Speer 160g BTSP

[remingtonman_25_06]

I have never really liked Speer bullets first off. I always thought they were kinda cheap and they were just never really thought of much by me. I think its safe to say that I've tried virtually every other brand of bullet you can buy from Sportsmans except for any kind of Speer. I have there manual that came with the RCBS reloading kit. I was just skimming through it last night and noticed something kinda odd to me anyways. There listed BC's seem to be somewhat exaggerated IMO, when compared to similar bullets like the Sierra Gameking. Here is a couple instances in 7mm caliber...

Speer 7mm 145g BT (.502)
7mm 160g BT (.556)

Sierra 7mm 140g BT (.416)
7mm 160g BT (.455)

Nosler 7mm 140g NBT (.485)
7mm 160g AB (.530)

Now is it just me, or do those BC's seem a little out of wack?? How can a shorter lead tipped bullet, have a higher BC then a longer plastic tiped one such as the Nosler AB?? How can the Speers published BC, be almost a full .1 value higher then Sierra Gamekings??

As I look through this Speer book, they seem to have some other bullets with pretty high BC's, .270/150g BT is .496 which is about the same as a 150g Nosler NBT. In .308", the Speer 165g BT is .477, the Sierra BT is .404, the 180g Speer BT is .540, while the Sieera is .501.

I guess I have to ask if anyones got experience with any of these Speer BT bullets??? They seem to be a good cheap alternative bullet out of the 7 RM. I would like to know how there BC's stacked up with real world shooting...If I can get the 160g Speer going 3000fps, it would be just as good if not better then the 160g AB at half the price...I realize I'd give up short range penetration, but thats really the least of my worries.

I think I"m gonna try some of the 7mm 160g BTSP. They claim .556 BC, so I'm gonna see if I cant find something that works with RL-22. Hopefully there accurate enough..

 

[Guest]

The issue you are noticing involves how BC's are calculated. Your Speer manual, or at least my #12 Speer, even discusses this discrepancy, and refers to the inability to compare BC's from one manufacturer to the next. They are not being disingenuous, as they are just using a different method to calculate the BC, and they state the issue clearly. I can tell you that most all of the BC's published by bullet manufacturers are not perfect, and many of them are exagerrated, it seems. Nosler even recalculated some of their BC's (most notably for the 8mm stuff) and it sure brought them down a bunch. In fact, I question the validity of the Nosler numbers for 30cal and 338cal, based on the comparitive BC's for those calibers and the new, recalculated BC's for the same weight bullets in 8mm.

The only true BC is the one you can derive from shooting at several known distances from a very accurate rifle, and even then, it is only valid for that elevation, at those environmental conditions, as BC is really a dynamic number with many factors impacting it.