Hey guys,
Just wanna share some of my findings regarding COAL testing. I finally got myself a bullet comparator, and I sure am glad I did. I picked one up off the forums that clamps on my calipers, and came with exactly what i needed, a .223 and .308 collets. Months ago, being the RANK Amateur I was, I was wondering why my COAL always seemed different load to load, using my LEE dies. Another member pointed out It was prolly always the same, but since I was measuring from the base of the round to the tip with my calipers, every bullet is slightly different, but always the same to the ogive.
In trying to achieve the most accurate loads, this does INDEED make a difference! Today, the wind is down, about 12 kph, and its only -7, so i decided to try three different loads in my .223. All the same cases, trimmed the same, using the same charge, but varying the COAL by .002. I made a round for my .223 to determine the optimum COAL by slicing two cuts on the neck, drilling the primer hole out, and then slipping a 53 gn. V-Max into it, I then took the bolt out, inserted the round and made sure it was in tight, I then took a thing carbon fibre rod and pushed on the bullet till it just contacted the lands, took it out and measured. I did this four times and ended up with an average of 2.305 (full length), and 1.792 with the comparator. I subtracted .010, and ended up with a COAL of 1.782, a good starting point. I then made six rounds of 1.780, with 23 gn of benchmark (I usually use 24-25 gn, but went a gn. lower because i figured pressure would go up). I also made six of 1.782, and six of 1.784....
I took my loads out and shot them, It turns out the 1.780 grouped .282" group at 100y, the 1.782 did 1.53", and the 1.784 did 1.27", WHAT a difference! My regular loads of 25 gn benchmark, with a COAL of 2.25" (using the old method), grouped .393, and were basically in the bullseye, not shabby but not .282"!, my shots that were using the higher coal were all approx 1" higher, and a bit to the left, telling the pressure was indeed higher, even though I was using 2 gn. less powder....
all in all, I'm sure i will be able to develop a one hole shooter out of my Vanguard now.... The addition of the Timney trigger, and the COAL guage will make a significant difference! For those of you that don't have a bullet comparator, and if you wanna make super accurate loads, IMO, without one, your spinning your wheels! get one, now! lol.... I can't believe how much of a difference this simple tool makes.
well, that's it for now..... hope this helps someone, other than just me ;-)
Ginnz!
Just wanna share some of my findings regarding COAL testing. I finally got myself a bullet comparator, and I sure am glad I did. I picked one up off the forums that clamps on my calipers, and came with exactly what i needed, a .223 and .308 collets. Months ago, being the RANK Amateur I was, I was wondering why my COAL always seemed different load to load, using my LEE dies. Another member pointed out It was prolly always the same, but since I was measuring from the base of the round to the tip with my calipers, every bullet is slightly different, but always the same to the ogive.
In trying to achieve the most accurate loads, this does INDEED make a difference! Today, the wind is down, about 12 kph, and its only -7, so i decided to try three different loads in my .223. All the same cases, trimmed the same, using the same charge, but varying the COAL by .002. I made a round for my .223 to determine the optimum COAL by slicing two cuts on the neck, drilling the primer hole out, and then slipping a 53 gn. V-Max into it, I then took the bolt out, inserted the round and made sure it was in tight, I then took a thing carbon fibre rod and pushed on the bullet till it just contacted the lands, took it out and measured. I did this four times and ended up with an average of 2.305 (full length), and 1.792 with the comparator. I subtracted .010, and ended up with a COAL of 1.782, a good starting point. I then made six rounds of 1.780, with 23 gn of benchmark (I usually use 24-25 gn, but went a gn. lower because i figured pressure would go up). I also made six of 1.782, and six of 1.784....
I took my loads out and shot them, It turns out the 1.780 grouped .282" group at 100y, the 1.782 did 1.53", and the 1.784 did 1.27", WHAT a difference! My regular loads of 25 gn benchmark, with a COAL of 2.25" (using the old method), grouped .393, and were basically in the bullseye, not shabby but not .282"!, my shots that were using the higher coal were all approx 1" higher, and a bit to the left, telling the pressure was indeed higher, even though I was using 2 gn. less powder....
all in all, I'm sure i will be able to develop a one hole shooter out of my Vanguard now.... The addition of the Timney trigger, and the COAL guage will make a significant difference! For those of you that don't have a bullet comparator, and if you wanna make super accurate loads, IMO, without one, your spinning your wheels! get one, now! lol.... I can't believe how much of a difference this simple tool makes.
well, that's it for now..... hope this helps someone, other than just me ;-)
Ginnz!
