5.7 spitfire bbl

[matconcrete 0]

Coming up on auction is a spitfire barrel , is this all that is needed to convert a m1 carbine into a spitfire? Phil

[eb in oregon 0]

12 hours ago, matconcrete said:

Coming up on auction is a spitfire barrel , is this all that is needed to convert a m1 carbine into a spitfire? Phil

That is the only piece of the carbine you need, the real issue is the modification of the feed ramp that will require the application of material and re-profiling. The difficulty there is I've never seen a drawing or a good description of the necessary work, and incorrectly done you can count on having a single shot carbine and not an autoloader. The Johnson I have has a very nicely profiled feed ramp, the IAI carbine has a ramp that appears to have been done by a physically challenged person with a die grinder. It will not feed 40 grain open tipped match bullets (the Johnson will) but it seems to feed semi-spitzers well enough, so I'm not screwing with it.

[matconcrete 0]

I appreciate the info, not sure how hard I’ll chase it as the lot includes 10 barrels 9 of which I have not much interest in.RIA

 thanks, Phil

[Tofan 0]

Can we not just have somebody here who has a "factory one" take a picture? Surely this can be reproduced easily, if you have a pic of the feed ramp I would love to see it.

[eb in oregon 0]

Inland M1 Carbine Johnson and Spitfire. While "a picture is worth a thousand words" dimensional differences are important.

 

[Tofan 0]

If you can take another picture of the 5.7 up closer and more light to see the rest of the "grooves". I will use the known distance of the primer to draw the "rough" specifications. Interesting to say the least though. Understand about the dimensions, but sometimes all you have to go off of are pictures with other things that you can measure and make drawings off that. A little bit harder way to do it, and probably impossible to perfect, but definitely get really close.

[eb in oregon 0]

42 minutes ago, Tofan said:

If you can take another picture of the 5.7 up closer and more light to see the rest of the "grooves".

Sorry, no camera I possess will get closer, nor am I a photographer. However I will say that Ed Johnson has stated elsewhere that the receivers originally used needed to have material added (brazing) and the profile changed a mite. The later receivers came with material added and the ramp profiled by contractors. I have an IAI in 5.7MMJ, it's ramp looks no different than a standard M1 Carbine. The IAI will feed semi-spitzers, nothing remotely long and pointy. Though the Hornady 35 grain seem to feed fine. The Johnson feeds semi-spitzers and pointy 40 grain match bullets and anything else.

Those grooves were machined in from the front of the receiver on a vertical milling machine. Using a fixture. I'll bet money. However today investment casting can do wonders. And an investment casting receiver is just fine.

[Tofan 0]

No worries, I appreciate what you did offer. I am going to use the pictures I can find, along with an actual receiver.

I just got some brass in, going to be looking for reloading dies, and I will be reaching out to pick up chamber reamers to make some barrels I believe.

[eb in oregon 0]

Good luck finding the tooling as it is as rare as fangs on a chicken. I've been waiting six months for a set of headspace gages I've already paid for. I also know of no one producing 5.7 M1 carbine barrels at this time. If you find a NOS barrel it will already be chambered I'm pretty sure. CH4D makes reloading dies and case forming dies. They are worth the money. While 5.7MMJ can be formed using resizing dies it's best to make several passes to completely form them. And don't forget to anneal the cases or you will suffer split necks. Either forming or on the first firing.

[Tofan 0]

Yeah I am going to give Pacific Tool a call monday about this. I will just end up making barrels, no point to sit around and wait for somebody else to do it. Also have a master plan, especially now that I have the brass on hand. Pretty nice little round.

[eb in oregon 0]

5 hours ago, Tofan said:

Yeah I am going to give Pacific Tool a call monday about this. I will just end up making barrels, no point to sit around and wait for somebody else to do it. Also have a master plan, especially now that I have the brass on hand. Pretty nice little round.

Who do you think has been sitting on my headspace gages for six months?

[Tofan 0]

Deductive reasoning tells me it's Pacific tool, but there are more companies that make headspace gauges.

[eb in oregon 0]

These guys appear to be up to the job.

https://www.jgsprecision.com/

But you might consider calling Criterion Barrels and ask them how many to make it worth the tool up costs. Here is the deal, the 5.7MMJ is a swell cartridge, it died as ammunition was "unobtainum." A guy can make a few hundred or a few thousand rifles, but no major manufacturer is going to produce ammunition. Johnson, IAI, Iver Johnson, Fulton Armory and a couple others offered rifles in 5.7MMJ. There is no ammunition made currently that doesn't cost less than a couple bucks a round. Rifles that one has to "roll his own" has a very small market.

[Ed Johnson 0]

The 2nd photo that shows grooves from either side is what our new spitfires looked like. the first photo is the IAI and i don't think they modified the feed ramp properly. If you add braising material to a .30 M1 carbine receiver, you need to add enough so that it will grab the smaller .22 cal bullet and raise it up enough as the cartridge is moved forward by the bolt. Otherwise, the tip of the bullet might not be raised enough and simply slam straight into the face of the chamber, and not go up and into the chamber. It would appear that IAI didn't pick up on this problem. Oh, well......