THIS Is the Dedicated 65G Bullet I Want

[Drifter]

While not everyone seems to agree on exactly what bullet design is really needed, most seem to believe that Grendel performance could be enhanced with new projectiles.

Instead of telling bullet makers how to design a bullet, maybe we should be telling them our applications and performance expectations. Then let them (the experts) design the bullet(s). Just saying...

[BluntForceTrauma]

A picture is worth a thousand words. Our applications and performance expectations actually are encapsulated in our concept proposal. The bullet makers can take it from there and use their expertise to tweak the basic concept into production. Is this not the path the very useful 6.8 SPC Barnes 95 TTSX took? I suppose we can tell them specifically we want a 6.5 Grendel solid to expand down to about 1600 fps, but then, if they're experts, they'd know this?

Industry is not always as innovative as the particular enthusiasts for any given product, and they can certainly feel free to ignore us if they like and come up with their own design from the ground up.

[stanc]

The best is yet to come , on these ideas. Hang for a few more weeks... No pre orders to be sent in... wait for the data sheets, samples, vids to be sent in firstly- we are all in this together- we have put a great effort into this, as a team.

The gel tests are the best end game . as a visual aide.

Stanc, voice of reasoning here ? We are not ready , yet!!!!

sneaky, be careful what you wish for, because you might get it.

I would probably be wise to stay out of this, but since you ask, here goes.

1. I think it is logical to do testing, not only to have data, samples, videos, etc, to send to bullet makers (prior to sending in a group buy request), but also to allow Horde members to see what performance can be had from lighter weight bullets before settling on any particular weight.

2. You and rickOshay are doing an incredible amount of work in creating and testing these modified bullets, but IMO those weighing less than 100 grains won't come close to having the 0.400-plus BC desired by HANKA and Variable. (In an affordable bullet, that is. I don't know about the expensive GSC bullets.)



L to R: 127gr LRX, 120 gr GMX, 120 gr TTSX, 120 gr E-Tip, 105 gr Sneaky LRX, 100 gr TTSX, 95 gr GS Custom HV, 90 gr Sneaky E-Tip, 86 gr GSC HV, 80 gr Sneaky GMX

3. The Nosler E-Tip looks to me like it is not worth pursuing. For one thing, the design of ogive and boattail results in a very mediocre BC, much too low for a 100-grain version to satisfy HANKA and Variable. For another, advertised expansion appears to be rather poor at distances much over 100 yards, when fired from the Grendel.



4. HANKA's proposed 100-grain bullet looks sexy, but unless it is certain that such a scaled-down .300 BLK TAC-TX bullet can actually be manufactured, and expand as desired, I think it would be best to go with modifications of existing designs. The Hornady GMX looks to have an ogive very close in shape to HANKA's ideal bullet, and the Barnes LRX appears to be nearly as good.

My suggestion is to:

a. shorten the 127gr LRX to reduce weight to 100 grains and shape the boattail like Barnes does; and

b. shorten the 120gr GMX to reduce weight to 100 grains and shape the boattail like Hornady does; and

c. test both for expansion and ballistic coefficient.

[LRRPF52]

Yup. GMX is probably the best candidate for existing shape, but is costly. Awesome pic BTW, Stan.

[BluntForceTrauma]

but unless it is certain that such a scaled-down .300 BLK TAC-TX bullet can actually be manufactured

Wait a minute, we talkin' bullets here, or machine-gun links?

[stanc]

Wait a minute, we talkin' bullets here, or machine-gun links?

Both!

No, seriously John. If (as it appears to me) the .300 BLK bullet has a larger cavity and thinner walls than other TTSX bullets, can you be sure it will be manufacturable when scaled down to 6.5mm?

Wouldn't it be prudent to consult with Barnes to find out if they see any potential problems in scaling it down?

[stanc]

Yup. GMX is probably the best candidate for existing shape, but is costly. Awesome pic BTW, Stan.

Yes, but I can't claim credit for the photo. It was posted by rickOshay in post #53.

[BluntForceTrauma]

A Google Image search turned up Hornady's original sell sheet for the GMX. Unfortunately, minimum expansion is rated at 2000 fps. This needs to be lowered to about 1600 fps for a 65G version.

[stanc]

If they are of otherwise similar construction---- a copper mono-metal bullet is about 80% of the weight (or thereabouts) of a lead cored gilding clad bullet right?

Well, the 120gr GMX and 140gr SST are both 1.4" long, and appear to my eye to be pretty much identical in shape. Divide 120 by 140 gives 86%.

No one complains about the shape of the Hornady 123 Amax, right? 80% of 123gr. is 98.4 grains. Then deduct a little more for driving bands... If a bullet was identical in shape to the 123 Hornady Amax, but weighed 95 grains instead, and had driving bands to reduce engraving pressure... It'd fly considerably faster, right?

Can some BC guru figure out how much the BC would drop because of the driving bands and weight reduction?

I'm no BC guru, but I'll take a stab at this, anyway.

140 AMAX - 0.585 BC
120 AMAX - 0.465 BC
100 AMAX - 0.390 BC

120 GMX -- 0.450 BC
100 GMX -- 0.375 BC (same shape as 120 GMX, shortened base)

123 AMAX - 0.510 BC
105 GMX -- 0.420 BC (same shape as 123 AMAX, 86% weight)
95 GMX ---- 0.385 BC (same shape as 123 AMAX, 86% weight, shortened base)

[stanc]

A Google Image search turned up Hornady's original sell sheet for the GMX. Unfortunately, minimum expansion is rated at 2000 fps.

Hmm. That looks much like the expansion Nosler shows for E-Tip bullets. And it appears that Barnes' LRX is about the same.

This needs to be lowered to about 1600 fps for a 65G version.

Yeah. I'd say a substantially bigger cavity diameter is needed, such as incorporated into the 85gr E-Tip and 95gr TTSX bullets developed specifically for 6.8 SPC.







To get decent expansion down to 1600 fps, your scaled down .300 BLK bullet may prove to be the only way to go.

[Von Gruff]

This is a fascinating discussion.

[BluntForceTrauma]

To get decent expansion down to 1600 fps, your scaled down .300 BLK bullet may prove to be the only way to go.

Ah! So we agree on something? I believe the Earth will start spinning backwards in 5 . . . 4 . . . 3 . . .

[stanc]

Oh, nooooooooooo...

[Variable]

So I'm guessing if Hornady cranked out some monometal bullets with the same length and profile as the 123 Amax --- plus:

1.) a larger polymer tip

2.) a deeper & slightly larger diameter hollow cavity

3.) and some engraving bands...


We might end up with an excellent Grendel bullet that weighs over 90 grains, expands down to 1600fps (or less), and may have a BC around .400 or a tad higher. If so, it might perform a lot like the .300 Blk Barnes Tac-TX in expansion, and from a Grendel could do it at a longer distance....


And I'm also guessing Barnes could apply the same treatment to a similar profiled bullet with the same likely results....


Me want!LOL

[Variable]

Well, the 120gr GMX and 140gr SST are both 1.4" long, and appear to my eye to be pretty much identical in shape. Divide 120 by 140 gives 86%.

I'm no BC guru, but I'll take a stab at this, anyway.

140 AMAX - 0.585 BC
120 AMAX - 0.465 BC
100 AMAX - 0.390 BC

120 GMX -- 0.450 BC
100 GMX -- 0.375 BC (same shape as 120 GMX, shortened base)

123 AMAX - 0.510 BC
105 GMX -- 0.420 BC (same shape as 123 AMAX, 86% weight)
95 GMX ---- 0.385 BC (same shape as 123 AMAX, 86% weight, shortened base)

True. I was going by the density of copper compared to lead (copper 8940kg vs. lead 11340kg --- in kilograms per cubic meter) that came out with copper being roughly 79% as dense as lead. Then I added back a bit for the copper monometal because of the conventional lead cored bullet's gilding metal jacket. It would likely be closer to your 86%, but then I deducted some more for driving bands and a larger hollow core.

Either way, an Amax profiled bullet in the 90-105 grain class (whatever it actually ended up weighing) with a .4 something BC would really get my attention. Like I said before, we already know the conventional 123gr. Amax profile was designed to play very well in the Grendel chamber. If that could give us our dream bullet performance-wise, and also be very accurate--- well that would get me downright tingly. As Jayne Cobb would say:

"I'll be in my bunk"