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Old 01-21-2017, 04:13 PM
17tbs 17tbs is offline
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Default 100 yards .172"

Quote:
Originally Posted by xring View Post
Some years back , I heard of a 1000 Yard Benchrest shooter who was making very heavy bullets in 17 Caliber for competing at 1000 Yards in Pennsylvania . I hesitate to say the bullet weight because it sounded incredible . The Bullets were not Lead , and I don't remember the exact details . Maybe someone can calculate what Tungsten Bullets would weigh . Anyway , you might want to search 1000 Yard Gun Clubs in the Williamsport Pa. area , contact them , and try to track down more information .
Right at 48.5 to 49 grains for a bullet with the same volumetric capacity as the 30gr Kindler Gold.

That might give about a .430 to .435 BC as compared to the .270 BC of the 30gr Kindler BTHP.

After considering the difficulties in production of the projectiles, barrel life loss and other unknowns, I don't know if the effort would be worth it, but it sure would/could produce an "out of bounds" performance enhancement for a .172 caliber weapon in terms of ballistic efficiency and penetration. If you could extrapolate the velocity loss due to the super heavy bullet and use the exact right powder in a long enough barrel, the mass difference between a 30gr and a 48.5gr bullet might cause a velocity drop by as much as 1000feet per second. If that were true, and that is a lot of "IF", then you might get the following:

JBM Stability calculator

Stability input data:

Caliber: 0.172 in Bullet Weight: 48.5 gr
Bullet Length: 0.663 in Plastic Tip Length: 0.000 in
Muzzle Velocity: 2700.0 ft/s Barrel Twist: 9.0 in
Temperature: 59.0 F Pressure: 29.92 in Hg

Output Data: Stability: 1.688

Barrel life on the other hand..... ehhhh,... probably not so enhanced. I think it would be very expensive in terms of accelerated barrel erosion.

You would obviously be much better off in terms of barrel life, component availability (bullets especially) by just using a .223" Rem IMP or .22PPC with an 80gr Berger.

Now, put that same projectile in a 6mm or 6.5mm sabot and fire it out of a rifle length barrel, and you would get a sort of super enhanced 6.5 x25mm CBJ.

I guess you could use something like this on those up armored prairie dogs when they charge your shooting position.



http://airbornecombatengineer.typepa...5cbjcomp_2.jpg


http://www.gotavapen.se/gota/cbj/soap_proj1280.jpg



http://www.thefirearmblog.com/blog/w...000851-tfb.jpg

http://www.cbjtech.com/dokument/6.5x...%20gelatin.pdf

http://www.cbjtech.com/sida.asp?sida=3_7.62%20CBJ

Last edited by 17tbs; 01-21-2017 at 08:06 PM.
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38.2gr .172"

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