Shooter264
Well-Known Member
By comparing all the measurements to the 140 JLK with a verified BC of .639 I wwould say .650 would be a minimum for the 150's. I will be verifying them as soon as marshal gets me a batch.
New 150 matrix test
- Thread starter elkaholic
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Outlaw6.0
Well-Known Member
elkaholic
Well-Known Member
Once 2 or 3 of us check it out, we should have it pretty well dialed in. I wish I had more free time
Shooter264
Well-Known Member
Got transferred back a year ago. Thank god, I was suffering in colofornia!!!
elkaholic
Well-Known Member
Here is the latest update, but I would like someone to check my math. The b.c. #'s are pretty high.
Here is the scoop:
I zeroed the rifle dead on at 100 yards with a 3160 mv. I then went over to my friends where I could shoot at distance (885 yards) I stood a 14' 2x6 straight up and attached a 4x4 piece of cardboard at the bottom where I thought the bullets would hit. I then backed off to the 885 yard distance and fired 3 rounds prone using my bipod and a sandbag. I was a little leary that the rounds might hit near the bottom of the carboard, so used my 2 moa hashmark on the SIII to gain a little more elevation. I aimed flush with the 2x4 top. The wind was variable at approx 10 mph, but blowing from about 11:00 most of the time. Temp was 53 degrees and pressure was 13.50 PSI measured on my Leica 1600, which I later converted on JBM to 27.48 Hg. I fired 3 rounds and went back to the target. The group measured 8" wide by 2" high so I felt pretty good about the drop measurements. The width was probably due to the wind, or maybe the shooter The avg. drop measured 135.3" from the top of the 2x4. I added 18.4" for 2 moa at 885 yards, for a total drop of 153.7". I then punched the #'s using JBM and came up with a G1 of .680 and a G7 of .337. WOW! This is very close to what the 160 gr. Matrix is. When I spoke with Marshal (Matrix) he said the difference in b.c. between the 270's he checked with a 10 grain difference in weight and using the same 2 jackets was very little. The 150 would have some advantage over the 160 because the 150 is a thinner jacket giving a higher sd, thus a higher b.c. all else equal. I have run these tests before and have come out VERY close to the two chrono method. Having said that, I would really like some of you to check my math. The older I get, the more mistakes I make (at least of this kind).......Rich
Here is the scoop:
I zeroed the rifle dead on at 100 yards with a 3160 mv. I then went over to my friends where I could shoot at distance (885 yards) I stood a 14' 2x6 straight up and attached a 4x4 piece of cardboard at the bottom where I thought the bullets would hit. I then backed off to the 885 yard distance and fired 3 rounds prone using my bipod and a sandbag. I was a little leary that the rounds might hit near the bottom of the carboard, so used my 2 moa hashmark on the SIII to gain a little more elevation. I aimed flush with the 2x4 top. The wind was variable at approx 10 mph, but blowing from about 11:00 most of the time. Temp was 53 degrees and pressure was 13.50 PSI measured on my Leica 1600, which I later converted on JBM to 27.48 Hg. I fired 3 rounds and went back to the target. The group measured 8" wide by 2" high so I felt pretty good about the drop measurements. The width was probably due to the wind, or maybe the shooter
The avg. drop measured 135.3" from the top of the 2x4. I added 18.4" for 2 moa at 885 yards, for a total drop of 153.7". I then punched the #'s using JBM and came up with a G1 of .680 and a G7 of .337. WOW! This is very close to what the 160 gr. Matrix is. When I spoke with Marshal (Matrix) he said the difference in b.c. between the 270's he checked with a 10 grain difference in weight and using the same 2 jackets was very little. The 150 would have some advantage over the 160 because the 150 is a thinner jacket giving a higher sd, thus a higher b.c. all else equal. I have run these tests before and have come out VERY close to the two chrono method. Having said that, I would really like some of you to check my math. The older I get, the more mistakes I make (at least of this kind).......Rich
barnesuser28
Well-Known Member
Rich, what is your scope height and what was the pressure and temp when you sighted in at 100 yards? Were you shooting almost perfectly flat at 885?
elkaholic
Well-Known Member
Scope height is 1.6" and pressure and temp was the same both distances. I did them back to back.There is about a 1% incline which I corrected to 885.....Rich
Rich,
I'm getting a G7 BC value of 0.322, referenced to the ICAO Standard Atmosphere, which is the BC reference Berger, Nosler, and Lapua use to rate their bullet BC values. ICAO Standard Atmosphere conditions are 29.92 in/Hg atmospheric pressure, 59F, 0% RH.
If your rifle was sighted in at 100 yds under 27.48 Inches/Hg atmospheric pressure and at 53F, I still calculate a G7 BC value of 0.322.
This BC determination was determined using Patagonia Ballistics ColdBore 1.0 ballistics software. It includes an allowance for an 11:00 wind at 10mph. Only thing I didn't include was coriolis, since I didn't know your direction of fire.
Think I did it right.
Paul
I'm getting a G7 BC value of 0.322, referenced to the ICAO Standard Atmosphere, which is the BC reference Berger, Nosler, and Lapua use to rate their bullet BC values. ICAO Standard Atmosphere conditions are 29.92 in/Hg atmospheric pressure, 59F, 0% RH.
If your rifle was sighted in at 100 yds under 27.48 Inches/Hg atmospheric pressure and at 53F, I still calculate a G7 BC value of 0.322.
This BC determination was determined using Patagonia Ballistics ColdBore 1.0 ballistics software. It includes an allowance for an 11:00 wind at 10mph. Only thing I didn't include was coriolis, since I didn't know your direction of fire.
Think I did it right.
Paul
How do you get your 8-32x56mm scope within 1.6" of centerline of bore? My 6-24x50mm is 1.9" above centerline!
With the 1.6 inch scope mount height, I calculate a G7 BC value of 0.338
You were fighting a headwind!
barnesuser28
Well-Known Member
I get .682 G1 and .337 G7 on shooter.
elkaholic
Well-Known Member
Hmmmmm! I wonder why I got those #'s on JBM? When I tested my 190's, I got very nearly what you tested by double chrono. Maybe someone will find a mistake when they run my #'s through JBM?
elkaholic
Well-Known Member
Approx. 45-50
