HuntingNut » Forums » Firearms, Shooting & Reloading » Reloading Ammunition » Confusion with OAL gage
HuntingNut
HuntingNut
   Login or Register
HomeCommunity ForumsPhoto AlbumsRegister
     
 

User Info

Welcome Anonymous


Membership:
Latest: sandcrash
New Today: 0
New Yesterday: 0
Overall: 12582

People Online:
Members: 0
Visitors: 144
BOT: 1
Total: 145
Who Is Where:
 Visitors:
01: Forums
02: Forums
03: Forums
04: Forums
05: Forums
06: Your Account
07: Your Account
08: Your Account
09: Your Account
10: Forums
11: Forums
12: Your Account
13: Your Account
14: Your Account
15: Forums
16: Forums
17: Your Account
18: Your Account
19: Forums
20: Forums
21: Your Account
22: Home
23: Your Account
24: Forums
25: Forums
26: Forums
27: Forums
28: Your Account
29: Your Account
30: Your Account
31: Your Account
32: Your Account
33: Your Account
34: Forums
35: Forums
36: Your Account
37: Forums
38: Home
39: Forums
40: Your Account
41: Forums
42: Forums
43: Your Account
44: Forums
45: Forums
46: Your Account
47: Forums
48: Your Account
49: Forums
50: Your Account
51: Forums
52: Forums
53: Your Account
54: Home
55: Home
56: Forums
57: Your Account
58: Forums
59: Your Account
60: Your Account
61: Your Account
62: Forums
63: Your Account
64: Forums
65: Forums
66: Forums
67: Your Account
68: Forums
69: Your Account
70: Forums
71: Your Account
72: Your Account
73: Forums
74: Forums
75: Forums
76: Your Account
77: Forums
78: Forums
79: Forums
80: Forums
81: Forums
82: Your Account
83: Your Account
84: Forums
85: Forums
86: Forums
87: Your Account
88: Forums
89: Your Account
90: Forums
91: Forums
92: Your Account
93: Your Account
94: Forums
95: Forums
96: Forums
97: Forums
98: Forums
99: Your Account
100: Your Account
101: Forums
102: Forums
103: Forums
104: Your Account
105: Forums
106: Forums
107: Your Account
108: Home
109: Forums
110: Your Account
111: Forums
112: Your Account
113: Forums
114: Forums
115: Forums
116: Forums
117: Forums
118: Forums
119: Forums
120: Your Account
121: Forums
122: Your Account
123: Home
124: Forums
125: Forums
126: Your Account
127: Forums
128: Forums
129: Forums
130: Your Account
131: Forums
132: Your Account
133: Forums
134: Your Account
135: Forums
136: Forums
137: Forums
138: Forums
139: Forums
140: Forums
141: Your Account
142: Your Account
143: Your Account
144: News
  BOT:
01: Forums

Staff Online:

No staff members are online!
 

Coppermine Stats
Photo Albums
 Albums: 305
 Pictures: 2358
  · Views: 372215
  · Votes: 1307
  · Comments: 85
 

Support our Advertisers

Confusion with OAL gage
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
dakota1
Member
Member


Joined: Aug 09, 2007
Posts: 37
Location: Mesa, Arizona

PostPosted: Sat Jan 26, 2008 8:32 am    Post subject: Confusion with OAL gage Reply with quote

Gun: is a Rem 700 BDL .270 Win
Measuring device: Stoney Point, compariter (sp), .270 ogive insert, digital caliper
Bullets: Speer 130 gr BTSP and Sierra 130 gr BTSP

When I measure the OAL length of the two bullets, in the stoney point gage, I get a difference of .037.
When I measure the length of the bullets alone, I get a difference of .0046.

Since the only variable in the measurement is the bullet, shouldn't the difference in the stoney point gage measurement be the same as the difference when measuring the bullets alone, when measuring, using the same caliper, comparitor and insert?

When measuring with the stoney point gage, I measured 10 different bullets of each manufacturer, threw out the high and the low, and averaged the remaining 8.
When measuring the bullets alone, I measured 5 different bullets of each manufacturer, and averaged the total.

What am I missing?
Back to top
View user's profile AIM Address
Deleted_User_2665
Super Member
Super Member


Joined: May 06, 2006
Posts: 380

PostPosted: Sat Jan 26, 2008 9:34 am    Post subject: Re: Confusion with OAL gage Reply with quote

A lot of time shooting.......................................
Back to top
View user's profile
ElyBoy
Super Member
Super Member


Joined: Apr 04, 2006
Posts: 1541
Location: Forest Lake Minnesota

PostPosted: Sat Jan 26, 2008 10:13 am    Post subject: Re: Confusion with OAL gage Reply with quote

Try weighing the bullets on your powder scale dakota.
That should tell the story.
I will bet that there is a difference.
I too check things like you do, and when I see disparities, I try my best to find out what causes them.
It makes a difference when you do go shooting.
As an example, I purchased some .41Mag Starline brass from Midway, and noticed at the range that the same reload using Starline brass compared to using Winchester brass seemed "hotter" with my Ruger Blackhawk 4 5/8" barreled pistol.

After using the caliper, weighing them etc., I found that the cases were a about .001" thicker on the Starline than the Winchester brass.
I dropped the powder charge by 1gr, and came up with a more accurate and easier load, with the same velocity.

Keep up the good work checking your bullets.
It keeps things safer, and like I said, the results will show at the range, and in the woods.

Eric

_________________
NRA Certified Chief Range Safety Officer
NRA Certified Pistol Instructor
DNR Certified Firearms Safety Instructor
NRA Life Member
Back to top
View user's profile
chambered221
Super Member
Super Member


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

PostPosted: Sat Jan 26, 2008 1:42 pm    Post subject: Re: Confusion with OAL gage Reply with quote

dakota1

wildswalker is right, your missing alot of time shooting, nothing wrong with haveing a better understanding of things though.

What you are seeing is common. Bullets are made in a die that forms them. That die wears over time. Most bullet manufactors will run a number of dies into the same production run. When they are packaged you end up with a box of bullets made off different dies. Therefor you get different ogive readings.[bullet comparitors read off the ogive]
Also keep in mind your seating die seats off the ogive. If ogive varies on the bullets, your OAL of a loaded cartridge will also vary.

As far as the OAL of the bullets themselves, hollow points have always varied. Benchrest shooters use a meplat trimmer to uniform them to the same lenght. Lead tips vary also, not as much from my measurements.
Plastic tipped bullets seem to be the most uniform.

Unless your match shooting don't worry to much about it. Its not one of those things that will shave a whole lot off of group size, if any.

_________________
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: Sat Jan 26, 2008 1:49 pm    Post subject: Re: Confusion with OAL gage Reply with quote

Just reread your post, I think I missed what you was asking!!!!!!!!!!!!!!!!!!!! Embarassed

I hate when that happens!!!!!!!!!!!!!!!!!!!!!!!!! Mad

_________________
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
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 4469
Location: NC foothills

PostPosted: Sat Jan 26, 2008 5:47 pm    Post subject: Re: Confusion with OAL gage Reply with quote

If I'm reading this right (remember, I work night shift and am rarely 100% awake...) Different brand bullets have different shapes. If you are measuring to the point where the bullet is the same diamter as the lands I would expect them to be different.

I measured a Speer .224 40 grain SP and compared to a Sierra .224 40 grain SP using a dial caliper and a Sinclair comparator.

OAL Comparator
Speer 0.505 0.266
Sierra 0.491 0.214

Difference 0.014 0.052

Now, if I've misread this question please excuse me for muddying the water!

_________________
Mike

"I ain't no better than anyone else, and there ain't no one better than me!" Ma Kettle

Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
ElyBoy
Super Member
Super Member


Joined: Apr 04, 2006
Posts: 1541
Location: Forest Lake Minnesota

PostPosted: Sat Jan 26, 2008 6:29 pm    Post subject: Re: Confusion with OAL gage Reply with quote

A guy can't figure that thinking take time away from shooting.
That is a pretty non-sensical statement.

For me, half the fun of shooting, is in my reloading room reloading, and trying to figure out how things either work of don't work.

Eric

_________________
NRA Certified Chief Range Safety Officer
NRA Certified Pistol Instructor
DNR Certified Firearms Safety Instructor
NRA Life Member
Back to top
View user's profile
Dawgdad
Super Member
Super Member


Joined: Feb 08, 2006
Posts: 1055
Location: On the Prairie

PostPosted: Sat Jan 26, 2008 7:06 pm    Post subject: Re: Confusion with OAL gage Reply with quote

Dakota1,

Your readings are perfectly normal. I see this much variation in Hornady match HBPT .224, 75 grain bullets. The .005 variation from Ogive to tip is within the machine tolerance of most manufacturers bullet making presses. If you us a caliper to measure COAL from case head to tip of bullet and set the ones that are the same OAL aside, you will see this .005" variation with your comparitor on the same set of loads that were very tight with previous measurement. As was stated in an earlier post as long as that is the max variation you probably will not shoot good enough to see the difference. In the service rifle 600 yard stage where x counts make the difference between winning and losing it matters that the jump from Ogive to rifling is the same every time.

Most seating dies have a Donut shaped seating stem that will hit the ogive of most all except the very long A- max VLD type bullets. Once you set a die to give the proper Ogive - OAL it is counter productive to measure OAL to tip anymore. Unless you do not have a comparitor then you must.

_________________
Alcohol, Tobacco and Firearms should be a convenience store, not a government agency...
Back to top
View user's profile Photo Gallery
dakota1
Member
Member


Joined: Aug 09, 2007
Posts: 37
Location: Mesa, Arizona

PostPosted: Sat Jan 26, 2008 8:11 pm    Post subject: Re: Confusion with OAL gage Reply with quote

Both measurements, COAL, and length of the bullets themselves, was done with a comparator and ogive insert. The tip of the bullet did not come into play. The COAL difference between two bullets was .037, yet the difference between the bullets themselves was only .0046.

Since all results were measured from the ogive, and the bullets being the only variable, why wouldn't the difference between the COAL be the same as the difference between the bullets alone?
Back to top
View user's profile AIM Address
Deleted_User_2665
Super Member
Super Member


Joined: May 06, 2006
Posts: 380

PostPosted: Sat Jan 26, 2008 9:04 pm    Post subject: Re: Confusion with OAL gage Reply with quote

I tend not to pizz up ropes nor fret things beyond my control, and can control bullet sameness via sourcing a known quality.......

The question is, how do they shoot....and that alone can answer many what if's/if then's.

Seat for mag box function and rock on........................
Back to top
View user's profile
woods
Member
Member


Joined: Oct 15, 2005
Posts: 89

PostPosted: Sat Jan 26, 2008 10:25 pm    Post subject: Re: Confusion with OAL gage Reply with quote

dakota1 wrote:
Both measurements, COAL, and length of the bullets themselves, was done with a comparator and ogive insert. The tip of the bullet did not come into play. The COAL difference between two bullets was .037, yet the difference between the bullets themselves was only .0046.

Since all results were measured from the ogive, and the bullets being the only variable, why wouldn't the difference between the COAL be the same as the difference between the bullets alone?

The difference could be that on one hand you are measuring from the ogive to the base of the bullet and then when measuring the COAL you are measuring from the ogive to the base of the case.

A comparator does not measure where the bullet is full diameter. For instance on a .308" bullet the comparator may measure where the bullet is only .293". There can be a variance in the curve of the ogive from where the comparator hits it to where it first measures full diameter. If the ogive curve is the same between those 2 points on different bullets then you should get the same measurement for seating depth.

However, as long as you are getting the same measurements on the same type of bullets then you are OK and need to go with it.

At times the Stoney Point can be very frustrating. Mad

That is why I also use a stainless rod from R-P Products (318-424-7867).



You insert the rod down the muzzle to the bolt face and lock the outside collet



then use the stoney point to insert the bullet and hold while you set the inside collet to the bullet tip. Then measure between the collets.



This will give you the COAL for that particular bullet. It is simpler than the Stoney Point and fool proof which helps me out. Then take the bullet out and measure with the comparator. Do that on 3 more bullets and you can get real close.

_________________
Guns only have 2 enemies, rust and politicians
Back to top
View user's profile
Vince
Super Member
Super Member


Joined: May 25, 2005
Posts: 13521
Location: Brisbane AUSTRALIA

PostPosted: Sat Jan 26, 2008 11:51 pm    Post subject: Re: Confusion with OAL gage Reply with quote

wildswalker wrote:
A lot of time shooting.......................................

I tend not to pizz up ropes nor fret things beyond my control, and can control bullet sameness via sourcing a known quality.......

The question is, how do they shoot....and that alone can answer many what if's/if then's.

Seat for mag box function and rock on........................

Gidday Wildman...how are you and the kids mate?

You had me a bit confused with your first post mate...but your second one has. I think, sorted me out.

Correct me if I am wrong, but is what you are saying...."the differences you have identified don't mean squat...get out, do some shooting and its the end result in the field that means something"?

Cheers, Vince

_________________
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
Deleted_User_2665
Super Member
Super Member


Joined: May 06, 2006
Posts: 380

PostPosted: Sun Jan 27, 2008 7:12 am    Post subject: Re: Confusion with OAL gage Reply with quote

We're humped up with winter and a fair bit of Lake Effect, temps are in the teens down to zero, colder at night........

The kids, as always, are chompin' at the bit to yank on steelheads and burn powder. The Boy told me last night he was gonna slay some cottontails today for supper tonight......

I owe 'em a winter survival weekend...but we're waitin' for colder temps to make things a tad more sporty.


Spent primers alone, can determine what makes a difference or not......

Much voodoo can be conjured up to complicate the process and many thrive on that willingly.

I'd rather just shoot 1/2 MOA or better out there a fer piece, and, can/do that less complicating things for myself.....

Find your lands, know you mag box max COAL, seat for unihibited function and rock on.....

Bad bullets with fugged up weights/ogive dimensions don't get much attention, nor get bought twice again, here.

On a side, never saw that bother me 'nuff to worry about it either...

Ain't hard...............................
Back to top
View user's profile
Vince
Super Member
Super Member


Joined: May 25, 2005
Posts: 13521
Location: Brisbane AUSTRALIA

PostPosted: Sun Jan 27, 2008 7:37 am    Post subject: Re: Confusion with OAL gage Reply with quote

wildswalker wrote:
We're humped up with winter and a fair bit of Lake Effect, temps are in the teens down to zero, colder at night........

The kids, as always, are chompin' at the bit to yank on steelheads and burn powder. The Boy told me last night he was gonna slay some cottontails today for supper tonight......

I owe 'em a winter survival weekend...but we're waitin' for colder temps to make things a tad more sporty.

I'd rather just shoot 1/2 MOA or better out there a fer piece, and, can/do that less complicating things for myself.....

Find your lands, know you mag box max COAL, seat for unihibited function and rock on.....

Bad bullets with fugged up weights/ogive dimensions don't get much attention, nor get bought twice again, here.

Ain't hard...............................

I'd rather just shoot 1/2 MOA or better out there a fer piece That makes a lot of sense to me, as does Find your lands, know you mag box max COAL, seat for unihibited function and rock on. This is basically the way I work out my loads. I select a starting load, use factory specs for OAL, confirm that the rounds fit the magazine then start shooting. Onlt thing I don't do is seat the bullet just off the lands.

Same same with bullets that don't deliver the goods...they simply do not get bought again.

Single hole groups, and fractions of MOA are fine, however all I am seeking is acceptable accuracy for hunting out to a maximum of around 300 metres...and even that is extending beyond what I would realistically shoot. As you say...its the shooting that shows the viability of a load, regardless of what has been done prior to pulling the trigger.

Having said that...there is a place for all the "mumbo jumbo"...Bench Rest, Long Range (600 metres +) target shooting or similar shooting disciplines.

make things a tad more sporty....Ohhhh, you're a hard man
Very Happy Laughing
When you say survival, what sort of things do you teach the kids?

Fishing is a great way to relax...I love it. Only problem I have is I never catch anything...all I ever seem to do is fatten the fish up with my bait for the next guy to catch. Laughing Did you get your "underground mutton" (aussie slang for rabbit) for supper? Nothing better than a nice rabbit stew/casserole or marinated rabbit back strap pan fried. mmmmm

Cheers, Vince

_________________
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
Deleted_User_2665
Super Member
Super Member


Joined: May 06, 2006
Posts: 380

PostPosted: Sun Jan 27, 2008 8:28 am    Post subject: Re: Confusion with OAL gage Reply with quote

I tweak powder charge first, then seating depth second....have never found that to fail me.

Single hole groups interest me none, unless they can be repeated all months of the year.

1/2 MOA at 100 yards is neat to look at on paper, but a 2 1/2 inch group at 500 or 600 yards is hard to argue with when fired out of a light weight or standard weight hunting rifle MPAJ, or off backpack/bipods/bipods + backpack......

I don't play the benchrest game with my hunting rigs, nor own an OAL gauge/comparitor. I am however, guilty of finding lands with a black marker..........

Dakota's BDL 700 in 270 win. is no doubt a long throated bastid anyway, mine was. Seating for mag box confines rules out kissing lands and it can be said many Critters have died over the ages with the 700/.270/130 Speer/Sierra combo less any worry over a few thousandths of bullet dimension.

Loading OCW busts a lot of myths.......

Yankin' on steelheads leaves little room for relaxation as it's an exercise in hand to hand combat with a dose of cold water survival throwed in......despite that, it remains my favorite type of fishing.

The Boy is sleeping in this Sunday morning and have never seen that hold him up. Would expect him to get around soon tho' and grab a rifle. We've an 18" base with a light snow falling now. Good tracking weather and the cottontails will be easy to spot in the underbrush....

The kids teach me................................
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 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


Advertisements
 


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 :.