How Deep Of A Hollow Point ?

[Johnch]

In the next few days I plan on going over to my friends shop to cut a few molds

The question I have is about the Hollow Point Mold I plan on cutting for the 357 Mag
I am planning on a .360 dia 150 to 160 gr semi wadcutter mold with a adjustable hollow point stem

What I want to do is use these bullets to hunt groundhogs out to (maybe) 100 yards with a Marlin 357 Mag rifle with as hot of reloads as I can get to group well
Most likely out to 75 yards will be the Max for most of the "Long" shots
But I want the hollow point to help anchor the groundhog
Also I want the hollow point to help control how much the bullet will keep going after passing through the groundhog
So I want the bullet to expand as much as possible

I will be casting these bullets out of a soft range lead
Mostly made of jacketed bullets and 22 LR bullets
But there is always some hard cast bullets in the mix

So my question
How much do I have to leave between the base of the bullet and the bottom of the hollow point with a plain base cast bullet ?
Same question of the amount I have to leave between the base of the bullet and the bottom of the hollow point with a Gator Gas Check on a cast bullet ?

I am asking as I don't want to blow the lead from the base of the bullet through the hollow point and leave a "Tube" of lead in the barrel [smilie=b:
As that would make "Cleaning" out any "Leading" a rotten job

Thanks
John

[Tom_in_AZ]

What velocities are you looking to get? Powder coated or lubed? With soft lead I’d be careful not to push them too fast. I would model a mold after one of the “hammer of thor” or “devastator molds”


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[Mk42gunner]

Its going to depend on a combination of how soft your lead is, depth of the cavity, diameter and probably shape of the pin i.e. if it is straight or tapered.

With a GC you can probably go pretty close to the base without blowing out. With a PB, again depending on velocity and lead, anywhere from 1/3 of the nose length to 2/3 of total boolit length can be made to work.

It has been several years since I made a hp pin for a Lyman 358429HP but I used 1/8" brazing rod for the pin. I put a gentle taper on it similar to the pin in my 457122 mold.

Good luck,

Robert

[beagle]

John. Good question there and I encountered the problem. I had a 358429HP with the standard factory .156" diameter pin. I found that this was too much of a good thing in my Marlin so I cut a .125" diameter pin and it worked out well in the Marlin. I always use the rule of thumb on HPs. Cavity depth is 1/2 the length of the bullet. Never have had any problems with the 60 or so I did when I started the HP game with Orygun Mark and he never mentioned any problems.
It always possible to make a tapered pin. Stay with the standard .156" and make a pin that drops down to .125" as it enters the mould. Takes a little fitting but gives you the best of both worlds.
I used the 358429 in the Marlin for years but it was too long to feed well unless crimped on the forward edge of the driving band. Then I picked up a RCBS 38-162-SWC. I HP'd it and removed the GC shank and it does a well or better than the 358428 and feeds crimped in the crimp groove. Shoots well in my Blackhawks as well./beagle

[Outpost75]

Cavity geometry is more important than depth. For .38 Special +P and .357 revolvers using 1 to 30 tin-lead from Roto Metals, in short-barreled revolvers of 3 inches or less, a cavity which mimicks that of the Winchester X38SPD all-lead hollowpoint +P "FBI Load" works very well from 800-1100 fps. At higher velocities use only the cup point described without the smaller diameter pilot.

60 degree included angle cup point of major diameter 0.66 of the meplat diameter, which will give a conical cup point of depth equal to the major diameter of the cone opening, terminating in a 0.078-0.082" diameter parallel-sided cylinder with 82-degree included angle at end of the core pin, having a total cavity depth measured from meplat to end of core pin of 1 cm. Profile almost identical to a No. 2 center drill.

[Larry Gibson]

I HP my 358156 cast of 16-1 alloy and driven to 1400 - 1600 fps. I use the 1/8" Forster HP tool and HP to a depth of 3/16" which gives excellent expansion and penetration. For more rapid expansion a counter sink is used to further open the HP. If really rapid expansion is wanted I HP to the middle of the front drive band and use the counter sink. Of course moulds can be had these days to do the same but i don't shoot a lot of them anyways so doing "the hard way" isn't a problem for me. Here is what it looks like on a 45 ACP.

280578

[Johnch]

What velocities are you looking to get? Powder coated or lubed? With soft lead I’d be careful not to push them too fast. I would model a mold after one of the “hammer of thor” or “devastator molds”


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Last time I loaded for the Marlin 357 Mag for "hunting" I used 4227
I would have to look up the exact load
But I remember I was getting about 1600 FPS with a 158 Gr Cast bullet with a Gas Check
But that was with a alloy close to wheel weight
So I figure I will have to back off some from that load

I will be Powder coating the bullets

As for the Hollow point Pin
I plan on the depth going into the bullet to be adjustable , so I can play with the right amount for the depth
I like to cut a slight taper to about the last 1/8" of the hollow point pin
But I plan on a round tip as I hope it helps with the release

John

[Land Owner]

For your consideration:

In an MP mold, the solid, flat based, 0.358" diameter, 38 Spc/357 Mag., 49-49-2 / Pb-WW-Sn alloy, SWC boolit drops with a weight of 155 gr. (+/-). Including the "long shank" HP pin, the SWC boolit weight drops to 144 gr. (+/-). YMMV.

[GregLaROCHE]

I HP my 358156 cast of 16-1 alloy and driven to 1400 - 1600 fps. I use the 1/8" Forster HP tool and HP to a depth of 3/16" which gives excellent expansion and penetration. For more rapid expansion a counter sink is used to further open the HP. If really rapid expansion is wanted I HP to the middle of the front drive band and use the counter sink. Of course moulds can be had these days to do the same but i don't shoot a lot of them anyways so doing "the hard way" isn't a problem for me. Here is what it looks like on a 45 ACP.

280578

That’s the same tool I used fooling around one night, making some hollow points out of 500 grain boolits for my .45/70. I just shot them as plinking rounds. I never checked them for accuracy.

[megasupermagnum]

I believe this is a rather easy task. If it were me, I would make the hollow point very wide and deep, and cast out of a rather hard alloy like hardball. I see no reason to go for magazine quality bullet mushrooms. Let the bullet explode inside, it would be even better than a bullet that stays together. At the velocities you can obtain, I would definitely opt for a gas check bullet. Something like the following NOE bullet is what I would choose. An even deeper HP wouldn't hurt either. No need to go too crazy on HP depth, if it expands at all with a hard alloy at high velocity, it is likely shatter, which is what you want.

https://noebulletmolds.com/site/shop/358/tl359-178-rf-ai5/tl359-175-rf-rg4-cavity-gc-rd/

[Outpost75]

It seems that Larry Gibson and I have similar thought process. The validation is refreshing.

[Forrest r]

It seems that Larry Gibson and I have similar thought process. The validation is refreshing.

Wasn't there someone else posting this very thing with the center drills back in 2017/2018???

[bluejay75]

I would just shoot a solid. At rifle velocities almost any HP and most any alloy is going to expand. 15.5-18 grains of H110 you’re going to be running near 2000 FPS. Unless you’re just trying to turn one inside out HP. If you have a chance of seeing a deer in that pasture...solid WFNGC.

[bluejay75]

I HP my 358156 cast of 16-1 alloy and driven to 1400 - 1600 fps. I use the 1/8" Forster HP tool and HP to a depth of 3/16" which gives excellent expansion and penetration. For more rapid expansion a counter sink is used to further open the HP. If really rapid expansion is wanted I HP to the middle of the front drive band and use the counter sink. Of course moulds can be had these days to do the same but i don't shoot a lot of them anyways so doing "the hard way" isn't a problem for me. Here is what it looks like on a 45 ACP.

280578

Is that bit small enough to bore out a match Bullet HP a little bigger? Like making a Nosler Custom Comp hp the size of a 165 Sierra Game King HP?