Saubier.com  



Go Back   Saubier.com > Saubier.com Forums > Bullet Making

Reply
 
Thread Tools Display Modes
  #1  
Old 01-11-2016, 08:03 PM
17tbs 17tbs is offline
Senior Member
 
Join Date: Oct 2007
Posts: 517
Default Super heavy .172" bore rider.

Has anyone tinkered with the idea of a super heavy .172"?

I copied one from a military ball ammunition example, in 4.6mm (.1815" ) using the Hornady 40gr fmj by turning it down to 4.3mm, or .172 with the front half of the bearing surface at .170".

It looks weird and I don't know if it will stabilize in a 1 in 9 at an estimated 2450fps from the original parent case converted to a .172"x30mm.

I just did it for grins. My 1 in 12 16".25" TC barrel in 223 is supposed to be incapable of stabilization of 69gr hpbt Sierras but it does it anyhow and ignored the calculation putting it at about .83 stab fact.

Last edited by 17tbs; 05-05-2016 at 04:09 AM.
Reply With Quote
  #2  
Old 01-11-2016, 08:04 PM
rickiesrevenge rickiesrevenge is offline
Senior Member
 
Join Date: Feb 2009
Posts: 1,632
Default

How long is it?

Aaron
Reply With Quote
  #3  
Old 01-11-2016, 08:12 PM
17tbs 17tbs is offline
Senior Member
 
Join Date: Oct 2007
Posts: 517
Default Long

Compared to the 30 grain Kindler gold its still a fair bit bigger in length. 17.9mm

Holy smoke, I just ran the jbm calculator for stability and it came out 1.087.... wheels are spinning... H-4198.... I ran 30grain Kindlers up to 2980fps on a very compressed load out of my longer barrel... and without any severe pressure indications.

EDIT: This bullet weighes in at 36.4gr, still giving a 1.036 stability factor according to the JBM stability calculator.

Last edited by 17tbs; 01-14-2016 at 08:50 PM.
Reply With Quote
  #4  
Old 01-12-2016, 09:26 AM
Chickenthief Chickenthief is offline
Senior Member
 
Join Date: Nov 2013
Location: Denmark
Posts: 537
Default

I'm by far an expert but is'nt the bore .168"?

The Berger 37gr (BC .331) was ,855" long and needs a 1:6.5 barrel to stabilise
Reply With Quote
  #5  
Old 01-12-2016, 03:30 PM
trotterlg trotterlg is offline
Senior Member
 
Join Date: Nov 2007
Posts: 3,108
Default

There must be some way to design an aero stabilized bullet. I am sure there must be some shape that will fly straight without spin. Larry
__________________
A gun is just like a parachute, if you really need one, nothing else will do.
Reply With Quote
  #6  
Old 01-12-2016, 04:49 PM
reed1911 reed1911 is offline
Board Sponsor
 
Join Date: Sep 2006
Location: OKC,OK
Posts: 737
Default

Depends on what you call straight.
__________________
Ron Reed
Reed's Ammunition & Research, LLC
www.reedsammo.com Main Page
http://shop.reedsammo.com Online store
info@reedsammo.com
Reply With Quote
  #7  
Old 01-12-2016, 06:46 PM
trotterlg trotterlg is offline
Senior Member
 
Join Date: Nov 2007
Posts: 3,108
Default

What I was referring to is a design that will keep the bullet flying one end forward without spin, an aerodynamically stable bullet. Then impart some spin to keep it straight, any spin rate would do. Larry
__________________
A gun is just like a parachute, if you really need one, nothing else will do.
Reply With Quote
  #8  
Old 01-12-2016, 09:31 PM
Mr Jacket Mr Jacket is offline
Junior Member
 
Join Date: Nov 2014
Location: Hudson Valley NY
Posts: 14
Default

I make a 37gr .172 bullet for my 1:71/4 twist 17-222.shoots very well.
Reply With Quote
  #9  
Old 01-12-2016, 11:19 PM
rickiesrevenge rickiesrevenge is offline
Senior Member
 
Join Date: Feb 2009
Posts: 1,632
Default

Whats the BC on your 37gr? Could you post a picture of it?

Aaron
Reply With Quote
  #10  
Old 01-13-2016, 02:41 AM
17tbs 17tbs is offline
Senior Member
 
Join Date: Oct 2007
Posts: 517
Default

Chickenthief,

Yes, the lands are typically 0.168" I don't know what mine is, I do know that my chamber throat was rather odd shaped with an incline from a .1730" to 0.1724" for the first 0.03" then a 1.5 leade angle from there onward. The effect is that I can seat the GSC banded 17 and 19 grain solids that mic at 0.1730 on the tops of the bands with groves cut at 0.1695" is right into the case and right into this tapered throat and therefore it's practically ensured of a straight start. At 0.170" the front half of my heavily modified 4.6 now floats way up into the area about half way between the 0.1724" end of the throat and where the tops of the lands are encountered, it pretty much kisses this whole transition area for about 0.05" .

It sort of just eases in on the lands since there is only 0.001" difference in each side, maybe even less since the calipers are not precise enough for a 0.00001" measurement.

Larry, yes there is a way to get it to fly straight, put some feletching on it.
Reply With Quote
Reply

Tags
38.2gr .172"

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 08:32 AM.


Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.