Wilson Neck size bushings for Wilson FL dies and Neck dies
- LE Wilson bushings for Wilson neck resizing dies are a steel bushing available in increments of 1 thousandths of an inch sizing (0.001″) so you can control the bullet grip which you need by changing bushing sizes.
- They are inserted into the die with the number up (showing). External size is is 0.5″ wide and 0.372″ long.
- The Wilson bushings are tapered internally (on purpose) and the sizing number stamped on each bush refers to the size inside the middle of the bush.
- It is possible to reverse the fitting of the bush and gain a slightly tighter result but this is only recommended as a short term emergency situation as you are resizing against the taper.
- Generally these are intended for use in LE Wilson dies but can be used in other dies which will accept the external dimensions.
- Typically for choosing the size of a Wilson bush you would need about 0.002″ – 0.003″ less than the measurement across the neck area of a case with a bullet seated into it.
- PLEASE take care in choosing your bushing sizes. Because we are sure you can understand we cannot accept returns on bushings which have been used or packages opened
To determine the bushing size (or sizes) which you will require:
Option 1) You need to carefully measure the diameter across the neck of a loaded cartridge. Or seat a bullet into an empty case and then measure. Take several measurements around the neck to determine and average size. Record that. Then check other cases the same way to determine if there are variations. Adjust your “average measurement” you recorded if that is needed. From that average measurement, choose a bushing size which is 0.002″ less or 0.003″ less. As an example: if your 6.5 cartridge measurement you determined was say 0.293″ across the neck on average, choose bush size “291” or “290”. All measurements are in Imperial. In general this will give you somewhere between 0.001″ and 0.002″ neck tension on the seated bullet. This depends and varies a little depending upon the variations in brass “spring back”. Therefore a second bushing may be useful to have which could be one size above or below this determined size.
Option 2) Alternatively, if you own a quality tubing wall thickness micrometer you can measure the neck wall thickness at several points around a case neck. Record you average size in Inches to the 3rd decimal place. Then check some other cases also looking for variations. If so, adjust you average size you previously determined. From this measurement you can determine reasonably well the potential overall size of a loaded cartridge. Add together twice the wall thickness size plus your bullet diameter. Preferably the bullet diameter measured at its largest part which is the heel of the bullet. Then, as per shown above choose a bushing 0.002″ or 0.003″less. Consider having other bushings too. Smaller or larger.
NB. (1) When comparing Wilson to other brands of bushings, like Redding steel and nitride bushings which are internally parallel, the resized results of a case neck will be different of course. This is due to the taper of the Wilson bush in the resize area. Having a taper has several benefits. A tapered bush helps align and start the resizing process and also does not leave a pronounced resize area down the neck at the bottom of resize. Many bullets have a pressure ring or “fattness” at the heel so a tapered resize area can be beneficial in this regard. In general terms we find that to gain a similar result using a Redding bush it would need to be one size larger.
NB.(2) If using a Wilson bushing in another type of resizing die, like for example a custom Newlon gunsmith made die, be careful of the bush height adjustment due to the internal taper of these bushings. You will note that a bush installed into a Wilson neck sizing die generally resizes about 2/3rds of the neck length. Try to adjust to achieve the same is what we recommend.
NB. (3) Remember when choosing bushings it can be a good idea to have at least 2 bushing around the size that you want. Brass spring back varies a lot between brands of cases so your final result can vary. Also if you change type of bullets there can be a different grip due to the difference in pressure ring at the heel of bullets. It is not uncommon to have a difference of 3/4 of a thousandths (0.00075″) in the size of this pressure ring between different brands of bullets. Remember this is only a small area on the bullet but will affect the bullet grip and if you are using the case in a special tight neck chamber you need to recheck your clearances to the neck diameter size indicated by the gunsmith.