More on Case Resizing the 303: Testing Brass

By Bill Lose

Bill showed us that, for Lee Enfields at least, neck resizing is so much better than the alternatives – full length or partial case resizing. He also clearly demonstrated the need to properly care for your brass.

A small bit of care yields longer case life and better performance.

California, USA
February 10, 2000

Dear Mr Redgwell,

Your “Full Length vs Partial vs Neck Resizing” made me wonder just how much difference in case stretch is there between the three resizing methods.

Fifteen once-fired REM-UMC cases were full length resized, trimmed to 2.210″ and fired with full power loads until they grew too long for safe chambering. Each of the three groups of five cases were sized either full length, partial or neck.

As expected, the full length sized cases were the first to stretch past the point of usefulness. They stretched to nominal length of 2.220″ upon the first firing. After three firings the cases had reached a length of more than 2.260″ and were hitting the end of the chamber, which could interfere with bullet release. Partial sized cases did not reach the critical length of 2.260″ until after ten firings. Neck sized cases were fired 25 times before they were too long for the chamber-quite a difference!

Cases were inspected for cracks, incipient separation, adequately tight primer pockets and length before each loading. The only problem was hard chambering of the neck sized cases after the sixth firing.

In future I will start with cases trimmed to minimum length, neck size until chambering becomes difficult and then partial or full length size only enough to set the shoulder back the minimum to restore easy chambering. I don’t recommend allowing cases to exceed normal maximum length. I knew beforehand that my No 4 rifle had a long chamber. This enabled me to allow stretching beyond normal maximum and observe stretch over a greater number of firings.

The other conclusion to come out of this comparison test is that REM-UMC brass is very durable indeed. Enclosed is a sectioned case fired 26 times. You can see that there is no sign of incipient separation.

Keep up the great work on the 303 Page! I also have the maintenance and repair guide and find it very valuable. You are a very effective advocate of the best bolt action military rifle in history.

Very Truly Yours,

Bill Lose

I did not solicit this letter. The results may not be typical (as they say in the weight loss ads), but this is just one example of emails and regular mail I’ve received from people that have tried neck resizing. IT WILL MAKE A DIFFERENCE FOR YOU!

I don’t have a camera to show you the sectioned case but it showed absolutely no sign of thinning. Thanks Bill for sharing the information with all of us!


Never exceed the maximum case length of 2.22 inches! Bill knew how to precisely determine the max length of his chamber.

Component care means longer brass life.

Since the case is the only thing that you retain after firing, keep an eye on the condition of your brass. Check the length, primer pockets and overall condition. Look for cracks and test for incipient case head separations. It only takes a few seconds to do.