The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

Hello there, I’ve assembled a couple test rounds as described in my earlier post. I’ve now moved on to using the Lee Precision Factory Crimp Die to apply a ‘light’ crimp to my .38 Special GM Hardcast Lead RN-FP 158gr bullets.

Before crimping, the COL was 1.425”± 0.002” after crimping the COL was 1.425”± 0.005”.

Any ideas as to the reason for change in COL ?

Is the crimping die finding the true ‘centre’ of the groove?

Is the crimping die seating the bullet further ?

Is the crimping die extracting the bullet on removal from the die?

Do I really need to worry about it ?

Many thanks in advance for your replies and advice.
Best regards.

.005" on a 38spl? no, you don't need to worry about it.

As above dont worry about it. It will not make the slightest bit of difference as I recall you will be using it in a 357.
I have been loading many different pistol cartridges over the past 40 years and cant even remember measuring the length of any!
If they fit and cycled that was enough.
Underlevers wont tolerate over long cartridges such as the yellowboy carbine in 45colt I used to have. Was designed to use the original bullet shape.

As above, I would not be unduly worries by .005" variance and this could even be down to irregularities of the individual projectiles. This is why it is always important to measure from the part of the bullet you are seating on which is not usually the part you measure from.