C
caroby
Guest
Confirmation tests...
I agree with ya Dusty........
Flame suit on........
I did a little test back in spring this year, not a rail gun but a 10.5 Sporter/LV bag gun and at 100yds... Found an evening that was as steady as possiable.... From 0-3mph 65-70 deg <50% humidity (Oh this don't matter.........) A known 6ppc chambered Krieger that was <400 rds.
Known bullets that are ON, and a good lot of 287-08 VV133. Fresh brass and Fed 205's
Brought out a borrowed ibalance 101 scale... Proven to be VERY consistent. once zeroed, didn't move off zero (3 check weights) at all through the evening. All weighed in the stat house.
http://balance.balances.com/scales/899
First I set-up 6 ranges of weight with .1gr increments centered around 28.8gr of 133. 4 dead on 28.8 then a known + and - .1-.3gr loaded case. I.E. ... First group 4-28.8 then one loaded 28.5 all the way to the sixth group at 4 - 28.8 and the fifth case loaded at 29.1.
The three groups that had the known lighter case load of 1 of 5 @ 28.5 - 28.7 showed ZERO vertical on the paper.
Now I did see a tad vertical on the heavyer side (1 of 5 @ 28.9 -29.1).. About 1 bullet, kind of an egg shaped .200 diag 8 oclock to 2 oclock.
Now I did test 28.5 load and 4 - 29.1..... Yes, big virtical 2-3 bullets almost stait up and down 4 tight and the light load down at 7 oclock 2 1/2 bullets...
One .6 gr case showed an obvious problem stay'n in the group.... As expected.
.2 tenths showed me damn near no change... .1 nothing that I could detect.
To cut through all the fluff..... I proved vertical mostly a diagnal one bullet diag with a hotter throw > .3 tenths.
So, I got my Harrell's 90 measurer out.......... The evenings good conditions were coming to an end (Cold air falling "temp inversion" causes bad things.) ...
I did my usual "technique" .. Powder thrown to the hopper and weighed, recorded and dumped into the case.
3 - 5 shot groups from my Harrells @ 53.3 clicks 28.7gr VV 133... Recorded every thrown charge/weighed.... This 53.3 is where I'm "at" a fair amount.
My notes show group one 28.5gr, 28.7, 28.7, 28.6, 28.7......... Group .157 nice and round.
Group two 28.6, 28.6, 28.7, 28.7, 28.5............... Group .179... Dot with half bullet up top... My bad, gun handling...
Group three 28.8, 28.7, 28.7, 28.7, 28.5............... Group .122... Nice and round. .3 gr spread and still a little one.......
This tells me, with a bag gun.................... Just load with the Harrells with my technique and spend the rest of the time between relays/matches >>>Watch'n the flags..!<<<
I'm getting .1-.2 with my thrown loads, but a .3 can sneek in... And I would not be supprised if through a 2-gun that I will shoot a few > .3 on occasion.
At the house I ran like 10 groups of 5 with the Harrells.... 5-thrown and weighed did this 10 times..... 70% were .1, 20% went .2 and 10% went .4 ....
One case outta 50 went -.4gr.......... Not bad at all. Even though........
But I will say that todays competition may very well require loads with no variation AT ALL............... But here in the plains were the wind is a puff'n, .3 gr vary wont be noticed......... Yes, I know this years NBRSA's Nationals was in the Eastern plains but the conditions REQUIRED loads that are ON..!
Can't find the picture of the above tests.....Errrrrr ... But at least kept my notes.
I'd perfer to re-run the same test at Gene Beggs tunnel with a good rail.
Some day.....
cale
Yes .2 is too far, i agree. But .03 is anal. Have you ever weighed primers? How close is your brass in weight? Better yet do they all hold the same water weight after firing once and sizing? Do you sort bullets according to weight down to .01 gr and ogive length? Did you buy one of them meplat trimmers?
I agree with ya Dusty........
Flame suit on........
I did a little test back in spring this year, not a rail gun but a 10.5 Sporter/LV bag gun and at 100yds... Found an evening that was as steady as possiable.... From 0-3mph 65-70 deg <50% humidity (Oh this don't matter.........) A known 6ppc chambered Krieger that was <400 rds.
Known bullets that are ON, and a good lot of 287-08 VV133. Fresh brass and Fed 205's
Brought out a borrowed ibalance 101 scale... Proven to be VERY consistent. once zeroed, didn't move off zero (3 check weights) at all through the evening. All weighed in the stat house.
http://balance.balances.com/scales/899
First I set-up 6 ranges of weight with .1gr increments centered around 28.8gr of 133. 4 dead on 28.8 then a known + and - .1-.3gr loaded case. I.E. ... First group 4-28.8 then one loaded 28.5 all the way to the sixth group at 4 - 28.8 and the fifth case loaded at 29.1.
The three groups that had the known lighter case load of 1 of 5 @ 28.5 - 28.7 showed ZERO vertical on the paper.
Now I did see a tad vertical on the heavyer side (1 of 5 @ 28.9 -29.1).. About 1 bullet, kind of an egg shaped .200 diag 8 oclock to 2 oclock.
Now I did test 28.5 load and 4 - 29.1..... Yes, big virtical 2-3 bullets almost stait up and down 4 tight and the light load down at 7 oclock 2 1/2 bullets...
One .6 gr case showed an obvious problem stay'n in the group.... As expected.
.2 tenths showed me damn near no change... .1 nothing that I could detect.
To cut through all the fluff..... I proved vertical mostly a diagnal one bullet diag with a hotter throw > .3 tenths.
So, I got my Harrell's 90 measurer out.......... The evenings good conditions were coming to an end (Cold air falling "temp inversion" causes bad things.) ...
I did my usual "technique" .. Powder thrown to the hopper and weighed, recorded and dumped into the case.
3 - 5 shot groups from my Harrells @ 53.3 clicks 28.7gr VV 133... Recorded every thrown charge/weighed.... This 53.3 is where I'm "at" a fair amount.
My notes show group one 28.5gr, 28.7, 28.7, 28.6, 28.7......... Group .157 nice and round.
Group two 28.6, 28.6, 28.7, 28.7, 28.5............... Group .179... Dot with half bullet up top... My bad, gun handling...
Group three 28.8, 28.7, 28.7, 28.7, 28.5............... Group .122... Nice and round. .3 gr spread and still a little one.......
This tells me, with a bag gun.................... Just load with the Harrells with my technique and spend the rest of the time between relays/matches >>>Watch'n the flags..!<<<
I'm getting .1-.2 with my thrown loads, but a .3 can sneek in... And I would not be supprised if through a 2-gun that I will shoot a few > .3 on occasion.
At the house I ran like 10 groups of 5 with the Harrells.... 5-thrown and weighed did this 10 times..... 70% were .1, 20% went .2 and 10% went .4 ....
One case outta 50 went -.4gr.......... Not bad at all. Even though........
But I will say that todays competition may very well require loads with no variation AT ALL............... But here in the plains were the wind is a puff'n, .3 gr vary wont be noticed......... Yes, I know this years NBRSA's Nationals was in the Eastern plains but the conditions REQUIRED loads that are ON..!
Can't find the picture of the above tests.....Errrrrr ... But at least kept my notes.
I'd perfer to re-run the same test at Gene Beggs tunnel with a good rail.
Some day.....
cale