Pointed 50cal Mold Design

[Dirtjumper895]

I have a 510 Whisper I am looking for a new bullet mold for. Currently I have a 512-975GC from CBE, which is a great mold however the nose is so short that it doesn't feed as well as I would like it to from the AICS magazine. My barrel is a 6 groove, 1:10 twist.

Currently my max OAL with the 975 boolit is 3.075". Projectiles feed best from these mags loaded at 3.4-3.6".
I've attached a photo of the profile I think I am looking for. Is it a bad idea to have this shaped projectile? I'll be editing this thread to add measurements and specs as I can get them. Any recommendations on a good manufacturer of a mold like this? These will all be shot subsonic.

The 2nd picture shows my PC'D 975 boolit, a couple 690 grain AP and M2 ball, and a 308cal 150 grain in a 30-50 Cal sabot.



Hopes:
1) Be 0.512" as cast
2) Be 700-850 grains
3) Able to be powder coated

The CBE 512-975GC is 2.035" long. My guns lands are 0.500" and grooves are 0.510", and the 0.500" part of this boolit starts at 0.655" from the meplat. The nose diameter is 0.504" after powdercoating. The meplat diameter is 0.188".

The projectile I am really trying to model this after is the mix of the 750 Amax and 690 Grain M2 ball, with just a longer base and more mass. I feel once I get the nose shape right, I can add more base to the design to get the mass I am looking for.

The M2 balls point less than 0.500" is 1.150" long, and the 750 Amax point is 1.475" long. The meplat on the M2 is 0.130" and the Amax is 0.100".

Probably should discuss the use of this one. Mostly to kill paper, however the dream of hog hunting was the main purpose of getting into 510 Whisper. I figured once I have a good hog killer, I will have to schedule a trip.

The last two photos are of my new accurate 50 Cal mold used for my beowulf.

[endwrench]

Wow, hope you get some answers you are looking for. I will not be of any help but I am very interested in your project. There is very little info on the .net about the 510 whisper and I happen to be putting together a project myself involving a .50 cal subsonic round. I would love to pick your brain a little if you wouldn't mind? I'll save it till the end of this thread or private message you.

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[Dirtjumper895]

One of the other things I have considered, is to use Corbin's ULD Aluminum tips in conjunction with this proposed mold. Either cast a hollowpoint boolit and bond the tip to the boolit, or cast the boolit with the ULD tip in the mold. Does anyone have any experience doing something like this?

[endwrench]

Search "long unsupported ogive" on this sight. It didn't really answer my questions but it may give you a few clues. Overall, spitzer designs in the cast bullet world seem to be looked down apon. I think you will be going in the right direction with the light weight tip. I understand your quest for the best BC. It matters. Even at subsonic velocities. If you reach out there very far you run out of scope adjustment. My theory is the bullet does not need to be perfectly stabilized because it never goes thru the transition. I believe a 3MOA bullet at 100 yds can become a 1MOA bullet at 300 yds. If you don't want to respond to any of this drivel then can you please tell me what case the 510 whisper is based on and the length? Thanks!

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[17nut]

Search "long unsupported ogive" on this sight. It didn't really answer my questions but it may give you a few clues. Overall, spitzer designs in the cast bullet world seem to be looked down apon. I think you will be going in the right direction with the light weight tip. I understand your quest for the best BC. It matters. Even at subsonic velocities. If you reach out there very far you run out of scope adjustment. My theory is the bullet does not need to be perfectly stabilized because it never goes thru the transition. I believe a 3MOA bullet at 100 yds can become a 1MOA bullet at 300 yds. If you don't want to respond to any of this drivel then can you please tell me what case the 510 whisper is based on and the length? Thanks!

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Google is your frined you know?
https://en.wikipedia.org/wiki/.510_Whisper

Unless a search is to much work.

[475AR]

The problem you will run into is a mold maker that will cut the mold. The issue it the length of the bullet, I have some .500 diameter and .308 diameter designs I would love to have cut and called everyone and their brother and since the length is so long and there is no market for a run of multiple molds they do not want to do 1 offs. If you do find someone that will cut a bullet that long please let me know.

[endwrench]

Google is your frined you know?
https://en.wikipedia.org/wiki/.510_Whisper

Unless a search is to much work.

Hmm, I know I went down the entire "whisper" rabbit hole at Wikipedia and there was little if any info on the 510 or the 458. But I have to admit it has been a while. Thanks.

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[endwrench]

The problem you will run into is a mold maker that will cut the mold. The issue it the length of the bullet, I have some .500 diameter and .308 diameter designs I would love to have cut and called everyone and their brother and since the length is so long and there is no market for a run of multiple molds they do not want to do 1 offs. If you do find someone that will cut a bullet that long please let me know.

Just as an aside, part of my project will include cutting my own molds. I don't for see this happening until deep winter though. I need to build some tooling for my lathe to accomplish the ogive profile I am wanting. I will be happy to share though if you have not found anything by then.

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[Dirtjumper895]

I did some more experimenting today, part of my issue with the 975 CBE mold is nose diameter after powdercoating. I am going to cast more, and maybe do a traditional lube or only PC the bullet below the nose to see if this gives me some more flexibility. I'm still trying to get a drawing together of what I would need to have a mold made that would work with Corbin's ULD Tips. I feel the longer pointy tip using the ULD tip would make these feed from the magazine better than they currenlty do.

As far as making the brass, that is another project.

510 Whisper uses 338 Lapua Magnum Brass as the parent case. To convert the brass I use the following process:

I use a K&M Micro Neck Turning tool for 50BMG to machine the case necks. After speaking more with Roger at K&M, the maximum cutter angle he could grind me is 77°. The chamber print for 510 Whisper shows a 83° angle. I got the K&M Expander as well to ensure the necks were expanded enough so the brass doesn't gall on the pilot. It took me a little bit to get the neck turner set up like I wanted, but it works great. The finished brass looks incredible, and have minimal machining marks. I polish with steel wool after turning. I got the 50bmg setup with a steel pilot and carbide cutter with the custom grind. I also got a 0.005" depth micrometer which installs on the neck turner to get good measurements. I'm pretty happy with it so far, but it is time intensive. I'd say 10+ minutes per case in neck turning, it is time intensive. It helps a lot to tighten the shell holder with a wrench, it eliminates any spinning of the case in the shell holder.

My process ended up like this:
1) Rough cut brass behind the neck. I use a Harbor Freight Chop Saw to do this step. Afterwards I debur and chamfer the case mouth, which helps the next step.
2) Trim brass to 1.885". Debur and chamfer case mouth again. (I chose 1.885" due to it is ~0.025" shorter than my chambers neck, and lets me crimp the neck later just inside the cannelure of my 690 grain milsurp projectiles)
3) Use 338 Lapua Mag FL sizing die to full length size brass to minimum dimensions
4) Use K&M 0.508 Expander die to expand case mouth to fit on pilot of neck turner
5) Lube case mouth and pilot on neck turner with good case wax.
6) Turn down neck to ~.012" thick, in 4 passes. I set the shoulder at 1.440" from the base of the rim, as my go gage's dimension was 1.437" and the no go was 1.443" from the base of the rim. This should put me right in the middle of the headspace I was having my chamber cut to. I chose 0.0115-0.012" thick neck for flexibility in projectile choices. I initially chose 0.0135", however this only worked with .510" projectiles. My .512" lead cast would not chamber.
7) Use 510 Whisper dies to full length resize case ( Shouldn't be much happening here)

From here on it is normal loading. I have also had some cutaway case gages made, so i can check cases and loaded ammo for fit. (Have 4 left in case anyone is searching for one). My reloading dies came from CH4D out of Ohio, and have a 0.508 expander for FMJ and a 0.512 expander (on order/shipment in progress) for lead cast.

[475AR]

Just as an aside, part of my project will include cutting my own molds. I don't for see this happening until deep winter though. I need to build some tooling for my lathe to accomplish the ogive profile I am wanting. I will be happy to share though if you have not found anything by then.

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When you get ready to do your mold let me know, as I said I have already called and spoken to most all custom mold makees and no go. Wish I had the skills and machines to do work like this.

[endwrench]

So, if I'm reading correctly, you are basically making a bottle neck case thru the neck turning process. That's some seriously thick brass! I also assume it headspaces off the shoulder. This should help your accuracy potential. If you don't mind can you tell me the case capacity? Maybe just fill with a common powder and weigh. I just need a comparison.

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[endwrench]

When you get ready to do your mold let me know, as I said I have already called and spoken to most all custom mold makees and no go. Wish I had the skills and machines to do work like this.

Tools, yes. Skills, ??

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