I received 500 of these today in 30 caliber 150 grain through a RCBS promotion. My question is does anyone have any experience with this bullet? I was thinking of using them in my 308's and 300 blackout but after reading mixed reviews am having second thoughts. Seems people have been having issues with expansion in non magnum calibers. I'm also interested in accuracy of these bullets. Any info good or bad would be greatly appreciated.

I received the same thing yesterday via RCBS. Also interested since I've never used them.

They're really pretty decent bullets, on the whole. They aren't in the Sierra league in terms of accuracy, but they hold together nicely and do considerable damage on game. I'm currently using them in my .300 SAUM Model 7. Should you decide to sell them all for $50, I'd like to be first in line.

An older design in it's 2nd version that never sold as well as the competition, the Nosler Partition. Decent "minute of deer" accuracy, but as mentioned not Sierra Quality accuracy wise.

IMO, These are a really "tough" C&C bullet that could use some MV to ensure expansion. My only experience with GS's was in a 270WCF and they drive right thru WTail & Black Buck shoulders with ease at my normal under 300 yards hunting shots. I was hunting for Red Stag and used them as the default bullet in Central Texas.

Lower BC numbers than same weight Flat Base SP's.

In 308 MV's I suspect they'd be great on Big Hogs for bone breaking deep penetration even in 150's. In 180's I'd prolly not choose them for a 308 except for thicker Elk sized critters than WTails at under 300 yards to allow the footage thickness of meat to create max expansion.

Free is Free though! And yes I could use them in my 300WSM if anyone wants to sell/swap what you got.
Cheers
Ron

Once upon a time I loaded a bunch of them and shot them in a 300 Win Mag in Colorado Hunting along w/Nosler Partitions..both grouped in the same hole...I took animals at extended ranges where Magnum velocity is non existant and killed w/them all..They
should be good Whitetail, Hog, or Exotic getters all the way down to a .308..DD

Thanks for the input guys, appreciate it.

My thanks also.

Ron, they weren't really free. The choice was $50 or the bullets. I believe I had to pay an additional $14 or something to cover shipping. So, we have about $6.40 per box. I doubt that I would ever have bought them. I'm more of a Sierra fan.

The GS bullets .257 and larger are dual core bullets to control expansion. The front core is soft to easily expand in game while the rear core is a harder lead alloy so it does not expand. The GS are tough bullets but like Ron said not as accurate generally speaking as some other designs. They are a tough bullet on game with accuracy good enough for any game animal they were designed to be used on.

For $6.40 a box they are by all means worth that price

kmon: several years ago Speer dropped the dual core design, supposedly beefed the shank and added folds at the base to provide a better mechanical grip. (Speer manual #14, pg23)

They are still good bullets, IMO, and well worth $6.40 a box. But Speer prices them at about double their Hot Core bullets, which seems a bit steep for what is essentially now just a beefed up cup and core design.

Thanks for the correction, I haven't shot the GS bullets in years.

From the Speer #13 Manual, Bullet Description's, page's 26 & 27
Mag Tip*
Speer Mag Tip represents an intermediate step between the original HotCore hunting bullets and the premium Grand Slam bullets. Mag Tip bullets are manufactured using the Hot Core process, but the jacket thickness in the critical shank area is roughly 45% thicker than the same area in the equivalent HotCore bullet. This added material gives Mag Tip greater strength for high velocity application. MagTip also features internal fluting at the jacket opening for reliable initial expansion at lower velocities....Mag Tip also has a protected point - the jacket is as long as the core. This feature is usefull in bolt action rifles that show a tendency to "batter" the bullet point in the magazine.


Grand Slam*
...Like the MagTip, Grand Slam has a jacket with a heavier shank tapering to a fluted mouth. That's where the similarity ends though....

In Grand Slam, two different core alloys are used. The rear core is formed from a hard five percent antimony lead alloy. After seating, this hard rear core is locked into place by a ring of jacket metal that is sheared down over the lead. This process leaves a button of rear core projecting above the lock ring. Then a front core of softer, one and a half percent antimony-lead alloy is poured into the jacket using the HotCore* technique. The front core partially melts the button of the rear core material for a firm "adhesion" grip.

The result is a premium game bullet that retains its rear core plus a portion of the front core for higher retained weight and deeper penetration.....Bullets returned to us typically retain around 83% of their original weight...

Grand Slam bullets in 24 & 25 caliber have a single alloy core.... the jacket walls in the shank are so thick relative to the diameter that the bullet is very tough even without the two-piece core.

WC sez IMO, Protected point bullets have lower BC's because of the larger & "flatter meplat" points, but usually give full expansion at lower velicities.

from Speer #13 Manual, page 296
Speer .308 diameter 150 grain bullet Ballistic Coefficient's
RN SP 0.266,
BT FMJ 0.425,
BT Spitzer SP 0.423,
FB Spitzer SP 0.389
MT Spitzer .301,
GS SP Spitzer .305

Cheers
Ron

Speer changed the design of the Grand Slam after they published #13.

They need to add a ballistic tip to make them hype again..

.these are good hunting bullets i fired at pigs with my .30-06. But theres nothing more to them...low bc take the fun out of them in my opinion