grand slams

[gregrn43]

I have over 20 years reloading experience and cant figure this one out. Maybe someone can help. In my rem 7mm mag i shoot 150gr. ballistic tips with RL22 powder, and have never had any problem at all. Groups extremly well with gooddown rangeenergy. I recently tried some 150gr. speer grand slam with the same load that i use for my bt's. My rifle is sighted in 2 inches high at 100 yards. These grand slams strike 10 inches low at 250 yards. I have double checked the grains of powder, same primers,everthing is the same, except for the bulletsI just cant figure out why there is so much difference? I would surely like to here someone elses opion.

This bullet gave me fits in a 300RUM. I was shooting 180gr partitions with 95gr of H1000. I was getting 3180fps. I worked up a load for 180gr grand slams and got 3350fps with 95gr of H1000. And started seeing pressure signs. I thought that was odd from a cup bullet like this. Best accuracy I got was 1.7MOA after trying a few things.

Another poster I used to talk too GAHunter, found something very interesting also. He tried several COL's and his groups went from 3MOA to 1" going from 3.3" COL in a 300winmag to so deep in the case that it was getting dangerous for a 300winmag. 300winmags don't have much of a neck anyway.

Bottom line is I have seenthe bullet do some strange things. And can't say I will buy again.

[Prairie Wolf]

I do a lot of comparisons in data. You will find that bullet construction matters. I've noticed Grand Slams have higher pressure. Not sure why, maybe the have a harder lead allow.

Another example is the old Winchester Fail Safe. It always maxed out a few grains less and 100 fps slower. You have to be careful switching from one bullet to the other.

As for point of impact shift, any time you switch bullets the point of impact can move even in the same weight. One rifle of mine will move 3 inches at 100 yds. Some rifles will shoot different bullets pretty close, some won't.

[redgreen]

The grand slams are poured in two stages. They are not a cup and core. The innards are molton when applied.They are poured with a harder compound in the base, then, the second stage is poured, They are then swaged to size and shape. I have hundreds of them, and they perform flawlessly. I haven't recovered one of them ever, as they do a complete pass through. The bearing surface is a little different on them than another bullet. You will have to develope a load for them starting from scratch again. IMO, they are as good as a Nosler partition.

ORIGINAL: redgreen

The grand slams are poured in two stages. They are not a cup and core.

Just because they are poured in two stages does not mean they are not cup and core.

[Mojotex]

I too have used this bullet in hand loads. I had no problems with groups or field performance. It seemed similar to the Partition as far as penetration. I simply like the Partition better and haven't loaded with the Grand Slam in 2-3 years.

[gregrn43]

I want to thank all of ya'll for your advice.....