Reloading Methodology - AllGunStuff Forum

Almost a Mono bullet velocity reduction

Treeman — Sun, 02 Aug 2026 17:20:12 +0000

I Cody was gifted a box of Spoor 140 gr bullets for his 7 mm. I am calling them half mono 🤣 because of the design/ construction. In the 7 mm 2800 fps is achievable, and I have no doubt of the effectiveness of these bullets at that velocity.

I have two questions though.
I have downloaded some to 2350 fps to try reduce meat damage at 100m or less type shots (80 % of all shots on the Impala)

I have also loaded some to 2555 fps for regular hunting.
Do you guys think there is any problem foreseeable with the 2350 fps load on game.
Do you think there will be a clear notable difference between the 2350 and 2550 fps bullet performance?

Odd Extraction Problem - what explanation ?

414gates — Sun, 26 Jul 2026 20:08:14 +0000

This was a 830 gr monolithic with 200 grains of Vihtavuori 20N and a CCI 35 primer. Lapua brass.

The three cartridges were for fouling shots, velocity came out at 2130 fps. Anaemic, just foulers.

The one extracted normally. The other two did not extract. Usually, when I open the bolt and nothing comes out, it's a case head separation. The entire case remained in the chamber. Barely a tap from a rod down the muzzle extracted the case.

I do not understand how the case rim escaped from the extractor when the bolt was opened.

It is possible that the primer pockets are loose, this is brass that I use for load development, it may have experienced a couple of hot firings already.

How does the primer back out just that far ? A loose primer pocket with a hot load tends to leave the primer stuck to the bolt face, so when the case ejects, the primer stays behind. There was no high pressure, bolt opened as easily as it closed.

primers-odd.jpg

Bullet diameter

Tripodmvr — Fri, 26 Jun 2026 07:34:46 +0000

Copied from Gunsite as I think it is appropriate for handgunners.

https://www.shootingtimes.com/editorial/9mm-38-357-barrel-bore-diameters-explained/509031

If GRT on Linux gives problems ...

414gates — Fri, 10 Apr 2026 10:22:54 +0000

I'd been running GRT for some time on Linux, and after an operating system upgrade, it wouldn't work anymore.

The quickest and easiest way to get GRT working in Linux is to run it on a Windows VM in VirtualBox.

You can share the GRT data folder with the VM, so it is accessible directly.

I've got a Windows XP VM, running the Windows version of GRT. And a couple of other bits of Windows software that I use once in a while, for which there is no Linux equivalent.

How to add a new powder to GRT

414gates — Fri, 10 Apr 2026 10:09:39 +0000

I want to add B12.7 to GRT.

I've used the data from VV 24N as an entry point.

What is the process to true the powder data against measured velocity.

Google says :

Steps to Add a New Powder in GRT:
Generate Data: Perform a 2x2x2x5 development run (2 calibers, 2 bullet weights, 2 charges, 5 shots each) over a reliable chronograph.
Input Data: Open GRT and input your specific load data, including accurate bullet measurements and case volume.
Use OBT (Optimal Barrel Time): Use the GRT OBT tool to match the pressure curve and burn rate to your actual measured velocities.
Save as New Powder: Click on 'Create grt load file' after the OBT simulation produces accurate results to save the new powder in the user section.

I just want confirmation that the method works as advertised.

Sus-Tac Bullets

Newton — Sun, 05 Apr 2026 09:51:21 +0000

Anyone here use them ?
I was given five of the HP tipped (metal tip ) in 180gr to try out
Looks to me to be a mono-metal - although it does not have any bands on the bullet body
It is a very long bullet 39.64mm but which I can use in / as a repeater without problems

When I came to use them I used GRT to work out a load - using all my measured data
I chose a low pressure load under 59,000

However when fired the cases exhibited high pressure and the velocities were much higher than indicated
I am not sure what is going on here ?

I have to use an additional two grs in the simulation to get to the velocity that was predicted - which has higher pressure and takes me above 63000psi

Perhaps the bullets being mono-metal exhibit higher pressure due to constriction in the barrel ?

The few loaded cartridges that were shot were however accurate
I did not carry on shooting when I noticed the much higher velocities

Bullet "jump" and Base to Ogive

Newton — Fri, 03 Apr 2026 23:16:41 +0000

When I have been measuring COAL (Cartridge overall Length) I have realised that that is not the most important dimension
Bullet manufacturers will (sometimes) supply the length of the bullet
However what is really important is the dimension / length at which the ogive starts
After all it is at the ogive ( full diameter ) that the bullet meets the rifling
and
This is where you measure "bullet-jump"
This is generally measured by ...BoT = Base to Ogive to give an indication of where the bullet will actually start engraving.
I am not sure if this information is provided - in a QL .bul file ?
I have discovered that I can actually load very long bullets ( as long as they fit in the magazine ) because a large part of the front of the bullet is NOT at ogive dimension - and my barrel / chamber has a long throat
This means that I can increase the load ratio without necessarily adding more powder ( pressure )

IF this information is supplied I would like to know where you find it ?
Rather than having to measure all the bullets manually

QuickLOAD - Berger bullets

Newton — Wed, 01 Apr 2026 11:23:07 +0000

Is there a new update for Berger bullets ?
I see a few that I do not have in my current berger.bul file

EXPLOSIA - LOVEX powders

Newton — Mon, 30 Mar 2026 22:31:04 +0000

Does anyone know who the South African importers / agents are for these powders ?

Differences between QL and GRT

Newton — Thu, 26 Mar 2026 00:41:43 +0000

Questions for Oom Driepoot and others that spend a lot of time in internal ballistic simulation programs
Simulations .. because there is no ACCURATE easy way to measure pressure - although it is possible to accurately measure velocity
Velocity and pressure are however not parametrically one to one linked !

My particular application is a bit different as my rifle has a very long throat - more than the total length of the magazine so I have to load long ie. you can get more powder in the case

Seeing as the easiest powders to get are the VV ( not Vryheids Vront ) I have been running simulations in the N555 / 560 / 160 burn rate - 5 powders are double base 1 powders are single base

They are all quite close differing on load ratio - how much you can stuff into a case
Seeing as powder is so hellishly expensive one tries to find a powder that works needing less

I have found that QL and GRT differ quite a bit in their simulation of these VV powders
( It is possible that my powder files are not 100% up to date ? )

However what have the maestros discovered - from real World experience - with the above powders
What is more accurate in load simulation .. QL or GRT ?