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Let's talk about 2 mile cartridges
- Thread starter EXPRESS
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Much better. That gives a .013 neck wall thickness.
Most target/ELR guys using bore rider/boat tail or similiar
and if bullets straight in bore, it don't matter if most of bullet in the case
or in bore as long as straight. And many say too much neck causes problems.
The Lethal one has a shorter neck and we saw it work..
We found that use no expander or min expander and load boat tail tight
with more bullet out in freebore drops pressure at least 6k, and can get
little more speed. Guys like CEB but the seal band sticking up drops
BC maybe 6-8%. If bullet used is bore rider and more out in freebore and straight
in the lands, maybe better, and it is faster with more powder in. Ed
and if bullets straight in bore, it don't matter if most of bullet in the case
or in bore as long as straight. And many say too much neck causes problems.
The Lethal one has a shorter neck and we saw it work..
We found that use no expander or min expander and load boat tail tight
with more bullet out in freebore drops pressure at least 6k, and can get
little more speed. Guys like CEB but the seal band sticking up drops
BC maybe 6-8%. If bullet used is bore rider and more out in freebore and straight
in the lands, maybe better, and it is faster with more powder in. Ed
Hello Express,
I would recommend for you to contact David Pisenti at Skiritai Legacy in Italy; as he is considered one of the foremost direct experienced ELR shooter in Italy
Ciao,
THEIS
D
Deleted member 46119
Guest
Well send me some please. That's a joke son. I I I mean that's a joke (Luney Toons, Forghorn Leghorn).
I would like some to make sure I'm in the right track.
A lot of stuff just worked right, lotta hands to help.
Myself I'm giving that bunch one more finishing pass with last
insert to get exact size of neck to hold bullet without crimping
and make neck corner little less rounded. Polish them up a little.
I'll get you a few to compare.Ed
Myself I'm giving that bunch one more finishing pass with last
insert to get exact size of neck to hold bullet without crimping
and make neck corner little less rounded. Polish them up a little.
I'll get you a few to compare.Ed
D
Deleted member 46119
Guest
I'm as far along as making the bushings. I have all the tooling and now just need to start turning again. About 5 minutes from now after dinner settles.
I even have my annealer tuned for the case and ready to go.
Hello,
Seems there are a few different threads in regards to "2 Mile" Shooting, BUT the threads are geared more to cartridge this vs cartridge that....Let us use this cyber space for discussions in regards to what it actually takes to consistently shoot that distance instead of just cartridge this vs cartridge that.
For sake of conversation lets use a 350gr CEB with G7 of .415 and lets give it a MV of 3400fps (guesstimate of the new 375 cartridges coming online) as base for this analysis.
Lets use target height of 24 inches and width of 36 inches as used at this past KO2M.
At 3400fps MV with .415G7 BC with 350gr CEB you have bullet drop of 6586 inches at 3500 yards.
At 3405fps MV with .415G7 BC with 350gr CEB you have bullet drop of 6563.5 inches at 3500 yards.
That gives you a difference in bullet drop of 22.5 inches with just a 5fps MV change..so KO2M ammunition needs to have 5fps or less in MV deviation.
At 3400fps MV with .415G7 BC with 350gr CEB your danger space for 24 inch height target at 3500 yards is 4 yards..so how accurate is the target distances measured at KO2M
At 3400fps MV with .415G7 BC with 350gr CEB and 5mph full value wind, you get 366.1 inches of bullet deflection at 3500 yards.
At 3400fps MV with .415G7 BC with 350gr CEB and 6mph full value wind, you get 439.3 inches of bullet deflection at 3500 yards.
That gives you a deflection difference of 73.2 inches with just 1mph wind change..so that 1mph wind change accounts for double the width of your target.
Now factor in a combination of the above errors and you get a very very small "error budget" that you must be under in order to fulfill the "2 Mile" task. I am NOT saying it cannot be done or that there are not shooters around the world doing it, but I am saying in order for it to be done "on demand" there are lots more variables than just what cartridge you using.
Factor in other details such as ammunition temperature related to chamber temperature related to increase in MV due to such changes.
Factor in other details such as micro-environments related to NOAA atmospheric elevation formula related to physical terrain related to actual projectile flight path.
Factor in MBIE (muzzle brake induced error) in relation to whether you preload, semi free hold, unload, etc in regards to bipod utilization..that is complicated even further by what type of bipod you use, under rifle, center line rifle or above rifle.
Factor in how precisely calibrated are the adjustments on your scope.
It gives you even less of error budget you are allowed and still make the shot. So we have way more to discuss than just what cartridge does this and what cartridge does that conversations. AND we have not even touched on shooter errors yet. gun)
THEIS
Seems there are a few different threads in regards to "2 Mile" Shooting, BUT the threads are geared more to cartridge this vs cartridge that....Let us use this cyber space for discussions in regards to what it actually takes to consistently shoot that distance instead of just cartridge this vs cartridge that.
For sake of conversation lets use a 350gr CEB with G7 of .415 and lets give it a MV of 3400fps (guesstimate of the new 375 cartridges coming online) as base for this analysis.
Lets use target height of 24 inches and width of 36 inches as used at this past KO2M.
At 3400fps MV with .415G7 BC with 350gr CEB you have bullet drop of 6586 inches at 3500 yards.
At 3405fps MV with .415G7 BC with 350gr CEB you have bullet drop of 6563.5 inches at 3500 yards.
That gives you a difference in bullet drop of 22.5 inches with just a 5fps MV change..so KO2M ammunition needs to have 5fps or less in MV deviation.
At 3400fps MV with .415G7 BC with 350gr CEB your danger space for 24 inch height target at 3500 yards is 4 yards..so how accurate is the target distances measured at KO2M
At 3400fps MV with .415G7 BC with 350gr CEB and 5mph full value wind, you get 366.1 inches of bullet deflection at 3500 yards.
At 3400fps MV with .415G7 BC with 350gr CEB and 6mph full value wind, you get 439.3 inches of bullet deflection at 3500 yards.
That gives you a deflection difference of 73.2 inches with just 1mph wind change..so that 1mph wind change accounts for double the width of your target.
Now factor in a combination of the above errors and you get a very very small "error budget" that you must be under in order to fulfill the "2 Mile" task. I am NOT saying it cannot be done or that there are not shooters around the world doing it, but I am saying in order for it to be done "on demand" there are lots more variables than just what cartridge you using.
Factor in other details such as ammunition temperature related to chamber temperature related to increase in MV due to such changes.
Factor in other details such as micro-environments related to NOAA atmospheric elevation formula related to physical terrain related to actual projectile flight path.
Factor in MBIE (muzzle brake induced error) in relation to whether you preload, semi free hold, unload, etc in regards to bipod utilization..that is complicated even further by what type of bipod you use, under rifle, center line rifle or above rifle.
Factor in how precisely calibrated are the adjustments on your scope.
It gives you even less of error budget you are allowed and still make the shot. So we have way more to discuss than just what cartridge does this and what cartridge does that conversations. AND we have not even touched on shooter errors yet. gun)
THEIS
Cartridge makes difference, Mitch at 2 miles was correcting 110-120 min,
elevation, where the closest competitor was over 150 min. And that also
cut 2 seconds off of the time of flight. And we plan on faster yet,
a 400 gr at 3400, with G7 about .500. I don't shoot except for speed
and powder testing.I'm internal ballistics practitioner. My brain geared to and
filled with that, So we specialize and we let the shooters and
spotters learn Bryon's AB books, we try to get them the speed..
And of course if a team has some special math shortcuts that are more accurate
than the next team, especially in a timed match, most would
not be here talking very much.Ed
elevation, where the closest competitor was over 150 min. And that also
cut 2 seconds off of the time of flight. And we plan on faster yet,
a 400 gr at 3400, with G7 about .500. I don't shoot except for speed
and powder testing.I'm internal ballistics practitioner. My brain geared to and
filled with that, So we specialize and we let the shooters and
spotters learn Bryon's AB books, we try to get them the speed..
And of course if a team has some special math shortcuts that are more accurate
than the next team, especially in a timed match, most would
not be here talking very much.Ed
Ed. I have a question for you and anybody else. Dave Viers had convinced me he could build me a .416 VM based on the 585 case and it would be better long range because of a theoretical better BC. What do others think? What twist? Clearly a 20mm has greater range and I know he built at least one single shot and that certainly would be a good candidate for 2 miles but not practical.
Who is reputable and builds your 375 or a 416 based on the big 585?
Who is reputable and builds your 375 or a 416 based on the big 585?
