The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Rifles Big Bores 12 Ga From Hell -WOWGo | New | Find | Notify | Tools | Reply | |
one of us |
Here are the pics. I made some design changes to more streamline the bullet, The weight with a .75inch TC .5inch insert is 940 grs. The depth of the 7/16 inner hole is 2.1 inches and I need to move that back to 1.8 as I'm running out of flute length with my screw machine drills. Each carrier takes 2 minutes to make. I also included a aluminum carrier without a TC insert. There is also a 900gr Copper cup point borerider and a 860 gr brass borerider for the .600Ok for comparison.-Rob  Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012 Nothing Up my sleeves but never without a plan and never ever without a surprise! | |||
|
| one of us |
Rob-The shape of the aluminum carrier looks perfect. That will streamline it very well. How long is aluminum? Ed MZEE WA SIKU | |||
|
| one of us |
Ed- The carrier is 2.35inches long. It has a 2.1 inch deep .435 hole and a .498, .75 inch deep hole for the TC insert. I heat the insert up till it expands and push in the TC insert. When it cools the insert is locked in place.-Rob Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012 Nothing Up my sleeves but never without a plan and never ever without a surprise! | |||
|
| One of Us |
BEAUTIFUL, Rob. Thanks for all the hard work. Time for Ed to try a few, and anyone else brave enough. Let's ring these things out, and see what they offer, and discover what improvements we can still discover. Henry | |||
|
| one of us |
Bravo!  | |||
|
| one of us |
Looking good. Rob gets the honor of testing first and then I'll be second. We'll get them tested. That shape with the insert in gives a nice wide meplat for penetration in game. Making one in two minutes from less expensive material than copper or brass is a real nice bonus...Ed MZEE WA SIKU | |||
|
One of Us |
Simply beautiful. streamlined and boat tailed to perfection. 
577 BME 3"500 KILL ALL 358 GREMLIN 404-375 *we band of 45-70ers* (Founder) Single Shot Shooters Society S.S.S.S. (Founder) | |||
|
| One of Us |
 This graph illustrates the extremes between the really blunt 12GaFH rounds and the extremely "slippery" ideal ellipsoidal 12GaFH rounds. I think Rob's current designs are a lot closer to the "slippery" ones. | |||
|
| One of Us |
Ellipsoidal bullet equations Here you can find the equations for the "true" ellipsoidal bullet shapes, discussed as rocket nose cones. | |||
|
| one of us |
Thanks for all the nice comments guys- This has been a very interesting project that has given me some interesting challenges and I LIKE THAT!I think I also figured out a way to make extremely pointed aluminum carriers, however the TC insert will be set back about .5 inches. resulting in less dart stability. It involves some interesting backturning and I'll see today if it is possible. I hope to test tomorrow in the 12GaFH with a Full power load. 300grs of RL25. I will knock out some more carriers and let ED have a go. -Rob Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012 Nothing Up my sleeves but never without a plan and never ever without a surprise! | |||
|
| One of Us |
Rob, TC has a density around 16 g/cc, but what is the density of the stuff you are using? I have a supplier of such stuff, and they list it at 14-15, as a comparison, lead is 11 and steel is 7.8. The stuff I'm using for my .458 bullets is >18 g/cc. This mix uses pure tungsten (19.3 g/cc) at 92.5%, with nickle and iron filling the rest. The WNiFe alloy is much harder then when mixed with copper, if that is important to you. The pieces I'm using are pressure molded to any shape, and cost about $25 a pound. If you are interested, I can get you the contact info. As an example, the sample cores I just got (going to change slightly) are .450" diameter, .910" long and have a .350 meplat, weighing 605-610 grains. I'll see if I can get a pic if you want. -Extremist "Pain is weakness leaving the body" -Instructor Victory in life is dying for what you were born to do. "I hope you live forever" -300 "Never judge an enemy by his words, he might turn out to be a better shot then a writer" http://www.gscustomusa.com | |||
|
| One of Us |
The big problem with sintered bullets produced by powder metallurgy is the possibility of inconsistent mixing of the various metal powder components. Inconsistent mixing causes inconsistent densities within the bullet. If this is outside specifications it produces vibrations of the bullet when it is “spun up†by the rifling of the barrel. In extreme cases this can result in bullets which fly apart in flight. One of the possible savings offered by increased dart stability is the POSSIBILITY that barrels with slower twists can perhaps be used without affecting accuracy. This possibility, if it occurs, could perhaps allow for the specifications on metal-powder mixing consistency to be relaxed somewhat. | |||
|
| One of Us |
another nosecone sight | |||
|
| one of us |
Extremist .458 - I'd love to have some of that stuff. I am using tool grade TC rods that are extremely expensive ($144/ 12 inch long .500 rod) and then I cut it into .75 inch long pieces with a diamond saw. Is your material sintered into a matrix or a compressed powder mix? I'd appreciate the contact info.-Rob Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012 Nothing Up my sleeves but never without a plan and never ever without a surprise! | |||
|
| one of us |
Some good info about drag as it relates to shape.. The little bit of streamlining Rob did on the aluminum as shown in picture will get you 2/3 of the way toward the best BC that military pointed projectiles of the same length/weight, would give you. IE, in going from blunt cylinder to a regular pointed bullet. And by pointed I mean like a .040" real small flat on the point that you see on bmg bullets. That little bit Rob did, makes a 75 yd slug into a 200 yard slug.. Rob -- Good luck testing. I only need couple of slugs with TC insert to test, and a half dozen without, that I want check by putting lead in them. .Ed MZEE WA SIKU | |||
|
| one of us |
Here are some pics from todays experiments. The first is a 12GaFH cartridge i plan to test tomorrow. Should be very interesting. I will probably not do penetration testing just flight stability. This will be fired from a 1:20 twist barrel. The other Boolit is a backturning project that came out quite good. It is also 2.35 inches long but has a base foreward 1.8 inch deep .5 inch diameter cavity. Can make them now out of Aluminum, brass or copper. If I dont get blown up tomorrow I'll make a run of carriers with TC inserts for ED.-Rob  Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012 Nothing Up my sleeves but never without a plan and never ever without a surprise! | |||
|
| one of us |
Rob, That is great looking brass and bullet. Quite an improvement on the Foster slug. Your load data and velocity results with the 940-grain "Terminator" slug will be interesting. If you load the case and hollow base bullet full of H50BMG, might make for an interesting "fire snake" or flame thrower effect. I see there may be a series of Terminator slugs: T1, T2, T3? | |||
|
| one of us |
You guys amaze me!  Always a pleasure to see what the AR "Brain Trust" comes up with John There are those that do, those that dream, and those that only read about it and then post their "expertise" on AR! | |||
|
| One of Us |
Rob, what keeps the back end of the bullet from blowing up like a balloon inside the barrel and jamming? I would rather like to see a rear bulkhead to keep the chamber pressure out of the bullet. That aluminum wall is so thin compared to the steel barrel thickness that it might just get "plastered" onto the barrel rifling. | |||
|
| one of us |
The hollowbase AL slug should do, as AL is tougher than lead hollowbase ones.Albeit it will need something heavier in the nose to have a good BC if AL is used.Unless made from copper or brass, The banded .729" dia brass 750 gr 12ga slugs I had John make had a 1/2" hollowbase, shown in pic. You can see hollowbase 3/4" deep on the right.Ed  MZEE WA SIKU | |||
|
| one of us |
Very nice, Ed. Please help: What would be a good starting load for this brass slug weighing 1125 grains, using 3" brass in a 3.5" chamber?  I could drill a 3/8" to 1/2" diameter hole to depth of one inch into the base of this one for lightening the slug. As is the SD = .302412 What is the heaviest slug you guys have worked with in the 12GaFH, and what top velocity did you get? Thanks in advance. | |||
|
| One of Us |
Ed, the tensile strength of aluminum is around 19,000 psi, and brass is a lot stronger at around 70,000 psi.. Rob could make very light steel plugs to cap the back end of the aluminum hole, and install them as he installs the TC insert, after the insert is installed but before the aluminum cools. Just want to be extra cautious, at this point. After all, if Rob blows up his 12GaFH barrel, that would put a major kink in our testing. I’m not so worried about Rob: what’s one PhD Chemist, more or less? (JUST KIDDING!!). | |||
|
| One of Us |
Check that again Boss...if you need some data I can e-mail it to you. | |||
|
| One of Us |
“http://en.wikipedia.org/wiki/6063_aluminium†“http://www.onlinemetals.com/brassguide.cfm†Just needed ball park numbers.... | |||
|
| One of Us |
You're not even in the same town as the ballpark. Both really bad sources for much of anything. If you would like some proper industry sources with comprehensive data I would be happy to forward them to you. If you're making calculations based on the numbers you posted here - something is going to fail somewhere.  | |||
|
| One of Us |
Okay, okay… The point is that a small tube of aluminum will swell more than an equally sized small tube of brass when exposed to an internal CUP of God-knows-what pressure. Or maybe the aluminum will even fail before the more malleable brass. At any rate, there is no reason to allow the CUP pressures into EITHER tube. | |||
|
| One of Us |
Not necessarily Henry...you better specify which alloys of aluminum and brass Rob is using or you would like him to use and what their respective conditions should be. I have a good idea what he's using. I'll leave your project stuff to you - I'm not getting involved with that - too much brain damage for me.  I sent you a handful of very useful materials resources. If you need help with them let me know - just don't ask me any whacky physics questions... | |||
|
| one of us |
The hollow base bullets are for a separate idea. I want to make a sintered TC inert to fill nearly the whole internal space. I've never liked the minnie ball approach in Big Bores! Remember, Gerhard showed some examples of hollow based bullets that he developed and the same question was asked about the bases balooning. The answer was they didn't. I actually have more concerns about thin walled aluminum bullets coming apart from extreme centripital forces. Hopefully if it occurs, this will happen outside the barrel. Long story, but I have seen this happen with swaged bullets. We will see today!-Rob Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012 Nothing Up my sleeves but never without a plan and never ever without a surprise! | |||
|
| one of us |
Henry- Rob starting with slow powder will be ok. Heat treated AL and regular brass have nearly the same tensile strength, 40-50k. As long as hole in the base is no more than .50" they should hold in a tight tolerance barrel. RIP- The brass case you will use, a RMC will have shotgun regular primers. So of my loads you will have to use IMR 4759, IMR 4227, VV110, I've never tested slugs that heavy with these 3 powders in plastic or RMC cases. Heaviest was a 870 gr hardened lead slug, stating with 60 gr of 4227 and top load of 75 gr. 1550 fps. Plastic case. What I'd do is like I did having John make a hollow base. Drill out base, 1/2" hole to lighten it up to 650-750 gr. Then work up in weight if you want by drilling out less. As weight goes up, velocity drops at same peak pressure so ME stays about the same, but as weightt goes up recoil goes up even at less velocity. Which why for all shotgun hunting guys I recommend 600 to 750 gr slugs, easier recoil, much easier load developement to keep peak pressures in a relatively narrow low band of pressures. Staying between 12-16,000 psi so cases, plastic or brass, last, are safe, and extract easy, takes a little finesse. Now with the heavier RMC cases we will be getting, we can go to 20-22,000 psi I figure, but that still a low/narrow pressure limit, so we need care in reloading .Ed MZEE WA SIKU | |||
|
| one of us |
Range report! Hauled the Borchardt to the range and loaded the round shown above. Used a load of 200grs of RL-25 and the 940gr TC hollow aluminum carrier. Ate my Wheaties and fired from the shoulder at 50yrds. Nice rewarding BOOM and bullet hit the target pretty much where I was wobbling around. Notice a very clean hole. No evidence of precessing! Brass was fire formed stuff and ironed out and extracted easily. Despite a clear impact point in the sand backstop we were unable to find the bullet or even pieces of it. we dug in a ft or so but didnt have shovels. Conclusions. Bullet was stabilized by a 1:20 twist. The relatively thin walled bullet did not become a bore obstruction. The TC penetrator did not get pushed out of the round. The Bullet was quite concentric and both spin and dart stabilized. The bullet did not explode in the air from centripital imbalances.There was some aluminum streaks on the lands of the barrel. Based on N=1, this looks extremely promising and safe.  Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012 Nothing Up my sleeves but never without a plan and never ever without a surprise! | |||
|
| One of Us |
N=1!!! YESSSS! I have no idea how you guys proceed from here on a new bullet development. Or just how far you push such development. So I’ll just lurk awhile, and only jump in when I might have something to contribute. If I see anything I can maybe quantify with graphs or simulations, I’ll check in. If you want other bullet weights computed, just mention it… For some reason, I’ve been looking at .338’s, so I’ll keep going on them for a while. I’ll also get back to the 45 ACP stuff, too. | |||
|
| one of us |
Ed, Thank you. Your recommendations have been noted. | |||
|
| One of Us |
If our 12GaFH bullets could all be made to be very “slippery†as in the previously posted graph of Cd vs. velocity, then there would appear to be very little penalty for shooting at high velocity. After all, Cd tells us how much energy is lost per meter of bullet travel, and most of this energy is lost as sound. So per meter of bullet travel, there is little penalty to be paid if our bullets are subsonic or supersonic. There is a “suck-out†in this thinking, however. It is the TIME over which this energy (or sound) is extracted from our 12GaFH round in a real-world shooting situation. A typical shot might be at 100 meters (yards). If we shoot subsonic, at say 850 fps, it would take 0.372 seconds for the bullet to reach the target. So our bullet will be radiating sound at a pretty constant rate for all this 0.372 seconds. But if we were shooting at 2000 fps, our bullet would still be losing about the same total energy on its way to the target, but now all this energy is crammed into only 0.111 sec. A remote observer would perceive the higher-velocity shot as about three times as loud as the subsonic shot, but lasting only about 1/3 the time. | |||
|
| one of us |
Now I ask in the proper thread: After how many years? After nearly 44,000 views? Is not the 12GaFH the most coveted cartridge for a big boy toy, worldwide? Why is there not some commercial source of brass for the 12 GaFH? It seems to me, that for fully suitable and full length brass, that I am going to have to get a machinist to fabricate the brass by screwing a 12 guage rim onto a 50BMG case that has had its rim turned off and threaded. Why no 12GaFH brass for purchase after all this? They would have mass appeal if available. | |||
|
| One of Us |
Someone needs to get their checkbook out and call Dieter... I'd buy a 1000 of em if they were a proper one piece rimmed case... | |||
|
| one of us |
Problem is the cost and wait when making from scratch. Like maybe 8-10 bucks each.We have a few guys trying to get to make them like we did as BMG cases are only a buck. How about this idea. Maybe Rob making rim pieces and you turning off old rims and threading bmg cases. Just a thought. And I'd even help by fireforming a few, to start with, as I have the powder. Here are more samples of nice slugs.....Here is pic of the ones RG Henson sent. Jacketed 12ga. 715gr hollowpoints, on the right and in front a jkt 675gr hollowbase. RG's number 1-770-366-4846. These will be great for shorter plastic and brass cases as well as long cases. Other slugs in pic, in the back, left to right Foster 436gr- Dixie 600gr- 750gr brass- my 750gr hollowbase brass, and a hollowpoint I put a filler in the nose.Ed  MZEE WA SIKU | |||
|
| One of Us |
You could probably get them properly deep drawn for $2.00 or $3.00 each in quantity... | |||
|
| one of us |
Mac- That would be great. But in 5000 quantity I was quoted for my 585, 3 bucks each, and only that low because he had the starting cups in stock. And for my 700 HE with 4000 run I was quoted over 3 times that much. And 12GA FH will need same cup and work as my 700. Prices on brass cups are crazy. And it takes a lot of work steps to do them. As for making from bmg cases, useful info. A small lathe that could turn off rim and thread them. It could hold them on live center in primer pocket,and in small chuck on the mouth with a bullet in for support,turn them out fairly fast, and have someone make rims with CNC. Example- Case one dollar, rim 55-75 cents, do the work and get 6-7 bucks. They are worth it. The turned 3.5" cases coming from RMC are 8 dollars..Ed MZEE WA SIKU | |||
|
| One of Us |
We can make the rims for you fast. Get a big enough order together and a print with tolerances and I'll get em done. I have no cheap way to do the cases. My best advice is to standardize the case and have 20,000 or more done to deal with the tooling cost. | |||
|
| One of Us |
So my reading of this is that brass will be some time in becoming available. Before these 12GaFH bullets will be generally available as big-boy toys, some TIME must pass. So what do we DO during this required time? Should we focus our attention on some other caliber? Just asking… | |||
|
| Powered by Social Strata | Page 1 ... 17 18 19 20 21 22 23 ... 75 |
 | Please Wait. Your request is being processed... |
|
The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Rifles Big Bores 12 Ga From Hell -WOW
Visit our on-line store for AR Memorabilia