Well, I finally printed up about 10 sheets of ballistic data available from the Hornady Ballistics calculator websight link to compare 300 and 400 yard zero performance of the various 55, 58gr, 65gr, 70gr, 75, and 87gr 6mm bullets compared to the performance of my .20 caliber rifle's Sierra 39gr bullet. (20Tactical) Much of what I found also holds true at the 200 and 300 yard ranges too.
http://www.hornady.com/ballistics/ballistics_calculator.php
Compared to all those traditional varmint rifle calibers, we've all heard and know that the 6mm is a step up and advantage in bucking the wind, right? We's assume that the heavier bullet and mass has to be that much more lethal on the PD too, right? Well, think again. Because what I found was that except for the 87 grain bullet, the stats for all these other 6mm cal bullets were dismal when compared to that tiny little 20 cal. And the stats show the 87 grain bullet still drops almost 5" further then the 20 cal at 500 yards when zeroed in at 400 yards. (in case you wonderd, the 39 grain 20 cal trajectory is considerably better at most other yard ranges too....not just at 400 and 500 yards.)The 6mm 87 grain bullet's redeeming quality is that at 500 yards it hits at 727 pounds of energy compared to the 20 cal pill's 413 lbs...even though the 6mm bullet is going 245FPS slower at that distance, and sinking 5" further. Unless you use an 87 grain 6mm bullet, the other lighter 6mm bullets will lose considerable energy, trajectory, and blow all over the friggin place at just 8 mph! For example, at 500 yards the small and light 39 grain Sierra .20 cal bullet is driftng 18.0", while the 58 Grain 6mm is blowing 23.3" to the side, while it only offers 40 pounds more of energy against the 20! Why even bother with a 6 x 47L chambering for a varmint rig if you plan on using these bullets? (and for that matter any of the the other smaller or weaker case 6mm chamberings)
I have previously decided that my second custom smithed varmint PD custom rifle (and accurate informal target rifle) should be the 6 x 47Lapua. I was serious enough that I have already bought the action and stock, and just Friday finished ordering the $80 worth of Lapua cases.
But now, after CAREFULLY comparing the performance of my 20 caliber 39 grain Sierra (BC of .287) doing 3820 FPS at the muzzle, NOTHNG ELSE LOOKS GOOD!!!! The 6x47L is kind of uninspiring in comparison. The 87 grain bullet (the only bullet that I explained is worth shooting) leaves the barrel at 2,975 FPS. So we are already in a deficit of 845fps compared to my 20Tac. But, I'm hoping that the 300 to 400 extra ft.lbs of hitting power of that heavier and better ballistic coefficient 87 grain bullet is what makes the difference and makes it worth doing.
Very simply, if you want to improve on a 20 caliber PD rifle, without some serious compromising.....simply put, there's nothing else out there to choose.
If you want a flat shooting, wind bucking rifle, that maintains a sight picture of the impacting bullet, and which barrel will also last a couple of thousand rounds, lotsa luck finding a substitute for the 20. That I can tell, it's non existant.
That I can tell, I already own the best all-around PD rifle that can be built (20tac-204Ruger),
I'm now a bit less enthused with this new $2,500 6x47L rifle I'm supposed to build. I sure wouldn't mind anybody out there telling me I'm misunderstanding something.....but I'm having trouble contorting the Ballistic statstics to how I'd like them to read.
http://www.hornady.com/ballistics/ballistics_calculator.php
Compared to all those traditional varmint rifle calibers, we've all heard and know that the 6mm is a step up and advantage in bucking the wind, right? We's assume that the heavier bullet and mass has to be that much more lethal on the PD too, right? Well, think again. Because what I found was that except for the 87 grain bullet, the stats for all these other 6mm cal bullets were dismal when compared to that tiny little 20 cal. And the stats show the 87 grain bullet still drops almost 5" further then the 20 cal at 500 yards when zeroed in at 400 yards. (in case you wonderd, the 39 grain 20 cal trajectory is considerably better at most other yard ranges too....not just at 400 and 500 yards.)The 6mm 87 grain bullet's redeeming quality is that at 500 yards it hits at 727 pounds of energy compared to the 20 cal pill's 413 lbs...even though the 6mm bullet is going 245FPS slower at that distance, and sinking 5" further. Unless you use an 87 grain 6mm bullet, the other lighter 6mm bullets will lose considerable energy, trajectory, and blow all over the friggin place at just 8 mph! For example, at 500 yards the small and light 39 grain Sierra .20 cal bullet is driftng 18.0", while the 58 Grain 6mm is blowing 23.3" to the side, while it only offers 40 pounds more of energy against the 20! Why even bother with a 6 x 47L chambering for a varmint rig if you plan on using these bullets? (and for that matter any of the the other smaller or weaker case 6mm chamberings)
I have previously decided that my second custom smithed varmint PD custom rifle (and accurate informal target rifle) should be the 6 x 47Lapua. I was serious enough that I have already bought the action and stock, and just Friday finished ordering the $80 worth of Lapua cases.
But now, after CAREFULLY comparing the performance of my 20 caliber 39 grain Sierra (BC of .287) doing 3820 FPS at the muzzle, NOTHNG ELSE LOOKS GOOD!!!! The 6x47L is kind of uninspiring in comparison. The 87 grain bullet (the only bullet that I explained is worth shooting) leaves the barrel at 2,975 FPS. So we are already in a deficit of 845fps compared to my 20Tac. But, I'm hoping that the 300 to 400 extra ft.lbs of hitting power of that heavier and better ballistic coefficient 87 grain bullet is what makes the difference and makes it worth doing.
Very simply, if you want to improve on a 20 caliber PD rifle, without some serious compromising.....simply put, there's nothing else out there to choose.
If you want a flat shooting, wind bucking rifle, that maintains a sight picture of the impacting bullet, and which barrel will also last a couple of thousand rounds, lotsa luck finding a substitute for the 20. That I can tell, it's non existant.
That I can tell, I already own the best all-around PD rifle that can be built (20tac-204Ruger),
I'm now a bit less enthused with this new $2,500 6x47L rifle I'm supposed to build. I sure wouldn't mind anybody out there telling me I'm misunderstanding something.....but I'm having trouble contorting the Ballistic statstics to how I'd like them to read.
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