HuntingNut
HuntingNut
   Login or Register
HomeCommunity ForumsPhoto AlbumsRegister
     
 

User Info

Welcome Anonymous


Membership:
Latest: RichardZ
New Today: 0
New Yesterday: 1
Overall: 13126

People Online:
Members: 0
Visitors: 337
BOT: 1
Total: 338
Who Is Where:
 Visitors:
01: Forums
02: Home
03: Forums
04: Forums
05: Forums
06: Forums
07: Forums
08: Forums
09: Your Account
10: Forums
11: Home
12: Forums
13: Forums
14: Forums
15: Your Account
16: Forums
17: Forums
18: Forums
19: Forums
20: Forums
21: Forums
22: Home
23: Your Account
24: Forums
25: Forums
26: Forums
27: Photo Albums
28: Forums
29: Forums
30: Forums
31: Forums
32: Forums
33: Home
34: Forums
35: Home
36: Forums
37: Forums
38: Forums
39: Forums
40: Forums
41: Forums
42: Forums
43: Photo Albums
44: Your Account
45: Home
46: Forums
47: Forums
48: Home
49: Your Account
50: Forums
51: Forums
52: Forums
53: Your Account
54: Your Account
55: Forums
56: Your Account
57: Forums
58: Forums
59: Your Account
60: Forums
61: Forums
62: Home
63: Forums
64: Photo Albums
65: Forums
66: Forums
67: Forums
68: Forums
69: Your Account
70: Home
71: Forums
72: Forums
73: Your Account
74: Forums
75: Photo Albums
76: Forums
77: Forums
78: Your Account
79: Forums
80: Forums
81: Photo Albums
82: Forums
83: Forums
84: Your Account
85: Forums
86: Your Account
87: Forums
88: Forums
89: Photo Albums
90: Photo Albums
91: Forums
92: Home
93: Your Account
94: Forums
95: Forums
96: Forums
97: Home
98: Forums
99: Photo Albums
100: Photo Albums
101: Forums
102: Forums
103: Forums
104: Photo Albums
105: Forums
106: Forums
107: Forums
108: Forums
109: Forums
110: Forums
111: Your Account
112: Forums
113: Your Account
114: Forums
115: Forums
116: Your Account
117: Forums
118: Forums
119: Forums
120: Forums
121: Your Account
122: Home
123: Forums
124: Forums
125: Forums
126: Forums
127: Your Account
128: Forums
129: Forums
130: Forums
131: Forums
132: Home
133: Your Account
134: Home
135: Forums
136: Forums
137: Forums
138: Forums
139: Forums
140: Forums
141: Forums
142: Forums
143: Home
144: Home
145: Your Account
146: Your Account
147: Forums
148: Forums
149: Forums
150: Forums
151: Your Account
152: Forums
153: Forums
154: Photo Albums
155: Your Account
156: Forums
157: Forums
158: Your Account
159: Home
160: Your Account
161: Your Account
162: Your Account
163: Forums
164: Your Account
165: Forums
166: Forums
167: Forums
168: Home
169: Forums
170: Photo Albums
171: Forums
172: Forums
173: Forums
174: Forums
175: Forums
176: Home
177: Your Account
178: Your Account
179: Forums
180: Home
181: Forums
182: Forums
183: Forums
184: Photo Albums
185: Forums
186: Forums
187: Photo Albums
188: Forums
189: Forums
190: Home
191: Forums
192: Photo Albums
193: Forums
194: Your Account
195: Forums
196: Forums
197: Forums
198: Forums
199: Photo Albums
200: Forums
201: Your Account
202: Forums
203: Forums
204: Forums
205: Photo Albums
206: Your Account
207: Forums
208: Your Account
209: Forums
210: Forums
211: Forums
212: Statistics
213: Forums
214: Forums
215: Forums
216: Forums
217: Forums
218: Forums
219: Forums
220: Forums
221: Your Account
222: Forums
223: Home
224: Your Account
225: Forums
226: Photo Albums
227: Forums
228: Photo Albums
229: Forums
230: Home
231: Forums
232: Forums
233: Photo Albums
234: Forums
235: Photo Albums
236: Forums
237: Forums
238: Forums
239: Forums
240: Forums
241: Forums
242: Forums
243: Your Account
244: Forums
245: Forums
246: Forums
247: Forums
248: Forums
249: Forums
250: Photo Albums
251: Home
252: Forums
253: Photo Albums
254: Forums
255: Photo Albums
256: Your Account
257: Forums
258: Forums
259: Forums
260: Forums
261: Forums
262: Forums
263: Forums
264: Photo Albums
265: Forums
266: Forums
267: Forums
268: Forums
269: Forums
270: Forums
271: Home
272: Forums
273: Photo Albums
274: Home
275: Your Account
276: Forums
277: Your Account
278: Forums
279: Forums
280: Forums
281: Forums
282: Forums
283: Photo Albums
284: Photo Albums
285: Forums
286: Your Account
287: Forums
288: Forums
289: Forums
290: Forums
291: Your Account
292: Your Account
293: Forums
294: Statistics
295: Forums
296: Forums
297: Forums
298: Forums
299: Forums
300: Forums
301: Forums
302: Photo Albums
303: Home
304: Forums
305: Home
306: Forums
307: Your Account
308: Your Account
309: Forums
310: Forums
311: Forums
312: Home
313: Forums
314: Forums
315: Forums
316: Forums
317: Forums
318: Forums
319: Forums
320: Home
321: Forums
322: Forums
323: Forums
324: Forums
325: Statistics
326: Home
327: Forums
328: Forums
329: Forums
330: Your Account
331: Photo Albums
332: Forums
333: Forums
334: Forums
335: Home
336: Forums
337: Forums
  BOT:
01: Home

Staff Online:

No staff members are online!
 

Coppermine Stats
Photo Albums
 Albums: 308
 Pictures: 2451
  · Views: 820723
  · Votes: 1316
  · Comments: 86
 

Ballistic Stabilty Calculator
Discussion regarding the reloading of ammunition and tuning of loads for accuracy
Go to page 1, 2  Next
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition

View previous topic :: View next topic  
Author Message
Ominivision1
Super Member
Super Member


Joined: Sep 20, 2010
Posts: 2984
Location: Iowa

PostPosted: Mon Jun 20, 2011 10:41 am    Post subject: Ballistic Stabilty Calculator Reply with quote

Getting ready to do some reloading for the /06 and was doing some checking at manufacturers web sites and noticed quite a difference on the bullets I have been using (good price) which are the Remington 150gr psp. What caught my attention at Noslers web site was the bullet length for their offering, was at 1.280" vs what I was loading with the Remington at 1.075".

Now thats .205" difference. So I fired up the ballistic stability calculator and ran my loads through it and sure enough, it appears that the Remington bullet is over stabilized and the Nosler is in the ballpark. Has any one else used this calculator before you made your bullet purchase?

The gun is a M700 and always shot 2 1/2" to 3" groups at 150 yards with them Remington 150gr bullets. Since I had bought 700 of these bullets I never gave it a thought to shop around until my supply ran low.



3006-nosler-spitzer.png
 Description:
 Filesize:  57.74 KB
 Viewed:  11944 Time(s)

3006-nosler-spitzer.png


3006-rem-psp.png
 Description:
 Filesize:  58.25 KB
 Viewed:  11944 Time(s)

3006-rem-psp.png


_________________
Regards

Limitations are but boundaries created inside our minds.
Back to top
View user's profile Photo Gallery
gelandangan
Super Member
Super Member


Joined: May 07, 2006
Posts: 6396
Location: Sydney Australia

PostPosted: Mon Jun 20, 2011 2:59 pm    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

Thats one of the time where I reckon changing muzzle velocity would make difference.
Vary the muzzle velocity and you can tune the stability factor.
Although I admit the differences might be very difficult to nullify, it might be a possible outcome.

Shorter projectiles requires less spin to stabilize.
And spin is a function of barrel twist and velocity.
You cannot change barrel twist unless you change barrel, so that left you with velocity to play with.

I reckon lowering your velocity will bring you better stabilization for shorter projectiles.

_________________
A straight line is the shortest distance between two points.
A smile is the shortest distance between two people.

Do - Not try!


gelandangan.weebly.com/
Back to top
View user's profile Visit poster's website
PaulS
Super Member
Super Member


Joined: Feb 18, 2006
Posts: 4330
Location: South-Eastern Washington - the State

PostPosted: Mon Jun 20, 2011 5:53 pm    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

As far as my experience goes you have to go way short to make the bullet "over-stabilized". I shoot 158 grain JHC from a 358 Win. with 10 " twist - to average groups of .33" at 100 yards at 2700 fps.

That is not overstabilized in my book but it should shoot best from a 18 twist according to the tables.

In my 30-06 I have successfully fired 110 gr HP all the way to 200 grain RN with a 10 twist. All shoot under MOA.

_________________
Paul
__________________
Speer, Lyman, Hodgdon, Sierra, and Hornady = reliable loading data
So and So's pages on the internet = NOT reliable loading data
Always check data against manuals
NEVER exceed maximum listed loads
Back to top
View user's profile Send e-mail
slimjim
Super Member
Super Member


Joined: May 16, 2009
Posts: 8314
Location: Fort Worth TX

PostPosted: Mon Jun 20, 2011 8:30 pm    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

I looked at your numbers and scratched my head as the SF seems abnormally high for a 150gr .308 bullet. I ran it through Don Miller's stability equation and got 3.1 SF. You might check some other stability formulas for comparison.

bulletin.accurateshoot...stability/

I agree with PaulS. I don't think you have a real problem. If your spin rate was too high, the lead-core bullet could self distruct but you are not at that point. You may find your loads with lower SF might be more accurate.

You can find some interesting information on bullets and stability at GS Custom bullets. They recommend SF greater than 1.5 in some hunting situations.

gscustom.co.za/

_________________
"To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt

"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein
Back to top
View user's profile Photo Gallery
Elvis
Super Member
Super Member


Joined: Jul 27, 2008
Posts: 9239
Location: south island New Zealand

PostPosted: Mon Jun 20, 2011 10:30 pm    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

Omni get ahold of some sample pack projectiles they are not too expensive and you get to play around with different options without being stuck with 675 projectiles your gun doesnt like.
what sort of group do you get with factory loads???
the only loads Ive ever used in my .270 that grouped like that were hornady 110grn fbhps at around 3000fps. good for wallabies if you hit em they dropped very explosive so maybe going too fast.
Ive loaded 06 for a buddy using 125grn taipans and they group ok.
the best thing about those sample packs is being able to get top line projectiles at a small cost.

_________________
You shot it You pluck it !
Them who eats the most duck eats the most feathers!
Back to top
View user's profile
Ominivision1
Super Member
Super Member


Joined: Sep 20, 2010
Posts: 2984
Location: Iowa

PostPosted: Mon Jun 20, 2011 11:46 pm    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

This rifle does not shoot to bad, its just that I stumbled across these figures and was a astonished when running the numbers through the calculator.

gelandangan: yup, when working up different loads with this bullet, I found out the best accuracy is at 200-250fps slower then published factory loads.

Paul: When loading for 180gr nosler spitzer, my groups are .50 at 150 yards. when loaded to 2650fps which are better than the 150gr. I just ordered the 165gr and see how it groups compared to the 150gr.

Elvis: this gun has never seen a factory load, I did order 100 of 165gr and will do some load developing with these noslers and see what happens.

Slim: yup, they have a couple of different calculators out there and with the miller formula, the values are much lower which is good.

_________________
Regards

Limitations are but boundaries created inside our minds.
Back to top
View user's profile Photo Gallery
Elvis
Super Member
Super Member


Joined: Jul 27, 2008
Posts: 9239
Location: south island New Zealand

PostPosted: Tue Jun 21, 2011 1:39 am    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

that 180grn load sounds great Omni you could be on to something with bullet length etc being the key to making her shoot. if your 165s arent flash keep trying you will find the magic bullet forsure.

_________________
You shot it You pluck it !
Them who eats the most duck eats the most feathers!
Back to top
View user's profile
slimjim
Super Member
Super Member


Joined: May 16, 2009
Posts: 8314
Location: Fort Worth TX

PostPosted: Tue Jun 21, 2011 2:55 am    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

Its common to find production .30-cal rifles with twist rates of 1:10, 1:11, and 1:12. When looking at bullet stability across those twist rates, I was surprised how much of a stability factor a .30-06 or .308 has with even a 1:12 twist using today's common hunting bullets, e.g., 130, 150, 165, and 180gr. Also, how much more stability a .30-06 has compared to a .270 with a 1:10 twist. The .30-06 with a 1:10 twist has a stability factor of 1.3 with 240gr Sierra Match Kings (1.591") on a cold day, 0 deg F. My .270 doesn't have that high of a stability factor with some of my 130gr bullets.

BTW, below is a reference website for bullet length.

www.jbmballistics.com/...gths.shtml

_________________
"To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt

"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein


Last edited by slimjim on Tue Jun 21, 2011 6:05 am; edited 1 time in total
Back to top
View user's profile Photo Gallery
Ominivision1
Super Member
Super Member


Joined: Sep 20, 2010
Posts: 2984
Location: Iowa

PostPosted: Tue Jun 21, 2011 3:25 am    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

Yup, that jmballistics site is pretty good, I submitted specs for some barnes and nosler bullets to him last fall. Hopefully with people helping him out with the specs, he can get his database completed.

_________________
Regards

Limitations are but boundaries created inside our minds.
Back to top
View user's profile Photo Gallery
chambered221
Super Member
Super Member


Joined: Aug 17, 2007
Posts: 3455
Location: Lost for good !!!

PostPosted: Tue Jun 21, 2011 9:10 am    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

I wouldn't let them figures keep you from using 150gr bullets if that's all you want or need !!!

The group size your getting is more about the bullet your using.........not stability factors.

_________________
Ask as many people needed, sooner or later your question will be answered the way you want it answered !!!

A free people ought not only to be armed and disciplined, but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government.
~George Washington
Back to top
View user's profile Photo Gallery
Ominivision1
Super Member
Super Member


Joined: Sep 20, 2010
Posts: 2984
Location: Iowa

PostPosted: Tue Jun 21, 2011 10:22 am    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

I agree Chambered, I have also loaded up 125gr Nosler spitzer and even then the formulas tell me the bullet is over stabilized. But yet I take these loads to the range with imr4831 with 57grs and its a tack driver with this load. I can put groups at 1" at 100 yards doing my part.

Like I said in an earlier post, the 180gr nosler will do better then the 150gr rem bullets and so will the 125gr nosler bullets. As soon as the new bullets get here, I will load them up and get back here with a post and pictures. And like Slim said earlier that some of the calculations showed the .270 with the 130gr had less stability then a 30/06 with a 240gr bullet. Shocked

I also own a .270 and it has always been a tack driver with the 130gr loads, sometimes what they come up with on these calculators is very different then reality.

_________________
Regards

Limitations are but boundaries created inside our minds.
Back to top
View user's profile Photo Gallery
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Tue Jun 21, 2011 1:22 pm    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

I think we've discussed this before and I don't think you can "overstabilize" a rifle bullet. This would only be a problem with artillery fired at a high angle. I pick a bullet based on two factors; terminal performance and accuracy.

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
Elvis
Super Member
Super Member


Joined: Jul 27, 2008
Posts: 9239
Location: south island New Zealand

PostPosted: Tue Jun 21, 2011 1:50 pm    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

pumpkinslinger Im sure you are right on the overstablilize thing its been thrashed before. If I get the theory correct overstablilize would be when it spins too fast and the structural integraty is comprimized. (hows that for a sentence of wheelbarrow words!!!) If you round things off abit for ease of calculations a projectile doing 3000fps fired through 1 in 12 rifling is rotating 3000 times per secound which is 180,000 rpm. so its no wonder we run into issues at times.

_________________
You shot it You pluck it !
Them who eats the most duck eats the most feathers!
Back to top
View user's profile
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Tue Jun 21, 2011 6:13 pm    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

Elvis, "over stabilized" and spinning a bullet so fast that it comes apart are obviously both related to the rotational speed, which is a product of the muzzle velocity and barrel twist rate, but they are different issues. Lets say we take two different .224" 45 grain bullets, one a light jacketed varmint bullet and the other a solid copper, and fired both in a .22-250 with a 1-in-9" twist. They would both be pretty equally "over stabilized" according to the "stability factor". The solid bullet would stay together though, while the thin skinned varmint bullet would likely come apart when it exits the muzzle.

Sorry, I'm trying not to beat a dead horse but I learned long ago that you have to really understand a problem before you can come up with a real solution. Over the years I've seen a lot of "gun shop gossip" muddy the waters when talking about the technical aspects of shooting, and I've fallen victim to it myself only to discover later that what I was told was the result of misinterpretation or just a mistake. I guess I get carried away trying to make sure that everyone in a discussion is on the same page.

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
gelandangan
Super Member
Super Member


Joined: May 07, 2006
Posts: 6396
Location: Sydney Australia

PostPosted: Tue Jun 21, 2011 9:40 pm    Post subject: Re: Ballistic Stabilty Calculator Reply with quote

Mike,
IMO over stabilization also applies IF you are shooting for a particular purpose.

For example, as you may know over the years, that I like to shoot 30 cal projectiles at subsonic MV for hunting.
Usually for a 30 cal at subsonic, there is not enough energy to deform the projectile on impact.
As one of the main purpose of projectile deformation is to transfer energy by enlarging surface area of the impact site,
shooting at subsonic cannot tap into this.
Instead subsonics shooters are trying to just unbalance the projectile enough to TUMBLE on impact,
thus in a way creating the same effect as deformation, that is enlarging the impact surface area.

Here is where the stabilization applies.
If the projectile is spun at too high velocity, they would simply cruise through the flesh
and creating a very tiny (usually not even 30 cal) wound channel, thus not suitable for hunting.
The shooter with these particular need, would need to just stabilize the projectile to promote tumbling rather than punching.

Thus, as above, over stabilization applies for subsonics hunting.

_________________
A straight line is the shortest distance between two points.
A smile is the shortest distance between two people.

Do - Not try!


gelandangan.weebly.com/
Back to top
View user's profile Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition
Page 1 of 2
All times are GMT - 7 Hours
Go to page 1, 2  Next



Jump to:  


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Valid CSS! Valid HTML 4.01!
Click to check if this page is realy HTML 4.01 compliant for speed :)

All logos and trademarks in this site are property of HuntingNut.com.
The comments are property of their posters, all the rest © 2011 by HuntingNut.com
Interactive software released under GNU GPL, Code Credits, Privacy Policy

.: Upgraded to DragonFly 9.2 by *Dizfunkshunal* :.