Another noobie with a question.

graham82 · June 3, 2007, 03:30 PM

I'm hooked. I started visiting this forum late last year and you guys are a great source of info. Thanks to this forum I have already puchased and read manuals, equipment, componets, and reloaded and shot my first reloads safely. Reloading your own is great!

Here is my question. Everything I read says to full length resize all rifle cases for semi-auto's. Why can't I just neck size a fireformed case if it is going to be used in the same rifle?

mrawesome22 · June 3, 2007, 04:22 PM

You can but it is not advised. Full length sizing is recommended for auto's to increase reliablity. Full length sized feed better since the tolerance between chamber and brass is not nearly as tight.

Art Eatman · June 3, 2007, 07:48 PM

A semi-auto doesn't have as much force to seat the cartridge into the chamber; it lacks the camming force of a bolt-action. If the case is a bit tight (enlarged) from the previous firing, the semi-auto can fail to lock into battery.

Assuring reliability is a major reason for "small base" dies.

Art

steve4102 · June 3, 2007, 11:20 PM

When a round is fired in a bolt gun the brass expands to fit the chamber and then springs back a bit for easy extraction. Things are a little different in an auto-loader. After the round is fired it can still be under a bit of pressure when it is extracted. This can cause the "head to shoulder" measurement to be greater than the chamber it was fired in. Brass that is too long/fat to fit easily into the chamber can cause problems like jambing and "out of battery" fire.
FL your semi-autos for reliability and safety.

Shoney · June 4, 2007, 10:55 AM

Just to add one step further to the excellent comments by Art Eatman and steve4102, consider that unburned powder grains may loadge in the chamber, or that under adverse and/or battle conditons, grit can find it's way into chambers and onto cartridges. Zero tollerance ammo in the chamber will cause problems of jambing, failure to fire out of battery, and out of battery firing.

For reliability, FL resize.

mc223 · June 5, 2007, 11:03 PM

zap

crowbeaner · June 6, 2007, 01:59 PM

I use a SB die to size my brass for my 742 in 3006. The loaded round has to sit on the bottom of the chamber to be able to obturate properly in the chamber and extract. I also stick to medium powders to avoid extraction problems.

graham82 · June 8, 2007, 04:07 PM

Thanks for all the great answers.

CrustyFN · June 8, 2007, 08:00 PM

graham82, congratulations on your equipment and your first reloads. There is nothing like the feeling of shooting your own reloads for the first time. Welcome to reloading and load safe.
Rusty

June 3, 2007, 03:30 PM	#1
graham82 Member Join Date: January 31, 2007 Location: Southside VA Posts: 35	Another noobie with a question. I'm hooked. I started visiting this forum late last year and you guys are a great source of info. Thanks to this forum I have already puchased and read manuals, equipment, componets, and reloaded and shot my first reloads safely. Reloading your own is great! Here is my question. Everything I read says to full length resize all rifle cases for semi-auto's. Why can't I just neck size a fireformed case if it is going to be used in the same rifle?

June 4, 2007, 10:55 AM	#5
Shoney Senior Member Join Date: February 21, 2002 Location: Transplanted from Montana Posts: 2,311	Just to add one step further to the excellent comments by Art Eatman and steve4102, consider that unburned powder grains may loadge in the chamber, or that under adverse and/or battle conditons, grit can find it's way into chambers and onto cartridges. Zero tollerance ammo in the chamber will cause problems of jambing, failure to fire out of battery, and out of battery firing. For reliability, FL resize. __________________ I pledge allegiance to the Flag - - -, and to the Republic for which it stands….Our Forefathers were brilliant for giving us a Republic, not a democracy! Do you know the difference??? and WHY?http://www.wallbuilders.com/LIBissue...les.asp?id=111

June 5, 2007, 11:03 PM	#6
mc223 Senior Member Join Date: January 20, 2007 Location: n/w Wisconsin Posts: 365	zap Last edited by mc223; June 6, 2007 at 05:59 AM.

June 8, 2007, 08:00 PM	#9
CrustyFN Senior Member Join Date: June 4, 2006 Location: West Virginia Posts: 2,258	graham82, congratulations on your equipment and your first reloads. There is nothing like the feeling of shooting your own reloads for the first time. Welcome to reloading and load safe. Rusty __________________ I don't ever remember being absent minded.

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June 3, 2007, 04:22 PM	#2
mrawesome22 Senior Member Join Date: November 9, 2005 Location: Ohio, Appalachia's foothills. Posts: 3,779	You can but it is not advised. Full length sizing is recommended for auto's to increase reliablity. Full length sized feed better since the tolerance between chamber and brass is not nearly as tight.

June 3, 2007, 07:48 PM	#3
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	A semi-auto doesn't have as much force to seat the cartridge into the chamber; it lacks the camming force of a bolt-action. If the case is a bit tight (enlarged) from the previous firing, the semi-auto can fail to lock into battery. Assuring reliability is a major reason for "small base" dies. Art

June 3, 2007, 11:20 PM	#4
steve4102 Senior Member Join Date: December 23, 2005 Location: Minnesota Posts: 2,952	When a round is fired in a bolt gun the brass expands to fit the chamber and then springs back a bit for easy extraction. Things are a little different in an auto-loader. After the round is fired it can still be under a bit of pressure when it is extracted. This can cause the "head to shoulder" measurement to be greater than the chamber it was fired in. Brass that is too long/fat to fit easily into the chamber can cause problems like jambing and "out of battery" fire. FL your semi-autos for reliability and safety.

June 6, 2007, 01:59 PM	#7
crowbeaner Senior Member Join Date: June 4, 2007 Location: Upstate SC Posts: 1,943	I use a SB die to size my brass for my 742 in 3006. The loaded round has to sit on the bottom of the chamber to be able to obturate properly in the chamber and extract. I also stick to medium powders to avoid extraction problems.

June 8, 2007, 04:07 PM	#8
graham82 Member Join Date: January 31, 2007 Location: Southside VA Posts: 35	Thanks for all the great answers.