AJC1
Member
Does a cowboy m die type expander screw into a standard carbide die. Was considering trying to get one for my 38/357 dies.
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Crunchy Frog
Member
The only carbide die is the sizing/decapping die. The expander die is the second die.
I have several RCBS pistol die sets. The expander plug simply screws into the top of the die. Don’t know if the RCBS Cowboy Die is built with a different size expander plug.
The M Die is a Lyman product but you said “type” so you probably knew that.
I have several RCBS pistol die sets. The expander plug simply screws into the top of the die. Don’t know if the RCBS Cowboy Die is built with a different size expander plug.
The M Die is a Lyman product but you said “type” so you probably knew that.
OP
OP
AJC1
Member
The set I have has carbide listed in the naming convention so i tried to stay technically correct. The threads is what i was curious about
243winxb
Member
Discontinued? https://www.midwayusa.com/product/1011555363?pid=270988. For lead bullets.
Found one here. Shipping $8.50. More then the part. https://palmettostatearmory.com/rcbs-cby-expander-assy-357-mag-38-9906.html
Found one here. Shipping $8.50. More then the part. https://palmettostatearmory.com/rcbs-cby-expander-assy-357-mag-38-9906.html
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OP
OP
AJC1
Member
But are the threads the same. I immagine they are.
243winxb
Member
I don't know. The photo at Palmetto is wrong, i think?
mstreddy
Member
OP if your question is "will the RCBS expander plug fit into a Lyman expander die body" the answer is a solid maybe. Many of the manufacturers use different dimensions for their die parts. Expander plugs, decapping stems, seating plugs, etc. Some times the manufacturers even have different size internals depending on the type of die (pistol/rifle), caliber, and even generation. Older dies may use different internal sized parts than newer.
GW Staar
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I was looking at the descriptions of the product and I saw no reference to "stepped expander" or "M" type anywhere. Nor can I see a step in the pictures....just the bevel to open the case mouth wider the deeper you seat it. So I'm curious....are they really stepped? For my progressive-mounted Uniflow Powder measure I have stepped expanders for .357, .45, .40 and 9mm., but that's used during powder drop after expanding.
For rifle, the new Tube Rifle Bullet Feeders (using ball bearings) for the Pro Chuckers, DO include a separate "M" style expander before the powder measure and they work well. And I've begged the RCBS engineer I know to make a similar feeder and die for their pistol calibers and phase out the old ones.....but of course I'm not much of a force for change there.
The picture below compares the non-stepped Dillon expander for their P.M. (left) compared to DAA's expander to replace it when using their bullet feeders. (right).
Similarly the RCBS expander for the tube rifle bullet feeder has the step as well. Below:
The reason I went to this trouble with illustrations and all was to warn you that the Cowboy expander may just be a hair wider diameter to make it fit lead bullets better? Where do I find a reference to a "M" style step? Very curious.
For rifle, the new Tube Rifle Bullet Feeders (using ball bearings) for the Pro Chuckers, DO include a separate "M" style expander before the powder measure and they work well. And I've begged the RCBS engineer I know to make a similar feeder and die for their pistol calibers and phase out the old ones.....but of course I'm not much of a force for change there.
The picture below compares the non-stepped Dillon expander for their P.M. (left) compared to DAA's expander to replace it when using their bullet feeders. (right).
Similarly the RCBS expander for the tube rifle bullet feeder has the step as well. Below:
The reason I went to this trouble with illustrations and all was to warn you that the Cowboy expander may just be a hair wider diameter to make it fit lead bullets better? Where do I find a reference to a "M" style step? Very curious.
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OP
OP
AJC1
Member
I was watching a fortunecookie45lc video and he was reviewing a set of the cowboy dies. He said they had a second step but I have nothing in hand to verifyI was looking at the descriptions of the product and I saw no reference to "stepped expander" or "M" type anywhere. Nor can I see a step in the pictures....just the bevel to open the case mouth wider the deeper you seat it. So I'm curious....are they really stepped? For my progressive-mounted Uniflow Powder measure I have stepped expanders for .357, .45, .40 and 9mm., but that's used during powder drop after expanding.
For rifle, the new Tube Rifle Bullet Feeders (using ball bearings) for the Pro Chuckers, DO include a separate "M" style expander before the powder measure and they work well. And I've begged the RCBS engineer I know to make a similar feeder and die for their pistol calibers and phase out the old ones.....but of course I'm not much of a force for change there.
The picture below compares the non-stepped Dillon expander for their P.M. (left) compared to DAA's expander to replace it when using their bullet feeders. (right).
View attachment 951990
Similarly the RCBS expander for the tube feeder above has the step as well. Below:
View attachment 951991
The reason I went to this trouble with illustrations and all was to warn you that the Cowboy expander may just be a hair wider diameter to make it fit lead bullets better? Where do I find a reference to a "M" style step? Very curious.
GW Staar
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I wonder if he thought the flare was a second step.....
The flare on a case prevents the case from slivering of a circle of lead from the bullet when you seat, but it doesn't hold the bullet stable and vertical very well .... you have to use your fingers to feed it straightish into the seater.
In contrast, the "M" step is a 1/16" deep step that the bullet falls into and is stabilized so the case...not you holds the bullet straight while you feed it.
Would be great if it this expander really did that....
The little video below demonstrates how it works on the rifle bullet, but the same thing for any "M" style die. or expander.
That's how well only 1/16" depth can hold.....next step you would seat it. On a progressive especially, such a stable hold is nice as you spin the case to the next station.
The flare on a case prevents the case from slivering of a circle of lead from the bullet when you seat, but it doesn't hold the bullet stable and vertical very well .... you have to use your fingers to feed it straightish into the seater.
In contrast, the "M" step is a 1/16" deep step that the bullet falls into and is stabilized so the case...not you holds the bullet straight while you feed it.
Would be great if it this expander really did that....
The little video below demonstrates how it works on the rifle bullet, but the same thing for any "M" style die. or expander.
That's how well only 1/16" depth can hold.....next step you would seat it. On a progressive especially, such a stable hold is nice as you spin the case to the next station.
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OP
OP
AJC1
Member
Check at 6:28
GW Staar
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For the price of the expander 243winxb posted, it'd be worth it to take the chance on the threads, if it truly has the "M" die step, IMO. I might get one myself!.....so beat me to it in case they only have one. Can't imagine RCBS stopping production of it unless they are bringing out something better.....you never know about those guys.....they make great dies....their marketing skills are terrible.
I think I'll email the engineer tomorrow and see if he'll tell us whats what here.
Here's a picture of the PTX expanders RCBS makes for the Uniflow powder measure. The arrow points to the "M" step. You can get those in most pistol calibers also. They do the same thing as the DAA one does in the Dillon P.M.'s...just a different design. I have 3....they work.
Can't imagine RCBS stopping production of it unless they are bringing out something better.....you never know about those guys.....they make great dies....their marketing skills are terrible.I think I'll email the engineer tomorrow and see if he'll tell us whats what here.
Here's a picture of the PTX expanders RCBS makes for the Uniflow powder measure. The arrow points to the "M" step. You can get those in most pistol calibers also. They do the same thing as the DAA one does in the Dillon P.M.'s...just a different design. I have 3....they work.
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2011redrider
Member
Most of my dies have already beed moved to our new home in North Idaho. Only calibers I still have to pack in both dies sets(cowboy and regular carbide sets) are in 45 Colt. Both sets have stepped style expander plugs and both threads are the same and will work in either set. I assume they will be the same in the 357 that you are looking for. RCBS will probably send you one if you call them, they did for me when I called them for a new decapping rod.
The 454 plug was stepped and the 452 one was not?
The 454 plug was stepped and the 452 one was not?
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