single lube groove or two smaller ones?

[Oklahoma Rebel]

http://www.accuratemolds.com/img/bullets/detail/37-280TB-D.png does a boolit design such as this usually work better (accuracy, cleanliness) with one big .2 deep lube groove, or two smaller ones half the width but same depth? would take a little musical chairs but I could change it to two if I get enough sensible answers saying to change it, or if its better to leave well enough alone. thanks!-Travis

[Bookworm]

Depends on if you listen to Elmer or not.

Elmer Keith was a proponent of a single, large lube groove. Of course, lube technology has changed a bit in the intervening decades.

[Soundguy]

I still like a Keith style bullet.

[lar45]

I'd say use that boolit mold just the way it is. Looks great to me.
You actually end up with part of a lube groove just in front of the gas check.

[Soundguy]

I like the meplat.

[Oklahoma Rebel]

cool, and thanks for the compliment lar45,coming from you that means a lot! I designed it myself! my dad put in on autocad for me, even though tom didn't need that, just a detailed drawing. I may have to make minor tweaks to it when I get my gun. every time I am soo close to getting it, something else comes up! I guess that's what being grown up is all about. life really isn't fair, they said it, but I never listened! lol

[quail4jake]

Now evaluate the theory and success of Loverin style boolits, I am!

[Oklahoma Rebel]

to be honest, I know they are the multi-groove tapered designed boolits, but that's about it...they gradually get smaller from base to nose, right?

[Oklahoma Rebel]

do you guys think the loaded OAL of this boolit/cartridge, crimped in the crimp groove, of 3.181 leaves enough room for loading considering the saami length is set at 3.291? I am just a bit concerned that the meplat may cause feeding issues, so I made sure to give it a bit of extra room. I know you can only give a halfway answer because all guns are different, this one being a CZ550FS 9.3X62.

[quail4jake]

That's right, Rebel and you and I will partner in answering your question. I just ordered a 6,5 mould from NOE in a Loverin style, this is my first so I'll tell you how we do! Some of the theory behind the multi narrow driving band boolits is the upset of the entire length on acceleration to apply hydrostatic force to all those lube grooves and slick the boolit down the bore, then there's the theory of gradual engraving of the incrementally larger driving bands and filling the throat with a tapered, self centering boolit! I clearly need more education in this corner of interior ballistics (as well as a lot of other things!).
OK, then there's the Elmer Kieth philosophy that says "don't over think it" or "Hell, I was there!". Mr Kieth is a man I truly admire and his boolit designs are unquestionably successful, with wide driving bands and one big groove for a couple pints of soft alox loob, made of squishy 16:1 alloy. How did he ever become so successful without IT? BALLS! just good old fashioned try it and see BALLS! One of my favorites,
Truthfully, I think in the end we will find that narrow or wide driving bands have specific applications in which each works best. Now to find the sweet spot!

[Oklahoma Rebel]

well good luck with your 6.5, I think the idea of having a boolit that starts narrow and gets wider towards the base does make sense, as far as helping to start and keep the boolit centered, especially when going from throat to rifling. as far as having the multiple grooves, I can see why having more grooves over more length of the boolit would seem to be better, but I think that a single deep groove makes a nice floating reservoir of lube, with gas pushing some out in front of the groove (lets face it, we cant seal out all those gas molecules!) while leaving behind a nice slick surface for the next boolit in line. i'll go check out that mold from noe, by the way, how many grains is the mold you ordered? which 6.5 are ya shooting? have a good'un!-Travis

[quail4jake]

This is a 6,5x55 Mauser and the boolit is the 270-149 RN GC from NOE. There is a great thread on Cast Boolits from 2005 about H. Guy Loverin, educational and comical. Best of luck!

[Oklahoma Rebel]

do you guys think the loaded OAL of this boolit/cartridge, crimped in the crimp groove, of 3.181 leaves enough room for loading considering the saami length is set at 3.291? I am just a bit concerned that the meplat may cause feeding issues, so I made sure to give it a bit of extra room. I know you can only give a educated guess answer because all guns are different, this one being a CZ550FS 9.3X62.
is .11 giving the cartridge a reasonable amount of extra space to feed that flat point?

[runfiverun]

it depends.
do the feed rails aim the nose of the round up, or does the bolt just push the round forward and rely on a feed ramp to guide the round into place.

I will tell you the secret to the multi and long drive band bullets.
it has to do with metal displacement and [dang I forgot the word but it occurs from the back of the accelerating bullet]
anyway your moving stuff under pressure, allowing it somewhere to go without distortion makes the difference.

[Soundguy]

Obturation?

[Oklahoma Rebel]

yup! that makes sense, and as it does so a loverin design would seep lube from almost its length also it spins of and some sprays forward with any gas leakage. it is mauser type action, I think its called controlled feeding? the rim slides up under a big claw and I think the cartridge points up a bit. like ii said various disasters have delayed the buying of the gun:killingpc

[runfiverun]

it's slump.
as the bullet is banged up by pressure the design of the bullet can change and the unsupported nose wants to stay where it is when the back of the boolit is shoved forward.
if that area is supported then the slump is taken up and moved along.
however if you don't have a place for that extra lead to go you end up with a lump of trying to be cylinder shaped piece of lead.

I use a boolit design sorta similar to the one Travis show's but with stronger rear drive bands
part of that is because I want a slightly rearward center of gravity and part is to move weight away from a less supported nose area.
I can also rely on the big single lube groove to suck up the lead displacement and the area above the gas check to take up the displaced lead from the rear drive band.
I'm however limited to long slow launches.

now Gearknasher will like your design for the most part [no I didn't ask him] except maybe he would vote for some slightly stronger drive bands.
he likes a crimp groove near the front just to insure the lead has a place to flow before hitting that middle drive band.
but his launch system is just a bit more violent than mine is.

the key to both systems is to make sure you are engaging the rifling and keeping it engaged without disrupting the shape of the boolit under acceleration.

those loverign designs are there to be more extreme in the engraving process.
they have plenty of room for the excess lead to flow but the entire bullet will change shape when fired at extreme speeds.
the angles of slope built in allow the bullet to change shape predictably and reliably [slump into another shape] they ain't there to hold 1/2grain of lube.
you only need to lube the bottom groove.

the point of the whole thing is to get the bullet from the mold to the paper/deer whatever without damaging it.
well that really doesn't happen so an appropriate design takes that change into account and allows it to happen, only it does so without really damaging the integrity or balance of the bullet.

[Rcmaveric]

I like to keep things simple. Bullet design is one of those that I barely have a basic understanding of. However I am more than happy to experiment with any bullet and powder combination to see if I can make something accurate. Never know what you might find.

[Bent Ramrod]

Elmer Keith was designing the perfect revolver boolit.

He wanted a thick, square shoulder that would support a heavy crimp plus the ability to fill the chamber throat and jump straight across the cylinder gap into the forcing cone with a minimum of gas blow-by. What lube was necessary only had to deal with 6 or 7 inches of barrel.

A rifle boolit needs to fill the leade, perhaps support itself on the bore, certainly fill the grooves without slumping or deforming, and stay lubed through 24 inches of barrel, sometimes more. Here, multiple smaller grooves do the lubing duties without the potential of collapsing and distorting the boolit.

I’ve noticed that the Keith and “High Velo-Pen” designs with big/deep lube grooves give usable but unspectacular accuracy, at best, in rifles, while the Keith design, especially, shoots significantly better than others in revolvers.

The only partial exception to this general trend is the “Big Lube” .44-40 boolit used in rifles with black powder. Cast oversized out of Lyman #2 type alloys, it deals with the BP fouling better than other designs and the hard alloy helps keep the lube groove from collapsing. So it shoots about as well as other designs with smokeless, and better than most with black.

I’d go with the two grooves, myself.

[Hickory]

To me, the number of grease grooves are only important in relationship to how well it shoots.
But, even then, accuracy is more important than grease grooves.

[Oklahoma Rebel]

double post- read post below. sorry!

[Oklahoma Rebel]

so run five, you think I should have thicker drive bands, at least the back one?even with the full width section in front of the crimp?right now the weight distribution is I guess close to 50/50. I'm pretty sure I allowed for more lube than needed so the rear band could be made a bit longer, it just has to take place of some of the lube groove because of the cartridges neck length and boolit seating depth. in my mind I think that the nose of the boolit is thick enough to keep from slumping much at all, especially not to one side or the other.

[runfiverun]

you only need about .25 grs of lube.
make sure the walls of the groove are cut with at least a 30* angle.
but yeah some more strength at the base would be helpful.

this is what happens when you don't have enough places for the lead to go.
http://artfulbullet.com/index.php?attachments/img_2695-jpg.4271/

[Soundguy]

Looks like you have to be logged in to view that link.

[Oklahoma Rebel]

im not trying to be a smart alec, but couldn't that groove have collapsed on impact? or are you seeing something im not....what do you know??!?!?!?!:grin:

[340six]

Now evaluate the theory and success of Loverin style boolits, I am!

I have an old Ideal .323 like that I will try when the Masuer is done.

[Oklahoma Rebel]

so if you have limited groove space, in a rifle, is a harder lube a better choice? I figure it would hold on a bit longer then a softer lube. oh and run, I added .02 to the rear band, .01 to the band right before the crimp, and managed to lose only .01 of the grease groove. there was a .02 flat on the bottom of the crimp groove that I didn't like and removed, so that's one less narrow spot to slump. you wont see these corrections on accurate until I get ready to order. so you would have to use your imagination.

[quail4jake]

I like NOE but someone please tell me about accurate molds, thanks!

[runfiverun]

custom cut molds that pour out to what you order.
if you specify the dimensions and the alloy and communicate clearly with Tom [through E-mails] he will make what you want.
he will walk you through the ordering process so you don't order a plus .002 by accident.

he has a few stipulations such as meplat size, and caliber restrictions. [which has stopped me from doing a ton of work with 25 and 7mm calibers]
http://accuratemolds.com/catalog.php?page=2

another one to talk to is Dan at Mountain molds.
use the box above the pay pal thing to navigate more stuff on the site.
http://www.mountainmolds.com/

[Oklahoma Rebel]

I have never been able to get that mountain molds program to work, it doesn't do what I tell it to!! sems to be a common thing between computers and I!! lol

[quail4jake]

custom cut molds that pour out to what you order.
if you specify the dimensions and the alloy and communicate clearly with Tom [through E-mails] he will make what you want.
he will walk you through the ordering process so you don't order a plus .002 by accident.

he has a few stipulations such as meplat size, and caliber restrictions. [which has stopped me from doing a ton of work with 25 and 7mm calibers]
http://accuratemolds.com/catalog.php?page=2

another one to talk to is Dan at Mountain molds.
use the box above the pay pal thing to navigate more stuff on the site.
http://www.mountainmolds.com/
Thanks! I'm anxious to check it out!

[Oklahoma Rebel]

anyone know where to find cast load info for the 9.3X62, I cant find much cast, and reloadersnest site is either down or not loading for me. thanks a lot-Travis

[Oklahoma Rebel]

sorry.... guess that last post was in the wrong place

[Rcmaveric]

Ran a search on loaddata.com for you. Only found two recipes for you about 9.3x62mm in a Husqvarna Mauser referenced in Handloader Issue 155.

[Oklahoma Rebel]

thanks for checking for me.as far as lubes, I have a homemade one that's worked good up to about 1800fpps, i'll just have to see if it continues to work well up to about 2200fps, if not I think I will try carnauba blue, since I don't have a heated lurisizer.

[runfiverun]

run your lube first.
Travis take a look at Brad's thread on the 43-286 at the other site.
his latest post is what the bullet looks like when it is just punched down the barrel.
we have been working that design over and working it again, we had him [Brad] cut different grooves in different places and have been nit picking the gun and stuff apart all summer.

it's a good read for anyone that is interested in how things really work.

[Oklahoma Rebel]

what forum is it in, and you are talking about the art and science of boolit casting right? or are you talking about another site?

[Oklahoma Rebel]

nevermind I found it. you gave faulty instructions!!! it is actually 287 lol

[Oklahoma Rebel]

wow!, now I know the last batch of boolits I made, I heat treated when they didn't need it, so I never saw any compression like that! but that was a rifle, pistols/ revolvers have to accelerate way faster in such a short time, could that be the reason for the greater compression? I don't want my lube groove to collapse like that, should I maybe keep its original length, but make it a bit shallower? right now the design is .368 O.D. and the lube groove is .326, mainly because that's how tom makes them in similar boolits of that caliber. maybe go up to .332 so the groove would be .18 deep instead of .21 deep.? if the guy from lss lubes is around, I forgot his name, I would love to hear his opinion on this, because I know how much lube I need depends on lube quality and type. any input is appreciated guys! thanks-Travis

[Oklahoma Rebel]

disregard that last one, I have a sample noe .368-280 boolit, and I measured it and the shank in the lube groove is .326, just like my original design, and it looks plenty thick to avoid excess slumping, and is already shallow enough as it is. so I am going to keep mine at .326. I think they just look deeper when they are on paper.