[BigSlick]

Just inherited a wad of both and would like to make a few rounds on my day off.

Not much published data out there for this combo, but both are popular/common so I'm hoping someone can give me a suggested load.

Bullets are cast TC, weigh in at 179-180gr, BHN of 12 and lubed with Blue Angel.

Will be loading to ~ 1.130 or +/- .002

Can't load em long in the gun I'm shooting them with.

From my amatuer extrapolation (read wild guess) I'm thinking 5.5 - 6.0 sounds about right, but thought I would ask before delving into unknown waters.

[Walkalong]

unknown waters
Like the caliber? .40 perhaps.

With 170 gr lead Winchester (http://www.wwpowder.com/data/handgun/40sw.php) (not Hodgdon) shows 5.2 to 6.2 grs. WSF for 950 & 1090 FPS at 23,500 & 33,200 PSI @ 1.135 O.A.L. in .40 S&W

For 180 gr JHP they show 5.0 to 6.2 WSF

Sounds like you are in the ballpark.

[BigSlick]

Duh !

Sorry.

Yes, 40SW.

I already got 10mm loads worked out for this bullet.

[Shoney]

What is the diameter of the bullet????

The 5.0 gr WSF should be a good start, working up in 0.2 or 0.3 gr increments.

The weapon, barrel length, and rifling will make a difference on leading, check often for signs of leading during load development.

Suggest you seat and crimp in seperate operations, with very light crimp, only enough to hold bullet so no setback occurs during firing.

[BigSlick]

Thanks for the suggestions.

Please elaborate how you come to think 5.0 would be a good starting point. Have you used this combo ? Maybe some pertinent chrono data ?

Bullet diameter is .4015

Taper crimp doesn't affect set back unless you have way over crimped. Case tension is what holds the bullet. If you wanna learn about this up close and personal, take a fired case and place a bullet and crimp it in place. Without resizing the case, you will find the taper crimp does nothing to hold the bullet.

Taper crimp dies exist only to remove belling from the case. Ideally, no crimp actually occurs, simple removal of the flare used to seat the bullet.

I am well aware of the factors that contribute to leading. I have slugged the barrel of the gun I'll be shooting these from. Groove diameter is .4006, throat diameter is .4015, thus, having a custom lube sizer die turned. I've fired tens of thousands of bullets sized exactly so out of this gun. I experience absolutely zero leading with a wide variety of cast bullets, ranging from 10 BHN up to 18, running up to 1400 fps.

What I'm hoping to find is pertinent info from someone who has loaded this combination, or a published data source.