Home Forums Hunting & Shooting General Big Game Are Speer Hot Core bullets good enough?

Hot Cores are a bonded bullet, but use a different bonding technology. Call Speer if you don't believe me. They use a flux type compound that is heated along with the alloy. It bonds the lead core to the jacket, similar to how solder holds copper fittings together in water heater pipes. I have recovered several Hot cores from game. The petals are peeled back clear to the base of the bullet and the lead is VERY much still fused to the jacket all the way to the tips of the petals.

The Grand Slams are a dual core design. A softer alloy is in the nose and a harder allow in the rear.

The "standard" Speer bullets are regular cup jacket design. The "real" Hot Core bullets are very durable and don't shed their jackets. I know this by experience, not by heresay. Flinch

SPEER� Grand Slam� Premium Big Game Rifle Bullets
Grand Slam� premium bullets for North American game have been the choice of many hunters since 1975. We started making them long before most other bullet makers had anything "premium." Over the years, continuing research and testing have evolved this bullet into one that meets today�s tough standards.
The success of Grand Slam starts in the jacket. The critical shank section is up to 45 percent thicker than standard game bullets. This section stops rollback at the point needed to retain weight. Ahead of the shank, we carefully profile the jacket to the tip. Near the tip, we add internal flutes to insure expansion over a wide range of launch velocities. The extended jacket protects the lead tip from recoil damage in magazines of hard-kickin' rifles.

Then there's the core. It's our proprietary ternary alloy (that means three metals) poured into the jackets molten at 900 degrees F to eliminate oxides that cause core slippage.

The cannelure has two functions. It lets you crimp the bullet in the case (recommended for rifles with lots of recoil), and provides additional locking of the core and jacket.

Grand Slam�respected for nearly 30 years across North America and on the African plains. Make it your choice when "second-best" isn't an option.

Grand Slams for North American game are available in calibers from 24 to 375.

Flinch �

When I was a kid I broke the news to my future wife about Santa. Please sit down, I have something to say to you.

A year or so back I DID contact Speer, via email, about their bullet technology. The response was that the Hot-Cor bullets are NOT bonded bullets � as dissecting one clearly shows. Speer does have bonded bullets � the Uni-Cor design in which the jacket is plated on and the Trophy Bonded which is a traditional bonded bullet. Speer also has Hot-Cor and traditional cup-and-core bullets.

That said, the Hot-Cor bullets (Hot-Cor, Mag-Tip and Grand Slam) are very good bullets. In over 20 years of using them in my 7mm Rem Mag I�ve only recovered one and that one had destroyed both shoulder joints of a big bull elk � no complaints here.

I have a dissected 170g .308� Hot-Cor in front of me as I write this. The jacket and core separated easily but the core and the inside of the jacket are both bright and shiny � no visible oxidation of either. The Speer claim is that the Hot-Cor technology eliminates oxidation of the core and thus eliminates (or at least significantly reduces) core slippage. This may be true most of the time but one Grand Slam I dissected had gunk between the core and jacket. Whether this was flux or what, I couldn�t say. Nor can I say how often this occurs.

Now that I think about it I should contact Speer again and ask just what the �ternary� core is (guessing lead, tin and antimony, which means the �ternary� description is a fancy term for nothing special) and how it compares in hardness to the cores they used to use in the Grand Slams.

Flinch- this is copied directly from the Speer website's FAQ section: Q.Grand Slam used to have two cores. Now it has one. Why?

A.Changes in raw materials beyond our control made it hard for us to maintain the previous bond we had between the front and rear cores. We tested alternatives extensively, and found that the single, ternary-alloy core gave better accuracy and increased retained weights by an average of 14 percent.

Hot-Cors are simply not bonded. Pouring molten lead into the jacket does not bond it. Flux may be used to reduce the oxide layer but in and of itself does not bond anything. Flux cleans surfaces and removes oxides to promote adhesion but there needs to be another "fusing" step (e.g. soldering). You might want to take a look at the Speer website to see how different the new Grand Slam is. Speer may want to give the impression that the Hot-Cor is bonded but if it was they'd be tooting that horn loudly in this market. They state the Hot-Cor technology minimizes core slippage. If it was a bonded core, it wouldn't be able to slip. I have sent the question "Are your Hot-Cor bullets bonded?" to Speer. I will post their response when I get it.

I don't need to call speer. Their bullets are poured molten into the jacket.

This does NOT bond them. Period. They infer that it does, but it does not.
Does it help them stay together. Maybe, maybe not.

The Grand Slams are NOT a dual core design. That was the OLD design, they changed to a single core about 2.5 years ago.


The other guys said everything else I wanted to say.

Here are the replies I received from Speer's Guy Neil when I asked about the new GS's about a year ago.



I haven't seen any problems on game with the new style, and the accuracy is better, though I never had a problem with them before.

Here is Speer's response to my question of "Are your Hot-Cor bullets bonded?":

Dale: no, bonding requires flux, we do not flux the Hot-Cor bullets, the
Trophy Bonded Bear Claws are bonded. The Hot-Cor has the substrate
material put into the jacket in a molten state, which stops oxidation of
both jacket material and substrate material.
Shoot Straight!
Coy Getman
CCI/SPEER Tech. Service Coordinator
800-627-3640 ext. #5351
Fax: (208) 799-3589

I've not shot elk with Hot-Cores but have taken deer with the 150, 165 and 180 grain bullets from my .300 Win Mag and the only bullet I recovered was a 150, which performed very well. (Actually, they all did, for that matter.) The core was intact and the frontal diameter was good after breaking bone and ending up against the opposite shoulder (long range with a .300 H&H type loading).

That said, for Elk I'd go to the Grand Slam if you want to use a Speer bullet, or the Hornady Interlock or their bonded bullet (something along those lines) if you don't use a Partition or some kind of X bullet.

The 250 grain .358 Speer Hot Cor, with a starting velocity of 2350 fps, works very well on elk. Haven't recovered one to check the expansion or weight retention though <img src="/ubbthreads/images/graemlins/smirk.gif" alt="" />.-Joe

We've been hashing around whether Speer hot-cores are bonded or not.......and completely ignored your question.

My opinion is, yes a 180 gr Speer Hot-core from a 30.06 would do fine on elk
the majority of the time.

Havind said that, I'd choose the Grand Slam if using Speer, or as another poster suggested a premium bullet like the Interbond, or Partition.

Or the 180 gr. Mag-Tip. Taint much difference between them and the Grand Slam these days. They'd all work.

I've been shooting 165 gr. Hot-cor's in my 30-06 for about 10 years. I've only recovered 1 out of 30 or so kills on deer and pigs. It was a deer shot about 60 yds in the shoulder and I recovered it in the opposite rear ham. The bullet weighed 144 grs. I think they are an excellent bullet. My 06 is the only gun I load them in. I use many brands and types of bullets. With that said Hornady is my favorite non-premium bullet.

Joseph

Thanks for all the replies! The hot-cores must be in the same league as core lokts, a good bullet but in a very inconsistent shell. Its amazing how the lowly core lokt still does the same job as the premium bullets and it seems we can add the hot core.

Despite what Speer has or hasn't claimed over the years (their claims change like their bullets), the hot cores that were recovered years ago most certainly are fused, bonded, soldered or whatever (130 grain .270's). When I talked to Speer 7-8 years ago, they quoted me as saying the hot cores are fused, similar to how copper pipes are soldiered together. The bullets that were recovered from game had NO bullet shank left. They looked like a dome shaped pancake with very little weigh loss. The lead was still stuck to the very edges of the bullet. If the lead wasn't fused to the jacket, there was no way it would all still be intact. Anywho, I don't really care what Speer says now days, since I don't use them anymore. Their bullets don't shoot very good, are WAY over priced, and their Grand Slams are a poor excuse for a premium bullet. Sorry to get off track, my appologies. Flinch

I have had Hot-Cores lose their jackets - one, a 105gr .243 that shed the jacket on a deer (still killed it, of course!) and the other was 170gr flat nose shot into newspaper. Still, as I said before, they are as good as any standard bullet, I believe.

I just ran out to the garage and ran a simple experiment. I cut off a 105gr .243 Hot Core with pliers, and then squeezed it perpendicular to the cut. The jacket clearly pulled away from the core. Hopefully you can see it in the attached pic.

Once again, this doesn't necessarily relate to the bullets game-killing ability.

Mauser96,
Sorry that I didn't get back to you sooner.Been outa town.
I shot a buck at about 150yds that field dressed 136lbs.
Caught him behind the shoulder and broke ribs in and out.
Exit hole the size of a half dollar.
Figger'd that buck went at least 160lbs live weight.
Bart

I would think the 180 flat base hot cor would be OK. But I would not trust the boat tail soft points.
My experience with Speer has been in 7mm rather than .30 cal. but a 145 flat base can shoot end to end through whitetails and a 160 BT did not shoot broadside through a mulie.

Myself and several friends here have used the 250 Hot Cor Spitzers for years, in everything from 358 Win to 358 Norma Mag with complete satisfaction. They always expand and pentetrate deeply.

Seems like up to 2800 fps or so is about the limit. I had a 35 Ackley Magnum, a blown-out full length magnum case. It was very accurate, but at over 3000 the bullets would not hold together very well on game. One friend has a 35-404 Jeffrey Imp that Bevan King built, and it gives them a genuine 3300 fps. You can imagine what happens to them at that velocity. <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" />

Ted

In my experience Grand Slams shoot very well in every rifle my hunting buddy and I have tried them in, but I recognize results will be different for each gun and load.

I agree they are a poor excuse for a premium bullet and have always considered them a �semi-premium�. Since I buy them at gun shows for about $11-$14 a box, the cost is not a deterrent. When I want a �premium� bullet I�ll go with a bonded-core bullet like a Swift A-Frame, Speer Trophy Bonded, or North Fork bonded. If I want a �semi-premium� I�ll use a Grand Slam or a Partition.