Bevel base molds?

[Mustang Gregg]

Casting Pards,

 

I hate ask something that I really should be able to find myself but - - -

 

In my whole collection of .44 cal molds, I cannot find a single one in a 200 gr  RNFP that has a bevel base.

 

Can anyone direct me as to which mold manufacturer makes the popular 44 mold that commercial casters are using and selling?

 

Much obliged,

Mustang

 

 

[Wildcatter]

I use accurate molds. Tom is a full custom mold maker and he creates works of art every time I order a mold. He will make flat and bevel based molds. 

[Larsen E. Pettifogger, SASS #32933]

Magma makes the majority of commercial casting equipment.  This sheet is all bevel base.

 

https://www.magmaengineering.com/PDF/BBOct132008b.pdf

[Mustang Gregg]

Much obliged, Larson.

I hadn't been able to find that Magma mold chart.

 

[Sedalia Dave]

7 hours ago, Wildcatter said:

I use accurate molds. Tom is a full custom mold maker and he creates works of art every time I order a mold. He will make flat and bevel based molds. 

 

THIS ^^^

 

He can make any of his molds plain or bevel base. Added bonus is there is no charge for the customization.

[Bison Bud]

I know this is not what you asked, but I prefer a non-bevel base mold for my bullets.  Although the bevel base makes seating the bullets easier and doesn't require as much belling of the brass mouth, I think it also helps to contribute to gas cutting and possible leading issues.  This may not be a big issue, but I do feel that it is better to avoid the bevel base if I can.  Personally, my .44 caliber mold of choice is a 200 grain, two cavity, tuncated cone mold, made by Saeco, which does not have a bevel base.  I've had great luck with this mold in .44 Special and .44 Magnum and have cast and fired thousands without leading issues.  Anyway, if you want a bevel base mold, you've already received some good information above, I just thought I'd kick in about why one choice might be better than the other.  It's your choice and your ammo, good luck and good shooting to all.      

[Reverend P. Babcock Chase]

howdy Casters,

 

In addition to helping during bullet seating, a bevel base theoretically provides a more precise base to exit the barrel. This eliminates the potential for the base being less precise due the effect of the sprue plate whiping the base of the bullet during sprue cutting. Probably not an issue for cowboy work. I think that's why many of the old timers preferred nose pour moulds for accuracy work. 

 

Rev. Chase

[Sedalia Dave]

For CAS distances bevel base (BB) or plain base (PB) makes no difference. BB bullets are easier to start than PB bullets.

It's kind of counter intuitive but imperfections on the nose of a bullet have significantly less impact on trajectory than those at the base of the bullet.  This is why PB bullets are preferred for long range as it is easier to see minor imperfections around the edge. 

 

Poor bullet fill out and improperly adjusted sprue plates are the causes of these imperfections which is why nose pour bullets are preferred for precision long range accuracy.

 

As for leading caused by gas cutting there is no advantage of a PB bullet over a BB bullet. Gas cutting is caused by the hot gasses escaping past the front driving band. Preventing this is a function of how well the bullet fits the bore and not the shape of the base.

 

As hot as the gasses are that push a bullet down the barrel they are not in contact with the base of a bullet long enough to heat it sufficiently to melt the base. This is easy to verify as many BPCR shooters use a couple of layers of thin paper between the base of the bullet and the powder charge to prevent the powder from sticking to the base of the bullet when it is seated against the powder charge. You will find these pieces of paper laying on the ground out in front of the barrel undamaged by the burning powder. It doesn't burn because the mass of the bullet acts as a heat sink preventing the paper from reaching the ignition point. A thick wad however may scorch or catch fire as the end touching the powder is sufficiently isolated from the bullet. 

 

I don't understand all the physics well enough to properly explain why gasses escaping past a bullet will cause the lead to melt when those same gasses do not melt the base of the bullet. However, I do know it has something to do with the velocity of the gasses as well as their temperature. This is why calibers whose case volume is significantly larger than the bore diameter (Large overbore index ) experience throat erosion while calibers with a small over bore index do not. 

[Tom Bullweed]

I cast with a Lee 6-cavity 240 grain tumble-lube mold.  No sizing.  The base has about a .05" radius, not a chamfer or bevel.  This shoots well in a Marlinh 1894 with a micro-groove barrel.

[Mustang Gregg]

22 hours ago, Tom Bullweed said:

cast with a Lee 6-cavity 240 grain tumble-lube mold.  No sizing.  The base has about a .05" radius, not a chamfer or bevel.  This shoots well in a Marlinh 1894 with a micro-groove barrel.

Thanks, but I only use 200 to 205 grain bullets. 

I'm just looking for a new mold that's a duplicate to the popular .430" 200 RNFP's that almost all of the commercial CAS casters sell.

I want one so I can cast up "home-made Hi Teks".