6mm vs 7mm in the wind - Am I missing something?
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How many people are running 2 rifles? Say a 6mm for the shorts and a 7mm for the longs? To me it seems like the ideal situation.
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Well this may be the plan, love my 6BR but have a 7mm almost ready for longs, tough days etc. Lets see how it works out ... As others have said a good 7mm can keep up to a 6BR even at 300m, but do you need it ? probably not for club shoots, or still mornings at 300 in a comp etc. Ammo availability is a factor too.
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Well this may be the plan, love my 6BR but have a 7mm almost ready for longs, tough days etc. Lets see how it works out ... As others have said a good 7mm can keep up to a 6BR even at 300m, but do you need it ? probably not for club shoots, or still mornings at 300 in a comp etc. Ammo availability is a factor too.
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Seddo, Thats my goal. Run those two cal with Hybrids or the 180gr SMK in the 7mm at around 2850fps and the 6mm at around 3000fps with a good bullet. That should cover it all I think. I was thinking 300WSM with 215gr Hybrids but the recoil wouldnt have been nice in my current rifle and I cant afford to build another whole new rifle....yet.
The main reason I went with a 6mm for my first F-Open rifle is that I wanted something I could learn with relativily easily. I knew when I went in it wasent as good in the wind as the 7mm but the lower recoil and ease of shooting it would help me focus on my wind reading and making good shots. I shot my first 60 at 700yds with this rifle the first application I ever shot it. I was hooked then and considering that F-Open isnt that big here in WA...yet, a 6mm would serve me well in that regard for mainly club shoots and the occasional OPM and this years Queens. but thats gonna change with Brad Y and Courtz Day both using 284 Shehanes now and us going to tassie next year. I'd love to have a 7mm barrel ready for Tassie but my 6mm one will need replacing soon as it will have nearly 1000rds on it after the Queens and Duke. I could keep using it and get a 7mm but the cost of running a 7mm also comes into it for now. I can probably swing a new barrel but cases, dies, bullets, etc will make that alot more.
The main reason I went with a 6mm for my first F-Open rifle is that I wanted something I could learn with relativily easily. I knew when I went in it wasent as good in the wind as the 7mm but the lower recoil and ease of shooting it would help me focus on my wind reading and making good shots. I shot my first 60 at 700yds with this rifle the first application I ever shot it. I was hooked then and considering that F-Open isnt that big here in WA...yet, a 6mm would serve me well in that regard for mainly club shoots and the occasional OPM and this years Queens. but thats gonna change with Brad Y and Courtz Day both using 284 Shehanes now and us going to tassie next year. I'd love to have a 7mm barrel ready for Tassie but my 6mm one will need replacing soon as it will have nearly 1000rds on it after the Queens and Duke. I could keep using it and get a 7mm but the cost of running a 7mm also comes into it for now. I can probably swing a new barrel but cases, dies, bullets, etc will make that alot more.
Shaun aka 'Quick'
Yanchep, Western Australia
308 Win F/TR & F-S
7mm F-Open Shooter.
Yanchep, Western Australia
308 Win F/TR & F-S
7mm F-Open Shooter.
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The choice is easy get one of each cal!
I'm not going to shoot my 7mm all that much honestly. It's being saved to decimate the rest of the country at tassie next year. My 6.5mm will get most use in WA prize shoots and my dasher will be for club use with maybe a hummer barrel left for prize shoots or short ranges.
My thoughts are that wind reading has to be number one. Although if you don't start with a gun that is capable of holding good waterline at long range then it does make things hard. So when it comes to trigger time I think that you need to still be able to make the correct call. Now heavy and high bc bullets do compensate for the error made in those calls.
Like has been mentioned your wind reading skills will be the same for a 6 or 7mm so if you score a 59.6 with the 7mm and a 58.5 with a 6mm and conditions were similar etc etc you can look at it and see that the 7mm is going to be of benefit. There are other factors too if you struggle with recoil then maybe running smaller calibers is for you, no point flinching and expecting to shoot 60's day in or day out.
There are the odd shooters who can drive 6's better than others can drive 7's. What is scary is put them behind a caliber that drifts less and you have one hard to beat SOB! But that's the name of the game in FO, you want to be competitive you use everything you legally can plus good wind reading to do well. But I must stress club shooting I see as just a bit of fun. Save some money and play with a nice easy to shoot cal until its time to practice for a prize shoot then get your 7mm out to rock and roll with.
I'm not going to shoot my 7mm all that much honestly. It's being saved to decimate the rest of the country at tassie next year. My 6.5mm will get most use in WA prize shoots and my dasher will be for club use with maybe a hummer barrel left for prize shoots or short ranges.
My thoughts are that wind reading has to be number one. Although if you don't start with a gun that is capable of holding good waterline at long range then it does make things hard. So when it comes to trigger time I think that you need to still be able to make the correct call. Now heavy and high bc bullets do compensate for the error made in those calls.
Like has been mentioned your wind reading skills will be the same for a 6 or 7mm so if you score a 59.6 with the 7mm and a 58.5 with a 6mm and conditions were similar etc etc you can look at it and see that the 7mm is going to be of benefit. There are other factors too if you struggle with recoil then maybe running smaller calibers is for you, no point flinching and expecting to shoot 60's day in or day out.
There are the odd shooters who can drive 6's better than others can drive 7's. What is scary is put them behind a caliber that drifts less and you have one hard to beat SOB! But that's the name of the game in FO, you want to be competitive you use everything you legally can plus good wind reading to do well. But I must stress club shooting I see as just a bit of fun. Save some money and play with a nice easy to shoot cal until its time to practice for a prize shoot then get your 7mm out to rock and roll with.
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I think of it as the "Fuzzy zone".
You line up the target and check out the wind conditions. Its obviously going a certain direction at a certain speed.
You put down the sighters and determine your wind correction. This correction will have some amount of +or_ value as the wind changes. This is the "Fuzzy zone".
You are confident that your next shot will land within this zone but not 100% positive exactly where to the mm.
The better wind readers and shooters will have a smaller "Fuzzy Zone" than the average mug shooter like me.
Those that shoot a high BC bullet will also have a smaller "Fuzzy zone" than those that shoot a lower BC bullet given similar shooter skill level.
Some days things go well for the shooter and things are not so "Fuzzy", on other days it can be so "Fuzzy" that it is more like a thick fog!
You line up the target and check out the wind conditions. Its obviously going a certain direction at a certain speed.
You put down the sighters and determine your wind correction. This correction will have some amount of +or_ value as the wind changes. This is the "Fuzzy zone".
You are confident that your next shot will land within this zone but not 100% positive exactly where to the mm.
The better wind readers and shooters will have a smaller "Fuzzy Zone" than the average mug shooter like me.
Those that shoot a high BC bullet will also have a smaller "Fuzzy zone" than those that shoot a lower BC bullet given similar shooter skill level.
Some days things go well for the shooter and things are not so "Fuzzy", on other days it can be so "Fuzzy" that it is more like a thick fog!
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Two guns - hat's sort of where I'm heading at the moment.
My 6BR nails them in quiet conditions until I get to 9 or 10 when those ones that drop out the bottom at Belmont drop way out - and then when it gets rough at any range after 6...... I'm not about to run 2 rifles (I want a lathe to replace the one that got wet in 2011 & a boat might come in handy) so I'm just going for a second barrel. As I sort of explained earlier, I have a spare .30 tube, so I'm using a case that fit my bolt face.
Maybe I'll get to prove my contention that the biggest calibre holds elevation best.
My 6BR nails them in quiet conditions until I get to 9 or 10 when those ones that drop out the bottom at Belmont drop way out - and then when it gets rough at any range after 6...... I'm not about to run 2 rifles (I want a lathe to replace the one that got wet in 2011 & a boat might come in handy) so I'm just going for a second barrel. As I sort of explained earlier, I have a spare .30 tube, so I'm using a case that fit my bolt face.
Maybe I'll get to prove my contention that the biggest calibre holds elevation best.
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Seddo
Will be interesting to hear how a 7 twist 22.250AI goes. A few years ago we had a member who tried a 22.250 with 8 twist and it would regularly vaporise Amax's 50 metres from the muzzle. Calculate the rotational rpm of an 80 grainer at the velocity you could achieve (approx 3400fps) and you will realise why some projectiles may not hold together. The Sierra's were less of a problem as far as blowing up was concerned.
Regards Malcolm.
Will be interesting to hear how a 7 twist 22.250AI goes. A few years ago we had a member who tried a 22.250 with 8 twist and it would regularly vaporise Amax's 50 metres from the muzzle. Calculate the rotational rpm of an 80 grainer at the velocity you could achieve (approx 3400fps) and you will realise why some projectiles may not hold together. The Sierra's were less of a problem as far as blowing up was concerned.
Regards Malcolm.
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Seddo
Will be interesting to hear how a 7 twist 22.250AI goes. A few years ago we had a member who tried a 22.250 with 8 twist and it would regularly vaporise Amax's 50 metres from the muzzle. Calculate the rotational rpm of an 80 grainer at the velocity you could achieve (approx 3400fps) and you will realise why some projectiles may not hold together. The Sierra's were less of a problem as far as blowing up was concerned.
Regards Malcolm.
Will be interesting to hear how a 7 twist 22.250AI goes. A few years ago we had a member who tried a 22.250 with 8 twist and it would regularly vaporise Amax's 50 metres from the muzzle. Calculate the rotational rpm of an 80 grainer at the velocity you could achieve (approx 3400fps) and you will realise why some projectiles may not hold together. The Sierra's were less of a problem as far as blowing up was concerned.
Regards Malcolm.
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Matt P wrote:Got a 30/338 Lapua reamer here, anyone interested !!!! Big bullet, capable of big velocity and recoil, reckon it'll be the next big thing !!!![]()
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Matt P
Matt,
I ordered a 7mm-338 Lap Mag and a 30-338 Lap Mag reamer a barrels a while ago. I went with a un improved case as i didnt think they needed more capacity.
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Seddo
Moe City Rifle Club
Seddo
Moe City Rifle Club
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Malcolm,
I wish i had of gone with an 8 or 9 twist but due tot he low round count i am expecting i might not have to live with it for a long time, i am also wishign i went longer than 26". I have been fireforming them with a mild charge of 2217 keeping the velocity around 2800 but ran into issues when the neck diameter wasnt what i thought it was going to be so i had to stop until i did some turning. I have a few boxs of Sierra and Berger 90's for when the cases are ready to go, if i have to drop the velocity so be it but i will find out the fun way!!
I wish i had of gone with an 8 or 9 twist but due tot he low round count i am expecting i might not have to live with it for a long time, i am also wishign i went longer than 26". I have been fireforming them with a mild charge of 2217 keeping the velocity around 2800 but ran into issues when the neck diameter wasnt what i thought it was going to be so i had to stop until i did some turning. I have a few boxs of Sierra and Berger 90's for when the cases are ready to go, if i have to drop the velocity so be it but i will find out the fun way!!
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Seddo
Moe City Rifle Club
Seddo
Moe City Rifle Club
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some years back, the flavour of the time in pommyland was the 404 Jeffery improved necked down to 7mm.
on paper this had it all.
from memory it drove 180 bergers at 3,400 plus.
then barrels started going south as low as 600 shots, even with bisley style.
it started life as a long range deer cartridge, and might still be used for this.
now they use the wsm, which probably seems to have really good life in comparison.
I suspect people sometimes hope that speed will do it all for them, when the elephant in the room is how much to wind the sight. kind of an attempt to avoid the issue.
when you think about it, a stolle fclass action fitted with a 280 Ackley barrel
is probably as good as it gets.
keep safe,
bruce.
on paper this had it all.
from memory it drove 180 bergers at 3,400 plus.
then barrels started going south as low as 600 shots, even with bisley style.
it started life as a long range deer cartridge, and might still be used for this.
now they use the wsm, which probably seems to have really good life in comparison.
I suspect people sometimes hope that speed will do it all for them, when the elephant in the room is how much to wind the sight. kind of an attempt to avoid the issue.
when you think about it, a stolle fclass action fitted with a 280 Ackley barrel
is probably as good as it gets.
keep safe,
bruce.
"SUCH IS LIFE" Edward Kelly 11 nov 1880
http://youtu.be/YRaRCCZjdTM
http://youtu.be/YRaRCCZjdTM
Bruce, simple Physics , or Metallurgy should tell people that burning a given amount of powder (and depending on powder 'speed') in a caliber barrel with a certain surface area in the throat will determine the erosion rate for that combination. So a 6BR with 2208 will out last a 6X47 with 2209 etc etc.
As for 'supermagnums' there is a keen NZ hunting guide who has been there and done that with his 7mm Remington ULTRA magnum (lasted 400 rounds) and has decided on a 7mm 'Practical Magnum' wildcat based on a 300 Win Mag. As target shooters we probably have a lower case capacity as our PRACTICAL limit because we fire more shots ....
for your ref :http://www.ballisticstudies.com/Resources/Articles/The+7mm+Practical.++A+Practical+Magnum..html
As for 'supermagnums' there is a keen NZ hunting guide who has been there and done that with his 7mm Remington ULTRA magnum (lasted 400 rounds) and has decided on a 7mm 'Practical Magnum' wildcat based on a 300 Win Mag. As target shooters we probably have a lower case capacity as our PRACTICAL limit because we fire more shots ....
for your ref :http://www.ballisticstudies.com/Resources/Articles/The+7mm+Practical.++A+Practical+Magnum..html
Last edited by macguru on Mon Sep 09, 2013 10:24 pm, edited 2 times in total.