What a difference a die makes...........

[Brad]

Hhmmm . . . I think that was suggested some time ago. That I'm aware of they don't make 44m Cowboy dies but if Brad gets the 44 spl Cowboy dies and neck sizes Brad will be a happy camper.

Yah, yah, yah

I could use them for the 624 too.

 

[Rick]

Had a discussion with Rick and he suggested I neck size the brass using RCBS carbide 44 Special Cowboy dies. I ordered a set from Midway and they showed up, midweek. I was skeptical, to say the least. Having developed reasonable (2 MOA) with heavy for caliber, oversize bullets with my 40 year old RCBS carbide dies for the Marlin.

John's next testing with his Marlin (after determining that the Accurate 210 gr bullet groups will repeat) should be with his hunting load. He's getting decent 2 inch groups with the RCBS 300 gr HPGC with his old dies. I wonder what those groups could be when he tests that load with the Cowboy dies.

 

[Pistolero]

Very intersting results. I may be getting a set of .44 Spl Cowboy dies, too. I have a Browning 92 in
.44 Mag which may benefit.

Bill

 

[Rick]

The Cowboy sizer die will size the brass less for a larger cast bullet. We can thank the Cowboy Action Shooters for RCBS coming out with these dies. Conventional Carbide dies are intended for and dimensioned for jacketed bullets and most in my experience size too much even for the jacketed loads.

Bullets were seated with the new seating dies but crimped separately, using the older RCBS crimping die.

John said that he used his old crimp die from his RCBS carbide set, my money is on that that crimp die is dimensioned to match the Carbide sizer and could well be too small for the case mouth using the Cowboy sizer and .433" bullets. The cowboy crimp die is dimensioned for the Cowboy sizer and uses a gentle roll crimp and that's all that's needed, just tuck the edge of the case mouth inside the crimp groove so that bullets can't be set back in the tube magazine under recoil. The Cowboy set also uses a seating die dimensioned for cast. There is a reason why it's a three die set.

 

[Brad]

Here is a question to ponder.
John expanded the case mouth back up to accept a bullet so what are the reasons the cowboy sizer made a difference?

I have my opinions, just wondering what others think.

 

[Rick]

John used the Cowboy sizer die which wouldn't size the brass down nearly so much, then he used the expander from the Cowboy set which again wouldn't move the brass nearly as much because it wasn't squeezed down like his old Carbide die did. I've been known to use the expander from a smaller caliber die set and not expand at all, only a slight bell at the case mouth. That works fine as long as there is enough neck tension which depends on the sizer die and the lot of brass. With .433" bullets I don't think bullet pull with not sizing nearly as much would be an issue for John. With virgin brass I don't size at all and use an expander for flaring that's small enough to not expand at all.

Bottom line, why mangle bullets seating them in a mangled case?

 

[Kevin Stenberg]

Winelover what measurement did your original carbide die size cases to? And what do the new Cowboy dies size to?

 

[fiver]

even with the expander the sized down cases will spring back.
many think .001... no, and not only no, it depends on the make up of the brass used it's thickness, and it's state of anneal.

I remember 44 man having a damn good write-up about neck tension and seating pressure totally affecting group size.
he even discussed it changing pistol groups down from coke can size on a good cylinder full to bottom of the coke can with room left over on the edges.
nobody believed him and blew him off [sound familiar?]

neck tension is one of my main focus areas when looking at various loads and reasons for flyers, and is why I really like to mention it in my load details somewhere.

 

[Rick]

I've posted these results several times in the past several years, it serves to quite clearly show that the crimp has little to do with consistent ignition. One thing all five of these tests have in common is consistent neck tension. Some are carbide die sized, some are not sized at all. Some have a roll crimp, some have a profile crimp and some are not crimped at all. 44man was right, straight wall handgun ammo accuracy is all about consistent neck tension. That means brass fired the same number of times and not so many times the brass has lost it's elasticity, all sized identically.

Crimp Tests​

FA 357 Mag 9”
RCBS 180 GC Silhouette @ 192 gr. (WW +2% Sn HT @ 18 BHN)
16.0 gr. H-110
Winchester brass
CCI 550 primer
Temp 70 Humidity 38%
January 29, 2008

All chrono tests 10 shots
​

1> My normal profile crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1518
S.D. 9

2> Roll crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1520
S.D. 9

3> No crimp, second firing of WW brass, Carbide die sized, very slight bell
E.S. 30
A.V. 1528
S.D. 9

4> Light profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1532
S.D. 8

5> My normal profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1536
S.D. 8

 

[Ian]

Good thread.

Many of my sizing dies have been re-worked to minimally size brass for specific guns. Steel revolver dies benefit from being honed to a taper and enlarged in the "neck" area. The whole cartridge needs to fit the gun, not just the bullet if accuracy is the goal.

.45 colt can drive a person nuts trying to get one load to work in a bunch of different guns due to so much dimensional variation. .44 magnum is a little better in that regard, but as John's targets show, there is still a lot of room for improvement when using standard tooling due to tolerance stacking.

Neck tension is a big deal, often overlooked, but when scratching my head over a load that prints two groups it is one of the first things that gets reviewed more closely.

 

[oscarflytyer]

Crap... am I gonna need to get Cowboy dies for my 38 SPC/44 SPC/44-40/45 Colts that all I shoot in them is cast?!!?

 

[358156 hp]

Rick- Profile Crimp? I have Redding PC dies for my major revolver calibers & quit using them when it appeared that I was distorting cast bullets with them. I still use them for jacketed loads, but I rarely load jacketed handgun ammo any longer. Is there any special procedure you follow when profile crimping? I'm kind of curious, it wouldn't be the first time I've overdone something.

 

[Brad]

I use a PC for SOME guns but not others. My 44 mag no longer gets used as it was squeezing down the bullets before I got a crimp.
I view the PC as a jacketed diameter or only slightly over crimp.

I believe Rick did that testing with his FA and I bet it got fed .358 bullets so no issues there.

 

[Winelover]

My original carbide dies will handle a bullet up to and including .432 diameter. However, the .433 bullets show a slight bulge in the case, after seating that bullet.

 

[Rick]

The FA bullets are sized .357". All 5 throats are spot on .357" and 358" won't chamber. The profile crimp die works here without damaging the bullets.

 

[Rick]

My original carbide dies will handle a bullet up to and including .432 diameter. However, the .433 bullets show a slight bulge in the case, after seating that bullet.

Slight? Yeah that's one way to describe it I guess.