Determining charge to use

[kc17 622]

I know the best option is to use published data, but what if published data does not exist for the powder & projectile combination I have?

My situation: I have Hodgdon Titegroup & two different projectiles from NE Reloading, 124gr Truncated Cone Coated & 147gr Round Nose FMJ. When I reached out to NE Reloading regarding the 124gr he suggested I use data for a Berry 124gr projectile. Hodgdon lists data for that combination so I went with that and had no problems. The only data Hodgdon has for a 147gr projectile using Titegroup is on a Hornady XTP Hollowpoint.

The closest Hodgdon has to what I have (using Titegroup) is a 145gr Acme RN Coated. This calls for a starting charge of 2.9gr with a max of 3.4 and a COL of 1.150". The 124 Berry was 3.6 to 4.7gr with the same 1.150" COL. Is the lower charge for the heavier projectile a result of the reduced space inside of the cartridge because the 147gr projectile is larger? I realize with all other factors being equal a smaller COL will have higher pressure. I believe that a larger COL would allow for a larger safety margin if the charge is on the high side as well, correct?

I've not seen any listings for projectile length factoring into load data. It seems to be that would be beneficial, and possibly solve my current conundrum.

The way I see it, my options are to 1: use the data Hodgdon provides for the 145gr Acme RN keeping the charge at the minimum; 2: buy different powder to use with 147gr FMJ; 3: post a WTS/WTT thread for the 147gr.

[Longranger 16]

kc17,

I just ran what I think you're looking at in GRT load simulation software.  Looks like 3.4gr of Titegroup is bumping up against the max recommended pressure.  This is just a simulation, like QuickLoad software.  So, all normal warnings regarding working up a load apply. 

[Longranger 16]

Forgot to answer your question.  Lower powder charges for heavier bullets are typically due to the pressure increase associated with getting the heavier bullet underway.  Lighter bullets are easier to get moving and the pressure rises more slowly.

[Bagarocks 36]

From Hodgdon website:

Lead bullets and copper plated lead bullets yield very similar pressure and velocity results, so when the weights are the same, the same data may be used for each. Jacketed Lead core bullets come in a variety of configurations. Jacketed Hollow points and Jacketed Flat points of the same weight use the same data. Round nosed, lead core, full metal jacketed bullets of the same weight can also use the same data.

In conclusion, bullets with similar shapes and construction materials will utilize the same data. And, above all else, work up your loads by starting with the beginning load and increase charges in small increments,

From the Blue Bullets website:

We recommend that you use published lead load data from reputable sources. A coated bullet will run slightly slower than a lead bullet (5FPS-10FPS.)

[kc17 622]

7 minutes ago, Longranger said:

kc17,

I just ran what I think you're looking at in GRT load simulation software.  Looks like 3.4gr of Titegroup is bumping up against the max recommended pressure.  This is just a simulation, like QuickLoad software.  So, all normal warnings regarding working up a load apply. 

Holy Cow! I'm going to need time to digest that!

5 minutes ago, Bagarocks said:

From Hodgdon website:

Lead bullets and copper plated lead bullets yield very similar pressure and velocity results, so when the weights are the same, the same data may be used for each. Jacketed Lead core bullets come in a variety of configurations. Jacketed Hollow points and Jacketed Flat points of the same weight use the same data. Round nosed, lead core, full metal jacketed bullets of the same weight can also use the same data.

In conclusion, bullets with similar shapes and construction materials will utilize the same data. And, above all else, work up your loads by starting with the beginning load and increase charges in small increments,

From the Blue Bullets website:

We recommend that you use published lead load data from reputable sources. A coated bullet will run slightly slower than a lead bullet (5FPS-10FPS.)

Thanks, I didn't see that on the site, but I was mostly just looking for load data.

[kc17 622]

I have since found some projectile length information for Speer & Berry's.

I placed an order for more Hodgdon Titegroup yesterday, I'm wondering if I should try to cancel that order and get powder that has more load data for a wider range of projectiles.

I'm going to download the Gordons Reloading software now, I see Quickload is a purchase.

[JackDaWack 2,895]

It doesn't matter if there is specific load data. You should take the opportunity to read how different types of boolit weights and coatings effect load pressure and velocity, and get used to bullets shapes driving seating depth and COAL. Once you figure that out, you can can pretty good estimates and starting points. 

When i started using titegroup, there was no load data except from the Hodgdon website. I use plated bullets for titegroup, 124 gr 9mm at 4.2 grain. It's actually now listed as beyond the max load in Hornadys book, but zero pressure signs and its accurate. 

There is so much useful data out there that you can mix and match.

The goal is to find as many similar bullets to what you want to load and use the available data, start low from what ever you can put together and work up. 

 

While it is nice to just pick up a book and be told what to throw in the case, you still end up testing multi charge weights and seating depths to improve accuracy, so its really just another level to reloading. 

 

What drives me crazy is that the newest Hornady book has Titegroup charges for 115gr, but is missing from the 124gr and 147gr charts. Im waiting for the day that someone compiles a massive google sheet and just shares it with the world. 

 

[JackDaWack 2,895]

4 hours ago, Longranger said:

kc17,

I just ran what I think you're looking at in GRT load simulation software.  Looks like 3.4gr of Titegroup is bumping up against the max recommended pressure.  This is just a simulation, like QuickLoad software.  So, all normal warnings regarding working up a load apply. 

What systems support this software?

[kc17 622]

5 hours ago, JackDaWack said:

What systems support this software?

Jack, thanks for the above. Here is the link to the software Longranger had the screenshot of:

https://grtools.de/index.php

It runs on Windows or Linux; I only played with it for a few minutes so far.

 

[Rob0115 1,105]

Actually looks better than quick load.  Thankfully for VMware I can run it in my Mac. 

[Longranger 16]

I found GRT while searching for an alternative to QL.  Actually, I was thinking of doing my own program from scratch, but I like to snoop around and see if anyone else has been there done that before I reinvent the wheel.  I was so impressed with GRT that I become a patron that supports their efforts.  GRT runs on Windows and Linux.  Wide support for Windows, only one distribution of Linux has been thoroughly tested.  GRT is available for free, but it is not open source.  Public release updates are provided in Windows and Linux versions.  Interim (or beta) updates are made available to patrons and only for Windows.  I think the model that provides the basis for the data is better (as in more accurate) than that used in QL and GRT includes a plug-in that allows any user to upload their load, chrony, component measurements, and pressure data (if they have Pressure Trace) to a database that is used to continually refine the powder burn characteristics.  The whole project seems exceptionally well thought out to me.

Now for some of the inner workings of GRT.  The program includes an OBT feature that supplies full and half node values and a target analysis module.  Accurate results REQUIRE inputting exacting measurements of your fired case capacity and measurements, barrel details, and bullet weight and measurements.  Default values for almost everything are preloaded in the database and wildcat cartridges and new bullets are added to the database as fast as users upload new info.  Do I sound like a salesman for GRT?  Sorry about that, I just think it’s an amazing tool that has resulted from the combined efforts of a great reloading community.  The GRT community forum is hosted on Discord, which I had never even heard of prior to stumbling across GRT.  Then I found that NJGF is also on Discord. No cost to join the forum, but patrons get a few perks like direct support and communication with the development team.  I haven’t found anything about GRT yet that I don’t like, so that’s also a plus.

[Rob0115 1,105]

I’m gonna try it out and if I like I will send them money to support the effort.