30 br bullet to barrel

M

MrGee

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i'm wondering what bullets are available in .970 ~ .980 in length an what weight..
i'm fire forming new cases with berger 110gr because i have them on hand.. next round of bullets i'd like to try others that would work in a 17tw/24"
i just got my dies an bushing straighten out with help from here on the board.. thank you..
i'm new to this Br stuff an working my way thru it, it has been positive so far an trying for a little more info
 
MrGee, the majority of the 30 caliber bullet makers have bullets in 110 to 118 grn on either .925 jackets or 1 inch jackets.

As an example, BIB makes 112-116 grn 7 ogive on a .925, and 118 10 ogive on a 1 inch..........jackie
 
jackie.. so thats the choices i thought 30cal. had more to offer
when you mention 7 or 10 ogive i'm not sure i get... when i use the comparator measuring a bullet i get numbers like
like .327 or whatever.. where does 7 or 10 fall in i get the .925 jacket an 1.000 inch.

i had the use of a friends computor last week an he came up with the bullet length .975 for a 17tw. ... is why i asked
 
MrGee,
You can shoot bullets made on either .925" jackets or on 1" jackets. The weights can range all the way from 110 gr on the .925" jacket to about 135 gr on the 1" jacket. What Jackie was refering to was the ogive radius. I have seen anything from a 7 caliber radius to a 10 caliber radius with everything in between. I make bullets with a 9 ogive. the higher the ogive number, the higher the ballistic coefficient, but also the shorter the shank on the bullet becomes. You lose between .050" to .075" of bearing or shank length everytime you increase the ogive radius by a full number, like going from a 8 ogive to a 9 ogive. A 9 ogive is about as high as you can go on the .925" jacket. You can go up to a 10 ogive on the 1" jacket. Just to see what would happen if I filled a 9 ogive bullet on a 1" jacket all the way to the tip with lead, it gave me a 144 gr bullet, that can be shot out of as slow as a 18" twist barrel. Use these two jacket lengths for 17" or 18" twist barrels. The overall length of the pointed up bullets can range all the way from .930" up to 1.040". Do not fill them all the way up with lead for match shooting. Make certain that the lead line is at least down .35" from the tip. If you have any more questions just ask.

Michael
 
this got technical in a hurry... i think i get what your saying. this "7 ogive number" is the radi of the outer point of the ogive. center of bullet to ogive. which in turn gives you the length of the shank or body of the bullet...
now lets get to .925 an 1.000 ..... is this where the lead is in the inside of the jacket from the tip back

remember now I-talians are a bit thic walled ... we still didn't find out who makes what :)
 
MrGee,
The lengths .925" and 1" are the lenghts of the bullets jackets before they become bullets. This is simply a copper cup of the same diameter from base to tip. After the lead core is seated and the bullet is pointed up, the overall length of the bullet on a .925" jacket comes out between .930" and .960", while the overall length of a bullet made on a 1" jacket falls between 1.020" and 1.040". The lead line would be down from the tip of the bullet between .300" and .450" range typically. And yes, the ogive radius is in calibers, for instance an 8 ogive radius on a .308 diameter bullet would be as follow: 8 X .308" = 2.464" radius, or a diameter of 4.928". So if you draw a circle with an outside diameter of 4.928", the radius on the nose of a .308 bullet with an 8 caliber radius will lay in that circle with a very nice match.

Michael
 
thank you Michael... your time didn't go without appreciation.. many years ago my friend was the inventor of Pin Grabers he originally produced a bullet .45acp for bowling pin matches but then expended into many other calibers at one point when i was out of work he had me making 12ga. shotgun slugs with 'lipstick cases' i operated a Corbin hydraulic machine that formed the bullet.. i don't remember what we used for lead it may have been another lead bullet to fill.. with that said no one has ever explained the numbers an what they meant
thank again an thanks to jackie for trying .. i got it
 
Keith,
I do for hunting purposes, but for a match bullet it is not recommended to fill it up all the way. Many custtom bullet makers will say something like no more than 2/3 the way up. Now here is one reason why some would believe it's not a good idea. The jacket starts out being very concentric, and just like when you neck a case down, it can become less concentric. As the nose of the bullet goes from .308" down to .062" it is very likely that the concentricity can go way out the window, so any lead at the tip could cause a greater imbalance. Now fortunately as the radius decreases, the effect of the imbalance also diminishes, but that imbalance could still have a small effect on agging ability.

Michael
 
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