What am I giving up if I were switch to 129 or 123gr heads 8n my 6.5x47l instead of switching everything over to a 6mm?
120gr 6.5 for competion?
- Thread starter regnar375
- Start date
A useful tool for me is to make mock Applied ballistics profiles and compare numbers. For ease of comparison, I change yardage steps to every 100 yards and manually enter 10 mph full value wind. I do a screenshot of a known load, say my 6 Dasher. Then do a screenshot of my new potential shiny, and try to determine if the juice is worth the squeeze.
I recently thought about 123's myself, just put my first 65x47 together. Read where some F class guys run them around 3000 fps with success. But also suspect they are using 28-30" barrels. I'm going to use 130 Normas, JLK and Berger have 130's I sometimes hear about. But never seen any 123's mentioned in PRS circles. The BC rules mindset likely among the reasons.
I like swimming upstream myself, try out the 123's, you may be surprised. But I would spend some time in my ballistic app first crunching numbers.
I recently thought about 123's myself, just put my first 65x47 together. Read where some F class guys run them around 3000 fps with success. But also suspect they are using 28-30" barrels. I'm going to use 130 Normas, JLK and Berger have 130's I sometimes hear about. But never seen any 123's mentioned in PRS circles. The BC rules mindset likely among the reasons.
I like swimming upstream myself, try out the 123's, you may be surprised. But I would spend some time in my ballistic app first crunching numbers.
They're certainly viable, but not your best option. I've used them in local matches and had good results, but we're talking 300 yd and 600 yd ranges. The issue is you don't really gain anything by choosing them over a heavier bullet. Off the top of my head, in a 10 MPH left to right wind, you'll need to hold 2 or 2.1 mils for wind. The 140s would do a little better, like 1.6 or 1.7, but the 123a aren't that much flatter shooting to warrant their use. I think you need 7.6 mils of elevation to get the 123 to 1K, but the 140s only need 7.7, so the difference is a wash. Plus, you still have almost all, if not all, the recoil of the heavier bullets. The 6mm cartridges are in favor not because they shoot a little flatter (my 107 SMK Dasher load needs 7.0 mils to get to 1K, and it's a pretty mild load by Dasher standards) or do a little better in the wind over the 123s (1.6 mil hold for MPH wind at 1K for my 107 Dasher), but the felt recoil is lower so watching your miss and following up are easier.
Not sure I completely agree with the above.
Most PRS/NRL match’s average yardage ends up being mid range, so really focusing on 1000 yards is logic that I don’t get.
My 24” 6.5 it is a 6mph gun, runs 3030fps. Here is my sea leave dope, and a stage card example from the last match.
I can self-spot 100% of my shots. Now that said, is a 6br easier sure. Is a Dasher better? Sure, but I have consently getting over 2k out of my 6.5 and I am tired of barrels going at 1200 for an extra point or two in a match.
My 140s in the same gun at 1k, need 1mil more elevation and only provide .1 better @ FV base wind. Same wind at 600, with .5ms more drop and yes, the recoil is noticeably more with the 140s.
Most PRS/NRL match’s average yardage ends up being mid range, so really focusing on 1000 yards is logic that I don’t get.
My 24” 6.5 it is a 6mph gun, runs 3030fps. Here is my sea leave dope, and a stage card example from the last match.
I can self-spot 100% of my shots. Now that said, is a 6br easier sure. Is a Dasher better? Sure, but I have consently getting over 2k out of my 6.5 and I am tired of barrels going at 1200 for an extra point or two in a match.
My 140s in the same gun at 1k, need 1mil more elevation and only provide .1 better @ FV base wind. Same wind at 600, with .5ms more drop and yes, the recoil is noticeably more with the 140s.
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Yeah, I knew I shouldn't have gone off memory alone, especially my memory lol.
For my 123 load, I'm running it at 3033 fps, and it only needs 6.7 mils to get to 1K, while my 140 load is 2836 fps and needs 7.2. The 140 does about 0.1 to 0.2 mils better in a 10 MPH FV wind, so the 123 shoots a bit flatter than my 140 once you get above 400 yards or so. It also helps that I shoot above 5000'.
@Diver160651 what's your MV on your 140 load?
For my 123 load, I'm running it at 3033 fps, and it only needs 6.7 mils to get to 1K, while my 140 load is 2836 fps and needs 7.2. The 140 does about 0.1 to 0.2 mils better in a 10 MPH FV wind, so the 123 shoots a bit flatter than my 140 once you get above 400 yards or so. It also helps that I shoot above 5000'.
@Diver160651 what's your MV on your 140 load?
With the 140s, out of my 26 run hit it is close to yours at 2810, but out of my 24 to get good groups, I am only getting 2770. The drops and wind are at 29” mercury.
If I traveled let’s say to Wyoming on a really warm day my 123s, normally a 6mph gun, starts acting like an 8mph gun with the 1k drop of 6.5mils. The relationship between my loads stay the same.
My only point is there are a bunch of ways to skin the cat. I would not discount the benefits of fast, especially for wonky unstable positions.
Btw have you used mil wind, it really uncouples us from the bigger 10-15 FV numbers- remember 15mph FV is 30 if in the 50% wind angle..
Using mil wind also helps manage wind strategies a bit faster, if not easier. Understanding mil wind also helps me look at a load in more realistic conditions.
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@Diver160651 If by mil wind, you mean the wind speed/BC x range/1000, and calling it a 6 MPH gun because that's the wind to get you a 0.1 mil hold at each yardage, then yes, for the most part. I'm not tracking on the 15 is 30 if it's in the 50% area, though. Shoot me a PM so we don't derail the conversation here. Thanks, brother!
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@Diver160651 @canezach
Of course, discuss the "mil wind" concept by PM if needed. Or you could start a post …. I'm interested in this concept as well, but haven't had it explained adequately so that I understand it. It could be I'm just slow.....
Thanks
Of course, discuss the "mil wind" concept by PM if needed. Or you could start a post …. I'm interested in this concept as well, but haven't had it explained adequately so that I understand it. It could be I'm just slow.....
Thanks
Thanks for this feed back. This is what I am looking for.
@Diver160651 , are you saying it's a wash going to a faster, lighter bullet or it's something I should play with?
I shoot 130 vld's now. It's very very accurate (sub .5moa 5 shot groups at 600. .75 20 shot groups at 600 ). I'm ok with staying with this combo on the new barrel but willing to try something different
@Diver160651 , are you saying it's a wash going to a faster, lighter bullet or it's something I should play with?
I shoot 130 vld's now. It's very very accurate (sub .5moa 5 shot groups at 600. .75 20 shot groups at 600 ). I'm ok with staying with this combo on the new barrel but willing to try something different
I think if th
if your load works, focus the the shooting and call it a day.
Faster (much faster) almost always trumps close BC inside supersonic ranges. Recoil, then becomes another issue.
Balance is everything and tilting the scales to your best use and futbis the goal.
Btw there are a lot of wind strategies.
Each discipline will have it’s own best practices. Mil wind or the idea that simplification and smaller units helps with speed and allows more brain power for other tasks is a good fit for timed long range precision like PRS/NRL. But understanding the concept of where and why is key.
Each discipline will have it’s own best practices. Mil wind or the idea that simplification and smaller units helps with speed and allows more brain power for other tasks is a good fit for timed long range precision like PRS/NRL. But understanding the concept of where and why is key.
I like and understand the idea behind this concept. Where can I read more about how to employ it?
Not sure there is a lot that is well written other than the discussion on how to determine your base wind.
The concept of implementing it and why you might want to divorce yourself from thinking in traditional wind units like 10mph or 15mph is harder to understand. The 10-15mph, often seen in dope cards or used when playing with solvers (to see what bullet is best) is usually a bit higher effective wind speeds than most people need, most of the time. It is harder to dissect into real usable units quickly and it is a hard concept to communicate the value of using lower mil wind units in a forum post. You also need to remember the application is not for every type of shooting.
Purely for speed and simplicity, if you brake wind into it’s effective FV speed and keep the zones simple, like 25/50/75% or 20/40/60/80% of FV, the effects of wind are easier numbers to work with.
Most newer shooters over estimate the wind speed and way under estimate the effect. I guess it is kinda a wash of sorts, but a wind on a clock @ 1 hour any side of 12/6 seems to be the hardest for new shooters as they underestimate the effect of the values.
Let’s use .3mil target at 600yards with a 123gr fast 6.5 at 3030fps. Anyway, let’s just assume that at 8mph a lot of shooters will start to think it is well over 10mph mostly because the results often wrongly seem to indicate so.
For sake of the example, it is coming from just right if 12 o’clock (let’s say 1ish), they think of it as a headwind so they don’t apply much wind maybe a .1 or .2 and miss left. Wow, is the first thought, it must be winder than it I looks. I bet is it 12+ , but it is effectively only 4mph FV (50%). So in reality, the wind they should have thought about was 1/3 less, but the effect was 2x, much greater and moving the 123gr, .4mil or a left POI off the plate.
Before we try to worry to much about finding the effective mil wind; we should really work on how we interpret effective wind speed. We should at least want to understand why one might want to use solverless solutions. If we can, then we might start to see the value in using a lower effective wind number to start with.
For instance, if it really is blowing your 10mph on your dope card, more often than not, it will not be a perfect FV wind.. So depending on how you divide up your wind clock, your working with 2.5/5/7.5 mph wind and of course, once in a while the 10mph FV.
I guess my suggestion is first understand if super fast non-solver based wind solutions are key to your type of shooting. Then decide if you can start thinking in effective FV as a natural step. If these make sence to your shooting style, then knowing that for every 100 yards with an effective adjusted 6mph FV (in my case of my match gun) moves my bullet .1 mil, will be very valuable.
Just note, that a effective 6mph FV wind could easily be a measured @ 12/18/24mph, using the same .1 at every 100 yards depending on the angle, same idea for a 5mph gun. Of course, if the true wind is FV or effective FV is more than your guns mil wind, you add to the .1 per 100; so a 12 mph FV would be 1mil at 500 yards not .5 for the 6mph gun in the example.
The concept of implementing it and why you might want to divorce yourself from thinking in traditional wind units like 10mph or 15mph is harder to understand. The 10-15mph, often seen in dope cards or used when playing with solvers (to see what bullet is best) is usually a bit higher effective wind speeds than most people need, most of the time. It is harder to dissect into real usable units quickly and it is a hard concept to communicate the value of using lower mil wind units in a forum post. You also need to remember the application is not for every type of shooting.
Purely for speed and simplicity, if you brake wind into it’s effective FV speed and keep the zones simple, like 25/50/75% or 20/40/60/80% of FV, the effects of wind are easier numbers to work with.
Most newer shooters over estimate the wind speed and way under estimate the effect. I guess it is kinda a wash of sorts, but a wind on a clock @ 1 hour any side of 12/6 seems to be the hardest for new shooters as they underestimate the effect of the values.
Let’s use .3mil target at 600yards with a 123gr fast 6.5 at 3030fps. Anyway, let’s just assume that at 8mph a lot of shooters will start to think it is well over 10mph mostly because the results often wrongly seem to indicate so.
For sake of the example, it is coming from just right if 12 o’clock (let’s say 1ish), they think of it as a headwind so they don’t apply much wind maybe a .1 or .2 and miss left. Wow, is the first thought, it must be winder than it I looks. I bet is it 12+ , but it is effectively only 4mph FV (50%). So in reality, the wind they should have thought about was 1/3 less, but the effect was 2x, much greater and moving the 123gr, .4mil or a left POI off the plate.
Before we try to worry to much about finding the effective mil wind; we should really work on how we interpret effective wind speed. We should at least want to understand why one might want to use solverless solutions. If we can, then we might start to see the value in using a lower effective wind number to start with.
For instance, if it really is blowing your 10mph on your dope card, more often than not, it will not be a perfect FV wind.. So depending on how you divide up your wind clock, your working with 2.5/5/7.5 mph wind and of course, once in a while the 10mph FV.
I guess my suggestion is first understand if super fast non-solver based wind solutions are key to your type of shooting. Then decide if you can start thinking in effective FV as a natural step. If these make sence to your shooting style, then knowing that for every 100 yards with an effective adjusted 6mph FV (in my case of my match gun) moves my bullet .1 mil, will be very valuable.
Just note, that a effective 6mph FV wind could easily be a measured @ 12/18/24mph, using the same .1 at every 100 yards depending on the angle, same idea for a 5mph gun. Of course, if the true wind is FV or effective FV is more than your guns mil wind, you add to the .1 per 100; so a 12 mph FV would be 1mil at 500 yards not .5 for the 6mph gun in the example.
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