No1_49er wrote:You haven't factored in the fact that the two projectiles can not be the same external dimensions and will therefore have different ballistic coefficients. Given that the diameter of the two is the same, then the length must be different, the 180gn being the longer.
The trajectories will not be the same.
disco stu wrote:I've just been mulling things over in my mind a bit recently, and I'll get to my reasoning after the question itself.
If you wanted to keep a somewhat similar trajectory between light and heavy projectiles in the same rifle, as in so sighting is close enough between the 2 for hunting, would keeping velocity the same be enough for ranges out to say 150m? I know lighter will lose velocity faster etc etc though.
I've just been pondering the viability of loading my own factory style hunting ammo. I've avoided it before now because of cost of equipment and what you read about load development etc etc. I'm not shooting target comps, just trying to put meat on the table and I figure I could just do a factory type load and be in the exact same position I am right now, and seeing I'm not shooting heaps of rounds then the lee classic hand loader would probably suit me just fine for investment and space it will take up.
I then had the idea of doing some very light projectiles for rabbits etc out of the 308. Can't find projectiles as light as what I would like, and sabot seems to be a no go from what I can tell, so it looks like 110gn is the lightest I can go. Anyway, I then pondered the sighting difference against 150-180 type weights, and thinking on the physics side of things.
Theoretically, if all else is equal then at the same velocity I am picturing that a 180 gn and a 110gn would follow the exact same trajectory, seeing acceleration due to gravity is constant between different masses. What I'm wondering is how well does this work in reality, or what ranges could you expect close enough trajectory for hunting type accuracy?
Cheers in advance
Stu
bladeracer wrote:disco stu wrote:I've just been mulling things over in my mind a bit recently, and I'll get to my reasoning after the question itself.
If you wanted to keep a somewhat similar trajectory between light and heavy projectiles in the same rifle, as in so sighting is close enough between the 2 for hunting, would keeping velocity the same be enough for ranges out to say 150m? I know lighter will lose velocity faster etc etc though.
I've just been pondering the viability of loading my own factory style hunting ammo. I've avoided it before now because of cost of equipment and what you read about load development etc etc. I'm not shooting target comps, just trying to put meat on the table and I figure I could just do a factory type load and be in the exact same position I am right now, and seeing I'm not shooting heaps of rounds then the lee classic hand loader would probably suit me just fine for investment and space it will take up.
I then had the idea of doing some very light projectiles for rabbits etc out of the 308. Can't find projectiles as light as what I would like, and sabot seems to be a no go from what I can tell, so it looks like 110gn is the lightest I can go. Anyway, I then pondered the sighting difference against 150-180 type weights, and thinking on the physics side of things.
Theoretically, if all else is equal then at the same velocity I am picturing that a 180 gn and a 110gn would follow the exact same trajectory, seeing acceleration due to gravity is constant between different masses. What I'm wondering is how well does this work in reality, or what ranges could you expect close enough trajectory for hunting type accuracy?
Cheers in advance
Stu
If you were using them on large game at close distances they'd be pretty close, but not for rabbits.
Ideally you want loads that fall along a vertical line, then you only need worry about holding over, and not windage. It is certainly possible to shoot several different loads, but they're not going to follow the same path. You need maximum precision for small game, so I would zero the rifle with your light fast load, at maybe 250m. Then you need to learn the trajectory of the heavier load so you can hold over/under to suit. In .30-cal you can get down to 86gn bullets, maybe even less, but the large diameter means the lighter bullets are quite short, with poor ballistic coefficient. In 7mm-08 I zero my fast 100gn load at 250m, and note the 145gn and 160gn trajectory for larger targets. The sabot let's you shoot very light bullets, like 30gn .224", but they generally lack the precision you want for small game. You can also load right down to rimfire levels for close-range small game if you want to.
If you go out specifically for small or large game, then you can just zero for the one load for the trip.
I would suggest choosing two readily available bullets, like a 110gn TNT and a 150gn SP, and play around to see if you can come up with loads that work decently together.
I might even be able to find time myself to look at it in my M1903A3 .30-06. I want to have a play with the 86gn bullet in it anyway.
disco stu wrote:Thanks BR. Not sure if my post above gives more of an idea what I was thinking, as it seems maybe my thinking isn't getting across, or I've got it all completely wrong.
What would be wrong with slowing down the light projectile with something like trailboss instead of sending it out fast?
At what sort of range will the effect of the crap ballistic coefficient really start to show up? When I'm seeing rabbits while out deer hunting its normally within 150m, so I'm not looking up to go taking 250m shots or anything.
What are the 85gn projectiles you mention being available? I couldn't find anything under 110 myself. Knowing that I might be able to plug things into ballistic calculator and get a better idea
bladeracer wrote:disco stu wrote:Thanks BR. Not sure if my post above gives more of an idea what I was thinking, as it seems maybe my thinking isn't getting across, or I've got it all completely wrong.
What would be wrong with slowing down the light projectile with something like trailboss instead of sending it out fast?
At what sort of range will the effect of the crap ballistic coefficient really start to show up? When I'm seeing rabbits while out deer hunting its normally within 150m, so I'm not looking up to go taking 250m shots or anything.
What are the 85gn projectiles you mention being available? I couldn't find anything under 110 myself. Knowing that I might be able to plug things into ballistic calculator and get a better idea
Busy day, sorry, couldn't even fit in some shooting.
Had a look at the 86gn and looks like it might be out of production, and I think I only have 100 of them. I do still have a lot of 100gn Plinkers though.
Nothing at all wrong with slowing any of your bullets down, as long as you still have enough terminal velocity at the target for the bullet to function, although that's not an issue on small game.
BC really becomes relevant past about 300m, out to there the differences are minimal.
150m on rabbits, assuming you want a meal out of them, is still going to require decent accuracy.
I'm just looking at Hornady and ADI now, and the 110gn VMax is a good choice for small game I think, while still having some BC (.290 to try to stay with a heavier bullet's trajectory). They do a 100gn semi-jacketed soft-point, and the 110gn soft-point also but with significantly lower BC's (.152 and .256).
.308 should have no trouble pushing the 110gn up to 3300fps, a 150gn to about 2900fps, and a 180gn to about 2600fps - depending on barrel length and such. ADI also list a Trailboss load of a 150gn bullet at 1400fps, and a subsonic AS30N load with a 168gn bullet at 1060fps. The VMax is designed to function above 1600fps.
For just varminting, the 110gn VMax at 3300fps zeroed at 150m will be zeroed at 50m, about 25mm high at 100m, 50mm low at 200m, and 150mm low at 250m. At 250m the 10mph wind drift is about 70mm.
For large game, the 150gn Interbond (BC .415) at 2900fps zeroed at 150m will be zeroed at 35m, about 20mm high at 100m, 65mm low at 200m, and 180mm low at 250m. At 250m the 10mph wind drift is about 55mm.
So both bullets are fairly compatible, if they happen to shoot with no significant windage difference. You could comfortably take small and large game out to 250m with no problems if you zero for the varmint load. I don't know the minimum velocity for the 150gn Interbond, but it's probably around the same 1600fps, it's designed to explode on impact like a VMax, so it immediately starts doing maximum damage, but the jacket and core are bonded so it stays together through bone and heavy meat.
If you wanted to you could also load the 110gn VMax back to 2000fps, which will hold 1600fps to about 150m, with significantly less report than a full-noise load. The 110gn VMax at 2000fps zeroed at 100m will be zeroed at 22m, about 20mm high at 100m, 110mm low at 150m, and 320mm low at 200m. At 150m the 10mph wind drift is about 75mm. As the bullet is still above its design velocity to about 150m, you could still use it against larger game at close range, though not the big stuff unless head-shooting.
You could also go subsonic if you wanted to take rabbits with minimal noise to scare off other game. The trajectory is getting closer to shooting a .22LR, which most people do okay with to at least 100m. The VMax won't deform, and there's no hydrostatic shock, but a .30-caliber hole through the brain or heart will still kill very emphatically. The 110gn VMax at 1070fps zeroed at 75m will be zeroed at 10m, about 50mm high at 50m, and 120mm low at 100m. At 100m the 10mph wind drift is about 15mm. A subsonic load is also handy for when you get to the animal you've dropped to find it still kicking.
You would need to try both bullets and see if they're at least close to vertical. If they are, then you can shoot them at various distances and record the holdovers for the heavy load, and the subsonic load, while maintaining the precision varmint zero.
Another option that I haven't managed to get hold of yet is the 190gn Sub-X, designed to function down to 900fps, or about 350m. The 190gn Sub-X at 1070fps zeroed at 100m will be zeroed at 22m, about 110mm high at 55m, 360mm low at 150m, and a meter low at 200m. At 150m the 10mph wind drift is about 15mm. The 190gn bullet only makes about 480 lb-ft of energy at the muzzle, and is down to 400 lb-ft by 150m, so I wouldn't be using it at long-range. It has a blunt polymer tip so I want to try it for subsonic .30-30 loads, when I get some.
This is just a rough example, there are other choices of bullet, light and heavy.
disco stu wrote:
Thanks Blade Racer. That's some solid info there. Don't apologise for not being at my beck and call!
I'll have to work my way through this over time. One initial question, you mention vertical spread only-does that imply that sometimes different projectiles will have some sideways/windage differences even in still conditions?
Thanks Zaine. I guess this confirms my initial thinking that velocity determines trajectory of all else is equal (which I know it isn't)
disco stu wrote:Thanks Blade Racer. That's some solid info there. Don't apologise for not being at my beck and call!
I'll have to work my way through this over time. One initial question, you mention vertical spread only-does that imply that sometimes different projectiles will have some sideways/windage differences even in still conditions?
Thanks Zaine. I guess this confirms my initial thinking that velocity determines trajectory of all else is equal (which I know it isn't)
straightshooter wrote:disco stu
Once upon a time I grappled with the exact same dilemma you ask about.
My solution for my 308w walking around rifle at that time was this:
First I established my larger game load with a 150 grain softpoint projectile and sighted it in for a reliable 200 yard zero.
I then tried various loadings of 110 grain FMJ carbine projectiles until I found a combination that shot to the exact same zero at 200 yards. It didn't take too much effort and the difference in midrange elevations was sufficiently small to ignore.
With the benefit of better educated hindsight I can see that trying to work things out from trajectory tables would have been useless due the effect of the markedly different recoil characteristics of the two loads.
This recoil phenomenon is what 303 lovers refer to as 'compensation' and what they believe is a 'secret ingredient' cooked into the Lee Enfield action.
Not withstanding all of the above, you will eventually find that the most satisfactory solution is to have a small game rifle of suitable caliber and a larger game rifle also of suitable caliber.
straightshooter wrote:This recoil phenomenon is what 303 lovers refer to as 'compensation' and what they believe is a 'secret ingredient' cooked into the Lee Enfield action.
bladeracer wrote:straightshooter wrote:disco stu
Once upon a time I grappled with the exact same dilemma you ask about.
My solution for my 308w walking around rifle at that time was this:
First I established my larger game load with a 150 grain softpoint projectile and sighted it in for a reliable 200 yard zero.
I then tried various loadings of 110 grain FMJ carbine projectiles until I found a combination that shot to the exact same zero at 200 yards. It didn't take too much effort and the difference in midrange elevations was sufficiently small to ignore.
With the benefit of better educated hindsight I can see that trying to work things out from trajectory tables would have been useless due the effect of the markedly different recoil characteristics of the two loads.
This recoil phenomenon is what 303 lovers refer to as 'compensation' and what they believe is a 'secret ingredient' cooked into the Lee Enfield action.
Not withstanding all of the above, you will eventually find that the most satisfactory solution is to have a small game rifle of suitable caliber and a larger game rifle also of suitable caliber.
Yes, I can't stress enough that you "must" learn the actual trajectory of your loads through shooting them at different distances, regardless of whether you use just one or several. Never rely on calculations when you are shooting at live targets without confirming the calculations beforehand on the range. And you must study how a second load falls, at those distances, when the rifle is zeroed for the first load. The trajectory calculations may be spot on, but the muzzle may not throw both trajectories from the same starting point due to the differences in how each load affects the muzzle, the rifle, and the shooter.
Carting an extra rifle around in difficult deer country is not something I recommend, unless it's perhaps a sub-2kg breakdown. But then it becomes useless, by the time you unpack it, the rabbit/fox/cat/dog has strolled away in tears of laughter. You're better off leaving it at home and ignore the pest targets when you're hunting bigger game. If you want the option to knock off some pests while you're on the way out or back, it's way more practical to carry a second mag or some different ammo in your pocket.
in2anity wrote:straightshooter wrote:This recoil phenomenon is what 303 lovers refer to as 'compensation' and what they believe is a 'secret ingredient' cooked into the Lee Enfield action.
Didn't realize you knew all 303 lovers. Amazing.
straightshooter wrote:bladeracer wrote:straightshooter wrote:disco stu
Once upon a time I grappled with the exact same dilemma you ask about.
My solution for my 308w walking around rifle at that time was this:
First I established my larger game load with a 150 grain softpoint projectile and sighted it in for a reliable 200 yard zero.
I then tried various loadings of 110 grain FMJ carbine projectiles until I found a combination that shot to the exact same zero at 200 yards. It didn't take too much effort and the difference in midrange elevations was sufficiently small to ignore.
With the benefit of better educated hindsight I can see that trying to work things out from trajectory tables would have been useless due the effect of the markedly different recoil characteristics of the two loads.
This recoil phenomenon is what 303 lovers refer to as 'compensation' and what they believe is a 'secret ingredient' cooked into the Lee Enfield action.
Not withstanding all of the above, you will eventually find that the most satisfactory solution is to have a small game rifle of suitable caliber and a larger game rifle also of suitable caliber.
Yes, I can't stress enough that you "must" learn the actual trajectory of your loads through shooting them at different distances, regardless of whether you use just one or several. Never rely on calculations when you are shooting at live targets without confirming the calculations beforehand on the range. And you must study how a second load falls, at those distances, when the rifle is zeroed for the first load. The trajectory calculations may be spot on, but the muzzle may not throw both trajectories from the same starting point due to the differences in how each load affects the muzzle, the rifle, and the shooter.
Carting an extra rifle around in difficult deer country is not something I recommend, unless it's perhaps a sub-2kg breakdown. But then it becomes useless, by the time you unpack it, the rabbit/fox/cat/dog has strolled away in tears of laughter. You're better off leaving it at home and ignore the pest targets when you're hunting bigger game. If you want the option to knock off some pests while you're on the way out or back, it's way more practical to carry a second mag or some different ammo in your pocket.
I agree with most of your post.
Although taking multiple rifles on a hunting trip isn't unheard of, at least where I come from, physically carrying around two rifles while stalking on foot, especially if one is interested in bagging a specific species of game, indeed sounds like a dumb idea.
I am nonplussed as to how anyone could have come to that interpretation.
straightshooter wrote:I don't know ALL 303 lovers just a few and among them a sprinkling of uncompromising zealots but I am unsure that I may have suggested that I did.
So in any event in this instance I have unfortunately succumbed to the "fallacy of composition".
I will try to do better in future and I hope others will learn from my humiliating experience.
in2anity wrote:straightshooter wrote:I don't know ALL 303 lovers just a few and among them a sprinkling of uncompromising zealots but I am unsure that I may have suggested that I did.
So in any event in this instance I have unfortunately succumbed to the "fallacy of composition".
I will try to do better in future and I hope others will learn from my humiliating experience.
You do realize this particular forum is generally fairly respectful? I mean, you really don't always need to stand up on your pedestal and patronize everyone with your big words and apparent elitism; perhaps it's out of a feeling of insecurity due to previously being mistreated .... because nobody is mistreating you here.
You can just speak layman like the rest of us, and still be quite respected. In fact it may actually be really beneficial for you. We all know you are very knowledgeable about shooting, how about just keep it light?
I get other forums are very much a pissing contest in this regard, and I can see how that sort of toxic elitism culture is brewed. But dude, here it's all good, it's really not a contest. Just a bunch of knockabout ozzies chatting about guns. #justsayin
straightshooter wrote:This recoil phenomenon is what 303 lovers refer to as 'compensation' and what they believe is a 'secret ingredient' cooked into the Lee Enfield action.
in2anity wrote:straightshooter wrote:This recoil phenomenon is what 303 lovers refer to as 'compensation' and what they believe is a 'secret ingredient' cooked into the Lee Enfield action.
Well Blade, I took it as a slander against 303 shooters, as if they are (all) some sort of blinkered Lee-Enfield action fanboys, which is garbage. But perhaps I misinterpreted, if so I stand corrected... perhaps I was being overly precious. Perhaps not.
disco stu wrote:I've just been pondering the viability of loading my own factory style hunting ammo. I've avoided it before now because of cost of equipment and what you read about load development etc etc. I'm not shooting target comps, just trying to put meat on the table and I figure I could just do a factory type load and be in the exact same position I am right now, and seeing I'm not shooting heaps of rounds then the lee classic hand loader would probably suit me just fine for investment and space it will take up.