OAL question on different 9mm projectiles - SIG Talk
SIG Talk Gun Forum

OAL question on different 9mm projectiles

This is a discussion on OAL question on different 9mm projectiles within the Ammo and Reloading forums, part of the Gun Forum category; I use the Lee Classic Turret press. I have been using XTreme plated 124gn RN bullets with absolutely no issues. I purchased both RMR and ...


Go Back   SIG Talk > Gun Forum > Ammo and Reloading


Ammo and Reloading Ammunition and Reloading Forum - For topics and discussions about ammunition and reloading your own ammo

Reply
 
LinkBack Thread Tools Display Modes
Old 12-22-2016, 06:19 AM   #1
Supporting Member
Supporting Member
 
rlherrick57's Avatar
 
Join Date: Apr 2014
Location: Florida
Posts: 360
OAL question on different 9mm projectiles

I use the Lee Classic Turret press. I have been using XTreme plated 124gn RN bullets with absolutely no issues. I purchased both RMR and Precision Delta 9mm 124 JHP to try out. I aim for an OAL of 1.145 to 1.150 with the XTreme. I measured the length of the new projectiles. The Extreme RN are a few thousandths longer than either of the other two hollow points.

If I leave my dies as they are, and seat the RMRs, I figured with the shorter length, they would not seat as deep since my die is set for 1.150. That is not the case and I cannot understand why. I did 5 rounds with the JHP (actually both the RMR and PD), I end up with a length of 1.10.

I made two of them the first day and shot with no issue. I really expected the OAL to be the same. My thinking is the projectile will either seat deeper or shallower with a different projectile.

What math, science, or engineering am I not understanding here? My only thought is the difference in the shape of the end of the projectile causes it to hit somehow differently inside the die.
rlherrick57 is offline  
Register

Welcome to the SIG Talk Forum dedicated to SIG Sauer Pistols and SIG Sauer Rifles.

We welcome everyone and the community is free to join so register today and become part of the SIG Talk Forum!

Old 12-22-2016, 06:23 AM   #2
Super Moderator
Supporting Member
 
Malicious Compliance's Avatar
 
Join Date: Jan 2013
Location: Location: Location:
Posts: 15,414
Yes, should really set the OAL for each different bullet. Different lengths will result from different shapes. And as you noted, the seating depth will be different due to the different bullet lengths. Really want to test out the bullets in small lots to make sure your recipe is what you want. Having a chronograph can help in this regard immensely. Be Safe!
Malicious Compliance is online now  
Old 12-22-2016, 01:44 PM   #3
Senior Member
 
Flash LB's Avatar
 
Join Date: Apr 2015
Location: Gilbert Arizona
Posts: 5,958
It mostly is because of the shape of the ogive of the bullet. Long thin ogives give one OAL and short fat ones give another.

It's okay to have them be different lengths as long as they feed and function in your guns correctly.

Here's a picture of two different ogive shapes. Which one will be seated deepest is a function of the shape of your seater plug on the inside.
Flash LB is offline  
 
Old 12-22-2016, 03:02 PM   #4
Supporting Member
Supporting Member
 
rlherrick57's Avatar
 
Join Date: Apr 2014
Location: Florida
Posts: 360
Thanks guys. Appreciate the pictures, always like pictures. They are great for us non-artistic, visually challenged..
rlherrick57 is offline  
Old 12-22-2016, 03:57 PM   #5
Senior Member
 
Flash LB's Avatar
 
Join Date: Apr 2015
Location: Gilbert Arizona
Posts: 5,958
I got onto pictures around 30 years ago when I was an Electronic Engineer working for a major Medical Electronics company.

My boss called me into his office for a closed door meeting and told me he'd finally figured out why certain things he did didn't register with me. He said I was verbally oriented while almost everyone else was visually oriented so he'd do things with me in the future.

I've never forgotten it, and to this day I primarily use visuals when I'm trying to get my point across.
Flash LB is offline  
Old 12-22-2016, 04:15 PM   #6
Senior Member
 
Mainer's Avatar
 
Join Date: Oct 2015
Location: Maine
Posts: 433
Quote:
Originally Posted by rlherrick57 View Post
My only thought is the difference in the shape of the end of the projectile causes it to hit somehow differently inside the die.
This may well be the answer.

You could verify by removing the seating punch and seeing if the various bullets contact the punch at the tip of the bullet or have a wide ogive that contacts before the tip reaches all the way into the punch.
Mainer is offline  
Old 12-23-2016, 07:12 AM   #7
Supporting Member
Supporting Member
 
rlherrick57's Avatar
 
Join Date: Apr 2014
Location: Florida
Posts: 360
Quote:
Originally Posted by Flash LB View Post
I've never forgotten it, and to this day I primarily use visuals when I'm trying to get my point across.
Thats me. There are some people who can paint a scene with words and others can see it in their minds... Not me.
rlherrick57 is offline  
Old 12-23-2016, 07:23 AM   #8
Supporting Member
Supporting Member
 
rlherrick57's Avatar
 
Join Date: Apr 2014
Location: Florida
Posts: 360
Quote:
Originally Posted by Mainer View Post
This may well be the answer.

You could verify by removing the seating punch and seeing if the various bullets contact the punch at the tip of the bullet or have a wide ogive that contacts before the tip reaches all the way into the punch.
A good option for sure. Still not to the point where I want to tear apart something working until I know I can get it back together again.
rlherrick57 is offline  
Old 12-23-2016, 08:43 AM   #9
Senior Member
 
Willard's Avatar
 
Join Date: Apr 2016
Location: Evansville, IN
Posts: 1,352
It's like RCBS has different "Seating Plugs" available for Speer "Gold Dots".
Willard is offline  
Reply

  SIG Talk > Gun Forum > Ammo and Reloading

Thread Tools
Display Modes


Similar SIG Talk Discussions
Thread Thread Starter Forum Replies Last Post
Trigger bar question Gobbletn P238, P938 Pistol 2 09-11-2016 07:13 AM
Another 239 question barrel swap question Nev SIG Sauer Pistols 6 07-14-2016 06:28 AM
Question, from Novice, for Expert Marksman... KM1 SIG Sauer Pistols 18 07-07-2016 05:42 PM


Top Gun Sites Top Sites List

Powered by vBulletin 3.8.7
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.6.1
Copyright © 2010 - 2017 SIG Talk. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.SIG Talk is a SIG Sauer Firearms enthusiast's forum, but it is in no way affiliated with, nor does it represent SIG Sauer, Inc. of Exeter, NH.