rcbs small base die question

poker2112 · August 30, 2007, 12:01 AM

im resizing my 223 brass in small base dies........then trimming all brass to 1.755.....do i really need a case gage to check oal of the brass ........its under the recomended size......or will i be fine? thanks !

fourrobert13 · August 30, 2007, 01:12 AM

Length wise you are fine. But the case guage will tell you if it will fit in the chamber of your rifle. You could make a dummy round and check this also, but the case guage IMO is a better tool. Just becuase the length is correct doesn't mean it will chamber. I tried it without a guage, and just going off the directions, but never did get it right until I got a Dillon case guage. $20 saved me a bunch of dummy rounds trying to get it right. Just my 2 cents.

**Unclenick** · August 30, 2007, 10:09 AM

You would need a special gage for cases resized in a small base die. They will already be smaller than a standard resized case, so a standard case gage will just tell you they all fit. It would be a waste of money, for that reason.

The purpose for using a small base die is to ensure feeding reliability from a magazine. Some autoloaders don't function reliably with cases sized in a standard die, but unless you have actually experienced feed failures with cases sized in a standard die I would not be using a small base die. The small base die works the brass more, which reduces the number of reloads you get between case failures. That can be a reliability issue in itself if you don't track and limit your reload count pretty religiously.

Walkalong · August 30, 2007, 05:58 PM

A case gauge is cheap and will not only let you know if your reloads will feed, but also if you have pushed the shoulder back too far. Good cheap insurance.

Slamfire · August 31, 2007, 01:40 PM

Quote:

do i really need a case gage to check oal of the brass

Yes, absolutely you need a case gage.

The set up instructions given with sizing dies assume a lot of things. And seldom following the instructions do you ever get the brass sized to the correct length. If possible you would like to set back the case shoulder about .003” from the fully expanded condition it comes out from the rifle. In no case do you ever want to size it more than .006” as you are likely to get a case head separation on the next firing. Sometimes following the instructions that come with the sizing die you will not be able to even set the shoulder back enough to avoid a crush fit in the rifle chamber. In a few instances I have had to grind material off the bottom of a sizing die to get it to set the case shoulder back enough. Just take the instructions that the factory sends with their dies, and toss out the part that tells you to size to the shellholder. Or shellholder plus a ¼ turn. You will find that such guidance is inaccurate at best, rubbish on the average.

You will also find, when you use case gages, how little error you have in setting up your sizing dies. If you are off by a quarter rotation on the die, you may have sized from maximum to below minimum.

This web site is really useful for showing how to use case gages. I recommend looking at the pictures, and it explains the special case gages needed for the belted cartridges.

http://www.realguns.com/Commentary/comar46.htm

As for the issue of small base dies. I would use them in all calibers if I could. It increases interchangeability of ammunition, improves function.

Quote:

The small base die works the brass more, which reduces the number of reloads you get between case failures.

I hate to disagree, but I have not found that to be the case with my ammunition. I took LC brass either 22 or 24 reloads in a M1a, used small base dies, what limits case life is brass flaws, primer pockets opening, or case neck splits. Case head separations occur if you oversize your brass. I think the most reloads I have on .223 brass is just over ten. Small base sized, only problem I am having is expanded primer pockets. (Federal brass, case head is soft)

However most of my rifles have standard SAAMI chambers, only have a couple of oversized military chambers. I usually shoot berdan in those, busting rocks.

poker2112 · August 31, 2007, 02:52 PM

thanks guys made a few dummy rounds, loaded up the mag, pulled the charging handle ,first one cycled fine but the extractor didnt spit up the first round,............then i loaded some other ammo and it cycled fine all three rounds .............so i guess i need a case gage thanks !!!!!!!

Bullet94 · August 31, 2007, 03:59 PM

I don’t use a small base die for my AR’s but I do check the headspace with one of these –

http://www.midwayusa.com/eproductpag...756&t=11082005

August 30, 2007, 12:01 AM	#1
poker2112 Member Join Date: September 24, 2006 Posts: 62	rcbs small base die question im resizing my 223 brass in small base dies........then trimming all brass to 1.755.....do i really need a case gage to check oal of the brass ........its under the recomended size......or will i be fine? thanks !

August 30, 2007, 01:12 AM	#2
fourrobert13 Senior Member Join Date: November 28, 2005 Location: South West Ohio Posts: 336	Length wise you are fine. But the case guage will tell you if it will fit in the chamber of your rifle. You could make a dummy round and check this also, but the case guage IMO is a better tool. Just becuase the length is correct doesn't mean it will chamber. I tried it without a guage, and just going off the directions, but never did get it right until I got a Dillon case guage. $20 saved me a bunch of dummy rounds trying to get it right. Just my 2 cents. __________________ Be aware of yourself and everything around you.

August 30, 2007, 10:09 AM	#3
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	You would need a special gage for cases resized in a small base die. They will already be smaller than a standard resized case, so a standard case gage will just tell you they all fit. It would be a waste of money, for that reason. The purpose for using a small base die is to ensure feeding reliability from a magazine. Some autoloaders don't function reliably with cases sized in a standard die, but unless you have actually experienced feed failures with cases sized in a standard die I would not be using a small base die. The small base die works the brass more, which reduces the number of reloads you get between case failures. That can be a reliability issue in itself if you don't track and limit your reload count pretty religiously. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

August 31, 2007, 03:59 PM	#7
Bullet94 Senior Member Join Date: September 8, 2004 Location: Kansas Posts: 723	I don’t use a small base die for my AR’s but I do check the headspace with one of these – http://www.midwayusa.com/eproductpag...756&t=11082005 __________________ PRO-SECOND AMENDMENT - Live Free or Die

August 30, 2007, 05:58 PM	#4
Walkalong Senior Member Join Date: May 30, 2007 Location: Al. Posts: 196	A case gauge is cheap and will not only let you know if your reloads will feed, but also if you have pushed the shoulder back too far. Good cheap insurance.

August 31, 2007, 02:52 PM	#6
poker2112 Member Join Date: September 24, 2006 Posts: 62	thanks guys made a few dummy rounds, loaded up the mag, pulled the charging handle ,first one cycled fine but the extractor didnt spit up the first round,............then i loaded some other ammo and it cycled fine all three rounds .............so i guess i need a case gage thanks !!!!!!!