is turned and the barrel finished crowned the lathe work will be done and the lug will be machined in the mill with the barrel being on divider centers.
The barrel being qualified to the receiver will give us top dead center indication for the front sight lug which is the reason for threading and fitting it to the receiver before hand.

[mdeland]

two more photos

[mdeland]

One point I should bring up to those who do their own machine work that may be helpful is the head stock brass plug center is not a bearing only a bore protecting barrel center but the tail stock plug becomes an actual bearing for the final taper passes, for most accurate taper concentric. I use a live center in the tail stock for the balk of the taper turning.

[alfajim]

mdeland, I am assuming that your lathe does not have a compound tool holder on the cross table for doing tapers with the auto feed?

The lathe's I used at my work in the race engine shop both had them great for doing tapers inside and or outside.

Jim O

[mdeland]

Yeah I have a compound but can only get about three inches of taper length on the cross feed screw. A sine bar would be a better attachment for long taper work on this lathe but I don't turn enough long tapers to make it worth the purchase.
I would still need a mid barrel steady rest to eliminate the flex and then chatter. The sine bar uses a follower rest attached to the table instead of the lathe bed as is the regular steady rest so I'm not sure how that can work on a taper. It would be neat if I could get the table to make a full length taper cut and have a mid barrel steady, back rest, that is lathe bed attached and the table could pass it without interference .

[alfajim]

Yeah I have a compound but can only get about three inches of taper length on the cross feed screw. A sine bar would be a better attachment for long taper work on this lathe but I don't turn enough long tapers to make it worth the purchase.
I would still need a mid barrel steady rest to eliminate the flex and then chatter. The sine bar uses a follower rest attached to the table instead of the lathe bed as is the regular steady rest so I'm not sure how that can work on a taper. It would be neat if I could get the table to make a full length taper cut and have a mid barrel steady, back rest, that is lathe bed attached and the table could pass it without interference .

Yeah I have seen those they work well for that purpose. Do you use regular lathe tools or inserts we tried to use inserts most of the time except for special curves or radius.

Jim O

[mdeland]

I use regular 1/4 inch square, high speed tool steel and carbide tip bits that I can grind to shape and sharpen.

[kenny sd]

I went to a gun show in Florida, North Port, yesterday. there was a nice trapdoor full length, well under a grand. 600 I think.
they are out there....don't blow the wad on a gun that is that bad.
Ken