HuntingNut
HuntingNut
   Login or Register
HomeCommunity ForumsPhoto AlbumsRegister
     
 

User Info

Welcome Anonymous


Membership:
Latest: etmci
New Today: 0
New Yesterday: 0
Overall: 12859

People Online:
Members: 0
Visitors: 372
BOT: 2
Total: 374
Who Is Where:
 Visitors:
01: Forums
02: Forums
03: Forums
04: Forums
05: Forums
06: Forums
07: Forums
08: Forums
09: Forums
10: Forums
11: Forums
12: Forums
13: Forums
14: Home
15: Forums
16: Forums
17: Forums
18: Forums
19: Home
20: Forums
21: Forums
22: Home
23: Home
24: Forums
25: Forums
26: Forums
27: Forums
28: Forums
29: Forums
30: Home
31: Forums
32: Forums
33: Forums
34: Forums
35: Forums
36: Forums
37: Forums
38: Forums
39: Forums
40: Forums
41: Forums
42: Forums
43: Forums
44: Forums
45: Forums
46: Home
47: Forums
48: Forums
49: Home
50: Forums
51: Forums
52: Forums
53: Home
54: Forums
55: Forums
56: Forums
57: Your Account
58: Forums
59: Forums
60: Photo Albums
61: Forums
62: Forums
63: Photo Albums
64: Forums
65: Forums
66: Forums
67: Forums
68: Forums
69: Home
70: Forums
71: Home
72: Your Account
73: Forums
74: Your Account
75: Forums
76: Forums
77: Forums
78: Forums
79: Forums
80: Forums
81: Home
82: Home
83: Forums
84: Home
85: Photo Albums
86: Home
87: Forums
88: Forums
89: Forums
90: Forums
91: Forums
92: Forums
93: Forums
94: Forums
95: Forums
96: Forums
97: Photo Albums
98: Home
99: Forums
100: Forums
101: Home
102: Forums
103: Forums
104: Forums
105: Forums
106: Home
107: Forums
108: Home
109: Forums
110: Forums
111: Forums
112: Home
113: Home
114: Forums
115: Your Account
116: Forums
117: Forums
118: Forums
119: Forums
120: Forums
121: Forums
122: Home
123: Forums
124: Forums
125: Home
126: Photo Albums
127: Forums
128: Forums
129: Home
130: Forums
131: Home
132: Forums
133: Home
134: Forums
135: Forums
136: Home
137: Forums
138: Forums
139: Forums
140: Forums
141: Home
142: Forums
143: Your Account
144: Home
145: Forums
146: Forums
147: Home
148: Home
149: Forums
150: Forums
151: Forums
152: Forums
153: Home
154: Forums
155: Forums
156: Forums
157: Forums
158: Forums
159: Forums
160: Forums
161: Home
162: Forums
163: Home
164: Forums
165: Forums
166: Forums
167: Photo Albums
168: Forums
169: Forums
170: Forums
171: Photo Albums
172: Home
173: Forums
174: Forums
175: Home
176: Forums
177: Forums
178: Statistics
179: Forums
180: Statistics
181: Forums
182: Forums
183: Home
184: Forums
185: Forums
186: Forums
187: Forums
188: Forums
189: Forums
190: Forums
191: Forums
192: Forums
193: Forums
194: Forums
195: Forums
196: Home
197: Forums
198: Forums
199: Forums
200: Forums
201: Forums
202: Forums
203: Forums
204: Forums
205: Photo Albums
206: Forums
207: Forums
208: Forums
209: Forums
210: Forums
211: Forums
212: Forums
213: Forums
214: Home
215: Forums
216: Forums
217: Forums
218: Forums
219: Forums
220: Your Account
221: Home
222: Forums
223: Home
224: Forums
225: Forums
226: Forums
227: Forums
228: Forums
229: Forums
230: Forums
231: Forums
232: Forums
233: Forums
234: Forums
235: Forums
236: Forums
237: Forums
238: Forums
239: Home
240: Forums
241: Home
242: Your Account
243: Forums
244: Your Account
245: Forums
246: Forums
247: Forums
248: Contact
249: Forums
250: Home
251: Forums
252: Home
253: Forums
254: Home
255: Forums
256: Forums
257: Forums
258: Forums
259: Forums
260: Forums
261: Forums
262: Home
263: Forums
264: Your Account
265: Forums
266: Home
267: Forums
268: Home
269: Forums
270: Home
271: Your Account
272: Forums
273: Home
274: Home
275: Home
276: Photo Albums
277: Forums
278: Forums
279: Forums
280: Statistics
281: Forums
282: Forums
283: Forums
284: Home
285: Forums
286: Forums
287: Forums
288: Forums
289: Forums
290: Forums
291: Forums
292: Home
293: Forums
294: Forums
295: Forums
296: Statistics
297: Forums
298: Your Account
299: Forums
300: Forums
301: Forums
302: Home
303: Forums
304: Forums
305: Forums
306: Forums
307: Forums
308: Forums
309: Home
310: Forums
311: Forums
312: Forums
313: Forums
314: Home
315: Photo Albums
316: Forums
317: Forums
318: Forums
319: Forums
320: Forums
321: Forums
322: Forums
323: Forums
324: Home
325: Home
326: Forums
327: Forums
328: Forums
329: Forums
330: Forums
331: Forums
332: Photo Albums
333: Forums
334: Forums
335: Forums
336: Forums
337: Forums
338: Forums
339: Forums
340: Forums
341: Home
342: Forums
343: Forums
344: Forums
345: Forums
346: Home
347: Home
348: Forums
349: Photo Albums
350: Forums
351: Forums
352: Forums
353: Home
354: Home
355: Forums
356: Forums
357: Home
358: Forums
359: Forums
360: Home
361: Forums
362: Forums
363: Forums
364: Forums
365: Home
366: Forums
367: Your Account
368: Home
369: Forums
370: Forums
371: Photo Albums
372: Forums
  BOT:
01: Forums
02: Forums

Staff Online:

No staff members are online!
 

Coppermine Stats
Photo Albums
 Albums: 307
 Pictures: 2397
  · Views: 717753
  · Votes: 1313
  · Comments: 86
 

PSI VS CUP apples and oranges?
Discussion regarding the reloading of ammunition and tuning of loads for accuracy
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition

View previous topic :: View next topic  
Author Message
bodyalter
Member
Member


Joined: Jan 10, 2007
Posts: 87
Location: Central Minnesota

PostPosted: Wed Feb 28, 2007 6:52 am    Post subject: PSI VS CUP apples and oranges? Reply with quote

so I'm looking through my 7-08 reloading manual and I'm faced with trying to compare pressure/recoil with these two different measurements. are they that different or is there a formula to convert one to the other?

_________________
There are only 10 types of people in the world, Those who understand binary and those who don't
Back to top
View user's profile MSN Messenger
Morax
Super Member
Super Member


Joined: Dec 18, 2006
Posts: 618
Location: Pittsburgh Pa

PostPosted: Wed Feb 28, 2007 7:04 am    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

give this a try
www.shootingsoftware.c...ticle2.pdf
Back to top
View user's profile
bodyalter
Member
Member


Joined: Jan 10, 2007
Posts: 87
Location: Central Minnesota

PostPosted: Wed Feb 28, 2007 8:33 am    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

thanks a lot morax. very good read even.

_________________
There are only 10 types of people in the world, Those who understand binary and those who don't
Back to top
View user's profile MSN Messenger
PaulS
Super Member
Super Member


Joined: Feb 18, 2006
Posts: 4108
Location: South-Eastern Washington - the State

PostPosted: Thu Mar 01, 2007 1:35 am    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

There is no correlation between CUP ans PSI because of the way that the two readings are taken and the sensitivity of each method.
The pressure piston method that is used to find CUP has a threshhold of several thousand pounds before anything registers. The longer it holds a pressure the more it deforms the copper "crusher". it measures a pressure over time - not peak, average or anyother kind just some amount of pressure and some period of time. It was used for years but when the pressure curve method was used, things changed.
The PSI instrument is a pressure transducer. The thing that makes it work is that when you put pressure on a crystal it produces a voltage. when you double the pressure you get 4 times the voltage. This method could not be used until computers got fast enough to measure the changes of the voltage in very short amounts of time. Once calibrated and hooked to a fast computer you can measure changes in pounds per square inch at a resolution of PSI/u seconds (1/ 1000000 of a second).
What that means is that as soon as you have 1 psi you get a reading and you continue to have a reading that is constantly changing all the way up to 1000000psi. Now you can read not only peak pressure, average pressure but you can also plot the actual time each pressure is exherted on the chamber. You get a curve that accurately defines the exact pressures over time. (exact means that you are within 0.5% of the maximum pressure recorded or 325 psi of 65000psi maximum)
Two very different loads can produce the same CUP reading and very different pressure curves in PSI.
You could get the same CUP reading with a 222 cartridge running a fast powder as you could with a 45-70 and a slow powder.
222 with a fast powder peaks very high pressure but holds it for a very short time while the 45-70 produces less pressure but holds it for a long time. The CUP might show both at a calibrated 30000 CUP but the PSI method would show that the 222 went to 60000 for .000004 seconds and the 45-70 only reached 25000 max but held it for .001 second. they both exerted enough force to squish the copper crusher to the same size but with very different real time pressure curves.
That is why there is no correlation between the two systems. if you want to see the real world facts send me an email at:
paulstephens2(AT)comcast(DOT)net
and ask me for the SAAMI pressures for rifles and pistols. I will send you a word document that list both pressures for the rounds that have been tested in both systems and then you can try to figure any correlation between one load that is 20000CUP and 45000 psi and two loads that have the same CUP and very different psi (one high the other low).
I'd be happy to share the files.

_________________
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
twofifty
Member
Member


Joined: Feb 07, 2007
Posts: 158
Location: BC Rockies

PostPosted: Thu Mar 01, 2007 11:11 pm    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

Morax wrote:
give this a try
www.shootingsoftware.c...ticle2.pdf

I agree with bodyalter - a good easy read and a great intro to statistical methods and plotting. Makes sense too. But then so does what PaulS has posted.
Back to top
View user's profile
bodyalter
Member
Member


Joined: Jan 10, 2007
Posts: 87
Location: Central Minnesota

PostPosted: Fri Mar 02, 2007 7:22 am    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

it would be nice if all the reloading manuals picked one of these methods and just used it.

_________________
There are only 10 types of people in the world, Those who understand binary and those who don't
Back to top
View user's profile MSN Messenger
SwampFox
Super Member
Super Member


Joined: Jul 15, 2005
Posts: 1040
Location: Destin, Florida

PostPosted: Fri Mar 02, 2007 8:57 am    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

Now there you go again with wishing for common sense.....
Ed

_________________
The inherent vice of capitalism is the unequal sharing of the blessings. The inherent blessing of socialism is the equal sharing of misery.
-Winston Churchill
Back to top
View user's profile Photo Gallery
Bushmaster
Super Member
Super Member


Joined: Jun 12, 2005
Posts: 11012
Location: Ava, Missouri

PostPosted: Fri Mar 02, 2007 10:14 am    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

If we had "common sense" in reloading, where would the fun be? And the challenge...Where would the challenge be? With "common sense" we wouldn't need these forums either...Just where would the fun be... Very Happy

_________________
I have one nerve left and yer standin' on it...

DEMOCRACY Two wolves and one sheep voting on what to have for lunch...
LIBERTY A well armed sheep contesting the outcome of the vote...
Back to top
View user's profile
Morax
Super Member
Super Member


Joined: Dec 18, 2006
Posts: 618
Location: Pittsburgh Pa

PostPosted: Fri Mar 02, 2007 12:08 pm    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

bushy i use these forums for common sense i hit you guys up for your thoughts and ideas and to double double check my thinking so thats common sense to me!! but like you said pertaining to the reloading aspect, if we didnt have two trains of thought we wouldnt have someone out there saying ok well i can do this better, reloading for me is not all about accuracy, its a nessisary evil.. and i read what Paul had wrote and it does go a long way with the aspect of time versus pressures, but the only thing i have a question on is pressure at "X" for the time "Y" dont matter when too much of either goes boom in your face!! other than that I agree
Back to top
View user's profile
Bushmaster
Super Member
Super Member


Joined: Jun 12, 2005
Posts: 11012
Location: Ava, Missouri

PostPosted: Fri Mar 02, 2007 12:11 pm    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

No arguement from me...And we do have an asset in PaulS...

_________________
I have one nerve left and yer standin' on it...

DEMOCRACY Two wolves and one sheep voting on what to have for lunch...
LIBERTY A well armed sheep contesting the outcome of the vote...
Back to top
View user's profile
bodyalter
Member
Member


Joined: Jan 10, 2007
Posts: 87
Location: Central Minnesota

PostPosted: Sun Mar 04, 2007 4:05 am    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

yes we do and I want to thank you PaulS for relating what the measurements mean before I went through my books converting everything. you more than likely saved me valuable time better used reloading

_________________
There are only 10 types of people in the world, Those who understand binary and those who don't
Back to top
View user's profile MSN Messenger
PaulS
Super Member
Super Member


Joined: Feb 18, 2006
Posts: 4108
Location: South-Eastern Washington - the State

PostPosted: Sat Mar 24, 2007 2:55 am    Post subject: Re: PSI VS CUP apples and oranges? Reply with quote

Been off for a while - duty called.
Thanks for your votes of confidence. If I had my way we would be using the PSI method because it tells you more about what is reaaly going on in the gun. It would be a lot harder to get a dangerous round into your gun. I have a hard time understanding why Hodgdon is staying with the older CUP method when it is so obvious that the PSI method is so much better.
PaulS

_________________
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
Display posts from previous:   
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition
Page 1 of 1
All times are GMT - 7 Hours



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* :.