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

Neck Tension
Discussion regarding the reloading of ammunition and tuning of loads for accuracy
Go to page Previous  1, 2, 3, 4  Next
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition

View previous topic :: View next topic  
Author Message
chambered221
Super Member
Super Member


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

PostPosted: Sun Jan 13, 2013 10:26 am    Post subject: Re: Neck Tension Reply with quote

The spammer is more interesting perhaps !!! Poke

_________________
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
chambered221
Super Member
Super Member


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

PostPosted: Sun Jan 13, 2013 10:36 am    Post subject: Re: Neck Tension Reply with quote

Seriously now ......... I've read some articles about neck tension in the past that only reinforced the too many variables concept.

Some shoot better with press fit bullets, others prefer a looser fit.
The thing that has always confused me is the press fit. No matter how much you shrink the neck it is always opened back up to the bullet diameter. Yet... the amount of under sizing can/will make a difference.

_________________
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
slimjim
Super Member
Super Member


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

PostPosted: Sun Jan 13, 2013 11:05 am    Post subject: Re: Neck Tension Reply with quote

Vince wrote:
Be interested to see pics of the force scale mate, and how you set it up. I have always relied upon the standard neck sizer that comes with the dies.

I wonder what sort of difference there may be in velocity and POI on the target? Also, what effect this had on accuracy, if any.

Thanks for the interest, Vince.

Here is how I set-up to measure the force required to extract a seated bullet. Now that I see the picture, the scale is working off a lever so the force measured is not the force of extraction (neck tension) which should be higher.

This test is not dependent on what type of die a reloader uses. It only measures the force of extraction between a new and fired case which has been sized to the same neck dimension. If I size the necks smaller, this force will go up (noticeably for the fired brass). If I size the necks larger, the force will go down. At the current neck size (.302 bushing for a .270), I'm going slightly beyond the 50 pound limit of this scale.

I could do some testing just for fun to see what the affect is on group size and point of impact. From my experience, I believe it will be measurable but I'm sure its significance is at longer ranges. For now, I use fired, resized brass when the POI is important, e.g., hunting with shot opportunities beyond 100 yards.



measuring neck tension via bullet extraction.jpg
 Description:
 Filesize:  169.86 KB
 Viewed:  7218 Time(s)

measuring neck tension via bullet extraction.jpg


_________________
"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 Sun Jan 13, 2013 11:28 am; edited 1 time in total
Back to top
View user's profile Photo Gallery
slimjim
Super Member
Super Member


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

PostPosted: Sun Jan 13, 2013 11:12 am    Post subject: Re: Neck Tension Reply with quote

chambered221 wrote:
No matter how much you shrink the neck it is always opened back up to the bullet diameter. Yet... the amount of under sizing can/will make a difference.

There is some elasticity in the brass so that when the bullet is pulled, the neck diameter of the case contracts. After I pulled these bullets, I could not insert them back into the cases by hand. I still had to press them back in.

_________________
"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 Jan 14, 2013 12:57 am    Post subject: Re: Neck Tension Reply with quote

very nice set up thankyou for sharing that slim.

_________________
You shot it You pluck it !
Them who eats the most duck eats the most feathers!
Back to top
View user's profile
Vince
Site Admin
Site Admin


Joined: May 25, 2005
Posts: 15701
Location: Brisbane AUSTRALIA

PostPosted: Mon Jan 14, 2013 2:50 am    Post subject: Re: Neck Tension Reply with quote

Thanks Slim...a good repeatable exercise.

When I say I use the standard neck sizer, there will always be variations in the actual neck sizing button between manufacturers and even machines used to produce said button. But the setup you have there will negate those variations unless you are chopping and changing between die made by different manufacturers and then only data from each individual manufacturer would be considered repeatable. You wouldn't be able to compare them to each other with any real accuracy.

_________________
Cheers, Vince Cheers

Illegitimi non carborundum
(Never let the bastards grind you down)

Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God.

"Nulla Si Fa Senza Volonta."
(Without Commitment, Nothing Gets Done)
Back to top
View user's profile AIM Address MSN Messenger Yahoo Messenger Photo Gallery
slimjim
Super Member
Super Member


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

PostPosted: Mon Jan 14, 2013 7:46 am    Post subject: Re: Neck Tension Reply with quote

I could run a test with every component the same except new brass vs fired brass and measure the difference in POI and accuracy. It will give me something to do this summer.

_________________
"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
slimjim
Super Member
Super Member


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

PostPosted: Sat Apr 13, 2013 7:34 pm    Post subject: Re: Neck Tension Reply with quote

Well, I've tried several attempts to measure the effects of crimping on neck tension. I went out and got myself some Lee crimp dies. Using the crimp feature built into my Redding bullet seating dies is too finicky. If everything isn't perfect the crimps are inconsistent and I found could bulge the neck. The Lee crimping dies do not require a consistent case length to function. I did some tests with my six8 and .270 Win with the Lee equipment. I used 150gr Berger VLDs in both brass cases. The Lee crimping die is a collet that presses inward on the case and has enough leverage to deform the bullet with the crimp. I can't say I have learned anything definitive but I thought that I’d share what I have found and see what comments you might have. I used fired brass that was sized and ultrasonically cleaned so did not have any powder on the inside of the neck. The longer necks on the .270 did result in higher neck tension than the shorter neck of the six8. Note, there is a mechanical advantage with the press so the true force to extract is higher than what I recorded.

The average extraction force of the 8 bullets from the six8 was 9 pounds without a crimp (4) and 11.1 pounds with the crimp (4). Force was about 20% higher with the crimp but variation in force did not get signnificantly better with the crimp.

The force to extract the bullets from the .270 was higher but my first attempt caused nothing but confusion. I loaded 4 and crimped 2 of them with a heavy crimp. Force varied from 24 to 44 pounds with no correlation to the crimp. The crimp was strong enough to deform the bullet and leave a groove where the crimp occurred. So I loaded up 10 more and crimped 5 with a light crimp. The ones without a crimp averaged 32 pounds (22 to 43 lbs). The ones with a light crimp averaged 25.5 pounds (21 to 32). It made me think that the crimp may have been bulging out the neck below the crimp causing a reduction in overall neck tension. So I loaded and crimped 4 more with a heavier crimp. I got nice consistency out of the first three, 34 to 36 pounds, then the fourth one slipped out with only 12 pounds of force (lowest ever for the .270 and it had a crimp?). I’m not eager to run more cases through this drill without figuring out what is happening. Going forward, I will continue to crimp the six8 just because I did get a slightly higher force and that can’t hurt with an autoloader. For my bolt action .270 , I’m not going to crimp when I’m using grooved bullets like the Barnes TTSX and Hornady GMX. The grooves in these all-copper bullets do increase neck tension as the neck grips the grooves. The lead-core VLDs have been very consistent shooters without the crimp (1/2 MOA). I may continue working with the crimp on the legacy lead-core bullets just to learn more. Eager to hear your thoughts.

_________________
"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
Pumpkinslinger
Super Member
Super Member


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

PostPosted: Sun Apr 14, 2013 1:51 pm    Post subject: Re: Neck Tension Reply with quote

The last time my neck crimped the chiropractor was able to fix me right up!

Sorry about that.

Slim, good effort and info there!

_________________
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: Sun Apr 14, 2013 2:41 pm    Post subject: Re: Neck Tension Reply with quote

+1, but I go to physio..

_________________
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
slimjim
Super Member
Super Member


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

PostPosted: Sun Apr 14, 2013 2:58 pm    Post subject: Re: Neck Tension Reply with quote

Maybe I should visit a witch doctor. I was expecting more consistency in the results. It was disappointing that there wasn't a direct correlation to increased and more consistent neck tension when crimped.

_________________
"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
gelandangan
Super Member
Super Member


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

PostPosted: Sun Apr 14, 2013 3:43 pm    Post subject: Re: Neck Tension Reply with quote

Slim, the pressure exerted by the neck could be considered as minor as compared to the pressure subjected tot he whole system when the powders are combusted.
Although uniform neck grip does increase in the uniformity of the end velocity, it is but one of many elements that contributed to the cause.
In fact, in the old days when boolits are paper patched, the whole neck tension is the result of the fit of the paper to shim the gap between the neck and the boolit.
Yet there are historical records of amazing shots with them.

_________________
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
slimjim
Super Member
Super Member


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

PostPosted: Sat Apr 20, 2013 2:34 pm    Post subject: Re: Neck Tension Reply with quote

Was at the work bench fiddling around so took four .270 cases, sized them, seated bullets, crimped them, and pulled them. Average extraction force was 32.3 pounds with a std dev of 5. Then for grins and without touching the necks, I reloaded all four cases, did not crimp them, and pulled them again. I wanted to see how much the neck tension would be reduced after a bullet had been through the neck once. Do you want to take a guess what the average neck tension was? Come on guess.


32.1 pounds but the std deviation doubled to 10.

_________________
"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
slimjim
Super Member
Super Member


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

PostPosted: Sat Apr 20, 2013 2:47 pm    Post subject: Re: Neck Tension Reply with quote

All right, why not do this one more time. Seat bullets back into the untouched cases but crimp them this time. Results.

Extraction force dropped a little bit down to 29.1 (3rd time a bullet had been seated into the neck) but the std dev dropped back down to 6.

So far it looks like the .270 has about 3 times more neck tension than the 6.8 most likely due to the longer case neck and I use a 0.002" tighter neck bushing when I resize the case. It also appears the the std deviation is improved with the crimp but on the .270 it has enough neck tension that it doesn't really increase neck tension. Again these are with lead-core bullets. I would not crimp an all-copper bullet like Barnes.

_________________
"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
MacD
Super Member
Super Member


Joined: Apr 08, 2011
Posts: 1052
Location: Canada

PostPosted: Sat Apr 20, 2013 3:57 pm    Post subject: Re: Neck Tension Reply with quote

The variables that relate to brass are both within and outside of our control. The alloy itself will in part determine elasticity and resistance to work hardening. The annealing at the factory between the steps necessary to produce the finished case plays a part. The relative thickness of the case wall will affect neck tension. Finally the diameter of the bullets also may vary slightly. We live in an anolog world which we measure digitally. Thank the maker for variabilty. It makes it all interesting doesn't it.?

Try the same bullets in the same cases and see if extraction force decreases consistently. I am betting it won't.

_________________
La a'Blair s'math n Cairdean
(Friends are good on the day of battle)
Back to top
View user's profile
Display posts from previous:   
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition
Page 3 of 4
All times are GMT - 7 Hours
Go to page Previous  1, 2, 3, 4  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* :.