The Firing Line Forums - View Single Post - Sizing Blinged LC 7.62 Brass in a Summit and a RockChucker II.

GWS · March 15, 2014, 09:26 PM

Lube was ample, sizing was easy, no excessive force pulling the expander out. Of course expander pulling got even easier with each successive sizing. All finished brass dropped in my Wilson gauge...heads flush with the lower groove. Trimming necessary...guessing 2 to 4 thousandths.

1. Pre-Sizing Run-out: I measured for run-out 1/8" from the case mouth, 5 cases. Then I marked an index in red on each case head extractor groove.

2. First Sizing: Using an RCBS lube pad and neck brush I lubed each case; oriented each case where the index was centered in the in-slot of the case holder; sized each in the Rock Chucker; then measured each case again for run-out.

3. I sized each case a 2nd time, same orientation, then measured again for run-out.

4. I sized each case a 3rd time, same orientation, measured again for run-out.

5. I sized a 4th time, orientation rotated 1/3 rotation clockwise, measured run-out again.

6. I sized a 5th time, orientation rotated 2/3 rotation clockwise, measured run-out again.

After doing 3 cases this far one actually showed worse run-out after step 6.....so I said what the heck and sized a 6th time, red mark back to index, to see if there was any change.

7. 6th sizing was back at zero (first) orientation.

Ending: All five cases were at a best .001" run-out.

Here's the numbers (run-out in thousandths of an inch):
Sizings: .1.....2.....3.....4.....5.....6
case 1: 2.0--4.0--2.0--2.0--1.5--1.0
case 2: 9.0--6.0--6.0--3.0--2.0--1.0
case 3: 5.0--3.0--2.5--7/8--1.0
case 4: 5.0--3.5--1.5--2.0--2.5--1.0
case 5: 4.0--2.0--1.5--1.25--1.5--1.0

A sixth case I simplified. Presized runout was .004" and first sizing was .005. I immediately rotated the case 1/3, sized, rotated 2/3, sized, and measured once. Run-out was .001"

Strangely nothing ever got better than .001" Well I take that back....case 3, 4th sizing was actually less....maybe 7/8 of a thousandth.

So! What's a progressive reloader to do with this brass!

This whole process blindsided me.....sure didn't expect it.

Will see what if anything changes using a lanolin spray lube next week. Here's hoping I don't get a stuck case trying.

March 15, 2014, 09:26 PM	#3
GWS Senior Member Join Date: September 8, 2010 Location: New Mexico Posts: 688	Saturday: The First Test Using the Rock Chucker Lube was ample, sizing was easy, no excessive force pulling the expander out. Of course expander pulling got even easier with each successive sizing. All finished brass dropped in my Wilson gauge...heads flush with the lower groove. Trimming necessary...guessing 2 to 4 thousandths. 1. Pre-Sizing Run-out: I measured for run-out 1/8" from the case mouth, 5 cases. Then I marked an index in red on each case head extractor groove. 2. First Sizing: Using an RCBS lube pad and neck brush I lubed each case; oriented each case where the index was centered in the in-slot of the case holder; sized each in the Rock Chucker; then measured each case again for run-out. 3. I sized each case a 2nd time, same orientation, then measured again for run-out. 4. I sized each case a 3rd time, same orientation, measured again for run-out. 5. I sized a 4th time, orientation rotated 1/3 rotation clockwise, measured run-out again. 6. I sized a 5th time, orientation rotated 2/3 rotation clockwise, measured run-out again. After doing 3 cases this far one actually showed worse run-out after step 6.....so I said what the heck and sized a 6th time, red mark back to index, to see if there was any change. 7. 6th sizing was back at zero (first) orientation. Ending: All five cases were at a best .001" run-out. Here's the numbers (run-out in thousandths of an inch): Sizings: .1.....2.....3.....4.....5.....6 case 1: 2.0--4.0--2.0--2.0--1.5--1.0 case 2: 9.0--6.0--6.0--3.0--2.0--1.0 case 3: 5.0--3.0--2.5--7/8--1.0 case 4: 5.0--3.5--1.5--2.0--2.5--1.0 case 5: 4.0--2.0--1.5--1.25--1.5--1.0 A sixth case I simplified. Presized runout was .004" and first sizing was .005. I immediately rotated the case 1/3, sized, rotated 2/3, sized, and measured once. Run-out was .001" Strangely nothing ever got better than .001" Well I take that back....case 3, 4th sizing was actually less....maybe 7/8 of a thousandth. So! What's a progressive reloader to do with this brass! This whole process blindsided me.....sure didn't expect it. Will see what if anything changes using a lanolin spray lube next week. Here's hoping I don't get a stuck case trying. Last edited by GWS; March 15, 2014 at 09:59 PM.