Sorting 223 Bullets using a Neal Jones 22 Rimfire Head Space Gauge

Sorting bullets by the bearing surface length is a step an additional step indicated by Mr. David Tubb.  David commented about doing this on one of the online message boards.  I contacted Mr. Tubb online to ask him about how much variation he was getting in the surface bearing length on bullets he was measuring.  David replied and indicated that his system which was used a surface plate with a dial indicator could differentiate the bullet’s surface bearing length by 0.001 of an inch.  David also mention he normally end up sorting the bullets into two groups or piles which differed by only 0.001 inch plus a few odd and ends.  This range got me thinking about measuring head space and my Neal Jones 22 Rimfire Head Space Gauge.  So here is how I modified my Neal Jones 22 Rimfire Head Space Gauge which as an 0.008 inch range to measure the surface bearing length on 80 grain Sierra MatchKing Bullets.

Neal Jones Rimfire Inert
(sort_insert.jpg)

Measuring the bullet’s surface bearing length was the 22 RF Gauge will include the boat tail length and all variations associated with it.  This boat tail length does not seem to me to be an area that would vary that much in the bullet manufacturing process.  I have always assumed that the boat tail length may be one of the most sable length dimensions on the bullet.  But do I know and you know why assumes mean.  In order to use the Neal Jones 22 Rimfire Head Space Gauge all I have to do is figure out how to hold or locate the 223 caliber bullet which just fits into the Rimfire Insert.  Looks like another job for some epoxy.  Little release agent on the bullet and clean the inside of the insert with some isopropyl alcohol.  The 80 grain Sierra MatchKings were long enough so the boat tail could stick up above the insert and still have a small portion of the nose stick out the other end of the gauge insert.  The bullet base must be slightly above the top end of the insert to make any measurements.  It also turned out to be very handy that having the tip of the bullet exposed at the bottom of the insert which help release the bullet for removing after measuring.
Neal Jones 22 RF Headspace Gauge & Bullet Pusher
(sort_neal_jones.jpg)

Once the chamber or pocket is cast into the gauge insert the insert may be adjusted and locked into position for measuring the surface bearing length which includes the boat tail length.  My first measurements on a hundred or so 80 grain Sierra MatchKings indicated reasons very similar to what Mr. Tubbs indicated he got.  I was able to sort the this first group of 80 grain bullet into two groups which varied by only 0.001 of an inch plus some odd and ends much like David’s results.  Using the Neal Jones 22 Rimfire Head Space Gauge I was able to easily differentiate the groups by 0.0005 of an inch.  The Neal Jones 22 Rimfire Head Space Gauge was easy to use and I could measure the 80 grain bullets just about as fast as measuring head space of 22 Rimfire cartridges.  The first batch of bullets I measured used only about half of the Neal Jones 22 Rimfire Head Space Gauge scale range.  However the next two batches of 500 bullets each I need the full eight thousands range and still have some odd and ends off scale.
Reading Neal Jones RF Headspace Gauge
(sort_gauge.jpg)

Using the Neal Jones 22 Rimfire Head Space Gauge seems to be helping my vertical grouping at 600 yards along with trimming the bullet’s Meplat.  I also think the 22 RF insert could be machined like throat on the 6mm and used for measuring 6mm bullets.  Using the epoxy cast chamber in the insert currently requires me to push the bullet into the insert in order to start the slide for measuring and push the bullet out of the insert after measuring.  I have a small pusher and the bullet falls out of the inverted gauge with a slight nudge.
Sierra 80 grain MatchKing Bullets

Sorted Value Using Modified Neal Jones 22 Rimfire Headspace Gauge
Bullet Lot Number <0.0
 0.0
 0.5
 1.0
 1.5
 2.0
 2.5
 3.0
 3.5
 4.0
 4.5
 5.0
 5.5
 6.0
 6.5
 7.0
 7.5
 8.0
 >8.0
 Total
0015070101855
 2
 0
 0
 0
 0
 0
 0
 0
 0
 4
 1
 2
 10
 44
 47
 11
 0
 0
 0
 121
0016138551825
 0
 30
 40
 24
 25
 84
 54
 5
 7
 27
 107
 71
 15
 15
 5
 1
 0
 0
 0
 510
0015889252626
 80
 84
 72
 62
 27
 3
 7
 36
 39
 17
 0
 1
 3
 29
 22
 16
 4
 3
 0
 505





















































































So if you have a Neal Jones 22 Rimfire headspace gauge gathering dust and here is a way to get some use out of it.  If you want to measure the surface bearing length on bullets other than 223 caliber, get the David Tubb's tool.  The small surface plate that comes with Bearing Surface Comparator should also make a great place for an electronic powder scale when not using the comparator.



Larry Medler
anyrange@comcast.net

Rifle Silhouette Shooting
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Released - November 1, 2004
Revised - November 3, 2004