View Full Version : COAL - how do you know when it is correct for best accuracy?
07-15-2011, 09:43 PM
i have heard about needing to adjust this so the pressure is right in the chamber which can affect accuracy... is this correct and if so, how do i adjust it to maximize accuracy?
07-15-2011, 10:05 PM
That was my question. Read through this thread ( http://www.65grendel.com/forum/showthread.php?574-Balance-of-Jump ) the guys helped me understand and adjust my loads.
07-15-2011, 11:04 PM
thanks steel! a lot of good info there... however 1. i don't have a comparator and 2. i don't understand how you know when you are in the lands and when you are .010 off of the lands. could you explain more? i'm new to rifle re-loading... thanks!
07-17-2011, 01:19 AM
I tried the homemade versions in that string to find the chamber's OAL, they work, but wasn't real confident with the results. The hornady OAL gauge was at BPShops so I bought that there, but had to order the related Grendel Case for the gauge at Midwayusa ($5). Using it was very easy and simple to know when your bullet hit the lands. If you have the bullet stick, tap it out and drop it back in the Grendel case and measure (the directions are simple). You now know the max length of a round that will fit in your chamber**. Load your cartridges .010 short of that for a starting place. After you have found a bullet you like and and a powder that gives you a velocity that gives good groups using the COAL you developed, try adjusting the COAL longer or shorter by small increments to tune it for your particular chamber. Some load/bullets combinations have a sweet spot a little longer or shorter. Some of the guys in the forum are much more experianced at putting it all together and can probably explain it better than this but that is a basic rundown of the process.
**Some bullets like the SMK and Scirocco will give you a chamber length longer than the magazine will allow, even when subtracting the .010, so you will be loading to the mag size or 2.260 to start
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