Anyone reloading cast bullets for 50 BMG?

[apu]

As the title indicate I am curious about other folks experience here.

I am thinking of trying an accurate molds 655 grain hard cast, gas checked, powder coated projectile. I see there is some load data for 600 grain cast bullets using 150 grains of IMR 4064 that will apparently produce 1900 ft sec out of a 36 inch barrel. Seems a reasonably stable cast projectile velocity.

 

[kg]

Where did you find the data?

 

[vagrantviking]

I'm just spit-balling here but my gut feeling is that you will get much more response to this question on the US based forums.
Sounds like a great project. Hope you can find the information you need.

 

[mbogo3]

A moose bullet

 

[apu]

Where did you find the data?

load data.com

I'm just spit-balling here but my gut feeling is that you will get much more response to this question on the US based forums.
Sounds like a great project. Hope you can find the information you need.

Yeah I have been hitting the interweb hard but the info is sporadic, inconsistent and somewhat dated, was just wondering if anyone here has any sage experience before I try and reinvent the wheel Nevertheless on wards and upwards, I have ordered some molds and gas checks and will post if I have any success or not. This is more of fun project(not to save money but just because) and I am not particularly interested in hyper velocity over reasonable accuracy. My barrel has a 1:15 twist so I figure a hard lead slug should be able to hold it together at moderate velocities but we will see.

 

[cigar_man]

NOE 513 850Gr. FN GC




Pics from http. castbullets

I have tried a few of these with Trail Boss.

Nothing at long distance.

Work seems to disrupt my shooting lately.

http://castboolits.gunloads.com/sho...-BMG-Loading-and-Loads-NOE-513-850G-FN-Boolit

http://castboolits.gunloads.com/archive/index.php/t-226050.html

 

[apu]

NOE 513 850Gr. FN GC


I have tried a few of these with Trail Boss.

Nothing at long distance.

Work seems to disrupt my shooting lately.

http://castboolits.gunloads.com/sho...-BMG-Loading-and-Loads-NOE-513-850G-FN-Boolit

http://castboolits.gunloads.com/archive/index.php/t-226050.html

Thank you for the link. How much trailboss are you using?

That is a nice looking bullet, I was also considering the CBE 975 grain bullet. He makes really good molds.

 

[cigar_man]

75 grains of Trail Boss


From the designer of the NOE 513 850Gr. FN GC (Rockrat)

I have been using Trailboss in my AR50 for a few years. I use an 850gr cast bullet over 74.8gr of TB for a velocity of 1608fps and accuracy wise, about 1.25"@100yds. Remember , TB doesn't like to be compressed and accuracy wise, it is said that it is best at around 90% of case capacity. Thats just about where my accuracy was with the cast bullet.

https://www.ar15.com/forums/armory/shot_the_50_BMG__loaded_with_trail_boss_Powder_today/3-431692/

 

[apu]

850gr cast bullet over 74.8gr of TB for a velocity of 1608fps and accuracy wise, about 1.25"@100yds.

Now that sounds like fun, thank you. Just need to get more trailboss now

 

[theshootist]

Time to buy a .50. I wonder where the cast 50BMG would sit in comparison to the large bore African hunting cartridges in terms of ftlbs of energy?

 

[tigrr]

Friends who tried did have pressure issues. The bullet base swelled to a point that there was a steep pressure spike causing flat primers and difficult bolt opening. To the point of one chap breaking his handle right off the bolt. Even a too soft of bullet jacket causes pressure issues in a 50 bmg. Be cautious.

 

[cigar_man]

Friends who tried did have pressure issues. The bullet base swelled to a point that there was a steep pressure spike causing flat primers and difficult bolt opening. To the point of one chap breaking his handle right off the bolt. Even a too soft of bullet jacket causes pressure issues in a 50 bmg. Be cautious.

Correct.

I make my cast BMG bullets as hard as I can, including water dropping.

No problems so far.

One thing, just dont push them too hard.

Remember, they are cast bullets. People like to push everything to the max these days.

I have been casting for many years.

There was a problem with BMG and other large calibers over the years with incorrectly made FMJ.

Bullets had thin jackets and a soft lead insert which caused pressure spikes during WW2 and Vietnam.

Hopefully, not todays manufacturing.

 

[apu]

Time to buy a .50. I wonder where the cast 50BMG would sit in comparison to the large bore African hunting cartridges in terms of ftlbs of energy?

Using mass x velocity to equal force, a 850 grain cast bullet travelling at 1600 ft/sec you would deliver about 14% more energy than a typical commercially loaded 458 Lott round or otherwise stated roughly 6800 ft/pounds vs 6000 for the 458.

 

[apu]

Finally got the appropriate pieces together to reload cast bullets for the 50 bmg. Cast my first few bullets today and assembled an initial dummy round, 660 grain hard cast, gas checked bullet, sized to .512 inches. Still have to powder coat but the round chambers nicely and hopefully I will have my first few rounds downrange by the weekend. I am going to try a load data.com recipe of IMR 4064 with a start around 140-150 grains. Ran the numbers on quickload which seems to agree its a safe pressure range. Theoretically should be able to see around 1900 ft sec. Will listen to Tiggr's advice and proceed cautiously.

 

[VinnyQC]

Maybe I'm crazy but 4064 seems a bit too fast burning for a 660grn imho.

 

[apu]

Maybe I'm crazy but 4064 seems a bit too fast burning for a 660grn imho.

Yes the burn rate is approximately twice that of Hodgdon 50BMG but the relationship is much more complex than just comparing burn rate. Assuming we wanted to achieve similar bullet velocities, a 660 grain lead cast bullet with 140 grain of 4064 will model a very similar safe peak pressure (33,000 psi) and burn time as ~ 220 grain of 50BMG powder. I suppose a somewhat similar analogy would be using titegroup for 308. Which interestingly Hodgdon has published load data for.

Generally speaking for reduced loads, use a faster powder, slow powders at reduced loads can quite possibly cause detonations.There are of course limitations and precautions but there you go.

 

[tigrr]

looks good!

 

[apu]

Well had the fiddy out with its first 40 reloads. I gotta say I am pleasantly surprised with the load that end up being the most accurate. First off I tried 75 grain of trail boss, very low recoil and pleasant shooting, could hardly tell I was shooting a 50 BMG. Can't comment on accuracy as I just did not have enough trail boss rounds to do so. Next up I tried the IMR 4064. Loads were in 5 grain increments from 125 to 145 grain. Somewhere between 125 and 130 grain is the sweet spot and I was stacking rounds on top of each other. The following is a 3 shot group at 100 yards.

The groups started to spread to 4-5 inches by 145 grain.

At 125 grain quickload says peak pressure is around 25K psi and muzzle velocity is just over 2000 ft/sec. Recoil definitely felt tame. Unfortunately I could not confirm bullet velocity as the BC fires kept the sky overcast and gave me unreliable chrony numbers. I really to need upgrade to a labradar. Nonetheless at 145 grain the recoil was more authoritative( estimated peak pressure at 35K) but there were no pressure signs, easy case extraction. I also have to note that there was never even a smidgen of leading in the barrel.

Again the projectiles were hard cast with a water quenched Linotype / wheel weight mix and powder coated. I flared the case necks with a suitably sized socket and couple of taps from a hammer. Otherwise the resized necks would shave the bullets on loading. I found my initial gas checks were a little loose after sizing to .512 inches so subsequent bullets got a dab of JB weld between the check and the bullet base. Finally rounds were crimped with Lee factory crimp die.
Although I did not do this to save money I have to note my final cost per round was $0.88 to $1.05 (depending how much linotype and using Canada Ammo primers and powder.

 

[theshootist]

Still following this thread with much interest. Thanks for taking the time to share your project with us APU. Mind if I ask what model of rifle you are experimenting with? I'm shamefully on the hunt for a fifty.