dia of drive band on cast

Forums General Discussion dia of drive band on cast

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    cpt_sfc
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    I wish to order a cast mold for a barrel with a land dia. .249 and a groove of .255 can anyone tell me what to have the drive band dia. made to fit properly. 25 cal.
    thanks

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    rockymtbiker
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    I’ve used NEI to make a number of custom molds for my handguns (they even made a duplex boat tail spire point for my .45-70 TC that was pretty trick), so I would recommend contacting them:  http://www.neihandtools.com/

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    I_Like_Irons
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    In powder burning rifles, it has been found that the best precision/accuracy is obtained when the nose portion is the size of the lands to a couple of ten-thousanths over: +.0002 / -.0000.  The driving band(s) at the base should be as close to the groove diameter as possible.  However, again you can go oversize a bit but not under size.

    In your case I’d try to find a mold and alloy that gets the nose to 0.2491 and the base to 0.2552.  If the base is bigger when you get the nose to size you can bring the base down by sizing. 

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    cpt_sfc
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    Thank you

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    pcphunter
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    I design molds for air gun slugs, check out some of my designs at higharchunter.com. What I_Like_Irons says is correct. on the sizing. I have a couple questions? what is the barrel twist rate? Are you looking For a hollow point? What weight bullet are you looking to make? How far are you looking to shoot? hunting or target bullet? And most of all is the barrel choked? Choked barrels do not shoot cast slugs well.

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    cpt_sfc
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    This is for my escape from airforce .25 cal.. I will have to call and ask about choke and rate of twist. The tech there did tell me that lands were .249 and groove was .255. thanks for the response. This will be most for hunting at up to 75 yards. I live in wood that most shot are at 35-50 yards. I have been shooting 380 acp slugs out of my evanix 9mm seems the bore on that is larger then 9mm. They shoot really quite well . But I have not come across the right slug for the 30 yet. I have a daystate 303 an evanix 30 rainstorm and a  flex which I am looking for a slug at this time. I would like to make 25 cal and 30 cal for future use. I like to cast and have done it for PB for over 50 years and even swaged some but my swage press is an old herters press , hard to come by the right dies.  I will take a look at your site. thanks again.

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    pcphunter
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    I have hollow point molds in the works for all calibers that the flex comes in. I am working with Jim Gaska to make slugs that will fit his flex mags. Get me the barrel specs and I can design something that might work. NOE molds can cut you the mold but the tooling will cost you around $300.00.

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    cpt_sfc
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    Great I will call Travis after he gets to slow down some and get the specs for it. Will get back to you on it.

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    cpt_sfc
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    UPDATE the drive band on the bbt for the noe BBT in my rifle had to be 250/252 the 255 did not want to group well in (escape), but the smaller 41gr shoots to same POI as my 29 gr domes and just about same size group. It will go through a coyote side to side /lung heart shot.

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