X frame 350 legend question

[keithhagan]

The chambers on a X frame are on about a .560 radius

That means a 1.12 dia circle with circumference of 3.517

divided by 5 it is .703 and by 7 it is .502

A 500 has an outside wall thickness of .100. If the 350 uses the same radius it would have about .236 outside wall and at least .11 space between the chambers. Actually a bit more as the closest spot between the chamber is outside the radius of chamber centers.

Your idea of using a 30-30 case and a 40 cal bullet is interesting as there would be no shoulder.

The place where the space between chambers is narrowest lies on the straight line between two adjacent chambers. Since the centers of the charge holes lie on the circle with radius 0.560, these lines form the heptagon inscribed within this circle (in general, for a cylinder with n charge holes, this point will lie on the n-gon so inscribed).

This means that the distance between the centers of the charge holes will be a little less than 0.502 (for large numbers of charge holes this difference tends toward zero).

I get a distance for the center of adjacent charge holes in the 350 of

y = 2 * R * cos(450/7) ≈ 0.560*0.86776747823 ≈ 0.48594978781

This leaves about 0.063" between chambers at their narrowest at the mouth assuming a 30-30 cartridge sized chamber (.423" at the mouth). This is more thickness than an N frame in 45 Colt, but a bit less than the thickness in an N frame 44 magnum (~0.075").

 

[Luke Duke]

It seems that would be like modifying a 357 magnum to only shoot 38 specials. If the 350 Legend has better ballistics than 357 Herrett, the only reason I can see to modify is for nostalgia. This coming from someone who has painstakingly formed .30 Herrett back in the early 80s!

Yeah I used to shoot .30 Herrett. What a pain to form brass. I've done several wild cats back in the day. That and .357 were the worst. If there's better cartridges use them. A couple 100 fps isn't worth the effort. Especially with today's supior bullet technology. Shoot placement is king. Critters expired with a T/C 14" 30-30 just as well as the 30 Herrett with out all the effort of case forming. Sounds like the Legend is a very efficient round to

 

[keithhagan]

Given that the centers of the chambers will only be ~0.486" apart, this also creates an issue with the rims overlapping. 30-30 rims are 0.506" in diameter. To accomodate that large of a rim diameter, the chambers would have to lie on a circle of radius 0.5831" or more.

You will either need to turn down the 30-30 rims, or use 225 win brass (same body size, but with a .473" rim). The issues with 225 win brass are that it is less common, more expensive, and only has a rim thickness of 0.049". An extended firing pin could solve the thickness issue, though collecting the brass would still be annoying.

 

[steelslaver]

That is a good reason to use a 5 shot cylinder instead of a 7. With a 5 shot you have lots of meat around each chamber, plenty of room for rims. I have both 30 and 357 Herrett barrels for my contender and never had any real problems forming brass. I myself, am not nearly as interested in a 357 HerretT X frame as a 30 caliber

The longer 30-30 case would not work in a X frame cylinder.

 

[keithhagan]

That is a good reason to use a 5 shot cylinder instead of a 7. With a 5 shot you have lots of meat around each chamber, plenty of room for rims. I have both 30 and 357 Herrett barrels for my contender and never had any real problems forming brass. I myself, am not nearly as interested in a 357 HerretT X frame as a 30 caliber

The longer 30-30 case would not work in a X frame cylinder.

Even a 6-shot cylinder would be more than enough for a 30-30/herrett body sized cartridge (by my calculations, ~0.1367"). Would leave more material between chambers than the 5-shot 500 (~0.125" theoretical, to be confirmed by direct measurement). Even with the cylinder notch, a 6 shot would still have more material on the outside than either the 460 or 500.

Agreed re: full-length 30-30 not working for your idea since you would want to use longer, 35 caliber projectiles. It'd only work for me since I'd load FP, 10mm pistol bullets that are much shorter for the same weight.

 

[keithhagan]

While you are building COOL stuff, make me up an X-frame in .327 Federal Magnum. See if you can stuff more than 8 shots in there!

Did the math, and assuming that the charge hole centers lie on a circle of radius .560", the most number of 327 that can be fit in an X frame is 9. Any more and the rims interfere with one another.

With 9, and assuming min SAAMI charge hole diameters, the centers of adjacent charge holes are 0.383063" apart, leaving 0.041863" of cylinder wall at narrowest. The rims will be about 8 thou from touching.

That's a little disappointing. I was expected at least 10, but the X frame cylinder just isn't *that* much bigger than the N frame cylinder. Given that, I'd rather have an 8 shot N frame (L frame too small), or, better yet, a 7 shot K frame in 327.