Lyman 10MM/40 SW Neck Expand (M) Die - #7340833

Lyman 10MM/40 SW Neck Expand (M) Die - #7340833
Item #:LY7340833
Shipping: One flat fee of $12.95 per online order.
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Availability:Less than 5 in stock
Read 2 Reviews

Product Information

Many reloaders consider Lyman’s Neck Expanding (M) Die a valuable tool for improving the accuracy of their reloads. The die’s expander plug has two steps. The first step expands the inside of the case neck to just under bullet diameter for precise case neck tension in the finished reload. The second step expands the case mouth to bullet diameter or slightly over. This allows the jacketed or cast bullet to be started perfectly centered in the case mouth and properly aligned with the axis of the case neck. (By adjusting the neck expanding plug slightly deeper, Step 2 also provides a slight flaring of the case mouth for reloaders using cast bullets.)

Read 2 Reviews - Average Rating: 5 stars

Lyman 40 SW Neck Expander - The Better Expander

By Fred M. on Oct 18, 2020
I have been getting decent results from the neck expander that came with my 40 SW die set. However, from time to time, I would notice some rocking of the bullet given the flaring at the mouth opening although barely noticeable with the naked eye. Adjusting the original expander to minimal depth resulted in more rocking as not enough of the bullet resulted in pre-seating depth. Adjusting to maximum depth resulted in bell shaped openings with much worse rocking results. Upgrading to the Lyman 40 SW Expander solved the rocking issue with the original die. Like other Lyman expanders, the 40 SW Expander expands the case gradually for smooth bullet seating. It also creates a ledge within the case on which the bullet will rest tightly against the mouth opening. The result is the bullet will pre-seat into the case with absolutely no rocking stopping on the ledge everytime. One you start to seat the bullet with the bullet seater, the ledge is expanded by the bullet just enough to merge with the remainder of the expanded case wall making for a smooth stroke on a single stage press. Highly recommended replacement if you are experiencing the same issue I had. Thank you for reading.

Excellent tool

By Cyrus J W. on Jan 20, 2020
I use a lot of polymer coated bullets and have found M dies to allow you to flare and expand the neck properly for them. Bullets are started more easily and are not damaged as they are seated. I have had excellent results with this type of die and it is well worth the modest cost. Graf's fast shipping is a big plus, as well.
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