What 7mm for a mile

Milo 2.5

The Dalai Lama of the Reload
Full Member
Minuteman
Aug 7, 2014
2,971
2,200
Gillette, WY
All depends, a 7mm saum perfect IMO, but first rd hits no guarantee. If you must hit it, a 28 Nosler your friend.
 

jbailey

Gunny Sergeant
Full Member
Minuteman
Jul 27, 2010
2,231
1,067
Arlington VA
my 7SAUM was a beast at a mile... and in a short action, 26" barrel. SAUM offers nice consistent MV given its short brass.
 

1J04

Lost Squirrel
Full Member
Minuteman
  • Aug 7, 2011
    15,242
    33,025
    PNW WA
    I'm gonna try the 7MM Remington Mag I built piece by piece right here on the Hide. Gonna try some 168 Bergers it loves since I haven't tried out the 180's yet. If that doesn't do it the STW is always the next option.



    obovWpL.jpg
     

    Iamero

    Barksa #1 Fanboy & Professional Paper Puncher
    Supporter
    Full Member
    Minuteman
    Supporter+
  • Feb 14, 2017
    6,735
    1,212
    Michigan
    28 Nosler is the new go to for a 7mm looking to really poke out some shots. Other ones like the 7mm Rem and 280 AI are capable, but the 28 Nosler will get it there faster and easier. Put a 183 SMK in there and let her rip.

    I was going to do a 7mm RUM to get out of the belted magnum round like the 7mm Rem, but it has such a damn long OAL it didn't make sense to do that over a 28 Nosler. The 28 Nosler with a 195 Berger is approximately 3.65" OAL, the factory OAL on a 7mm RUM is 3.600" and much longer with the Berger (although I could be corrected on this). My understanding is that the Nosler has a better case design and it isn't quite as long so it feeds in a standard 3.715" magazine and standard long action without opening up the port. But with so many offerings today you could just stick it in a 3.775" or 3.850" magazine/bottom metal combo and not worry about it.

    The only reason I would do a RUM over the Nosler is because you can find once fired brass on occasion for pretty cheap. The Nosler is so new that there isn't much out there yet and new brass is expensive.
     
    Last edited:

    Fursniper

    Captain, USMM (retired)
    Full Member
    Minuteman
    Feb 13, 2017
    2,173
    52
    Arizona
    28 nosler or 7mm-300 winchester magnum

    100% on the 7mm/300WM. I wanted to build a 28 nosler for the longest time but after watching a couple of friends struggle to get them to shoot unless they downloaded their loads, I decided against it. The 7/300 was easier to get to shoot and got the same velocity as what the downloaded Nosler's were accurate at and did it with less powder and way cheaper brass. Both were using berger 195's.
     

    M47Patton

    Private
    Full Member
    Minuteman
    Feb 10, 2012
    71
    7
    48
    TX
    Timely thread as I am also planning out a purpose built 1 mile rifle, and like the OP I had zeroed on 7mm. Will be interesting to see where this thread goes.

    I keep waffling on different calibers. I thought I had finally settled on 7mm rem mag. The 7 rem mag seems to be a good balance of performance, component availability, component costs and barrel life.

    Then I see a video by "Mark and Sam" comparing the 7mm rem mag to a 300 win mag at 2300 yards (Berger 180 hybrid vs Berger 230 hybrids) and was surprised to see the 300 win mag needed less elevation.

    That sent me back to JBM and it looks like, at typical velocities for each cartridge that the 30 cal actually edges the 7mm (with the only exception being the hornady 7mm 180 eld).

    In truth the difference between the two is slim but it has me rethinking.


    https://www.youtube.com/watch?v=Vjp7SdjMZGA&t=32s
     

    Milo 2.5

    The Dalai Lama of the Reload
    Full Member
    Minuteman
    Aug 7, 2014
    2,971
    2,200
    Gillette, WY
    Timely thread as I am also planning out a purpose built 1 mile rifle, and like the OP I had zeroed on 7mm. Will be interesting to see where this thread goes.

    I keep waffling on different calibers. I thought I had finally settled on 7mm rem mag. The 7 rem mag seems to be a good balance of performance, component availability, component costs and barrel life.

    Then I see a video by "Mark and Sam" comparing the 7mm rem mag to a 300 win mag at 2300 yards (Berger 180 hybrid vs Berger 230 hybrids) and was surprised to see the 300 win mag needed less elevation.

    That sent me back to JBM and it looks like, at typical velocities for each cartridge that the 30 cal actually edges the 7mm (with the only exception being the hornady 7mm 180 eld).

    In truth the difference between the two is slim but it has me rethinking.


    https://www.youtube.com/watch?v=Vjp7SdjMZGA&t=32s

    Not sure on vid, why was the saum part edited to not have the pic in pic, only the hit had the 2nd window. In my experience, the 180 hybrid does not fare well in transonic range, I shoot to 2100 often enough, usually at night, as the DA drops, it is like clockwork at 5800 or so, bullet at 2965, it starts to tumble and chasing your misses is futile. Maybe my 9tw barrel the culprit, I don't know.
     

    M47Patton

    Private
    Full Member
    Minuteman
    Feb 10, 2012
    71
    7
    48
    TX
    Not sure on vid, why was the saum part edited to not have the pic in pic, only the hit had the 2nd window. In my experience, the 180 hybrid does not fare well in transonic range, I shoot to 2100 often enough, usually at night, as the DA drops, it is like clockwork at 5800 or so, bullet at 2965, it starts to tumble and chasing your misses is futile. Maybe my 9tw barrel the culprit, I don't know.

    There was no saum in that video. It was a 7 rem mag. That particular video just got me re-debating 7mm vs 30 cal for my build. If you are shooting out to 2100 on a somewhat regular basis then you are more experienced than I am. Furthest I've shot was 1 mile with a 260.

     

    Milo 2.5

    The Dalai Lama of the Reload
    Full Member
    Minuteman
    Aug 7, 2014
    2,971
    2,200
    Gillette, WY
    There was no saum in that video. It was a 7 rem mag. That particular video just got me re-debating 7mm vs 30 cal for my build. If you are shooting out to 2100 on a somewhat regular basis then you are more experienced than I am. Furthest I've shot was 1 mile with a 260.

    Crap, you're right, my mistake, but a 7mag can't run much harder than a saum, bullet still had to be subsonic.
     

    Madarcher419

    Private
    Minuteman
    Aug 8, 2017
    27
    6
    What is the difference between the 7-300 and the 7-300 Norma mag?What are the advantages or disadvantages?
     

    Jeffvn

    Gunny Sergeant
    Full Member
    Minuteman
    Apr 26, 2004
    1,187
    28
    63
    Las Vegas, NV
    My 7WSM does just fine out to 2,000 yards in the desert with 180 Hybrids and 195 Bergers (desert range is at 2,950 ft. elevation).

    My 7 Dakota runs the 195 Bergers @ 3,1000 she runs solid to 2,200 so far I've not tried beyond that point (JBM ballistics says I have room to go).


    The Answer to your question depends which 7/300 you are referring to. If you mean 7 / 300WSM - that is virtually the same as my 7WSM, more powder capacity than a 7SAUM.

    if you mean 7 / 300 Win. Mag, that is above teh 7WSM in case capacity but well below my 7 Dakota. It should easily best my 7WSM by roughly 100 fps (powder depending of course).

    the 7/ 300 Norma is roughly the same as a 7 / .338LM. lots of powder capacity, should go very fast (195 Bergers NOT a good choice here as they come apart @ 3,100+ ; I've seen it happen)(revision on the 3,100 fps limit of the 195 gr, it is very likely my barrel is toast, so the jacket issues may well be related to gator skin throat, and not super thin jackets).

    JeffVN
     
    Last edited:
    • Like
    Reactions: McCrazy

    mdesign

    Gunny Sergeant
    Full Member
    Minuteman
    Nov 2, 2004
    2,131
    10
    Nebraska
    I'm gonna try the 7MM Remington Mag I built piece by piece right here on the Hide. Gonna try some 168 Bergers it loves since I haven't tried out the 180's yet. If that doesn't do it the STW is always the next option.



    obovWpL.jpg

    Looks like a cool place to shoot regardless of caliber.
     

    1J04

    Lost Squirrel
    Full Member
    Minuteman
  • Aug 7, 2011
    15,242
    33,025
    PNW WA
    Looks like a cool place to shoot regardless of caliber.

    One of my favorite spots. Lot's of angles and can get to 2100. There are 3 draws between here and the target. Usually full of Elk and/or Blacktail, or Black Bear. This spot is growing up fast so it'll be time to move before ya know it. Thankfully they just keep on logging. ;)


    IzIYJJA.jpg


    zghA0R5.jpg
     
    • Like
    Reactions: Rthur

    Madarcher419

    Private
    Minuteman
    Aug 8, 2017
    27
    6
    My 7WSM does just fine out to 2,000 yards in the desert with 180 Hybrids and 195 Bergers (desert range is at 2,950 ft. elevation).

    My 7 Dakota runs the 195 Bergers @ 3,1000 she runs solid to 2,200 so far I've not tried beyond that point (JBM ballistics says I have room to go).


    The Answer to your question depends which 7/300 you are referring to. If you mean 7 / 300WSM - that is virtually the same as my 7WSM, more powder capacity than a 7SAUM.

    if you mean 7 / 300 Win. Mag, that is above teh 7WSM in case capacity but well below my 7 Dakota. It should easily best my 7WSM by roughly 100 fps (powder depending of course).

    the 7/ 300 Norma is roughly the same as a 7 / .338LM. lots of powder capacity, should go very fast (195 Bergers NOT a good choice here as they come apart @ 3,100+ ; I've seen it happen)

    JeffVN

    Thank you ! Can you tell me more about the 7 Dakota?
     

    fdkay

    Gunny Sergeant
    Full Member
    Minuteman
  • Nov 27, 2009
    6,481
    3,390
    59
    Ingleside, Tx
    One of my favorite spots. Lot's of angles and can get to 2100. There are 3 draws between here and the target. Usually full of Elk and/or Blacktail, or Black Bear. This spot is growing up fast so it'll be time to move before ya know it. Thankfully they just keep on logging. ;)


    IzIYJJA.jpg


    zghA0R5.jpg

    I hate you.
     

    1J04

    Lost Squirrel
    Full Member
    Minuteman
  • Aug 7, 2011
    15,242
    33,025
    PNW WA
    I hate you.

    lmfao It's all good Brother. You got plenty of awesome spots in TX I know that'll make us all envious as all hell. You make it over this way let me know and we'll go for a drive. ;) Unfortunately the woods are shut down right now and it's fricking Bear season. Null Bueno.
     

    1J04

    Lost Squirrel
    Full Member
    Minuteman
  • Aug 7, 2011
    15,242
    33,025
    PNW WA
    Haha, walk down and paint the targets and get back with us on this.

    Milo you know that's not happening and even when we take a Quad or just the Truck it's a helluva drive back and forth. Gotta smarten up an get a video feed camera. SOON. :p
     

    Jeffvn

    Gunny Sergeant
    Full Member
    Minuteman
    Apr 26, 2004
    1,187
    28
    63
    Las Vegas, NV
    Sorry for the delay in putting this up. My 7 Dakota holds 92.1 gr. of H2O. From what I understand that is roughly the same volume as the 7/300 Win. Mag.

    JeffVN
     
    Last edited:

    TC308

    Private
    Full Member
    Minuteman
    Feb 2, 2014
    148
    13
    Fort Worth, TX
    I just finished my 28 nosler shooting 195's. Shot at a mile for the first time in my life last weekend and had relative success. I don't know what would be better than a 28 nosler, I'm shooting the 195's at 3160fps from normal cip mag length. I'm not an experienced elr shooter obviously, but I did have 3/5 hits first time out. I think that 195 berger is a cheat bullet haha. I can see how big guns with crazy BC bullets have their appeal.
     

    Bradu

    Full Member
    Full Member
    Minuteman
    Aug 24, 2011
    3,406
    1,527
    IL
    I love my 7 WSM @ a mile. Best 7 out there IMO

    I love mine but I wish brass wasn't so hard to find. I think I might switch to a 28 nosler when my 7 wsm brass is trashed.
     

    stwcattle

    Sergeant
    Full Member
    Minuteman
    Apr 22, 2017
    374
    74
    I have a 7SAUM and would not recommend it for 1 mile shooting. Its capable but there are better choices.

    A hunting partner has a 7-300 Norma. I believe he loads the 180 hunting vld's. I have been really impressed with his results hunting with this rifle and 1 mile steel shots.

    7-300WM be a good choice as well in my opinion.
     

    spaniel

    Sergeant
    Full Member
    Minuteman
    Mar 26, 2006
    400
    216
    People have to add their elevation to the context in long range shooting exploits.

    I was just at a match where we started at 1000 yards and progressed out to 2000 yards. 500ft elevation. Nobody with a 7mm made a mile with the minimum score to move out. A couple 300WMs hung in there, but they were subsonic by 1700-1800 yards. Funny thing was same bullet similar muzzle velocity, one of them was much less stable than the other and dropping bullets so steeply at 1900 that they had to stop shooting it because the bullets were dropping so steeply as to come in past the roof of the target pit but short of the target -- danger danger.

    I'd say whatever you can get 3200fps in, if you want to say supersonic. The 338s, both Lapua and Edge, were so far superior past about 1500. Though one of the 300WM guys I give a lot of props to right up to the point he went subsonic, he was holding his own.
     

    Centurion123

    Private
    Full Member
    Minuteman
    Feb 20, 2017
    30
    4
    What bullet did the 300wm shooters use spaniel? I have found most heavy, high BC 30 cal bullets pass through transonic just fine.
     

    Milo 2.5

    The Dalai Lama of the Reload
    Full Member
    Minuteman
    Aug 7, 2014
    2,971
    2,200
    Gillette, WY
    People have to add their elevation to the context in long range shooting exploits.
    Funny thing was same bullet similar muzzle velocity, one of them was much less stable than the other and dropping bullets so steeply at 1900 that they had to stop shooting it because the bullets were dropping so steeply as to come in past the roof of the target pit but short of the target -- danger danger.

    Good point on elevation!
    Also, just .5 more in twist rate makes a huge difference on extended stability.
     

    M47Patton

    Private
    Full Member
    Minuteman
    Feb 10, 2012
    71
    7
    48
    TX
    People have to add their elevation to the context in long range shooting exploits.

    I was just at a match where we started at 1000 yards and progressed out to 2000 yards. 500ft elevation. Nobody with a 7mm made a mile with the minimum score to move out. A couple 300WMs hung in there, but they were subsonic by 1700-1800 yards. Funny thing was same bullet similar muzzle velocity, one of them was much less stable than the other and dropping bullets so steeply at 1900 that they had to stop shooting it because the bullets were dropping so steeply as to come in past the roof of the target pit but short of the target -- danger danger.

    I'd say whatever you can get 3200fps in, if you want to say supersonic. The 338s, both Lapua and Edge, were so far superior past about 1500. Though one of the 300WM guys I give a lot of props to right up to the point he went subsonic, he was holding his own.

    Everything I'm looking at on paper gives the edge to 7mm at all elevations. Are you saying that in your experience the 338 bullets hold true longer and further once sub sonic, and that's what makes it superior?

    I have only shot out to a mile once, so maybe I'm depending on the JBM results too much.
     

    Milo 2.5

    The Dalai Lama of the Reload
    Full Member
    Minuteman
    Aug 7, 2014
    2,971
    2,200
    Gillette, WY
    Everything I'm looking at on paper gives the edge to 7mm at all elevations. Are you saying that in your experience the 338 bullets hold true longer and further once sub sonic, and that's what makes it superior?

    I have only shot out to a mile once, so maybe I'm depending on the JBM results too much.
    It's not that simple or cut and dried, First, your bullet must be able to pass through the transonic range w/o starting to tumble going into subsonic speeds. Some bullets do, some do not.
    2nd, even though most heavy 338 bullets start out way slower, they retain their speed farther out, a 300gr 30 cal Berger hybrid leaving muzzle at 2875fps will still most likely be supersonic at my elevation to 2300 yards. Where a 7mm bullet needs to start out way way faster accomplish the same thing.
    Make sense?
     

    Diver160651

    Who cares
    Full Member
    Minuteman
    Supporter+
  • Feb 7, 2013
    3,559
    4,196
    La Honda
    vh20 if your going to click "dislike" on a post have the balls to post why and your position. It is very ironic that you have a post very much reenforcing exactly what I said above. I posted this below in the thread were you're having questions regarding the Stability of 147 vrs 140 in trans. Again I am doing so because your issues/tests/questions absolutely illustrates what I was saying above that you disliked. https://www.snipershide.com/shooting/forum/...ldm-comparison


    vh20 -

    It is absolutely - stability, not even sure why up'd question that, from your side by side.

    I'll assume your DA around 2500 the SOS is around 347mps/1140fps so your going to run into trans effect somewhere around 417mps/1,370fps. With that MV, that should be relatively close to 1,097m +/- were you might see the effects transonic. I doesn't surprise me that by 1,216m your seeing performance difference in the two bullet shapes out of the same 1:8 barrel.

    As I said in the post you disliked, nothing is like a light switch as the SOS crossing, it happens WELL before, will slow dispersion, more drop and continue well past. While the longer 147 may perform better in smooth air, it may not as the decay continues. I've seen the same in my 6.5.. better trans predictability in the Amax.

    We've experienced this more so with all the new crop of solids 6.5/7/30/338/375s as well as many of the traditional offerings. Some shapes like the 175SMK 6.5AMAX, 338A-MAX seem far more tolerant and starve of the effects of trans much, much further; but do to lover MV and BC they also enter that space sooner.

    My point of the post you disliked, is that we are better off not thinking of the SOS as a definitive point that is at a static distance and velocity day to day, that all is great until the projectile hits that point, that the effects are over after that point, or that at the exact SOS, bullets trajectories go bad or bullets just tumble. Generally the first sings show up before the SOS crossing as slightly larger grouping and a click here and there more drop than the calculator is asking for, eventually turning to shit, but it is not a light switch event.

    Even the guys at AB can't create a model that is click accurate through transonic as the variables move daily as does engraving, and the ability for each projectile to remain effective. This is exactly why in FFS, CB, AB (you must) etc you are encouraged to tune in trans.

    FWIW (to clarify my magical SOS crossing statement) My Flatline 38's were I shoot ELR runs into trans (condition, day, even time of day dependent) around 2,270 the SOS is 2,850 but trans continues to 4,130 (Theoretically, as it would actually be much shorter as the decay rate accelerates because the speed decelerates with instability) no way can anyone, hit a reasonable sizes target (or any target reliably, when the CEP is many many times the target size). Somewhere between the transonic zone of 2,270-ish thru 4,130-ish, the effects keeps my Flatlines and my system from going any-further. While my Amax's window is shifted back, the shape is more tolerant and thus actually seem to perform better at 2500, that's after the Amax SOS crossing and before the Flatlines, yet both however, are transonic.
     
    Last edited:

    vh20

    Gunny Sergeant
    Full Member
    Minuteman
    Dec 2, 2012
    3,172
    2,844
    57
    vh20 if your going to click "dislike" on a post have the balls to post why and your position. It is very ironic that you have a post very much reenforcing exactly what I said above. I posted this below in the thread were you're having questions regarding the Stability of 147 vrs 140 in trans. Again I am doing so because your issues/tests/questions absolutely illustrates what I was saying above that you disliked. https://www.snipershide.com/shooting/forum/...ldm-comparison


    vh20 -

    It is absolutely - stability, not even sure why up'd question that, from your side by side.

    I'll assume your DA around 2500 the SOS is around 347mps/1140fps so your going to run into trans effect somewhere around 417mps/1,370fps. With that MV, that should be relatively close to 1,097m +/- were you might see the effects transonic. I doesn't surprise me that by 1,216m your seeing performance difference in the two bullet shapes out of the same 1:8 barrel.

    As I said in the post you disliked, nothing is like a light switch as the SOS crossing, it happens WELL before, will slow dispersion, more drop and continue well past. While the longer 147 may perform better in smooth air, it may not as the decay continues. I've seen the same in my 6.5.. better trans predictability in the Amax.

    We've experienced this more so with all the new crop of solids 6.5/7/30/338/375s as well as many of the traditional offerings. Some shapes like the 175SMK 6.5AMAX, 338A-MAX seem far more tolerant and starve of the effects of trans much, much further; but do to lover MV and BC they also enter that space sooner.

    My point of the post you disliked, is that we are better off not thinking of the SOS as a definitive point that is at a static distance and velocity day to day, that all is great until the projectile hits that point, that the effects are over after that point, or that at the exact SOS, bullets trajectories go bad or bullets just tumble. Generally the first sings show up before the SOS crossing as slightly larger grouping and a click here and there more drop than the calculator is asking for, eventually turning to shit, but it is not a light switch event.

    Even the guys at AB can't create a model that is click accurate through transonic as the variables move daily as does engraving, and the ability for each projectile to remain effective. This is exactly why in FFS, CB, AB (you must) etc you are encouraged to tune in trans.

    FWIW (to clarify my magical SOS crossing statement) My Flatline 38's were I shoot ELR runs into trans (condition, day, even time of day dependent) around 2,270 the SOS is 2,850 but trans continues to 4,130 (Theoretically, as it would actually be much shorter as the decay rate accelerates because the speed decelerates with instability) no way can anyone, hit a reasonable sizes target (or any target reliably, when the CEP is many many times the target size). Somewhere between the transonic zone of 2,270-ish thru 4,130-ish, the effects keeps my Flatlines and my system from going any-further. While my Amax's window is shifted back, the shape is more tolerant and thus actually seem to perform better at 2500, that's after the Amax SOS crossing and before the Flatlines, yet both however, are transonic.

    OK, man. Chill. I read the post you made in my thread (repeated above) first, and had no idea what post of yours I disliked that you were referring to. Especially, since I don't ever click Like or Dislike, I simply reply to the post if it is my intention to comment on it. I decided to search your posts to see if I could find what you were referring to. I found this post as a result. The reason I didn't "have the balls" to post why I clicked Dislike is that I never intentionally clicked it, and was not aware that I had. But you are correct that I did, in fact, click it. I don't know how, but it was simply a stray click. I don't even think I have even read that post all the way through yet, so I certainly have no reason to dislike it. From what I have read of it so far, it seems entirely reasonable to me. I have rescinded the accidental Dislike, with my apologies.

    No need to call me out. I wasn't even aware of it. Sorry to upset you.
     
    Last edited:

    vh20

    Gunny Sergeant
    Full Member
    Minuteman
    Dec 2, 2012
    3,172
    2,844
    57
    All good here. Thanks for the in-depth analysis on the other thread. I will respond further over there.
     

    spaniel

    Sergeant
    Full Member
    Minuteman
    Mar 26, 2006
    400
    216
    What bullet did the 300wm shooters use spaniel? I have found most heavy, high BC 30 cal bullets pass through transonic just fine.

    No idea. But these were quality shooters with quality equipment so I expect the best. And I can tell you, once transsonic, in a scored match, things went south pretty quickly, except for a single rifle which scored well 200 yards past transsonic transition. We had two guys shooting same twist, same bullet, essentially same MV, one was scoring at 1900 yards and the other dropping bullets so steeply into the pits that they had to have him stop shooting for safety reasons.
     

    spaniel

    Sergeant
    Full Member
    Minuteman
    Mar 26, 2006
    400
    216
    Everything I'm looking at on paper gives the edge to 7mm at all elevations. Are you saying that in your experience the 338 bullets hold true longer and further once sub sonic, and that's what makes it superior?

    I have only shot out to a mile once, so maybe I'm depending on the JBM results too much.

    What I meant was that at high elevation, people can shoot a lot further out before the subsonic transition. Shooting at 500ft elevation I can tell you that the exploits that people talk about shooting in the mountains out west are entertaining. It's just a whole different world. So elevation is important.

    As to your point of 7mm being superior, please share with me your calculations showing any 7mm cartridge (aside perhaps the Allen Magnum) being superior to a 338 launching 285gr ELD-M or 300gr SMKs at 2850-2950 fps at extended ranges, regardless of elevation?

    Recently working pits at a scored 2000 yard match, I can tell you things fell apart very quickly for anything not a 338 past 1600 yards.
     
    • Like
    Reactions: cperazza

    M47Patton

    Private
    Full Member
    Minuteman
    Feb 10, 2012
    71
    7
    48
    TX
    What I meant was that at high elevation, people can shoot a lot further out before the subsonic transition. Shooting at 500ft elevation I can tell you that the exploits that people talk about shooting in the mountains out west are entertaining. It's just a whole different world. So elevation is important.

    As to your point of 7mm being superior, please share with me your calculations showing any 7mm cartridge (aside perhaps the Allen Magnum) being superior to a 338 launching 285gr ELD-M or 300gr SMKs at 2850-2950 fps at extended ranges, regardless of elevation?

    Recently working pits at a scored 2000 yard match, I can tell you things fell apart very quickly for anything not a 338 past 1600 yards.


    I've been using JBM ballistics to play with with different bullets at different velocities. When I run these numbers, I am paying the most attention to the windage with a 10 mph cross wind.

    Using JBMs bullet database, I compared many different combinations. For example, a 7mm 180gr eld @ 2950 vs a 338 285gr eld @2850.


    At 1000 ft elevation:

    180 eld @ 1000 yards shows 4.1 moa
    180 eld @ 2000 yards shows 10.7 moa

    285 eld @ 1000 yards shows 4.4 moa
    285 eld @ 2000 yards shows 11.7 moa

    So this is giving a full moa advantage in a 10 mph crosswind to the 180 eld @ 2000 yards. This is what got me thinking that 7mm was the sweet spot for ELR. If I change the altitude to 6500 ft, the edge is still with the 7mm.

    Now, with that said.. I made a little discovery a couple of days ago. The BC listed on JBM for the 285 eld is lower than what hornady published (.394 vs .417 g7). Running the numbers again but using the .417 g7 bc actually gives a slight edge to the 285 eld.

    The 338 LM is starting to look more attractive to me.








     

    MACHTECH

    Machinist
    Full Member
    Minuteman
  • Feb 12, 2017
    1,374
    2,845
    Michigan
    Try running the numbers for the Berger 195. In the 28 Nosler at 3100 the G1 BC jumps to .811. I have proven this in my 30" barreled 28 Nos. Desert Tech.

    Todd
     

    sandwarrior

    Sergeant
    Full Member
    Minuteman
    Apr 21, 2007
    6,468
    1,941
    in yooperland
    Try running the numbers for the Berger 195. In the 28 Nosler at 3100 the G1 BC jumps to .811. I have proven this in my 30" barreled 28 Nos. Desert Tech.

    Todd

    That's almost cheating!;)

    While you're at it, run the numbers on the new Sierra 197 as well.
     

    spaniel

    Sergeant
    Full Member
    Minuteman
    Mar 26, 2006
    400
    216
    I've been using JBM ballistics to play with with different bullets at different velocities. When I run these numbers, I am paying the most attention to the windage with a 10 mph cross wind.

    Using JBMs bullet database, I compared many different combinations. For example, a 7mm 180gr eld @ 2950 vs a 338 285gr eld @2850.


    At 1000 ft elevation:

    180 eld @ 1000 yards shows 4.1 moa
    180 eld @ 2000 yards shows 10.7 moa

    285 eld @ 1000 yards shows 4.4 moa
    285 eld @ 2000 yards shows 11.7 moa

    So this is giving a full moa advantage in a 10 mph crosswind to the 180 eld @ 2000 yards. This is what got me thinking that 7mm was the sweet spot for ELR. If I change the altitude to 6500 ft, the edge is still with the 7mm.

    Now, with that said.. I made a little discovery a couple of days ago. The BC listed on JBM for the 285 eld is lower than what hornady published (.394 vs .417 g7). Running the numbers again but using the .417 g7 bc actually gives a slight edge to the 285 eld.

    The 338 LM is starting to look more attractive to me.

    At least compare apples to apples. If you are going to give 2950fps to a 7mm, my Edge does that velocity with the 285 ELD-M with very moderate pressure. My load is actually 2945-2970 depending on powder lot, I could easily hit 3000 if I wanted to abuse my brass.

    What I observed was that, approaching transsonic, the 338s where more accurate than the 7s, on average. So on paper at the same velocity they are extremely close, but the 285-300gr 338 bullets vs the heavy 7s on the field simply showed better ability to hold it on target as velocities approached or dropped below Mach 1. Granted, nobody had a 7mm on the line that day which would stay supersonic to 2000yds at 500ft elevation and 80F. Someone with such a rifle likely would not want to shoot such a match due to the severe impact it would have on their barrel life. Even with the relocations back 100yds at a time, my Edge never had time to cool and was hotter than I would have liked by the end of the match. If I shoot it again I'll have a barrel cooler blowing through it from the time I stop shooting until it is time to shoot again.

    I can look back at several years of results, the 7mms simply don't compete, even when driven by very proven marksmen, at mile plus ranges. I really wish they would, it would be easier on my shoulder if my 284 F-class gun would hang.
     

    sandwarrior

    Sergeant
    Full Member
    Minuteman
    Apr 21, 2007
    6,468
    1,941
    in yooperland
    Everything I'm looking at on paper gives the edge to 7mm at all elevations. Are you saying that in your experience the 338 bullets hold true longer and further once sub sonic, and that's what makes it superior?

    I have only shot out to a mile once, so maybe I'm depending on the JBM results too much.

    I'll give my $.02 to what's been said above. JBM is great for giving you a computer trail of where your bullet should be going. What it doesn't take into account is the trans-sonic crossing or as diver put it the SOS.

    The trans-sonic crossing causes a disruption in every bullet out there. It depends on what DA (density altitude) you are at as to A. when your bullet begins to be affected by it, and B. How much your bullet is affected by it. Computer programs can tell you A. But, none I've seen yet can predict B. And remember, ALL bullets are affected, how much is based on design, weight, twist of barrel and atmosphere. I also believe type of rifling may/may not be an edge factor under some conditions. Square cut rifling may grip the air rotationally more than 5R type rifling. Again, DA will play into that.

    A really good comparison of bullet design working better through the trans-sonic is the Sierra .30 cal 168 SMK and the 175 SMK. The 175 has a slightly longer ogive, but the real difference is the reduced angle of the boat-tail. The 168 has a 13 deg. BT and the 175 has a 9 deg. BT. While both slower than shit, the 175 will transcend the speed of sound crossing with less disruption.

    An explanation of what happens when a bullet goes through the sound barrier is like a boat on the water. When a bullet is above the speed of sound there is a sonic boom. The snap you hear if you're in the pits hearing them go overhead. It actually isn't just a sound, it's a physical thing. And, when it catches up to the bullet it hits the back of the bullet and moves it. Like a boat, the bullet wants to then take a different direction. Gyroscopic precession is kicked in, and to a certain point the bullet begins to yaw. Rotational energy will straighten (stabilize) the bullet back on to the course it is now on. How much it is disrupted is how accurate you are going to be past the trans-sonic range. If you ever get the chance to take the two bullets above out to 1k on a cold day or at sea level you'll see what I mean. The 168 is very accurate out to 800. Past 800, it's accuracy suffers immensely. While the 175 continues on, seemingly with little issue.

    As to the 7mm's out shining the .338, I ran the numbers with 100 fps slower on the .338 using Berger to Berger comparisons, a 7mm 180 VLD (Litz) and a .338 300 VLD (Litz estimated) and the .338 drifted less.

    As a general rule I've found, not always, a heavier bullet of relative design that is pushed to a relative speed will drift less. It sounded odd you having the 7mm drifting less.

    The point being in all this is we've known about trans-sonic flight disruption through aviation for a long time. And we haven't yet catalogued all the different factors yet that make aircraft do what they do when coming back down through the trans-sonic flight envelope. Mostly, they flutter and are in minimal control when descending in speed. Ascending in speed, they go through a period of disruption, but under power they handle it better.

    Added: I forgot to add, that when considering BC, two factors make up BC, form and weight. A slick form is great, but without weight to maintain inertia, it won't go as far as you may want. Consider the original G-1 BC model. It is a 1-inch, one pound, 3R (radius) tangent ogive bullet. Very little form and mostly weight as it's momentum factor. The .338 300 gr. VLD is less that 1/20th of that weight and it approaches the equal of that model. It has a much higher BC than 7mm's, but it takes a lot of case to push it to usable velocities. There is always the trade-off
     
    Last edited:

    M47Patton

    Private
    Full Member
    Minuteman
    Feb 10, 2012
    71
    7
    48
    TX
    At least compare apples to apples. If you are going to give 2950fps to a 7mm, my Edge does that velocity with the 285 ELD-M with very moderate pressure. My load is actually 2945-2970 depending on powder lot, I could easily hit 3000 if I wanted to abuse my brass.

    What I observed was that, approaching transsonic, the 338s where more accurate than the 7s, on average. So on paper at the same velocity they are extremely close, but the 285-300gr 338 bullets vs the heavy 7s on the field simply showed better ability to hold it on target as velocities approached or dropped below Mach 1. Granted, nobody had a 7mm on the line that day which would stay supersonic to 2000yds at 500ft elevation and 80F. Someone with such a rifle likely would not want to shoot such a match due to the severe impact it would have on their barrel life. Even with the relocations back 100yds at a time, my Edge never had time to cool and was hotter than I would have liked by the end of the match. If I shoot it again I'll have a barrel cooler blowing through it from the time I stop shooting until it is time to shoot again.

    I can look back at several years of results, the 7mms simply don't compete, even when driven by very proven marksmen, at mile plus ranges. I really wish they would, it would be easier on my shoulder if my 284 F-class gun would hang.

    I was considering a 7mm rem mag, and 2950 fps seemed pretty typical with 180gr class bullets. The 2850 fps is pulled from what seems like typical numbers from a 338 lapua mag which I am now considering. The 338 edge uses a little more powder right?

    Thank you for your comments.
     

    M47Patton

    Private
    Full Member
    Minuteman
    Feb 10, 2012
    71
    7
    48
    TX
    As to the 7mm's out shining the .338, I ran the numbers with 100 fps slower on the .338 using Berger to Berger comparisons, a 7mm 180 VLD (Litz) and a .338 300 VLD (Litz estimated) and the .338 drifted less.

    As a general rule I've found, not always, a heavier bullet of relative design that is pushed to a relative speed will drift less. It sounded odd you having the 7mm drifting less.

    Thanks for the information, good stuff.

    I too found it odd that the 7mm drifted less. A couple posts ago I noted that JBM did not have the correct BC listed for the 285 eld. When I plugged in numbers taken from hornadys website, the 285 338 eld had a slight advantage over the 180 eld. The 180 elds BC just seems borderline unbelievable. That said, I shoot 147gr elds from in my 260 and the drop has been accurate so I have no reason to doubt hornadys numbers. It does require a pretty fast twist to max out the the BC on the 180 (7.5 iirc).
     
    • Like
    Reactions: Troy G

    lennyo3034

    Gunny Sergeant
    Full Member
    Minuteman
    Apr 18, 2010
    2,967
    819
    37
    Southern MD
    I have a brand new 7mm Rem mag. Currently still doing load development on it and haven't left the 100 yard range yet. I have zero ELR experience as the furthest I've shot is 1000.

    Im narrowing on a load that is giving me 3075 with the 180 ELD. Again, I have no experience actually shooting at distance with this because im still developing a load, but on paper it looks good. I am at sea level and the 1000 yard range I shoot (peacemaker) is at 800 or so feet.

    I have no idea if the ridiculous high BCs for that bullet is accurate or not.

    Rifle is a Bighorn TL3 with 30" Bartlien 1-8 twist.
     

    hondo1312

    Sergeant
    Supporter
    Full Member
    Minuteman
    May 8, 2011
    508
    145
    Wichita, KS
    I'll be shooting my 7SAUM with 180 hybrids at 2990 fps at a mile and further the next two weekends. Hopefully I can return with some informative data (although probably not; this will only be the second and third time I've shot that far and really have no idea what I'm doing at that distance).
     

    Milo 2.5

    The Dalai Lama of the Reload
    Full Member
    Minuteman
    Aug 7, 2014
    2,971
    2,200
    Gillette, WY
    How does the heavy, .30 bullets do against the 7mm 195 and the 338 285 gr at 1 mile?

    Lol, you must admit this a vague question. Consider the 230gr hybrid in a 300 Norma mag, or improved version, or a 300 Lapua Imp, (338 necked down and improved). If you've paid attention to much in this thread, you'll see case capacities really dictate performance.

    I used to shoot a 338 snipetac, 300gr Berger at 3250fps, and a 275gr Rocky Mtn bullet at 3325fps, shit happens when you stuff a lot of powder into a case.
     

    Milo 2.5

    The Dalai Lama of the Reload
    Full Member
    Minuteman
    Aug 7, 2014
    2,971
    2,200
    Gillette, WY
    I'll be shooting my 7SAUM with 180 hybrids at 2990 fps at a mile and further the next two weekends. Hopefully I can return with some informative data (although probably not; this will only be the second and third time I've shot that far and really have no idea what I'm doing at that distance).

    Do report back, always fun to hear results. Today I'm all about pushing the limits of smaller cases to distance with above average expectancies of accuracy. Comes a point where lobbing lead is just that though, but if it takes 20 shots to hit 1900, tell us, maybe someone can offer insight. Just remember to shoot "conditions" as you see them, no reason firing if wind is picking up or letting off, you'll just chase your misses.