.308 copper

[Yew Tree Fieldsports]

I have hard time believing 30cal bullet arriving at 3300+ FPS "don't make a stupid mess" in such a small carcass as roe. Or are you talking about head or neck shots? Where no bullet would "make stupid mess".

Also based on previous threads, Yew Tree seems to mislead their customers by stating high BC numbers for certain velocity windows, that then drop like stone. E.g. 30cal 119gr TLR has .610 over 2765 FPS and .310 for 2426-2765 FPS.

With respect, I’m not misleading any one. The bc’s you are quoting are measured by me to produce a viable and accurate trajectory using a multi G1 bc solution. G1 bc’s (of efficient bullets) vary massively dependant on bullet velocity. If you input the correct information into any multi bc ballistics calculator they will give an extremely accurate prediction of the bullet trajectory over the speeds quoted which is the point of publishing them.
If you look at the variation possible in .30 cal for example, the bullets could be fired from anything from a 30 BR to a 300 win mag and everything in between. I’d guess you’d have a potential variance in MV’s from the different cartridges of up to 1,000 fps. As such I am trying to provide a solution that covers everything.
I wrote a post some time back as to why I use multi g1’s I’m sure it will come up if you do a search and you may find it interesting.
It is possible to provide a G7 equivalent but that is not as accurate as the multi G1.
Regards
Richard

 

[jthyttin]

Thanks, I do understand the multi G1 approach but most calculators in use are single BC. Why don't you provide single G1 and single G7, with a warning that they're not as accurate? When a customer has calculator that requests single G1 BC, which one of your multi G1 do you think he chooses (the highest one of course)?

Also your BCs vary quite radically, when comparing to e.g. Sierra that also publishes multi G1 BCs. I'm quite ready to bet that e.g. 119gr 30cal TLR doesn't fly with half the resistance once it reaches 2765fps.

 

[Yew Tree Fieldsports]

Thanks, I do understand the multi G1 approach but most calculators in use are single BC. Why don't you provide single G1 and single G7, with a warning that they're not as accurate? When a customer has calculator that requests single G1 BC, which one of your multi G1 do you think he chooses (the highest one of course)?

Also your BCs vary quite radically, when comparing to e.g. Sierra that also publishes multi G1 BCs. I'm quite ready to bet that e.g. 119gr 30cal TLR doesn't fly with half the resistance once it reaches 2765fps.

The bc’s are an average over the speed band. In G1 terms the bc degrades continually as the bullet slows down. What this methodology does is essentially split the trajectory into shorter trajectories and stitches them together thereby providing a very accurate performance prediction.
The reason I don’t quote single G1’s is that they would be useless in the case of my tipped bullets. I do quote G7’s on some of my tipped bullets and will probably continue to do so in future, as whilst not ideal, they provide a reasonable solution for the earlier parts of flight.
If people are shooting at ranges where they require a precise trajectory prediction, I would suggest that they ordinarily would already have or should purchase a calculator that accepts multi bc inputs. That said if you had to use one bc it would be most sensible to use the one for the band where your MV is, logically. It still wouldn’t work very well once the bullet is out of that speed band though.
Bottom line is I am trying to provide a ballistic solution that works for those that need it. The multi bc’s have been calculated after a huge amount of testing and they work. If they are not for you that’s fine but don’t sit behind your internet veil of anonymity and accuse me of trying to mislead people.

 

[Steff]

Also your BCs vary quite radically, when comparing to e.g. Sierra that also publishes multi G1 BCs. I'm quite ready to bet that e.g. 119gr 30cal TLR doesn't fly with half the resistance once it reaches 2765fps.

You‘d be surprised how quickly such a light bullet will drop.
The other day I was shooting .308 Aero bullets at 300m. A 115gn, a 130gn and a 150gn. All the same design and all loaded to what QL told me was the max. safe load.

The 115 and 130gn loads basically required the same number of clicks in elevation. The higher velocity basically compensated the higher BC of the heavier bullet.
But the 150gn load won hands down needing 2 clicks less to hit the bull. In other words it hit 6 cm higher than the lighter bullets.
Not a scientific approach, for sure. But it was an eye opener to see that the math I had before became reality.

 

[jthyttin]

If people are shooting at ranges where they require a precise trajectory prediction

I think one of the main reasons people are looking at BC and using calculators is VELOCITY at given range not drop (with "copper" i.e. non-lead monometals). And all of that is done, behind the veil of anonymity, on your couch. Drops you can find out by shooting and many will even though first resort to calculator.

If I lived in UK I'd buy a box of 119gr 30cal TLR, shoot them over dual chronos (say at muzzle and 200y) and find out whether the .610 BC holds. Launched with conservative 3120fps (308Win) they should be >2765fps until 220y or so.

 

[jthyttin]

You‘d surprised how quickly such a light bullet will drop.

Yes they drop, and their velocity will drop. The question is, if there's a narrow velocity band where the BC drops dramatically (in this case, from .610 to .310)

There are other things that affect POI, than muzzle velocity and BC. You cannot judge or estimate POI without shooting, at least with rifles that have light barrel and recoil is not negligible.

 

[Yew Tree Fieldsports]

I think one of the main reasons people are looking at BC and using calculators is VELOCITY at given range not drop (with "copper" i.e. non-lead monometals). And all of that is done, behind the veil of anonymity, on your couch. Drops you can find out by shooting and many will even though first resort to calculator.

If I lived in UK I'd buy a box of 119gr 30cal TLR, shoot them over dual chronos (say at muzzle and 200y) and find out whether the .610 BC holds. Launched with conservative 3120fps (308Win) they should be >2765fps until 220y or so.

It most certainly is not done under any veil of anonymity on my couch. There have been various people, some from this forum, that have come and shot their rifles in particular calibres and muzzle velocities to either gather initial data or verify existing findings.
There is a fair bit of coverage demonstrating this on either my facebook page or instagram.
By all means go out and shoot my bullets over a chrono and gather impact velocities at various distances with electronic targetry. It is exactly what I do to gather the data. You will find the results are as predicted.

 

[jthyttin]

Sorry for the bad wording, I meant people spend time on their couch, calculating whether bullet X has velocity Y at distance Z. Especially relating to hill shooting.

 

[Bowland blades]

Got to be fair and say good data for long range target shooting . TBF i personally now rely on real word shooting data for drops and windages with stalking rifles . I dont even feel a wind meter is much more use over visual signs reading wind as contour matters . However i call a halt at around 400 yards on live animals even in good conditions after that time of flight and a misjudged wind matters too much , anyhow that is also a decision taken on need and conditions .
Its interesting seeing folks go further but i have seen some pretty dabbed poor first shot sighters from some very good shooters . Absolute BC from your rifle, how much relevance is there in it in the field ? As regards the bullet I put way more relevance in how reliable and fast it puts beasts down dead.
Am i missing something?

 

[User00035]

You‘d be surprised how quickly such a light bullet will drop.
The other day I was shooting .308 Aero bullets at 300m. A 115gn, a 130gn and a 150gn. All the same design and all loaded to what QL told me was the max. safe load.

The 115 and 130gn loads basically required the same number of clicks in elevation. The higher velocity basically compensated the higher BC of the heavier bullet.
But the 150gn load won hands down needing 2 clicks less to hit the bull. In other words it hit 6 cm higher than the lighter bullets.
Not a scientific approach, for sure. But it was an eye opener to see that the math I had before became reality.

That doesn't surprise me. Light, "flat" lower BC bullets always put me in mind of a shuttlecock. They accelerate and fly extremely fast with a flattened trajectory for a relatively short distance then shed energy rapidly and drop like a stone. You clearly demonstrated where that drop-off point occurred with a lightweight .308 bullet and it was closer than might have been imagined.
Heavy and more stable higher BC "raindow" rounds are more like a well slugged cricket ball - and I know which I'd rather try to catch at terminal velocity. The same applies when it comes to bullet impact on game.
Fast and flat has its uses but also it limitations. You can stretch the envelope with clever cartridge development and bullet design but you can't change the laws of physics.

 

[Bowland blades]

That doesn't surprise me. Light, "flat" lower BC bullets always put me in mind of a shuttlecock. They accelerate and fly extremely fast with a flattened trajectory for a relatively short distance then drop like a stone. You clearly demonstrated where that drop-off point occurred and it was closer than might have been imagined.
Heavy and more stable higher BC "raindow" rounds are more like a well slugged cricket ball. And I know which I'd rather try to catch at terminal velocity. The same applies when it comes to bullet impact on game.

Simple terms ELDX 143 grain TTSX 100 grain . 400 yards both will drop a big Stag ! Both work but you will get less recoil and less needing to be cut away on the opposite flank and no Lead Contamination also and less recoil with the 100 grain ttsx and pretty much 100% weight retention 400 fps or so faster out the barrel at the start

 

[kopcicle]

Simple misunderstanding that I may be able to clear up.
Same dimensions in copper, lighter, faster, similar BC.
Same weight, longer projectile, better BC, similar muzzle velocity but retains velocity better at distance.

Issues

Consistent expansion
Method of engraving by rifling.
Critical diameter
Over all cartridge length of similar weight can either be into the lands or backed off to avoid jam and subsequent pressure spike can take up case volume otherwise used for propellant.

Solutions?

I haven't a clue. I just understand the questions.

 

[KimE]

Solutions?

New cartridges designed for copper bullets, like 8,5 blackout. Some of the problems are mag length or throat lenght in old cartridges. Making a new rimfire for copper seems like one of the first things to keep low cost shooting. Rangefinders and new riflescopes has made flat trajectory less important.

 

[jthyttin]

If by "similar" you mean "5-10% less" then I agree. If we leave out stuff like Naturalis.

I think biggest "problem" is that most of US has not adopted any kind of lead ban. So big manufacturers are not required to develop non-lead in full steam. Why US? Because that's a) the largest market and b) about the only market where longer distance hunting demand has critical mass.

Let's take Naturalis as example. Here in Finland average hunter shoots maybe 0-2 shots on large game in a year. And average shooting distance for moose is something like 25-40 meters. So average customer is not very educated in (any kind of) ballistics, and is happy if the bullet works up to 50 meters. 100 meters would be a long reach that he'd probly pass (remember this is mostly for moving game, and also dogs are involved). So Lapua can take a brick, call it bullet and everything is fine. Marginal proportion of customers DID complain, so there were multiple generations of Naturalis, but they usually stayed in the brick format.

There are offerings from US companies, but they usually loose their performance at 300 meters/yard mark even if pushed fast (in standard chamberings). If I've understood correctly, there are certain types of hunting in US where 300-400 yard shot would not be considered unusual (let's leave LR hunting out).

Enter the Sako Blade. They tried to make it more aerodynamic, and to open at lower velocities. They seem to have done well, only problem is they feared to go down enough in weight to make truly universal bullets (there are references to e.g. 150gr 30cal Blade but it's vaporware). Take 308 for example, I'd consider 150gr best weight class for monometals. Muzzle velocity is lower than 130gr class, but you match the velocity at 300 meters thanks to better BC. Lower MV means "nicer" terminal velocity at close shots, and 20 extra grains means more penetration in larger game. People always speak about weight retention in relation to penetration. Well weight retention is also bad for penetration.

So currently if you want universal monometal bullet the choice is boutique manufacturers. They have always been there, for example GS Custom has been making monometal bullets for 30 years (not entirely sure they had expanding from the beginning). If you shoot factory the choice is very limited, and in case of silly UK limits also sporadic.

 

[KimE]

If by "similar" you mean "5-10% less" then I agree. If we leave out stuff like Naturalis.

I think biggest "problem" is that most of US has not adopted any kind of lead ban. So big manufacturers are not required to develop non-lead in full steam. Why US? Because that's a) the largest market and b) about the only market where longer distance hunting demand has critical mass.

Let's take Naturalis as example. Here in Finland average hunter shoots maybe 0-2 shots on large game in a year. And average shooting distance for moose is something like 25-40 meters. So average customer is not very educated in (any kind of) ballistics, and is happy if the bullet works up to 50 meters. 100 meters would be a long reach that he'd probly pass (remember this is mostly for moving game, and also dogs are involved). So Lapua can take a brick, call it bullet and everything is fine. Marginal proportion of customers DID complain, so there were multiple generations of Naturalis, but they usually stayed in the brick format.

There are offerings from US companies, but they usually loose their performance at 300 meters/yard mark even if pushed fast (in standard chamberings). If I've understood correctly, there are certain types of hunting in US where 300-400 yard shot would not be considered unusual (let's leave LR hunting out).

Enter the Sako Blade. They tried to make it more aerodynamic, and to open at lower velocities. They seem to have done well, only problem is they feared to go down enough in weight to make truly universal bullets (there are references to e.g. 150gr 30cal Blade but it's vaporware). Take 308 for example, I'd consider 150gr best weight class for monometals. Muzzle velocity is lower than 130gr class, but you match the velocity at 300 meters thanks to better BC. Lower MV means "nicer" terminal velocity at close shots, and 20 extra grains means more penetration in larger game. People always speak about weight retention in relation to penetration. Well weight retention is also bad for penetration.

So currently if you want universal monometal bullet the choice is boutique manufacturers. They have always been there, for example GS Custom has been making monometal bullets for 30 years (not entirely sure they had expanding from the beginning). If you shoot factory the choice is very limited, and in case of silly UK limits also sporadic.

I think the Blade162gr weight are perfect for a hunting bullet in .308. Isn`t 160gr minimum for moose in finland? Sweden will allow 120gr 2000j/100m for big game next month. Norma has a 150gr ecostrike but its expensive Barnes has 150grttsx a little cheaper.

 

[jthyttin]

Old requirement used to be 10 gram (155gr) and 2000J @100m or 9 gram (139gr) and 2700J @100m.

Two years ago legislation was amended so that non-lead needs only 7.5 gram (116gr) and 1900J @100m. Presumably to allow certain 120gr 6.5mm.

I also hunt in Estonia where requirement for large game is 6.5mm and 9 gram.

 

[jthyttin]

I think the Blade162gr weight are perfect for a hunting bullet in .308

If you compare it to something like 150gr Nosler E-Tip, you begin to see where the problem IMHO lies.

 

[KimE]

You mean low BC?
Its strange now they think a lower engergy level is good enough with coppper. 2700j/100m with a 139gr bullet and only 2000j/100m with a 120gr copper bullet. So a Throphy bonded or Swift A frame 6,5 140gr are still illegal as they most likely cant get to 2700j in 6,5*55.

 

[kopcicle]

I've turned a few in ones and twos for .308 and .277.
Results in gelatin and media have been hopeful but small sample size.
The battle rattle has sufficient freebore to load long but the CF2 is a bit shy in this area.
I'll need to use another rifle for .277 over 130gr.

Throphy bonded or Swift A frame 6,5 140gr are still illegal as they most likely cant get to 2700j in 6,5*55.

Curious because that is near my results. I do have a soft spot for the 6.5x55 as well.

I haven't been getting a lot of trigger time as of late so don't wait on me!

 

[Gandy]

Does anyone know if you can buy just the sako blade bullet to reload ?