The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Reply
 
Thread Tools
Old June 20, 2000, 12:48 AM   #1
DAL
Senior Member
 
Join Date: October 15, 1999
Location: Colorado Springs, CO, USA
Posts: 653
I learned something new today, which most of you probably already knew.

I recently bought some new RP .30-06 brass, neck sized it (just to make all the mouths round), used my chamfer and deburring tool on it, and primed it. Then, as I began to charge the cases, that's when the surprise happened. I threw a 56.5 gr. charge of IMR 4350 into the new case and--lo and behold--the powder was all the way up to the very top of the case. I've used this charge in fired Federal brass before with no capacity problem, and it also fits in some once-fired RP brass I have.

Does new brass have that much smaller a capacity than fired brass? Apparently it does, or else the charge would have fit. This is the first new, unfired brass I've ever bought.
DAL

------------------
Reading "Capitalism: The Unknown Ideal," by Ayn Rand, should be required of every politician and in every high school.
GOA, JPFO, PPFC, CSSA, LP, NR

[This message has been edited by DAL (edited June 20, 2000).

[This message has been edited by DAL (edited June 20, 2000).]
DAL is offline  
Old June 20, 2000, 11:55 AM   #2
Nukem
Senior Member
 
Join Date: January 29, 2000
Posts: 709

Makes sense, the cases get blown out to chamber size. Try to cc both and compare.
Nukem is offline  
Old June 20, 2000, 03:02 PM   #3
DOCSpanky
Senior Member
 
Join Date: August 21, 1999
Location: Ashland City, TN
Posts: 779
Need definition of "RP", if its military brass, it makes sense, but I have never seen fire forming make that big of a difference.

------------------
I thought I'd seen it all, until a 22WMR spun a bunny 2 1/4 times in the air!
DOCSpanky is offline  
Old June 20, 2000, 03:45 PM   #4
Paul B.
Senior Member
 
Join Date: March 28, 1999
Location: Tucson, AZ
Posts: 2,669
DAL. Hinda makes me wonder if the case before the overfilled one had a full load of powder. Sometimes large grained powders like the 4831's, 4350's etc. bridge, and not all the powder gets dropped. Then the next load gets not only its charge, but the remainder of the previous charge. If you've already loaded the ammo up, check weigh each rfound. If one is light, it should show up when you weight it.
It pays to inspect the charged cases before bullet seating. I use a flashlight to insure I can see into the casings.
Paul B.
Paul B. is offline  
Old June 20, 2000, 04:51 PM   #5
Mal H
Staff
 
Join Date: March 20, 1999
Location: Somewhere in the woods of Northern Virginia
Posts: 14,548
I think there is a fundamental problem here and it isn't the case capacity. DAL, did you triple check the calibration of your scale?

I just filled 3 different 30-06 cases (Win., Fed. and L-C) with I4350 and all 3 took a consistent 65.0 grains. That's a big difference from 56.5 gr. If several of you would try this we might be able to figure out what's wrong - instead of putting in a weighed amount, fill any available 30-06 case to the top and then weigh it. I'll bet it's near 65 grains. If DAL's weighs a lot less, we have the problem.
Mal H is offline  
Old June 21, 2000, 01:38 AM   #6
DAL
Senior Member
 
Join Date: October 15, 1999
Location: Colorado Springs, CO, USA
Posts: 653
I recalibrated my Pact scale twice tonight and then I tried the charge again. This time, I noticed the charge in the RP case (Remington-Peters) was lower in the case,
about a quarter inch or so down from the top, whereas the powder level in the Federal case was, as usual, down to the bottom of the neck.

Maybe it's not that big a deal, but I'm a little concerned that the powder charge will be compressed in the RP cases when I seat my bullets (165 gr., Speer, BTSP).

Mal H, when filled to the brim, my Federal case holds 62.8 grains of IMR 4350. Hmmm...
DA

------------------
Reading "Capitalism: The Unknown Ideal," by Ayn Rand, should be required of every politician and in every high school.
GOA, JPFO, PPFC, CSSA, LP, NRA
DAL is offline  
Old June 21, 2000, 02:02 PM   #7
Mal H
Staff
 
Join Date: March 20, 1999
Location: Somewhere in the woods of Northern Virginia
Posts: 14,548
Doesn't anybody else have some IMR 4350 and an empty 30-06 casing besides DAL and me? We're trying to help out a fellow reloader.

You can use any '06 based case for this experiment. I tried a 25-06 and a .270 and still got powder weights above 64 grains.

DAL, if your Pact is battery powered, did you change the battery? (Please forgive me for asking, but you never know.)
Mal H is offline  
Old June 21, 2000, 05:33 PM   #8
DAL
Senior Member
 
Join Date: October 15, 1999
Location: Colorado Springs, CO, USA
Posts: 653
Mal H, no problem asking questions which may seem obvious; often, that's where many solutions are found. In this case, however, I am not using a battery, but an AC adapter, so I don't think that's the problem.

If you're consistently getting 65.0 grains of IMR 4350 in your case, and I am getting <63.0 grains, I wonder where the difference is coming from. I thought it might be my scale, but I weighed a few 165 grain bullets and they were all within a couple of tenths of 165.

Will compressing a powder charge in the RP case cause any problems? I know that the Speer manual lists some other loads as compressed, so I'm wondering if it will be okay in this instance. If nothing else, I suppose I could drop back down to 54.0 grains of IMR 4350 and shoot that to expand the cases, but that seems like a waste of components, especially since the accuracy of that load (my starting load) stinks.
DA

------------------
Reading "Capitalism: The Unknown Ideal," by Ayn Rand, should be required of every politician and in every high school.
GOA, JPFO, PPFC, CSSA, LP, NRA
DAL is offline  
Old June 21, 2000, 05:46 PM   #9
Mal H
Staff
 
Join Date: March 20, 1999
Location: Somewhere in the woods of Northern Virginia
Posts: 14,548
Compressing a charge is often a good thing to do as long the max is not exceeded. It will usually give you more consistent results. But the amount you might be compressing is what worries me. The manuals show compressed loads of 59 to 60 grains depending on the bullet weight. But if you are compressing 63 to 65 grains thinking it is <= 60 grains, then we (you) have a problem.

I was trying to get someone to help out because we need 3 data points to find an answer to the puzzle. But I guess no one has any I4350 or time.
Mal H is offline  
Old June 21, 2000, 08:12 PM   #10
beemerb
Junior member
 
Join Date: October 2, 1999
Location: AZ
Posts: 1,759
Case is a R-P with IMR 4350 useing a dillon digital scale.I get 59.9 grs
Hope it helps.
Sounds like this might be a case difference problem.The case I used I don't think has been fired.I pulled a slug out of it.I know my scale is on.
------------------
beemerb
We have a criminal jury system which is superior to any in the world;
and its efficiency is only marred by the difficulty of finding twelve men
every day who don't know anything and can't read.
-Mark Twain

[This message has been edited by beemerb (edited June 21, 2000).]
beemerb is offline  
Old June 21, 2000, 09:17 PM   #11
Mal H
Staff
 
Join Date: March 20, 1999
Location: Somewhere in the woods of Northern Virginia
Posts: 14,548
OK, now we're getting somewhere. And I'm even more confused. If beemerb filled a case all the way to the top including the neck and gets 59.9 grains of I4350 and I get 64.0 grains, then I have no idea which is correct. I would have expected maybe a grain or 2 difference at most. BTW, I checked the weight with both an electronic scale and a balance scale and they were equal. ???
Mal H is offline  
Old June 21, 2000, 10:17 PM   #12
beemerb
Junior member
 
Join Date: October 2, 1999
Location: AZ
Posts: 1,759
Use water as a case filler.It takes the guess out of it.Fill to mouth and weigh.Ok this what I got
case full of water-268 gr
just water-64.9 gr
volume of water-4 cc
case empty-199.9 gr
Useing water is an old method of finding case capacity.hope this helps solve the mystery.
this is with the R-P case

------------------
beemerb
We have a criminal jury system which is superior to any in the world;
and its efficiency is only marred by the difficulty of finding twelve men
every day who don't know anything and can't read.
-Mark Twain

[This message has been edited by beemerb (edited June 21, 2000).]
beemerb is offline  
Old June 22, 2000, 02:28 PM   #13
beemerb
Junior member
 
Join Date: October 2, 1999
Location: AZ
Posts: 1,759
Just got 3 more cases and this is what I found.
empty weight
R-P-205.6gr
Military-205.6
super X-186.2.
These weights makes me believe that the R&P brass is mil spec.Mil spec has a smaller case capacity and you decrease powder by 10%.I think I would go with that.

------------------
beemerb
We have a criminal jury system which is superior to any in the world;
and its efficiency is only marred by the difficulty of finding twelve men
every day who don't know anything and can't read.
-Mark Twain
beemerb is offline  
Old June 22, 2000, 03:01 PM   #14
Mal H
Staff
 
Join Date: March 20, 1999
Location: Somewhere in the woods of Northern Virginia
Posts: 14,548
Here are the case weights and their water capacity for the 3 different cases I have:

Fed.
empty case = 204.9 gr.
water weight = 68.7

Win.
empty case = 192.0 gr.
water weight = 68.8 gr.

L-C (mil)
empty case = 197.2 gr.
water weight = 68.6 gr.

The capacity differences between the 3 cases are statistically insignificant. I guess we just need to leave it as an unsolved puzzle.

To paraphrase the old carpenters rule: "Measure twice, explode never."
Mal H is offline  
Old June 22, 2000, 05:29 PM   #15
DAL
Senior Member
 
Join Date: October 15, 1999
Location: Colorado Springs, CO, USA
Posts: 653
Thanks, guys, for all of your help. I'm not sure what conclusion we reached here, but just to be on the safe side, I think I'll load a few RP cases about 5-10% under what I use in the Federal cases and see how things turn out. I'm really interested to see if, after firing, the capacity of the RP brass will increase to match the Federal cases.
DAL

------------------
Reading "Capitalism: The Unknown Ideal," by Ayn Rand, should be required of every politician and in every high school.
GOA, JPFO, PPFC, CSSA, LP, NRA
DAL is offline  
Old June 22, 2000, 05:29 PM   #16
beemerb
Junior member
 
Join Date: October 2, 1999
Location: AZ
Posts: 1,759
Mal H;I think so.I am out of ideas.I think just treat it as a mil case and drop charges by 10%

------------------
beemerb
We have a criminal jury system which is superior to any in the world;
and its efficiency is only marred by the difficulty of finding twelve men
every day who don't know anything and can't read.
-Mark Twain
beemerb is offline  
Old June 22, 2000, 06:27 PM   #17
HankL
Senior Member
 
Join Date: March 11, 1999
Location: The Sunny South
Posts: 2,174
Beemerb got it "R-P-205.6gr
Military-205.6"
While Remington rifle brass is not necessarly MilSpec it is most always heavier than the other commercial brass. Heavier case with same outside dimensions equals less internal capacity. This is why most reloading manuals advise to load military brass to different levels than commercial brass. This is also why when changing any component in a load you should back up to mid levels and work it up again.
HTH
HankL is offline  
Reply

Thread Tools

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 -5. The time now is 04:18 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2014 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.10332 seconds with 7 queries