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PistolPete75
07-08-2008, 7:41 PM
How many of you measure barometric pressure?

I've been messing around with my ballistics software, and came across this. I never calculated this into the equation before.

How important is this is in shooting 1000yards and less?

rksimple
07-08-2008, 7:48 PM
Very important, perhaps the most important environmental factor to get accurate data. Best bet is to set the Kestrels reference altitude to 0 and get the station pressure. This will take elevation and pressure into account when put in the software as station pressure.

PistolPete75
07-08-2008, 7:55 PM
Nope don't have a kestrel yet. Mayby when I get one you can show me how to use it.

For the mean time, if I just use the standard barometric pressure it shouldn't effect mid range shooting right (600yard and less)?

rksimple
07-08-2008, 8:00 PM
At 600 and less, its not too big of a deal. Just use the standard pressure at that elevation and you should be good to go. It should get you within 1 MOA or so.

PistolPete75
07-08-2008, 8:04 PM
A descent kestrel is like $150, right?

Which model has that feature? Kestrel 4000 with the density altitude feature?

rksimple
07-08-2008, 8:10 PM
About that. You don't need the fancy ones. Humidity won't matter inside of 1000 so you can skip that feature. I have the 2500 and it does all that I need.

PistolPete75
07-08-2008, 8:16 PM
good looking out. after my rock barrel purchases, this is next on my list.

Teletiger7
07-08-2008, 8:29 PM
Do any of you guys have experience with the Brunton ADC? I found a good deal on it and wondering how well it would work for these types of measurements.

http://www.opticsplanet.net/brunton-instruments-adc-pro.html

rksimple
07-08-2008, 8:39 PM
That brunton looks good. Looks like it will do it all.

PistolPete75
07-08-2008, 8:45 PM
Do any of you guys have experience with the Brunton ADC? I found a good deal on it and wondering how well it would work for these types of measurements.

http://www.opticsplanet.net/brunton-instruments-adc-pro.html

that looks mighty good to me right now. is this thing accurate?

goldfinger
07-08-2008, 8:58 PM
its accurate, i got mine here
http://www.natchezss.com/brand.cfm?contentID=productDetail&brand=BR&category=0&prodID=BRADCPRO

PistolPete75
07-08-2008, 9:03 PM
its accurate, i got mine here
http://www.natchezss.com/brand.cfm?contentID=productDetail&brand=BR&category=0&prodID=BRADCPRO


nice. optics planet price matches. they'll probably ship it for free too.

Teletiger7
07-08-2008, 9:20 PM
that looks mighty good to me right now. is this thing accurate?

I got one on the way. Yes it's free UPS through Opticsplanet. I will put it through some testing when i get it. Try to see how accurate or off it is on my hikes with known elevation points and check the barometer against the weather channel stats for the day.

ar15barrels
07-08-2008, 10:26 PM
A descent kestrel is like $150, right?

Which model has that feature? Kestrel 4000 with the density altitude feature?

I spent some time with the Kestrel folks at the shot show.
I went with the 4000 because it has density altitude.
Density altitude takes everything into account, station pressure, temperature and humidity.
You can use standard atmoshpere conditions in your ballistics software and only adjust for altitude and you will be using the same air density as the density altitude figure.

See my other thread where I posted 7 quicktarget passes at different density altitudes from sea level to 6000ft.
There was 2.5 MOA difference at 1000yds.
Of course thats over 2ft so yes, pressure really matters.

Were you hitting higher than expected sunday?
If so, that's because we were shooting at 6300ft density altitude in a standard atmoshpere.

PistolPete75
07-09-2008, 7:55 AM
I spent some time with the Kestrel folks at the shot show.
I went with the 4000 because it has density altitude.
Density altitude takes everything into account, station pressure, temperature and humidity.
You can use standard atmoshpere conditions in your ballistics software and only adjust for altitude and you will be using the same air density as the density altitude figure.

See my other thread where I posted 7 quicktarget passes at different density altitudes from sea level to 6000ft.
There was 2.5 MOA difference at 1000yds.
Of course thats over 2ft so yes, pressure really matters.

Were you hitting higher than expected sunday?
If so, that's because we were shooting at 6300ft density altitude in a standard atmoshpere.

I was shooting higher cause my fc brass spits the bullet out faster then my lupua brass.

Thanks for the info on the model 4000.

rksimple
07-09-2008, 8:00 AM
Pete-run a JBM trajectory on your load and see what 2000 ft of elevation does to your 600 yard dope. Its just a few inches off. Under match conditions, I have a hard time holding that difference.

PistolPete75
07-09-2008, 8:32 AM
at 2500 it's the same at 4.1mills. at 4500 it's 4.0mills. not that much difference.

seems to be right on. using a slightly faster load and looking up my old angeles data, 600yard dope is right on.

Flyliner
07-09-2008, 1:32 PM
How does one use a density altitude reading with JBM, which fields do you fill out and which boxes do you check/uncheck?

Vu 308
07-09-2008, 2:40 PM
In my experience Temp is the bigger factor.

Going from 265ASL to WEGC which is 2450ASL it may be 1/4MOA to maybe 1/2MOA higher than my standard dope. But since it has been hotter up here than down there I am willing to bet my dope won't be that far off.

YMMV

wildcard
07-09-2008, 3:00 PM
To my understanding, density altitude accounts for temperature. It's sort of like a summary of all the environmental factors you would normally have to account for (e.g. temperature, humidity, elevation) expressed as elevation/altitude only.

Going by this logic..

If you are using JBM, check the box marked "Standard Atmosphere at Altitude" at the bottom left. Now all you have to do is use Density Altitude as your elevation/altitude.

Somebody please correct me if i'm wrong as I haven't actually uses "Density Altitude" before. I think I'm correct though from the few minutes I just spent tinkering with JBM..

Vu 308
07-09-2008, 3:15 PM
The man to ask about this type of stuff would be Blaine Fields of Lex Talus Corp.

He has posted on our club forum before about ballistics and it made my brain hurt reading it. The man is a wizzard at this and is the brains behind the Field Firing Solution. (he donated 3 copies this year to our prize table)

I never really messed with the density alt. Just temp and stardard info. My computer dope is within .5MOA out to 1K

rksimple
07-09-2008, 4:29 PM
Temp is quite important if you're using a temperature sensitive powder. The resulting increase in velocity will throw off your dope more than most environmental factors.

ETA: My RL15 load goes from 2830 in the winter to 2890 in the summer (155 scenars). That seems to make more of a difference than anything.

ar15barrels
07-09-2008, 7:01 PM
If you are using JBM, check the box marked "Standard Atmosphere at Altitude" at the bottom left.
Now all you have to do is use Density Altitude as your elevation/altitude.

I don't use JBM, but that sure sounds right to me.
The neat thing about Density Altitude is that you can print out dope sheets for each increment (sea level, 1000, 2000, 3000 etc...) and when you get to a match, look at the density altitude and grab the nearest density altitude range card.
You can ignore station pressure, temperature, altitude and humidity if you work within the "standard atmosphere" model that density altitude is based on.

postal
07-09-2008, 8:46 PM
Temp is quite important if you're using a temperature sensitive powder. The resulting increase in velocity will throw off your dope more than most environmental factors.

ETA: My RL15 load goes from 2830 in the winter to 2890 in the summer (155 scenars). That seems to make more of a difference than anything.

I use varget because it's supposed to be fairly stable regardless of temp. I'm curious though, do you take extra care to keep your ammo in the shade?

rksimple
07-10-2008, 5:38 AM
I use varget because it's supposed to be fairly stable regardless of temp. I'm curious though, do you take extra care to keep your ammo in the shade?

Of course. Often times that's negated by having a round sit in a hot chamber a little longer. I didn't have those swings with varget. Oh well. Only 10 more pounds of RL15 to go before I go back to varget.

PistolPete75
07-10-2008, 8:35 AM
Of course. Often times that's negated by having a round sit in a hot chamber a little longer. I didn't have those swings with varget. Oh well. Only 10 more pounds of RL15 to go before I go back to varget.

I'm down to my last pound of rl15 which is going in my last loads of my 168s for the year. I have a 8lb jug of varget that I will be testing soon after the scprc match. Hope I get good results with it.

rksimple
07-10-2008, 8:41 AM
I'm down to my last pound of rl15 which is going in my last loads of my 168s for the year. I have a 8lb jug of varget that I will be testing soon after the scprc match. Hope I get good results with it.

You should. I always had great results with Varget. I got the RL15 because I had a buttload of midway money and they didn't carry Varget. I got 20 pounds and am halfway through it. I'll finish out this years matches with it, but Varget is calling me...so is a 243 surgeon...

PistolPete75
07-10-2008, 8:43 AM
.243 Surgeon, nice. that is going to be a laser rig.

don't they have a surgeon group buy going on?

rksimple
07-10-2008, 8:51 AM
.243 Surgeon, nice. that is going to be a laser rig.

don't they have a surgeon group buy going on?

They did. I messaged him about it and he said due to agreements they had with certain vendors, they wouldn't be doing the standard short actions in the group buy. Oh well. I'll call George and have him start putting it together. He's running a few months out so I have some time to save some money. I'll probably have him do 2 barrels right off the bat. Its nice that he stocks all that stuff.

Cypriss32
07-10-2008, 9:40 AM
LOl 243? You give in easy. 7wsm or 7saum. It will last. Once you cant get the 180s to shoot very well, switch to 175gr SMKS and jump them for ever. About 2k Ill switch to moly and rum those SMKS harder.

Carefull Ryan George is REALLY fast right now. My M70 rebarrel is almost done. Its just getting flueted and then sent back. Will need to have the stock bedded by Randy and thats IT!

rksimple
07-10-2008, 10:29 AM
Well, the 180 bergers are what make the 7 a very capable round. Switching to the 175 smk's, I'm really no better off than the 243 running dtacs at 3000+, not to mention I'd be using a lot more powder and burning up barrels faster with the 7. The dtacs are $90/500 too. I know, its a gamer gun, but what can I say? I'll probably have a 7wsm built up for my out of state hunting in the next couple years. But until then, I think the 243 will serve me better for match shooting. Its just paper after all...

PistolPete75
07-10-2008, 10:44 AM
So what your saying is that your bullets for your .243 will only cost you $90/500? That sounds like a deal. Sounds like a good trade off for the low life on the barrel if bullets are that cheap. Good move. High performance at a reasonable cost.

What's the recoil like on a .243? Pretty much to nothing huh? A .243 braked would probably be like shooting a .223 With that kind of recoil, you should go with a lighter stock. If you get that around 12 pounds fully built that'll be a true performer.

I'm going to stick with my .308, and my small bore rifle will be a .22lr
Shooting a 22lr is more of an even playing field, plus rifle and ammo is butt cheap. My 09 shooting season is going to be mainly .22lr

rksimple
07-10-2008, 11:31 AM
Recoil on the 243 is nothing. I probably won't get a brake. I'm so close to ordering it, but I still have a little doubt. In running the numbers, the 6.5x47 with a long barrel and 139 scenars gives about the same windage as the 243 with dtacs all the way to 1k. The 243 is just flatter and will be better for UKD stuff...at the expense of maybe 1500 rounds less barrel life than the 6.5x47. What do I do? I've been going back and forth for a couple weeks.

PistolPete75
07-10-2008, 11:40 AM
shooting flatter does have it's advantages. more forgiving up to 400/500yards. if your going for performance go all the way. you'll probably end up shooting it just for matches and here and there anyways. pure performance and no regrets. might as well brake it while your at it. shooting a laser rifle that is about 12 pounds would have some serious advantages. i see good all around performance with it. with your s& b scope that thing will be all about performance.

when your getting your surgeon let me know. i might get a short action with you depending on price. short action/ repeater/ 20 moa base/ bolt knob mod

Cypriss32
07-10-2008, 12:01 PM
6x47, Brass is not cheap BUT..... Barrel life is more then good. Shoot same powders as your 308s. it makes life easy, TRUST me.
I shoot Rl22 threw 3 rifles.
BLC-2 threw 3 rifles and RL15 threw the same 3 rifles.

You can shoot the 115gr DTACS at 3000.
The thought of trading my AI 7mm for a S&B 5-25 is tempting and building a 6x47.

Dont waist your time with a brake. I wouldnt brake my 30-06, again. ive opted against running them on my 7mms. You can shoot 100 shots a day and not be bothered at all. 300win+ brake is usefull.

Those lapua ....x47 rounds have ALOT more barrel life then 3,000. I was told 138s touching lands have no been changed in seating depth for 2500 rounds.

rksimple
07-10-2008, 12:09 PM
6x47, Brass is not cheap BUT..... Barrel life is more then good. Shoot same powders as your 308s. it makes life easy, TRUST me.
I shoot Rl22 threw 3 rifles.
BLC-2 threw 3 rifles and RL15 threw the same 3 rifles.

You can shoot the 115gr DTACS at 3000.
The thought of trading my AI 7mm for a S&B 5-25 is tempting and building a 6x47.

Dont waist your time with a brake. I wouldnt brake my 30-06, again. ive opted against running them on my 7mms. You can shoot 100 shots a day and not be bothered at all. 300win+ brake is usefull.

Those lapua ....x47 rounds have ALOT more barrel life then 3,000. I was told 138s touching lands have no been changed in seating depth for 2500 rounds.

Reloading with another powder is no big deal. I have about 10 calibers I load for now, so whats one more. The alluring thing about the 6.5x47 is loading mag length easily with the 139's, good brass, and better barrel life. Getting the 139s up to 2800 should be easy with a 26in tube and that should get me about the same windage as the dtac doing 3000 or so...plus another 2k rounds of barrel life. Decisions.........

Cypriss32
07-10-2008, 12:11 PM
Ryan run a manners GAT, saves weight. Wait till i get my M70 back from GAP and is bedded. You might change your mind about run 7wsm. They are just barrels after all. Minor cost for playing this game.

PistolPete75
07-10-2008, 12:21 PM
Anyone have a complete rifle in a McMillan stock? I would love to try it out.

Cypriss32
07-10-2008, 12:35 PM
Pete you building a new rifle?

PistolPete75
07-10-2008, 12:38 PM
i have two rock barrels that i should be recieving soon. so i have to decide what to do.

i have two hs stocks, 1 700 sa, and i'll have two rock barrels. i will definitely build another .308, but i might sell one of my extra barrels off and build something else. i don't know yet. i really want a custom action like a stiller or surgeon.

if i ever build another competition rifle, i know one thing for sure. bring down the weight as light as you can. my current rifle is just too heavy to go offhand in. mcmillan has so many options, i would love to have their lightest version of like an a3/a5. caliber wise, i don't know yet. i haven't done any research yet.

another issue is that i don't know how much time i'll have for shooting next year. i might have another baby coming on the way. so for now, things are up in the air.

wildcard
07-10-2008, 12:39 PM
i have two rock barrels that i should be recieving soon. so i have to decide what to do.

i have two hs stocks, 1 700 sa, and i'll have two rock barrels. i will definitely build another .308, but i might sell one of my extra barrels off and build something else. i don't know yet. i really want a custom action like a stiller or surgeon.

Haha.. what are you going to do with all them rifles? :) Oh.. pick up your phone!

Cypriss32
07-10-2008, 12:45 PM
Look into manners stocks. I wont buy another MCM now ive used many of Toms stocks. MCM has one thing, molded in camo, that phase is over with. It looks pritty and thats it.

wildcard
07-10-2008, 12:48 PM
Look into manners stocks. I wont buy another MCM now ive used many of Toms stocks. MCM has one thing, molded in camo, that phase is over with. It looks pritty and thats it.

Yeah.. I didn't care much for the McMillan that time you brought one for me to try..

PistolPete75
07-10-2008, 12:54 PM
Haha.. what are you going to do with all them rifles? :) Oh.. pick up your phone!

my current .308, shoot it.

my next .308, give to albert to shoot. if he doesn't, then i'll pull of the stock and sell it and keep the action/barrel as a spare for my aics.

as for the next custom, i would like to build a super light rifle. $$$ and time wise, i have to see. depends on so many factors.

phone, opps. i'll go get it. it's in my car.

rksimple
07-10-2008, 1:03 PM
I'd love to try out the manners. I wouldn't mind something like the T2 with the badger BM. I can get it with a little lighter fill, right? Didn't you do something like that Adam?

PistolPete75
07-10-2008, 1:20 PM
good info the manners. i would love to test out the MCS-GAT.

Cypriss32
07-10-2008, 1:23 PM
Id get the GAT, its SAME as AICS. Its 90% carbon. VERY light, Little over 4.5 pounds with bottom metal and stock pack.
Rifle will be under 10 pounds, i have GAP deep flute my barrel.
This will be my new match rig, USO 3.2-17x Milspec canadian scope If i can pull that money from somewere.
http://i6.photobucket.com/albums/y230/adam5432002/GAT002-1.jpg
http://i6.photobucket.com/albums/y230/adam5432002/GAT001-1.jpg

Cypriss32
07-10-2008, 1:25 PM
http://i6.photobucket.com/albums/y230/adam5432002/AIMAN004.jpg
http://i6.photobucket.com/albums/y230/adam5432002/AIMAN005.jpg
http://i6.photobucket.com/albums/y230/adam5432002/AIMAN006.jpg
http://i6.photobucket.com/albums/y230/adam5432002/AIMAN007.jpg
http://i6.photobucket.com/albums/y230/adam5432002/AIMAN008.jpg

wildcard
07-10-2008, 1:29 PM
http://i6.photobucket.com/albums/y230/adam5432002/GAT002-1.jpg

I thought it was a paintball gun stock.. your green lamp looked like a hopper..

rksimple
07-10-2008, 1:44 PM
Id get the GAT, its SAME as AICS. Its 90% carbon. VERY light, Little over 4.5 pounds with bottom metal and stock pack.
Rifle will be under 10 pounds, i have GAP deep flute my barrel.
This will be my new match rig, USO 3.2-17x Milspec canadian scope If i can pull that money from somewere.
http://i6.photobucket.com/albums/y230/adam5432002/GAT002-1.jpg
http://i6.photobucket.com/albums/y230/adam5432002/GAT001-1.jpg

Now I have your verizon password.

wildcard
07-10-2008, 1:46 PM
Now I have your verizon password.

Hahahahaha. Now That's funny.

rksimple
07-10-2008, 1:49 PM
But seriously, the stock looks awesome. I liked the feel of various mcm's I shot, but the AICS feels so stable. I'll have to get behind a lot of rifles at the scprc to see what they feel like. That manners T2 or T4, with a weight of less than 3 lbs, is super appealing.

wildcard
07-10-2008, 1:52 PM
Who makes that stock pack?

ar15barrels
07-10-2008, 1:57 PM
Now I have your verizon password.

I was thinking the same thing, but you beat me to the punch.

PistolPete75
07-10-2008, 4:12 PM
so is everyone packed for the match?

rksimple
07-10-2008, 4:15 PM
so is everyone packed for the match?

Not yet. I'll be doing it all tomorrow. Got 200 rounds loaded. Is anyone going to hit angeles tomorrow?

PistolPete75
07-10-2008, 4:20 PM
i got babysitting duties tomorrow. i have to finish reloading today, and perhaps the rest tomorrow. i'm deciding how to pack for tomorrow. gunslinger or my drab mat/mechanics bag.

rksimple
07-10-2008, 4:29 PM
I'll have everything in the gunslinger. Hopefully it all fits.

wildcard
07-10-2008, 4:37 PM
Not yet. I'll be doing it all tomorrow. Got 200 rounds loaded. Is anyone going to hit angeles tomorrow?

I'll be losing $$$ tomorrow going to WEGC.. but I hope it'll pay off this weekend :)

You know how I complained about the Gunslinger not having a side handle for those times where you really don't need to gear it up on your back to go 10 yards? I solved the problem by braiding paracord on the side molle straps and making a handle.

Cypriss32
07-10-2008, 6:06 PM
Not yet. I'll be doing it all tomorrow. Got 200 rounds loaded. Is anyone going to hit angeles tomorrow?

ASR tommarrow wana meet at my house at 8am?

ar15barrels
07-10-2008, 7:07 PM
Not yet. I'll be doing it all tomorrow. Got 200 rounds loaded. Is anyone going to hit angeles tomorrow?

Meet at Jack-in-the-box at 5:45 tomorrow morning if you want to shoot from the WEGC 500M line at sunrise tomorrow...
You can only go with a member, but I'm a member and I'll be there.

wildcard
07-10-2008, 7:12 PM
Meet at Jack-in-the-box at 5:45 tomorrow morning if you want to shoot from the WEGC 500M line at sunrise tomorrow...
You can only go with a member, but I'm a member and I'll be there.

wait.. can we ONLY shoot 500 yds? Or is there steel in between too?

ar15barrels
07-10-2008, 7:13 PM
wait.. can we ONLY shoot 500 yds? Or is there steel in between too?

There's steel in bewteen.
We could also go to the 200yd or 300yd lines too.
I just think we should start at 500m.

Don't forget the spray paint.

wildcard
07-10-2008, 7:20 PM
There's steel in bewteen.
We could also go to the 200yd or 300yd lines too.
I just think we should start at 500m.

Don't forget the spray paint.

Yup yup. i'll bring the orange paint.

Prc329
07-10-2008, 8:10 PM
:(

Well family first. Next year. I'll have plenty of time to work on my wind reading skils. BTW I finally got a job in SD. No more spending the week in Long Beach :D

ar15barrels
07-10-2008, 8:36 PM
I finally got a job in SD.
No more spending the week in Long Beach :D

You ought to update your profile. ;)

Prc329
07-10-2008, 9:05 PM
You ought to update your profile. ;)

You are correct.

wildcard
07-10-2008, 9:26 PM
You are correct.

Don't you hate that.. :)