Seating depth for revolvers

[S Mac]

I have following Brad's threads on his 44 with interest. I'm thinking what I need to experiment with is seating my bullets into the throat more than published OAL. The cylinder length and a place to give a bit of crimp, sufficient neck tension,(enough bullet in the case ) would be determining factors in OAL. Am I on the right track? I guess pressures are going to be a bit lower.

 

[Brad]

I pretty much ignored the amount of bullet in the case beyond having a crimp groove, 2 bands, a grease groove, and a gas check. I actually went with as little in the case as possible as it helped keep weight under control. I didn't want a 325 gr bullet.
As a test you could even take a Keith type swc and crimp it at the top of the grease groove if the loaded round isn't too long. It would certainly move bearing surface forward.

 

[fiver]

case volume is what your going to be using to determine load density.
move the bullet out .2 and you'll more than likely have to bump the powder amount.
unless your jamming it against steel.

I would make a little project out of this and set up the chronograph and write some stuff down on paper..

 

[Brad]

Yes, a chrony makes a huge difference. Move the bullet out and increase powder slowly until velocity matches what you had at normal seat depth.
I don't know how I lived without a chrony as long as I did. I rarely shoot without one unless using a well established load. Load development is just better with a chrony, at least in my opinion.

 

[RBHarter]

First and foremost it will depend on the throat , cylinder and magazine.
Think how far out you can seat an 45 ACP in a revolver that gets a 454 also ...... Crimp in the bottom groove and thumb seat sized to the smallest throat and still have over a 1/4 " of cylinder left . With the top band well into the throat should be enough but some 45 Colts will barely clear the mouth at standard lengths .

I load a 45 ACP 250gr 454424 at 1.305 way past the longest length of 1.240 but it chambers fine in a 1917 but it won't fit in the mags for the High Point carbine . A 452-255 RNFP will go but hangs sometimes about 8-9 down in the 14 rn mags . Those will of course seat out at 1.35+ for the Revolver and don't fit the mags at all .
None of this is a problem of course if you can keep 1917 , 945 and 1911 ammo separated .

I'm all for the 45 Colts out into the throat of the BlackHawk but it won't feed in the companion rifles . The .454 dia helps a lot here as the throat is the same (or close enough) .

 

[S Mac]

Don't have access to a crony. I thought you would have to increase powder charge a bit to maintain velocity.

 

[Brad]

According to Quickload I need .7 gr more H110 using the longer 445 brass trimmed down. That brass is roughly .050 longer.
I can easily see where searing a 429421 to crimp at the top of the grease groove instead of the crimp groove would allow and extra gr of powder.