227-79-SP-B5 modifications

I think that you meant the 227-79-SP, not the 277-79-SP.
Your seem to refer to 22 caliber bullet diameters.
Attached are the bullet image and the dim drawing from the store website.
That will allow someone with the proper software to mark up the drawings.

Attached you will find a modified version of the 22 caliber cast bullet in question with what I believe are the mods that you suggested.
The cast bullet software (using wheelweights as the alloy) appears to show that the as cast bullet will be around 58 grains.
The 22 caliber Cu GC will add about another 1.3 grains to the total weight.
So you should be right close to your 60 grain goal.
What is the twist rate on your rifle’s barrel?
Have you sent the request to Al via email, as the group discussions were I believe put on hold  on January 28 of this year…

Personally I think that the GC shank is a bit too long for both designs.
The extra GC shank length potentially puts traditional lube down much nearer the powder charge than it might need to be.
If the finished bullet is then inadvertently seated a tiny bit too deep to allow for the COAL of the finished cartridge to load more easily through through a short action.
Then that ~ .015 or so excess GC shank that is above the GC which is now potentially filled with traditional bullet lube.
That lube in contact with the powder charge can potentially begin to react with the powder potentially causing erratic burn rates.
Personally I would shorten the GC shank length from .075 down to around .060.
Most of the Cu GCs “D” dimensions are I believe listed to be around .054 overall
I would add that ~ 015… or so… to the .075 base length making it around .090.
This will add and give the resultant cast bullet a bit more bearing surface area, which I believe will aid in accuracy.
I believe that you also mentioned that the 22 case necks are pretty short.
Maybe another reason to make the GC shank only as long as needed for the deepest GC available.

But then shorter GC shanks are just my personal preference… being a bit more of a traditional lube cast bullet shooter.

I am also interested to see what Al says on this group buy discussion, so I am glad that you are going to contact him on this subject.

I have attached two cast bullet sketches to the following replys in the hopes of getting some more individuals in the que to say that they are interested. It takes at least 10 people signing up to buy at least one mould to get a group buy off the ground, & considered for production. Shortening the GC shank also increases the BC coefficient ever so slightly. One rifles chamber and cut free bore tends to vary ever so slightly from rifle to rifle. What may work in your rifles combination of cartridge OAL may not be optimal in some other rifle.
I have attached the .060 & .050 GC shank bullet sketches to this reply in the hopes of getting some others to chime in that they are interested in an ~ 60 Gr cast bullet for their rifles. I sincerely hope that you understand why I am offering these options. I have also researched the different Cu GCs out there and the longest still has around .006 of shank left when installed. That is shown too in the two latest attachment images. Long GC shanks are fine with longer case necks… However they don’t apparently mix too well with shorter case necks as in this instance.

Most probably the cast bullet shooters that are using the original 70 + grain cast version are also powder coating their cast bullets, and their individual free bores in the individual barrels are most probably cut & optimized for the longer cast bullets in their 1 in 7 twists.
Powder coating might just possibly account for their ability to utilize the deeper seating depths, and not having so much of a potential issue from traditional lube.
Also if one happens to be reloading individual, or a small group of cartridge cases during the match then the time involved would be very short, but still possible.
Finally It is my understanding that 1 in 9 twists are a compromise twist rate.
That’s not to put down that twist rate.
From what I have read and seen the heavier cast bullets may or may not preform with the heavier cast bullet weights.
So going to a 60 grain version would tend to be a benefit to you and your rifle.
Hopefully the 60 Grain cast whether it has a long GC shank or a shorter one will work for you as you hope.

Your thoughts…

What I would suggest if you truly want the 60 Grain version as we have been discussing, is to get the other shooters that you know… who might also be interested in this ~ 60 grain version to sign in on the forum thread, & say in a reply that they are also interested too.

That is the way that the group buys used to get started last year.

Personally I would be interested in a 4 cavity aluminum version 60 grain version with ideally an .050 GC shank… if we could ever get the forum group buys started again.

The version that I drew up with the .050 GC shank is from what the software says with wheelweights is technically the only really true 60 grain SP version.

That particular short shank version also happens to have the highest Ballistic Coefficient of the lighter 60 grain versions.

The SG Calc that I ran (using software from the internet) says that the SG = 2.02 which means that said bullet with BC of .2479 is stable and should be comfortably stable as the SG is well above the 1.5 marginally stable limit on that website SG ballistic calculator.

The .060 GC shank alternately is also a viable option that in reality only weighs ~ 59+ grains in the exact cast alloy (wheelweights) that the software did the calculations with.

It all really depends on the alloy that you are casting with to come up with the exact cast bullet weight… when all is said & done.

Have you heard back from Al or possibly from the forum website administrator Cornmastah?

Cornmastah ran the group buy discussions before they were shutdown in late January of this year… when NOE changed its website server, & concentrated on updating the NOE store format?

If you truly want a 60 grain version with which ever GC shank that most floats your boat…that we have been discussing in this thread… then that is what needs to happen.

Those individuals who have similar rifles with twists of 1 in 9, & / or shorter barreled actions (such as yours) need to take up the torch, & say on the forum thread that they are also interested too.

So far we are only two… It took a verbal confirmed commitment of 10 moulds to get a group buy in the que last year, once the final version was decided upon by the group.

That’s the formula that was used to get the pump primed last year … Nuff Said…