600 IBS practice day at T'ville
Posted: Sun Feb 25, 2007 8:24 pm
Well our first ever go at 600 has been fun for those that attended. As i thought the heat, mirage and wind kept a few away with only six of us turning up. Suprisingly the wind was quite a bit slower than the 20-25 knots we were having in town and was somewhere around the 10-15 mark as a maximum with drop-offs to less than 5 knots on the odd occasion lasting only a minute or so. The mirage was quite good aswell with times of near perfect vision of the target when the cloud cover came in. All in all not a real horrible day.
As for the groups and scores there were some mixed results. The two 6 BRs showed a decisive edge in the light gun area over the one 223 and two 284s. There was one heavy gun being JRs and i will let him tell you all about it. Needless to say a drop port magnum with 187 BIBs is in a seperate class. The 223 was a lot better than what most of us felt it would be, complete with a 55 grain Ballistic Tip Nosler pill at 3200 fps, it was able to hold about 1 MOA in the conditions. The 284s were diametrically opposite each other with the 168 SMK showing a clear edge over the others 175 SMKs. Both did shoot a single group of around the 2.75 inch mark but the 175 SMKs loaded in Eric Gs rifle showed a very clear vertical pattern in the following 3 groups with one being well over the six inch mark. Of the two 6 BRs, Chris Js with the Lapua 105 and 30 grains of 2208 and a 205M showed a flat 3 incher for his first up group in tricky wind and his follow up group of .5 of a grain more powder nearly doubled the vertical component of his first at the 2.5 inch mark.With my own 6 BR i fired 10 shot groups as i wanted to do an extended test of SMKs over the Lapua 105. The first group was the Lapuas at 4.7 inches, 8 in 2.6 inches and 2 dropping out of the sky. Next up i shot the SMK in two groups of five, just pausing briefly to allow the marker to circle the five shots and then i continued with the next 5 to complete the 10 shot group. The 10 shot group measured 5.3 inches. The first five were selected on meplat cutting where there was a piece of the pie missing whereas the next five were selected on concentric meplat cuts as in a circle within the circle for those familiar with my style of bullet selection and yet another attempt to convince myself that i don't need a Juenke. The first five shots gave the measured 5.3 inch group with a very open inverted triangle shape and the second group of five were inside the first group and measured 3.2 inches, 4 in 1.25 inches with the fifth split right on a wind push. For me the choice is either to go with the Lapua that measures good and have few cast-offs but drop the occasional low one, or go with the SMK that measures like a cow turd and has a cast-off rate of over 60%, but when you do your bit they can really shoot.
Finally i fired one five shot group with the Lapuas and 33.5 grains of H4350 but instead of the 450 i used the 210M in the opened up primer pockets and flasholes of the Lapua 6BR cases. The group measured 2.85 inches with 4 Liberals and again 1 Green left of centre this time, but the whole group was elevated 9.25 inches from the small rifle primed group shot earlier. Knowing that this load at 200 yds impacted 1 inch higher (.5 minute) than the standard load with the 450, this elevation change would have to be caused by an increase of almost 100 fps, placing this load at around 3020 fps as i know the original load runs at 2930 fps. As i said in another post, i have yet to try the 215M, but i would expect atleast another 50 fps as i have done in some of my other chamberings using both this powder and primer. Primers were quite rounded and the cases showed no signs of stress and would freely re-chamber so i would assume that bumping is still a little ways off yet.
As for scores, the target is very generous as compared to a Fly target, and there were many scores in the high 40s. I would expect that a 50 with some Xs should not be to hard to get.
Generally this shoot is the same as 1000 IBS excepting the Heavy Guns only shoot 5 shots for each of their 4 targets as opposed to 10 shots for each of 2 targets, which makes it a walk in the park both for the barrels and the shooters. Overall this shoot is F Class without the spotting, and group shooting without the ability to see a thing at the target. It is easy to see why a whole brigade of cruiser weight 6 BRs/Dashers complete with their drop port Stiller actions, are starting to dominate the scene in the US. My old Hunter gun with an aging barrel seems pedestrian compared to the likes of JRs drop ported magnum as at one point we both started at the same time and he had one through the target, three in flight and one in the barrel before i had the second fired. It is very clear why the 6 mil is the caliber of choice in the Light Guns as re-aquisitioning of the rifle is paramount. Do not expect to see any bullet holes unless they are in the white X ring or outside the blue of the 9 ring and this would have to be on a good day with a 6 mil. This is a fun shoot for those that like to either chase the groups or the scores, but i can see that there is a side of this shoot that can catch the very serious participant very easily. As for me it is clearly a lot of fun but i also see the need to nail Daves feet to the floor so he can make me some more of his wonderful 88 grain flat base pills while i sit at the CAD and design another gun.
Our first official match is on March 11 and those that need any assistance would be best advised to contact JR as i am always busy meplat cutting golf balls these days.
Tony Z.
As for the groups and scores there were some mixed results. The two 6 BRs showed a decisive edge in the light gun area over the one 223 and two 284s. There was one heavy gun being JRs and i will let him tell you all about it. Needless to say a drop port magnum with 187 BIBs is in a seperate class. The 223 was a lot better than what most of us felt it would be, complete with a 55 grain Ballistic Tip Nosler pill at 3200 fps, it was able to hold about 1 MOA in the conditions. The 284s were diametrically opposite each other with the 168 SMK showing a clear edge over the others 175 SMKs. Both did shoot a single group of around the 2.75 inch mark but the 175 SMKs loaded in Eric Gs rifle showed a very clear vertical pattern in the following 3 groups with one being well over the six inch mark. Of the two 6 BRs, Chris Js with the Lapua 105 and 30 grains of 2208 and a 205M showed a flat 3 incher for his first up group in tricky wind and his follow up group of .5 of a grain more powder nearly doubled the vertical component of his first at the 2.5 inch mark.With my own 6 BR i fired 10 shot groups as i wanted to do an extended test of SMKs over the Lapua 105. The first group was the Lapuas at 4.7 inches, 8 in 2.6 inches and 2 dropping out of the sky. Next up i shot the SMK in two groups of five, just pausing briefly to allow the marker to circle the five shots and then i continued with the next 5 to complete the 10 shot group. The 10 shot group measured 5.3 inches. The first five were selected on meplat cutting where there was a piece of the pie missing whereas the next five were selected on concentric meplat cuts as in a circle within the circle for those familiar with my style of bullet selection and yet another attempt to convince myself that i don't need a Juenke. The first five shots gave the measured 5.3 inch group with a very open inverted triangle shape and the second group of five were inside the first group and measured 3.2 inches, 4 in 1.25 inches with the fifth split right on a wind push. For me the choice is either to go with the Lapua that measures good and have few cast-offs but drop the occasional low one, or go with the SMK that measures like a cow turd and has a cast-off rate of over 60%, but when you do your bit they can really shoot.
Finally i fired one five shot group with the Lapuas and 33.5 grains of H4350 but instead of the 450 i used the 210M in the opened up primer pockets and flasholes of the Lapua 6BR cases. The group measured 2.85 inches with 4 Liberals and again 1 Green left of centre this time, but the whole group was elevated 9.25 inches from the small rifle primed group shot earlier. Knowing that this load at 200 yds impacted 1 inch higher (.5 minute) than the standard load with the 450, this elevation change would have to be caused by an increase of almost 100 fps, placing this load at around 3020 fps as i know the original load runs at 2930 fps. As i said in another post, i have yet to try the 215M, but i would expect atleast another 50 fps as i have done in some of my other chamberings using both this powder and primer. Primers were quite rounded and the cases showed no signs of stress and would freely re-chamber so i would assume that bumping is still a little ways off yet.
As for scores, the target is very generous as compared to a Fly target, and there were many scores in the high 40s. I would expect that a 50 with some Xs should not be to hard to get.
Generally this shoot is the same as 1000 IBS excepting the Heavy Guns only shoot 5 shots for each of their 4 targets as opposed to 10 shots for each of 2 targets, which makes it a walk in the park both for the barrels and the shooters. Overall this shoot is F Class without the spotting, and group shooting without the ability to see a thing at the target. It is easy to see why a whole brigade of cruiser weight 6 BRs/Dashers complete with their drop port Stiller actions, are starting to dominate the scene in the US. My old Hunter gun with an aging barrel seems pedestrian compared to the likes of JRs drop ported magnum as at one point we both started at the same time and he had one through the target, three in flight and one in the barrel before i had the second fired. It is very clear why the 6 mil is the caliber of choice in the Light Guns as re-aquisitioning of the rifle is paramount. Do not expect to see any bullet holes unless they are in the white X ring or outside the blue of the 9 ring and this would have to be on a good day with a 6 mil. This is a fun shoot for those that like to either chase the groups or the scores, but i can see that there is a side of this shoot that can catch the very serious participant very easily. As for me it is clearly a lot of fun but i also see the need to nail Daves feet to the floor so he can make me some more of his wonderful 88 grain flat base pills while i sit at the CAD and design another gun.
Our first official match is on March 11 and those that need any assistance would be best advised to contact JR as i am always busy meplat cutting golf balls these days.
Tony Z.
Those guys in Adelaide re a bit slow answering emails 
but I have sent the money down for 200x200g Sierra's, they should be here in time for the six hundred.
.