The new 33XC & 37XC cartridges designed by David Tubb

Jim Boatright

New Hide Member
Feb 21, 2018
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#51
I fear my earlier reply to this question from Skookum got lost when my internet service went down.

I cannot foresee any possible deleterious effects of shifting the tripping ring back about an inch behind the tip of any rifle bullet. For those bullets which can benefit from adding such a ring, it would not matter where it is relative to the ogive/body junction or any other break in the surface angles. The boundary layer L/T flow transition occurs after about 1.25 to 1.5 inches of laminar flow even for a flat plate in a wind tunnel. By shifting the transition point back about an inch, more of the bullet would experience the significantly lower-drag laminar flow.

One could ask David about this change, since he probably tried it.
 

Skookum

Flattus Domini
May 6, 2017
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Your mom's
#52
I fear my earlier reply to this question from Skookum got lost when my internet service went down.

I cannot foresee any possible deleterious effects of shifting the tripping ring back about an inch behind the tip of any rifle bullet. For those bullets which can benefit from adding such a ring, it would not matter where it is relative to the ogive/body junction or any other break in the surface angles. The boundary layer L/T flow transition occurs after about 1.25 to 1.5 inches of laminar flow even for a flat plate in a wind tunnel. By shifting the transition point back about an inch, more of the bullet would experience the significantly lower-drag laminar flow.

One could ask David about this change, since he probably tried it.
Thank you for that answer, it makes sense.

In light of what you've said, it would make sense also that Tubb would want to put the ring farther forward to market his ringing tool more effectively. Because you can't know what bullet will be ringed, the further back you place it, the more likely it will not work for any single particular bullet. I'm not knocking or criticizing that, I'm just drawing logical conclusions. As long as it still has the advertised effect, more power to him.
 
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