45acp boolit design questions

[truckjohn]

Hey all

Been fooling around with the Mountain Molds mold designer program.
Pretty neat for some of the stuff it will let you do.

Did one mold already for a 577/450 Martini. The mold casts great
and shoots really well.

I am curious about the 45 ACP mold designs out there.....
Maybe this is well trod ground, but it seems like there are
3 types of molds out there for 45 ACP:
Round nose
HG 68 style -- long nose, 2-thin bands.
LSWC -- Shorter nose, more bands.

What I want is a design with a strong front band
that will fly straight at longer distances (If I was so
inclined.)

I am thinking a 225g Round Flat Tangential Ogive nose
with a 70% Meplat

0.558" OAL,

0.380" nose
Front driving band 0.170"
1 grease groove about 0.090" wide
Plain base about 0.090" thick,

My worry is that many "WFN" type designs don't
fly well past the 50 yard line..... and this may be getting
too close to WFN territory.

Tell me what you folks think -- or if you know a design
that will fly better -- smaller meplat, longer nose, etc..

Thanks

John

[MtGun44]

My only experience with long range with the .45 ACP is plinking at the
18" gong at 200 yds on our range. With a 950 fps load with a
H&G 68 I can hit it with 6-7 shots out of 10 once I have the amount of
front sight to hold up. I know that the old bullseye shooters found
excellent accy with the short nosed designs in the 190-205 gr range,
and have bought (but not yet used, need more free time!) a mold
to try this style. H&G 68 reputation is as a more reliable feeder than
the short nosed styles.

Good luck.

Bill

[Bass Ackward]

What I want is a design with a strong front band
that will fly straight at longer distances (If I was so
inclined.)

I am thinking a 225g Round Flat Tangential Ogive nose
with a 70% Meplat

0.558" OAL,

0.380" nose
Front driving band 0.170"
1 grease groove about 0.090" wide
Plain base about 0.090" thick,

My worry is that many "WFN" type designs don't
fly well past the 50 yard line..... and this may be getting
too close to WFN territory.

Tell me what you folks think -- or if you know a design
that will fly better -- smaller meplat, longer nose, etc..

John


John,

Some things to think about.

Why do other factory designs look like they do? How far does yours stray from this history?

I think you make an incorrect assumption that a wide front band aids bullet flight. It may allow softer metal use to hold the rifling, but a simple truth is that the easiest bullet to stabilize has the center of gravity towards the back. My work says that the farther back, the better for low velocity use. A wide front band is counter to that. My guess is that the wide front band is more negative than the meplat itself.

The limiter to meplat is usually the olgive angle that people try to match to the angle of their throat or the leade of their rifling. But if this isn't a concern, then look at other successful long range designs for ideas.

[truckjohn]

Bass,

My thoughts were based on Veral's book -- his critiques of the various designs.
The H&G 68 has itty bitty bands, but is a known performer -- probably because it feeds great more than anything else....

A bunch of the shorter nose cast SWC designs have a fatter rear band and thinner front band, probably because they are easier to cast that way. Those feed fine in my 1911, so I am not too worried, I was just thinking that a ball-ish nose might work OK.

The strong front band probably does nothing for flight -- but should help get the bullet into the barrel straight.

Maybe I need to put it into AutoCad and see how far back the CG is from the physical middle of the bullet. Any suggestions for how far back to put it?

Thanks

John

[felix]

Ideally, the location will be determined on where the center of gravity and pressure is desired to be for that application. ... felix

[truckjohn]

Felix,

Re: design center of pressure

Are there any handy reference methods for calculating the center of pressure
that don't require me to fire up the 'Old Cray supercomputer?

Thanks

John

[felix]

Yeah, there is John, and Tom Myers has already included that in his software. PM him under that ID name, and ask him either for the software, or let him help you with the design. ... felix

[44man]

I don't know why the theory that a WFN doesn't fly good at distance, keeps going around! Can't prove it by me anyway. Yes, there is more drop but weight has a more drastic effect. Boolit design and a match to the twist is more important.
Accuracy has held to 500 meters with no tipping or funny flight with WFN and WLN boolits as long as the drive bands are right for the twist rate. OK, I had to aim higher, gee whiz, so what! I hit pop cans at 100 yd's with a WFN out of my .475, center hits, not nicks.
I think someone with a mismatched WFN boolit that shot decent at 50 feet, then tried 50 or 75 yd's and got bad results, came up with that notion.
Truckjohn, GO for it. Don't blame the nose if it doesn't shoot good. Look for something else. The lube you use, alone, can make or break long range accuracy.
Boolit design means a lot and I don't have it figured at all. I have two boolits that are real close in weight and everything else. One shoots to 500 meters and the other is poor at 50 yd's. Don't ask, I can't tell you why. No one else will either. When I put these side by side and study them, I feel real stupid and humbled. The gun knows more then I do.

[felix]

The gun itself can destroy the flight characteristics built into the boolit by design. The angles of the boolit must match, or better yet, must be compatible, with all of the throats of the gun. Just make sure the boolit design has more than enough "design slop" built in so it can be banged around by the various orifices of the gun and not effect the center of pressure relationship to the center of gravity. One boolit shoots and one "just like it" won't for this reason, assuming everything else about the boolit is apparently equal. Hopefully, the design you come up with will be in excess of that is required to allow the boolit to be hammered somewhat. ... felix

[Bass Ackward]

Bass,

My thoughts were based on Veral's book -- his critiques of the various designs.
The H&G 68 has itty bitty bands, but is a known performer -- probably because it feeds great more than anything else....

The strong front band probably does nothing for flight -- but should help get the bullet into the barrel straight.

John

John,

That is why I said things to think about. Design can be used to cure problems. Question is, do or will you have a problem to correct that warrants sacrificing BC to get it? Remember, those are time tested designs.

I figured you got that from Veral. If you also read his book under bullet design, he tells you that better accuracy will result with the heavier weights per caliber and then when driven hard. I think it's on his sales form too. Both of those statements are classic descriptions of stabilization problems as velocity can stabilize anything if you can push it fast enough. I figure that he probably knows that, but if you are trying to sell the wide concept, it's a detail better left out of the discussion.

I have a 44 caliber, 230 grain ogival wadcutter as he names it. Never could get it to work at low velocity until I turned it around. So I simply think of, and treat it, as a boat tail wadcutter. :grin:

[Bass Ackward]

I don't know why the theory that a WFN doesn't fly good at distance, keeps going around! Can't prove it by me anyway. Yes, there is more drop but weight has a more drastic effect. Boolit design and a match to the twist is more important.


44,

Never said not accurate. Just harder to get and maintain accurate. Want proof? How many high speed aircraft do you see with a meplat? Ever watch that old movie how the first planes that had meplats threatened to shake apart as they approached the barrier? How many planes that do go beyond the sound barrier are the engines (weight) forward of the center of gravity?

Remember, turbulance occurs up .... and back through the barrier. Your load and barrel can control the front of the bullet as it breaks this level going up through, but coming back through, it's on it's own. The more meplat you have to negotiate that level and the more forward the center of gravity is, the more chances you have for things to go wrong.

need more proof? Just play the wind game with your hand next time you go down the road. If you can keep velocity up clear to the target you are OK. Otherwise yaz takes yer chances. :grin:

[Char-Gar]

I have no problem with anyone wanting to lay down his cash to "do it my way". That is what we cast boolit folks are all about.

That said, H & G 68 or Lyman 452460 have been proven over and over again in the 45 autopistol. They will feed, shoot like a house-a-fire, and kill anything that should be shot with a 45 ACP round, at any range you should be shooting with the round and pistol.

The bullets will weight from 200 to 220 grains depending on which design, and do their best work at about 850 fps.

For just plain shooting and accuracy, nothing can beat the old Lyman 230 RN with the GI profile. It doesn't cut clean holes in a target or kill critters very well, but it will do everything else. The RCBS and SAECO designs don't do near as well in the accuracy department. At least in my experience.

[BD]

I think I designed something pretty close to what truckjohn is looking for a few years back. I called it the BD 45 acp and we had a run of Lee six bangers made. Anthony then adapted the RCBS CW nose to that bullet and there was another run of Lee sixbangers in that configuration. Someone who knows the "search" function on these forums better than I could find the drawings I'm sure. I designed this bullet with an eye to accuracy and killing ability as the primary criteria. The size of the meplat is limited by the slide stop button in the 1911 pattern pistols. Too fat at the nose and it will lock the slide back as each round feeds. In the glocks most anything will feed just fine. I have had very poor luck with the SWC designs for killing critters, even as small as racoons. They also greatly reduce the powder capacity of the cartridge. IMHO the main problem with the WFN designs is in coming down through the sound barrier. The WLNs are much better in this regard. My primary experience with this phenomena is in my .44 using a 265 grain WFN. 4" groups at 100 yards, 8" groups at 150 yards and 4 foot patterns at 175 yards. Shooting these offhand at the 200 yard gong is unsafe as some of them hit the ground. Before I came down to the low country I shot the .45 acps at 100 yards quite frequently. The SWCs do OK, but have some wild fliers. The round noses and th BD acps do alot better, as did the JHP Ranger RTs.
BD

[Lloyd Smale]

there are some rare wfns that shoot well if pushed hard enough out to 500 yards but there RARE. Ive learned enough in just the last month on here to completely rule out any bullet or design but theres one thing ive done a lot of thats long range shooting and believe me ive give wfns all the efford in the world to get to shoot well. Why wouldnt I? if they could be made to shoot well at long distances they woud be an ideal bullet. Never once has anyone ever said a larger metplat isnt better on game. If i could get a bullet with a big metplat to shoot well at long range id be jumping all over myself to cast them. Hell to me id love to see a full wad cutter that would shoot long range! Aint going to happen though. Like bass said if you can shoot them fast enough and cast them hard enough to not deform when being shot theyd proably be fine. But thats a pretty fine line to cross. I have about given up on them as its just to much work to deal with a bullet that isnt a good design to start with. Got to admitt one thing though if a guy isnt going to hunt past 50 yards there probably the best bullet design made.

[truckjohn]

That Lyman round nose GI design looks pretty decent.

Wasn't so sure about the Saeco/RCBS "bore ride" type round nose -- I would think the extra band junction area up front might actually help out. I do see the point about pushing the CG farther back by trimming the nose a little.....

Anybody got pictures of what a 45-cal WFN vs WLN vs WLFN vs LFN patterns look like.... especially in a short stubby 230gr 45 Auto type package?

On the subject of badly designed WFN's -- I got some Cast Performance 410g 475-410-wfngc bullets as plinkers in my Martini rifle. At 950 FPS, they keyhole so bad that at 200 yards, 1/2 of them hit within a 50-ft circle of the target. The rest land somewhere out yonder between 200 and 400 yards. You can see them shank and hook off hither and yon. Same rifle shoots my 525g custom Mountain Mold "Lead Cylinder" with a stubby 1/2 caliber long tangential ogive 70% Meplat bullet straight and true at 300 yards -- started at 900 FPS no problems.

Thanks

John

[AnthonyB]

John, the BD45 and BD45CM are available for viewing on Catspics at
http://www.castpics.net/RandD/Lee_moulds/Lee_Moulds.html
Tony

[44man]

I have a semi pointed .44 boolit I designed for silhouette long ago and a nice pointed 45-70 boolit for my BPCR. Both are junk for distance. Both are very accurate at close range. I have tried everything with them and you can watch them through the spotting scope. Once they get so far out, it looks like some one smacked them with a paddle. I can measure patterns in yards not inches.
Yet my WFN flies true in the scope. The WLN is even more accurate and flies true and straight.
I have no explanation for any of it. I have had other semi wadcutters, truncated cones, round noses and such that flew good and others that were junk so I understand a lot of the frustration. When I sit and draw a boolit, I have no idea if it will work until it is done. There are a lot of molds in my drawer that will never be used again. Then some will be buried with me.
I follow a lot of the theorys here about drive bands, GG's, weight more to the rear, etc. Doesn't help me because one will shoot and another won't no matter what.
I have the huge Lyman .44 boolit that is fantastic and it shoots with any load so I was going to buy the .45 boolit of the same design. Lyman stopped making it because no one could make it shoot.
Whats going on? Gremlins I say! Here's one of them!

[44man]

OOPS, lost a gremlin

[robertbank]

Like Charger said. Particularily true with the .45acp cartridge. If there was a better way it would have long ago been discovered cuzz this round had been tweaked seven ways to Sunday...twice.

Take Care

Bob

[Lloyd Smale]

44 man i agree totaly with you for a change. It seems like some bullets that should fly like the wind fall on there faces and some that look like crap shoot. Ive even seen where to of the same molds lathe cut and not cut with a cherry would shoot totaly differnt just because there not exact. I too blame them dammed gremlins!!
I have a semi pointed .44 boolit I designed for silhouette long ago and a nice pointed 45-70 boolit for my BPCR. Both are junk for distance. Both are very accurate at close range. I have tried everything with them and you can watch them through the spotting scope. Once they get so far out, it looks like some one smacked them with a paddle. I can measure patterns in yards not inches.
Yet my WFN flies true in the scope. The WLN is even more accurate and flies true and straight.
I have no explanation for any of it. I have had other semi wadcutters, truncated cones, round noses and such that flew good and others that were junk so I understand a lot of the frustration. When I sit and draw a boolit, I have no idea if it will work until it is done. There are a lot of molds in my drawer that will never be used again. Then some will be buried with me.
I follow a lot of the theorys here about drive bands, GG's, weight more to the rear, etc. Doesn't help me because one will shoot and another won't no matter what.
I have the huge Lyman .44 boolit that is fantastic and it shoots with any load so I was going to buy the .45 boolit of the same design. Lyman stopped making it because no one could make it shoot.
Whats going on? Gremlins I say! Here's one of them!

[dromia]

John do you fancy telling us about the Martini mould you had made?

Perhaps in a new thread so as not to hi jack this one, Thanks.

[44man]

Here is a boolit I can't get to shoot better then mediocre no matter what I do with it. I don't know if it is the wide front drive band or what it is.
The one on the left just won't shoot.
The next is my WLNGC and it has shot to 500 meters great. Shoots an inch and less at 50 yd's. This boolit shoots real tight with 1/2 gr more powder but gives me sticky cases. I put 5 in a half inch but it is too hot.
Then the WFN has been shot to 400 yd's and is the boolit I shot a bunch of 5/8", 50 yd groups with. Drops deer in their tracks.
The Lee boolit also is extremely accurate at all ranges.
The two commercial boolits on the right shoot OK but won't do quite as well although the lighter one has shot some impressive 50 yd groups. It does better if I take the blue lube off and use Carnauba red.
I had some semi wadcutter boolits and they just sprayed the target. No way I would try another.
This is just one caliber but I run into this with other guns too. I have some boolit molds without the wide front drive band for other calibers that just don't have the accuracy, yet another will go the distance.
The gremlin was chewing on the boolit box and I blame her.

[Bass Ackward]

Here is a boolit I can't get to shoot better then mediocre no matter what I do with it. I don't know if it is the wide front drive band or what it is.


44,

Well let me give you my rational. Look at those bullets and try to picture in your mind where the center of balance is. Sticks out like a sore thumb on some of those. If the center of balance is forward, you will need more velocity or twist rate to stabilize them. In other words, your launching system can't produce enough velocity cause you can't change twist rate.

Just look at the ones that work and compare to traits to the others have that are more difficult. Of coarse this means that some bullet designs may be balanced OK if they are heavy enough, but simply need to be harder too to resist deformation. Why? Realize that in addition to balance, you are weakening the base area with thinner bands and putting the heavy weight up front where you have no or little obturation force. If the weight is more evenly displaced (drive bands the same width) you have a stronger design or one that can be shot with softer mixes. But no wonder you like rocks!

The weaker the base, the harder my bullets have had to be to withstand the pressure or the more valuable a GC has been. So you get two things working against you. Look at the design you like. Length for BC, even band dispersal with narrower grease grooves and a GC on the base with a narrow groove.

Let's take that left bullet that you don't like. Put it in a rifle with a 20 twist and drive it fast enough and it will stabilize. Betchya. Would probably make a fairly good 444 bullet for somebody using rock hard and slow for caliber powders.

I am going to take a gamble. I assume this is a 44. One that has thousands of rounds out of it. Correct? Take the cylinder out of your window. Take each bullet and drop it in the cone one at a time. Notice how the semi wadcutter drops out of sight (shorter bearing area). My guess is that the longer bearing area of the olgivals is reaching forward and making contact with the rifling or cone sufficiently before the base let's go out of the throat. Easy call then cause your losing alignment. What happens to accuracy if you lose alignment?

Now go back and evaluate your designs. See if any of that rings a bell. I'l bet that if you cut off a couple of threads and set that barrel back and recut the cone, your results for good / bad would flop some. Then only weight distrobution would be the big factor. (If I guessed right)

[44man]

Bass, they are .475 boolits and the gun has not had the rounds through it like my .44 has. I understand the weight distribution and wish I could just add another grease groove. Someday I might grind one on the cherry and cut another mold. Not a whole lot of sense in it though because my other boolits do what I want so it would just be an experiment.
If you notice, some of my other boolits have short base bands, yet shoot super groups. My boolits are fairly hard but not excessive. Even WW metal does good with them. I have tried wide base bands and short front bands and some shoot and some don't.
The more I mess with this, the more I think it is the gun itself. That bad boolit might be the ticket for a different gun. I do know some of my best boolits will not shoot for beans from a friends gun.
The whole gist of this is that a guy that buys one mold and the boolit doesn't shoot good is just stuck! Most times it takes a bunch of different boolits to find what a gun likes.
Same as all the rifles I had over the years. Some loved Hornady and some loved Speer or Sierra and even though they weighed the same, with a given rifle, I would say such and such bullet was junk and might not try it in another rifle. Bad move, all must be tried in each gun. A friend bought some real expensive bench rest bullets for his varmint rifle. I never seen such bad groups, yet they win in competition from other rifles with the same twist rates.
Gremlins!!!!!

[felix]

A BR gun (I really mean a heavy varmint class or better BR gun) will shoot any boolit within its vibe and twist requirements. If the boolit/bullet won't shoot in that gun, then the boolit design is indeed worthless, or not rotationally balanced. ... felix

[44man]

Felix, the heck with the boolits. Do you like my gremlin?

[Bass Ackward]

Dang,

Was hoping to make a point. When I talk characteristics for flight, like weight on the back etc, these are flight characteristics. Not launch ones. There is a major difference.

IF a great bullet design is not launched properly, meaning that it was altered by the launching or misaligned in the process, then as Felix said, it's worthless no matter how precision the firearm, how aerodynamic or balanced the bullet is. A bullet design must withstand this process, which is why the mechanicals are everything.

I had my 5.5" Redhawk barrel cleaned up, set back, and taylored to smooth the transition from .432 down to .429. I was anxious to get it back. Sadly, what shot before doesn't want to now. Basically, the same barrel. So I gotta break it in all over again.