gutterman
Member
Can anyone tell me what the COL for the 9mm would be using a 124 Hornady XTP and 4.2 grns of Titegroup?
No, the gauge checks headspace and OD, but not anything else. Someone should come along soon and give us a definitive answer on what OAL the 124 XTP is loaded at by the factory.Or he could get a case gauge and be assured that it will fit any SAAMI-spec chamber and barrel, right?
http://www.thehighroad.org/showthread.php?t=506678Do the barrel test as rc recommends;
After you determine the OAL that will work with your pistol/barrel/magazine, I would follow the lower load data for JHP bullets and work up from 3.8 gr instead of starting out at 4.2 gr.gutterman said:Can anyone tell me what the COL for the 9mm would be using a 124 Hornady XTP and 4.2 grns of Titegroup
125 gr Sierra FMJ Titegroup OAL 1.090" Start 4.1 gr (1069 fps) 27,300 CUP - Max 4.4 gr (1136 fps) 30,600 CUP
125 gr Sierra JHP Titegroup OAL 1.075" Start 3.8 gr (962 fps) 26,100 CUP - Max 4.2 gr (1045 fps) 31,200 CUP
BTW, one of the most puzzling experiences of my relatively-young reloading career was finding that two manuals had start/max loads for the same powder and very similar bullets that had NO OVERLAP. In other words, one manual's max load was under another's start load! That's when I decided that finding one set of published data would not generally be sufficient to me - I want multiple sources.
ATLDave said:one of the most puzzling experiences of my relatively-young reloading career was finding that two manuals had start/max loads for the same powder and very similar bullets that had NO OVERLAP. In other words, one manual's max load was under another's start load!
Due to these reasons, when I am doing my initial load development, I will compare all available load data (and the test specs) and use the lowest start/max charges for my powder work up.Hodgdon load data - Hornady case (.845" Trim Length) - 4" Barrel length (1:16" twist) - Winchester SP primer
180 gr Hornady XTP W231 OAL 1.125" Start 4.1 gr (797 fps) 23,800 PSI - Max 5.0 gr (947 fps) 32,900 PSI
Lyman #49 load data - Winchester case (.845" Trim length) - 4" Barrel length (1:16" twist) - Winchester SP primer
180 gr Sierra JHP W231 OAL 1.115" Start 5.0 gr (927 fps) 20,400 CUP - Max 5.6 gr (1015 fps) 22,800 CUP
This is what I do. If the working OAL that I am using for my load development is significantly shorter than the published OAL for the same nose type of the bullet, I will calculate the actual bullet seating depth (OAL - length of bullet = bullet seat depth). If the bullet seat depth is greater than say .010"+, I will incrementally decrease my start/max charges for my load development.ATLDave said:I don't suppose anyone has a good formula or method for figuring out what a reduction of OAL by X does to pressure/max loads? IOW, if a published load shows 1.2600 OAL and I want/need to make it 1.2500, is there a predictable way to anticipate what pressure change would result and/or what reduction in charge is needed to hold pressure constant?
1.125" - .620" = .505" bullet seat depth for the CN
1.080" - .565" = .515" bullet seat depth for the RN
So for my work up, I used 3.6 gr as my start charge and 4.1 gr as my max charge (I did work up to 4.4 gr but I got leading at 4.2-4.4 gr).125 gr LCN W231/HP-38 OAL 1.125" Start 3.9 gr (1009 fps) 25,700 CUP - Max 4.4 gr (1086 fps) 31,200 CUP