.45 Lyman Mold - Seating depth Question

[BNE]

I have the following Lyman mold. http://www.midwayusa.com/product/204749/lyman-4-cavity-bullet-mold-452374-45-caliber-452-diameter-225-grain-round-nose

It is the 4 cavity 225 grain round nose boolit. The ogive shape is not as round as I expected. I had been buying a cast .45 boolit that had a much more rounded nose. The round shape gave me more room to seat and crimp the boolit. (See picture below) The Lyman mold produces a boolit that is
~.020" longer than the previous boolits I loaded. The result is that I am making cartridges at the top end of the length for an ACP, but barely have enough room to taper crimp the brass into the boolit.

84505

These function fine, but I don't like the narrow range they give me to seat the boolits, and I just don't like the way the finished cartridge looks. Is this supposed to be used for 45 ACP? Any input or suggestions would be appreciated.
BNE

[45 2.1]

If you look at Lyman's designs over a long period of years, you will see many changes in the boolit shape. I have several molds with the same number on them that are barely recognizable as being the same boolit. Not all people machining cherries can cut to specification or know how to cut the correct radius (as shown on yours). Right now in the Active Group Buy section is the 452374 that, other than a modified lube groove, is a proper Lyman 45 RN. The actual dimensions, radii etc. were given to me by a Lyman tech many years ago, over the phone as that is a proprietary design, and match my best shooting 452374 mold.

[williamwaco]

It looks to me like the cartridge on the right has too much crimp.
It is not really close enough to be sure but I did expand it 2x.

For that caliber the case wall should be perfectly straight.
Look closely at a factory load to see what I mean.

As for length, with that style bullet, I seat just them just deep enough to cover the lube ring. Then test for function. If they function reliably, I stay with that length. If necessary to get reliable cycling, I will adjust it longer or shorter.

[prs]

The 374 is a classic hardball clone. I use 1.272" as COL with a taper crimp to reduce case mouth outside diameter to .470". Such rounds "plunk" test well in my barrels and my Wilson guage. Mt copy of that mold was produced less than two years ago. The currect Lyman cast handbook uses that boolit on almost every page as a logo.

prs

[prs]

It looks to me like the cartridge on the right has too much crimp.
It is not really close enough to be sure but I did expand it 2x.

For that caliber the case wall should be perfectly straight.
Look closely at a factory load to see what I mean.

As for length, with that style bullet, I seat just them just deep enough to cover the lube ring. Then test for function. If they function reliably, I stay with that length. If necessary to get reliable cycling, I will adjust it longer or shorter.



William, if you seat that boolit to just cover the lube groove it will be way too long to fit magazine. My seat depth is close to the ogive and within .002" of SAMMI max. I do crimp ACP brass to below straight wall condition, but never so much that 90 degree probe finds the inner surface of the case smaller than the head space rim of the chamber. Clear as mud?

prs

[MtGun44]

I rarely disagree with William, but I have used "push about 1/3-1/2 of the thickness
of the case wall into the boolit" for decades and measuring cases this works out to around
.463 or .465 in most that I measured. Not much but a noticeable, visible TC has never
caused me any grief. To LITTLE TC has cause a LOT of grief. IMO, err on the side of
a bit too tight. Failures to close are most frequently caused by inadequate TC.

I usually recommend ".465 to .470", but I always go for the tighter end of that range or
more TC.

Bill

[captaint]

Those 2 boolits look to be totally different designs. One is the Lyman that has been around forever and the other looks like the H&G design - #73 ??. I'm just guessing.
Mike

[huntrick64]

I'm with Bill on the amount of crimp, I taper crimp into the bullet a few thousandths and usually end up with .468. I use the "plunk test" to determine my case trim length. Then I seat the bullet a little long (along with the right crimp) and start cycling them through the gun. I keep seating the bullet deeper and deeper (.003 at a time) until they cycle flawlessly, then seat another .005 for a margin and call it good. However you crimp, make sure you leave plenty of case width to headspace on or you will have bigger problems.

[williamwaco]

William, if you seat that boolit to just cover the lube groove it will be way too long to fit magazine. My seat depth is close to the ogive and within .002" of SAMMI max. I do crimp ACP brass to below straight wall condition, but never so much that 90 degree probe finds the inner surface of the case smaller than the head space rim of the chamber. Clear as mud?

prs


Yes, that was covered by

Then test for function. If they function reliably, I stay with that length. If necessary to get reliable cycling, I will adjust it longer or shorter.

Also I don't disagree with Mtgun44's crimping method. In fact I use it occasionally.