7 mm bullet mold

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blaser.306

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I am looking for any info about a 7 mm lyman bullrt mold that I just purchased from another member on the EE, it is a lyman 7 mm 160 gr. silh gc # 287641(av) but is diferent than the normal type this bullet casts with a pair of lube grooves just behind the bullet nose . Is this designed for higher velosity ? Any info would be appreciated tnx.
 
My information shows this to be a normal borerider design with out any forward grooves such as a Loverin design. Your 287641 is a very std. design and there must be some error in the numbering given to you. Aside from this, boreriders are made to have the front smaller portion ride tight on the lands while the rear portion is sized to fill the grooves, regardless of whether the front has grooves or not. The borerider portion centers the bullet very well in the bore and will be responsible somewhat for good accuracy. If the forward portion is to small in dia., nothing good can come of it. If the forward portion is too big, you won't be able to seat it way out into the rifling, as boreriders should be. The rear grooves should contact the rifling on chambering for best cast bullet results.....Ben
 
Lube grooves are for just that. They have nothing to do with velocity. A 7mm cast bullet likely needs gas checks. Those are about velocity. Even with 'em, cast bullets can't be driven too fast.
 
Last years Cast Bullet Association national tournament was won by a gentleman, using a pistol and competing against rifles in the unlimited class, his cast bullet load, out of that pistol was 2700 fps.
 
I believe it was a 6mmbr, and weighed something like 17 lbs, if anyone is interested, I will dig up the results. It seems to be a new trend in cast bullet benchrest comp. to lighter for cal. bullets at higher velocities. My results/tests don't mirror his results, the higher speeds, yes, but I have best luck with long bullets and slow as possible twists.
 
Thanks for the input on my question , a quick call to lyman on friday morning cleared everything up . It appears that instead of this mold being a new revition of the 160 gr this block was manufactured in the 80's the only real difference is the nose punch and the two lube grooves behind the bullet nose . I wouldnt have beleived that this mold was of that age being that it didn't look like it had ever been cast .
 
Lyman did silhouette moulds back in the 80's and 90's in 7mm and 30 cal for sure. Mould has cast several hundred bullets--they last a long time if you take care of them. :)

I don't have the chronograph data any more but as I recall we loaded them to around 1800 fps in the 7mmBR. If your T/C is a 10" you shouldn't have to worry about too much velocity.

44Bore
44Bore
 
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