Hollow point design advice, please

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  • Last Post 05 September 2022
JimmyDee posted this 29 May 2022

I'm considering sending a mold to Eric for hollow point conversion.  Hunting effectiveness using Lyman #2 at rifle speeds is the goal.

From what I've read, a pin with a 5 degree taper ending in a spherical point seems to be the preferred form for good expansion and weight retention.

I have not been able to find a recommendation for depth of the hollow or the diameter of the hollow with respect to bullet diameter.  (Obviously, they are related.)  Is there a rule of thumb?

What about terminal velocity?  It seems that slower bullets need larger (and deeper) hollows and I would guess there's a significant difference between 1600fps and 2000fps.  Or is there?

Advice, please.

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ClydeF posted this 05 September 2022

I have the same rifle and use the Gould bullet often.  My Marlin guide gun in 45-70 loves those bullets and it is my go to rifle during deer season in NC.

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Aaron posted this 04 June 2022

JimmyDee,

David Reiss is attempting to attach a file to this post for you regarding HP Cast Bullets. The articles located on the LASC web site are a wealth of information if you did not know that. Hope the attachment works.

With rifle in hand, I confidently go forth into the darkness.

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Ed Harris posted this 02 June 2022

Proven is cup point 0.6 of meplat diameter with 60 degree draft angle so that depth of cavity does not exceed major diameter of cavity. Very effective at subsonic velocity up to 1300 fps with soft alloy 8-11BHN. Below 900 fps reduce draft angle to 30 degrees with 8-10 BHN alloy.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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Aaron posted this 30 May 2022

I too have learned over the years through trial and error about the hollow point bullet and the mystique surrounding it with its ability to absolutely devastate the intended target Oh well - we learn.

As mentioned already, my FP cast bullets in the 30-30 or 32 WSP cast in Lyman #2 alloy and run to about 2000 fps perform exceptionally well on deer sized game and pigs IF, and I emphasize IF, the shot placement is good. A hole through the heart or lungs on a game animal is always fatal. The "shock" of the bullet usually drops them in their tracks if the shot was a surprise and the animal was not pumped full of adrenaline.

As for the hollow points, I tried my first trial with the 44 Mag for boar hunting. Now when I say boar, I mean large, big, aggressive Russian boar. Having hunted with J.D. and Handgun Hunters International for many years, I saw boar absorb multiple 44 Mag hits and keep running. I purchased the Lyman 429640H and cast them in Lyman #2 alloy because I knew, against all advise in the literature, that MY bullets would perform perfectly. From this photo, you can see the results of my arrogance! The bullets at 1300fps completely shattered.

After swallowing my pride or eating crow, if you prefer, I began to cast them in 20:1 alloy and the results were immediate and impressive. Velocity used was about 1200 fps on average. Would this bullet have killed a boar any better than a 30-30 if it had gone through the heart? That's another whole debate but this bullet did, in fact, drop the hog in its tracks. Below is the image of the 20:1 alloy recovered bullet.

I have also played with 38 caliber bullets for the 38 Special, 357 Mag, 35 Rem, and others. My experience there has been that large flat meplats have more of a killing effect on game than any HP designed bullet. Here you can see a Lyman 358439 bullet cast in Lyman #2 and fired at 1100 fps out of a 38 Special. Velocity had to remain lower to keep the bullet from shattering but the velocity was not enough to initiate mushrooming. Casting in 20:1 or 30:1 alloy and adjusting the velocity would have accomplished this but I have seen the results of a large flat meplat on game. Below is the image of the Lyman 358439 Fired directly into a barrel of water. The tip opened up some just prior to the bullet fragmenting. It ran out of steam before ripping itself apart.

Next year I plan on hunting the boar with my Winchester 1886 in 45-90. I may actually fire the rifle rather than whacking the boar on the head with it - a sure killer. I chose the Lyman 457122 "Gould Express Bullet" that was a favorite in the day. I have cast these in 20:1 alloy and will be using Black Powder to push these along at 1600fps. This alloy and speed, with this bullet, has proven to be a solid performer. Heck - even if it doesn't expand, the meplat alone is large enough to stop a rhino. Initial test have shown positive expansion but I did not take photos yet. That is a project for this summer.

I wish you all the best on your specific quest. While we all reply like we know everything about the matter, I remind myself I learn something new every day. If I have missed a specific detail on your initial post, my apologies for this long-winded reply! Please keep us informed with what you determine and find to work best in your situation with your unique parameters.

 

 

 

With rifle in hand, I confidently go forth into the darkness.

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Idahocaster posted this 30 May 2022

Larry, thanks for the alloy information! I've been trying to figure out what the ideal alloy for a rifle hollow point would be, and that sounds like a good one.

Ed, I am willing to go slower. In my admittedly limited cast bullet experience lower velocity is generally more accurate, and who wants more recoil if you don't have to have it?

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Ed Harris posted this 30 May 2022

I am aiming for 1900 to 2000 fps.

A hollowpoint isn't needed above 1800 fps. A flat nose with meplat 0.6-0.7 of the bullet diameter is helpful. Larry's advice for alloy is spot-on.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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Idahocaster posted this 29 May 2022

I am aiming for 1900 to 2000 fps.

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Idahocaster posted this 29 May 2022

I forgot to mention that the diameter of the hollowpoint is 0.100 inch in a 30 caliber bullet.

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Idahocaster posted this 29 May 2022

I got a 311-291 hollowpointed by Eric last year that has approximately the shape you describe. The depth of mine is about 3/4 of the nose, as I still want reasonable weight if the nose shears. Unfortunately I haven't been able to hunt with any yet.

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Larry Gibson posted this 29 May 2022

Over many years i have worked and tested in medium and then on game the use of HP cast bullets in rifle cartridges of 6.5 up through 45 calibers.  Let me say first of all, #2 alloy (as much as I prefer it for HV and match shooting) is not really a good alloy for expansion with weight retention.  It is still too hard and somewhat brittle for that application.

The best alloy I've found for HP cast bullet expansion at impact velocities from 1400 upwards of 2400 fps is with a 97/1.5/1.5 alloy (COWWs with 2% tin then mixed 50/50 with pure lead).  Such an alloyed bullet is AC'd, lubed with a good soft lube and GC'd.   I've found in 7mm through 35 caliber bullets a 1/8" diameter HP 3/16" deep works well as well as any other configuration for expansion and weight retention.

I load such softer bullets with medium (4895 range) burning or slower burning powders (H4831range) to maintain not greater than 4-6" max grouping with 8 rounds +/- at the maximum range to be used [usually 200 yards].  Further, as I've often mentioned, I clean the barrel every 6 - 8 rounds to maintain that accuracy when pushing the softer alloyed bullets to 1900 - 2400 fps muzzle velocity, 

LMG

Concealment is not cover.........

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