Fiftydriver
Official LRH Sponsor
Been working on a customers rifle for a few days. This is one of my big 458 Maximus wildcats. All of these rifles previously have been set up with a special throat designed for use with the heavy Hammer Match bullets. Customer wanted to give the new 700 gr CE Lazer a try with this one so we went with a minimum length bore rider throat to test these projos.
the 458 Maximus is a wildcat based on the full length 50 bmg parent case, necked down to 458 cal and the shoulder moved significantly forward. Then fireformed to my standard wildcat shoulder angle used on all my wildcats. Case body taper is more then most would expect. Many that improve large cases fail to use enough case body taper to allow top working pressures to be used with good extraction performance, especially after the brass gets a few firings on them.
Standard 50 bmg case on left. Necked down to 458 cal with properly positioned secondary shoulder for supporting case during fireforming in the Middle and on the right fully formed 458 Maximus case.
the transformation is dramatic, taking the far out of date bmg case design to a fully modern magnum case design intended to be used at max pressures with proper function in every way.
some have said the standard 50bmg is an extremely inefficient case design and far larger then it needed to be to accomplish its performance goals. This is true considering the standard BMG was designed go be loaded to around 55,000 psi. For the time it was designed, a good design but today, with modern powders with a variety of burn rates, yes you can match the 50 bmg performance with much smaller cases. Example my 50 Allen Tactical will drive a 647 gr projo to within 75 fps of the original BMG load performance. Thats another story though…..
the 458 Maximus has a dramatic capacity advantage over the BMG. Some would say this makes the case design even worse for efficiency….. anyone that has been around for a while knows efficiency does not rank high on my priority list, as long as the performance is there and its accurate and consistent, thats all i care about. Faster, flatter, farther thing…..
in the past i have tested projos from Hammer bullets in weights from 600 grains up to 800 grains and found many powders work extremely well, VV20N29, US869 and surplus powders such as WC860 and WC872 work very well and offer very good load densities.
this project however, the customer wanted to test the 700 gr. CE Lazer projo. First powder tested and only so far was VV20n29. Started at 235 gr and worked up from there, topping out at 253.0 gr. Results were in a 38" Bartlein 10 twist barrel with min length bore rider throat design.
235.0 gr………2909 fps
240.0 gr………2984 fps
245.0 gr………3047 fps
247.0 gr………3073 fps
250.0 gr………3102 fps
primer pockets and case head expansion was perfect at 250.0 gr and considered this max working load for this combo.
batch of test loads ready for +1000 yard accuracy testing soon as wind allows. Little guy on right is the 300 win mag. For comparison, a standard 50 bmg with same weight projo will generally get 2900-2950 fps with max pressure loads in this length barrel. The 458 Maximus will add significantly higher BC in same weight bullets as well as add 150-200 fps in velocity potential with same length barrels. 15,000 ft/lbs is a significant muzzle energy payload and even better yet, the 458 Maximus will carry its energy dramatically batter then the big 50 bmg can. So even though it bests it significantly at the muzzle, that advantage just builds greater as the distance grows.
crappy indoor pic of customers finished rifle but better pics coming once i get it on the range. I have had mixed results with the CE bullets in my wildcats, especially with their heaviest options in faster twist barrels. I feel this is a throat design issue more then anything but if these projos shoot well, we will also be working more on the Hammer Match bullet design to allow it to also be used in this min length throat design, giving customers shooting the 458 Maximus several new options which is always a good thing.
the 458 Maximus is a wildcat based on the full length 50 bmg parent case, necked down to 458 cal and the shoulder moved significantly forward. Then fireformed to my standard wildcat shoulder angle used on all my wildcats. Case body taper is more then most would expect. Many that improve large cases fail to use enough case body taper to allow top working pressures to be used with good extraction performance, especially after the brass gets a few firings on them.
Standard 50 bmg case on left. Necked down to 458 cal with properly positioned secondary shoulder for supporting case during fireforming in the Middle and on the right fully formed 458 Maximus case.
the transformation is dramatic, taking the far out of date bmg case design to a fully modern magnum case design intended to be used at max pressures with proper function in every way.
some have said the standard 50bmg is an extremely inefficient case design and far larger then it needed to be to accomplish its performance goals. This is true considering the standard BMG was designed go be loaded to around 55,000 psi. For the time it was designed, a good design but today, with modern powders with a variety of burn rates, yes you can match the 50 bmg performance with much smaller cases. Example my 50 Allen Tactical will drive a 647 gr projo to within 75 fps of the original BMG load performance. Thats another story though…..
the 458 Maximus has a dramatic capacity advantage over the BMG. Some would say this makes the case design even worse for efficiency….. anyone that has been around for a while knows efficiency does not rank high on my priority list, as long as the performance is there and its accurate and consistent, thats all i care about. Faster, flatter, farther thing…..
in the past i have tested projos from Hammer bullets in weights from 600 grains up to 800 grains and found many powders work extremely well, VV20N29, US869 and surplus powders such as WC860 and WC872 work very well and offer very good load densities.
this project however, the customer wanted to test the 700 gr. CE Lazer projo. First powder tested and only so far was VV20n29. Started at 235 gr and worked up from there, topping out at 253.0 gr. Results were in a 38" Bartlein 10 twist barrel with min length bore rider throat design.
235.0 gr………2909 fps
240.0 gr………2984 fps
245.0 gr………3047 fps
247.0 gr………3073 fps
250.0 gr………3102 fps
primer pockets and case head expansion was perfect at 250.0 gr and considered this max working load for this combo.
batch of test loads ready for +1000 yard accuracy testing soon as wind allows. Little guy on right is the 300 win mag. For comparison, a standard 50 bmg with same weight projo will generally get 2900-2950 fps with max pressure loads in this length barrel. The 458 Maximus will add significantly higher BC in same weight bullets as well as add 150-200 fps in velocity potential with same length barrels. 15,000 ft/lbs is a significant muzzle energy payload and even better yet, the 458 Maximus will carry its energy dramatically batter then the big 50 bmg can. So even though it bests it significantly at the muzzle, that advantage just builds greater as the distance grows.
crappy indoor pic of customers finished rifle but better pics coming once i get it on the range. I have had mixed results with the CE bullets in my wildcats, especially with their heaviest options in faster twist barrels. I feel this is a throat design issue more then anything but if these projos shoot well, we will also be working more on the Hammer Match bullet design to allow it to also be used in this min length throat design, giving customers shooting the 458 Maximus several new options which is always a good thing.
