Reloading down from 308 and 7mm-08 to 30-30 levels w/ 2206H

[Tubs]

Howdi all,

Trying to get my hunting rifles to replicate 30-30 dynamics.

I dont have a chrono, Blade was explaining to me how to measure bullet velocity using bullet drop stats but I dont have a PhD in physics

Anyone got any load data on 2206H loads required to get a 139gn 7mm and 130gn 30 Cal bullet down to aprox 2500 f/sec?

I figure Id be shaving aprox 15-20% off ADI's min load data but thought someone here has actually done it.

Cheers!

[bladeracer]

Howdi all,

Trying to get my hunting rifles to replicate 30-30 dynamics.

I dont have a chrono, Blade was explaining to me how to measure bullet velocity using bullet drop stats but I dont have a PhD in physics

Anyone got any load data on 2206H loads required to get a 139gn 7mm and 130gn 30 Cal bullet down to aprox 2500 f/sec?

I figure Id be shaving aprox 15-20% off ADI's min load data but thought someone here has actually done it.

Cheers!

You can extrapolate from load data, but shooting at 100m and 200m would get you closer to the actual velocity.

Which bullet exactly? I may have them.

Do you have a .30-30 that you want these to shoot similarly to, or just using .30-30 ballistics as a basis for the load performance you're looking for?

Federal factory 150gn SP (I think they used a Speer HotCore) is rated at 2650fps and made 2649fps in my 22" Ruger the first time I chronoed it, and 2603fps the second time. Average over both tests (10rds) made 2628fps - velocities are never written in stone.

So 2500fps with a 140gn bullet is only reduced by about 300-400fps from factory levels in the .308, enough to reduce noise, recoil and throat erosion, while still hitting pretty hard. The 140gn .30-30 factory load is probably in the 2200-2300fps realm, with 130gn in the 2300-2400fps realm, although your rifles may have longer barrels than most .30-30 carbines.

7mm-08 160gn Speer BTSP makes 2435fps for me on 36gn of AR2206H, so I'd guess you're looking around the 32gn to 33gn region behind a 140gn jacketed bullet to see velocity similar to .30-30 from the 7mm-08, or 35-36gn for 2500fps. For a 130gn jacketed bullet in the .308 to make around 2500fps I would guess around the 36-38gn region with AR2206H. If it's a short bullet though you might find you need a little more powder to make the velocity, with a longer bullet you can seat it deeper into the case to reduce the volume and increase the pressure from a lighter charge. Obviously you'll need to go lower still to replicate actual .30-30 loads with those bullet weights, but if you're not using similar bullets, the trajectory past about 100m could be significantly different due to the flat .30-30 style bullet. The 7mm-08 and .308 are significantly larger cases than the .30-30, about 25% larger volume so you need more powder in them to make the same velocities as the smaller case - in the .30-30 you'd be using 30-32gn for the same velocities.

Cast bullet loads would be different.

[Tubs]

Howdi all,

Trying to get my hunting rifles to replicate 30-30 dynamics.

I dont have a chrono, Blade was explaining to me how to measure bullet velocity using bullet drop stats but I dont have a PhD in physics

Anyone got any load data on 2206H loads required to get a 139gn 7mm and 130gn 30 Cal bullet down to aprox 2500 f/sec?

I figure Id be shaving aprox 15-20% off ADI's min load data but thought someone here has actually done it.

Cheers!

You can extrapolate from load data, but shooting at 100m and 200m would get you closer to the actual velocity.

Which bullet exactly? I may have them.

Do you have a .30-30 that you want these to shoot similarly to, or just using .30-30 ballistics as a basis for the load performance you're looking for?

Federal factory 150gn SP (I think they used a Speer HotCore) is rated at 2650fps and made 2649fps in my 22" Ruger the first time I chronoed it, and 2603fps the second time. Average over both tests (10rds) made 2628fps - velocities are never written in stone.

So 2500fps with a 140gn bullet is only reduced by about 300-400fps from factory levels in the .308, enough to reduce noise, recoil and throat erosion, while still hitting pretty hard. The 140gn .30-30 factory load is probably in the 2200-2300fps realm, with 130gn in the 2300-2400fps realm, although your rifles may have longer barrels than most .30-30 carbines.

7mm-08 160gn Speer BTSP makes 2435fps for me on 36gn of AR2206H, so I'd guess you're looking around the 32gn to 33gn region behind a 140gn jacketed bullet to see velocity similar to .30-30 from the 7mm-08, or 35-36gn for 2500fps. For a 130gn jacketed bullet in the .308 to make around 2500fps I would guess around the 36-38gn region with AR2206H. If it's a short bullet though you might find you need a little more powder to make the velocity, with a longer bullet you can seat it deeper into the case to reduce the volume and increase the pressure from a lighter charge. Obviously you'll need to go lower still to replicate actual .30-30 loads with those bullet weights, but if you're not using similar bullets, the trajectory past about 100m could be significantly different due to the flat .30-30 style bullet. The 7mm-08 and .308 are significantly larger cases than the .30-30, about 25% larger volume so you need more powder in them to make the same velocities as the smaller case - in the .30-30 you'd be using 30-32gn for the same velocities.

Cast bullet loads would be different.

Hey mate, I just picked 30-30 as its standard loads are similar in fps to what I am trying to achieve ie: 2500ish fps. In short, am still trying to work out how much 2206H will get me there for these bullets:

7mm08 - 139 grain Hornady Interlock Softpoints
308 - 130 grain Speer HP Flat base

[Oldbloke]

GRTools will calculate that for you. Free I believe. (German software)
A member here "geoff" was kind enough run some numbers for me for my 223 about 6 weeks ago.

If you need a fair bit of work done perhaps download it. Looks fairly sophisticated.

http://Www.grtools.de

More info here,

https://www.thereloadersnetwork.com/201 ... art-using/

And here,

https://m.youtube.com/watch?v=sehV1jeHa ... _rel_pause

The file size is 225mb

[LawrenceA]

There is about 400fps different between the 30-30 and the 308 for a 130gn pill.
ADI has starting loads with 2206H and lists the max load as compressed so no worries there but we also know that 2206H can be taken down to 60% case capacity so

I would suggest working out your case capacity and see if you can go below the listed minimum safely.
Please note that reducing the velocity may get to a point that the bullets will not stabilise so I would suggest starting at the minimum and working back to try and determine an accuracy node.
Extrapolating back a grain of the 2206H seems to be about 50fps. So start at minimum and work back but not below 60%.

Same sorta deal with the 7mm08

Good luck.

[Tubs]

Thanks chaps

[bladeracer]

There is about 400fps different between the 30-30 and the 308 for a 130gn pill.
ADI has starting loads with 2206H and lists the max load as compressed so no worries there but we also know that 2206H can be taken down to 60% case capacity so

I would suggest working out your case capacity and see if you can go below the listed minimum safely.
Please note that reducing the velocity may get to a point that the bullets will not stabilise so I would suggest starting at the minimum and working back to try and determine an accuracy node.
Extrapolating back a grain of the 2206H seems to be about 50fps. So start at minimum and work back but not below 60%.

Same sorta deal with the 7mm08

Good luck.

ADI says AR2206H can be reduced to 60% of "maximum loads", and maximum loads vary widely among firearms, and load data, so "maximum load" is a _very_ fluid concept. You can go way below 60% without issues, down to low-subsonic if you want. With low case fill you might see better consistency using a filler to hold the powder in place, or even better, just switch to Trailboss.

I don't believe I have ever seen any load data for AR2206H/H4895 list minimum loads, they just list a handy starting point - minimum is _way_ lower than those starting data.

Occasionally a really long bullet that is marginally stable anyway may become unstable launched at subsonic velocities, but I haven't found that as yet. If it's stable at 3000fps it's very likely to be stable at 1000fps. If it's not stable and you want to use it anyway, shorten the tip until it becomes stable, or pull out any ballistic tip it might have and use it as a hollow-point. I've read that the subsonic 190gn Sub-X is extremely effective with the BT removed.

Extrapolation is not linear with powder charges. At near-full levels, adding a half-grain of powder can see very large increases in pressure, with a lesser increase in velocity. Come down two-grains though and half a grain can make a big drop in velocity due to the increasing empty space in the case and vastly-lower pressure produced. I've never tried it myself but if you reduced the charge and kept seating the bullet deeper to maintain the same case volume I guess you might be able to extrapolate the charge-vs-velocity more closely, an experiment I probably should investigate one day.

But to get 2500fps with these bullets in 7mm-08 and .308 we're just talking a basic starting load rather than what anybody would consider a reduced load.

[Tubs]

Mainly doing it for a reduction in felt recoil, but also to reduce wear n tear and powder consumption. Its for my LH Tikka's which Id like to preserve for a long time......

[LawrenceA]

There is about 400fps different between the 30-30 and the 308 for a 130gn pill.
ADI has starting loads with 2206H and lists the max load as compressed so no worries there but we also know that 2206H can be taken down to 60% case capacity so

I would suggest working out your case capacity and see if you can go below the listed minimum safely.
Please note that reducing the velocity may get to a point that the bullets will not stabilise so I would suggest starting at the minimum and working back to try and determine an accuracy node.
Extrapolating back a grain of the 2206H seems to be about 50fps. So start at minimum and work back but not below 60%.

Same sorta deal with the 7mm08

Good luck.

ADI says AR2206H can be reduced to 60% of "maximum loads", and maximum loads vary widely among firearms, and load data, so "maximum load" is a _very_ fluid concept. You can go way below 60% without issues, down to low-subsonic if you want. With low case fill you might see better consistency using a filler to hold the powder in place, or even better, just switch to Trailboss.

I don't believe I have ever seen any load data for AR2206H/H4895 list minimum loads, they just list a handy starting point - minimum is _way_ lower than those starting data.

Occasionally a really long bullet that is marginally stable anyway may become unstable launched at subsonic velocities, but I haven't found that as yet. If it's stable at 3000fps it's very likely to be stable at 1000fps. If it's not stable and you want to use it anyway, shorten the tip until it becomes stable, or pull out any ballistic tip it might have and use it as a hollow-point. I've read that the subsonic 190gn Sub-X is extremely effective with the BT removed.

Extrapolation is not linear with powder charges. At near-full levels, adding a half-grain of powder can see very large increases in pressure, with a lesser increase in velocity. Come down two-grains though and half a grain can make a big drop in velocity due to the increasing empty space in the case and vastly-lower pressure produced. I've never tried it myself but if you reduced the charge and kept seating the bullet deeper to maintain the same case volume I guess you might be able to extrapolate the charge-vs-velocity more closely, an experiment I probably should investigate one day.

But to get 2500fps with these bullets in 7mm-08 and .308 we're just talking a basic starting load rather than what anybody would consider a reduced load.

You are correct as usual Bladeracer. I was trying to simplify the process. Yet maintain the need to be able to place the bullet and as such look for an accurate load.
And yes they are starting loads not minimum. Personally I take 60% of 2206H as minimum and generally 70% for others.

[Oldbloke]

The recommendations from ADI are:
AR2206H 60% of max
All others 75% of max.

They are always conservative. But I would not go far below those recommendations. There is always a remote chance of a "detonation".

[bladeracer]

The recommendations from ADI are:
AR2206H 60% of max
All others 75% of max.

They are always conservative. But I would not go far below those recommendations. There is always a remote chance of a "detonation".

Of max what though, that's the issue. Max is a wide variable, making the 60% even more variable.

I don't believe that remote chance "always" exists, at least no more than the possibility any cartridge might explode if too many tolerances added up wrong.
I wouldn't recommend all others to be 75% though, some powders in specific cartridges can be very fiddly to safely load, there are some I wouldn't experiment with at all.

[bladeracer]

While you can extrapolate muzzle velocity from load data, it's difficult to do it with any degree of accuracy without at least once confirming the velocity as some point in the process in your firearm. The load data might suggest your bullet should be doing 2850fps on a particular load, so you can get a vague idea of where you need to be to get around 2400fps. But you don't know if your rifle actually makes that 2850fps to begin with to extrapolate from it. If you can even fire a single round through a chrono and figure the load is making roughly 2760fps then you have something you can work with.

Without a means of measuring the actual speed of the bullet, I think the most precise second option is measuring the trajectory of the bullet at two distances, then calculating the velocity back from the known BC of the bullet and the measured real-world drop.

If the load is very accurate, say sub-minute at 100m, shoot a group at 50m and 100m and measure the trajectory difference. The amount of drop over that 50m will give you a relatively close idea of the velocity. But if the groups are not tight you would have to shoot a lot of rounds to ascertain the precise centre of each group to be able to measure the difference. If you can extend the range to 100m and 200m you'd get a better idea.

A quick example with the 6.5x55mm.
147gn ELDM zeroed at 100m:
At 2600fps it's 8mm high at 50m.
At 2000fps it's 23mm high at 50m.
At 1500fps it's 51mm high at 50m.

Obviously you're not going to determine your bullet drop to within 2mm if it's only grouping 29mm at 100m, but it will get you into the ballpark, even with a 2-minute load, as long as the group is roughly circular (if it's just a pattern of fliers it's not going to very indicative). You don't need to zero at either distance, you just need to measure what the difference is from a datum, the datum being your point of aim being identical at both distances.

The same figures but with a 50m zero your drops at 100m will be 16mm at 2600fps, 46mm at 2000fps, 101mm at 1500fps.
Or if you zero at 100m, the 200m drops will be 151mm at 2600fps, 277mm at 2000fps, 515mm at 1500fps.

How close can we get using the 100m/200m test. At 2000fps the drop is 277mm at 200m, at 1900fps it's 310mm, at 1950fps it's 293mm. So as long as you can measure your drop to within about 15mm at 200m you'll know the muzzle velocity to within about 50fps. For what it's worth, if we determine this 147gn ELDM to be doing 2000fps at the muzzle, it drops to 1600fps at 360m, so well within most people's hunting abilities with a very light-recoiling load in the 6.5x55mm. This is a very-high BC bullet though. My preferred low-velocity bullet in the 7mm-08 is the Speer HotCor 145gn FBSP with a BC of just .416. Launching this at 2000fps it is down to 1600fps at just 210m, so I wouldn't be shooting goats, pigs or deer with it beyond about 150m max. I actually wouldn't be using it beyond about 50m as it would be my close-range load.

The actual group size is not relevant to this (except that a very large group will be less indicative of actual bullet drop), all we need to know is the amount of drop from the datum. If you take a spirit level with you, draw a horizontal line across the target through the aiming point (your datum), then you can simply measure how far above or below that line each bullet hole is, and average them to get the mean drop. This avoids trying to guesstimate a group centre. You would want to shoot this is over a short time period so outside influences (like wind, light and temperature) have minimal effect on the trajectory - don't shoot 100m today then 200m tomorrow.

But if you can fairly precisely measure the trajectory you can get a very close idea of your velocity, very likely closer than you could extrapolate from load data, and still without needing a chronograph.

[Oldbloke]

The recommendations from ADI are:
AR2206H 60% of max
All others 75% of max.

They are always conservative. But I would not go far below those recommendations. There is always a remote chance of a "detonation".

Of max what though, that's the issue. Max is a wide variable, making the 60% even more variable.

I don't believe that remote chance "always" exists, at least no more than the possibility any cartridge might explode if too many tolerances added up wrong.
I wouldn't recommend all others to be 75% though, some powders in specific cartridges can be very fiddly to safely load, there are some I wouldn't experiment with at all.

The 60% of max is not a variable. It is 60% of the max ADI recommended in their Data. NOT what you think max is. Believe what you like, they are clear in what they recommend just read the manual.

[bladeracer]

The 60% of max is not a variable. It is 60% of the max ADI recommended in their Data. NOT what you think max is. Believe what you like, they are clear in what they recommend just read the manual.

So if ADI say that 30gn is "max" in the load data, then the minimum 60% load is 18gn. But if I'm at 32gn and not seeing any pressure signs I can still go down to 18gn? What if I get to 34gn still without seeing pressures, is 18gn still safe at 53%? So what exactly is the actual safe minimum charge then? Max load data is a variable regardless of how you measure it, and load data is not written in stone. All of it is just rough data to allow you to start working up your own data.

[Oldbloke]

If you don't understand this, it because you don't want to.

Reduced loads 60% max 2206H.JPG (72.59 KiB) Viewed 2764 times

Me, I prefer to keep my face intact.

[bladeracer]

If you don't understand this, it because you don't want to.

Reduced loads 60% max 2206H.JPG

Me, I prefer to keep my face intact.

I disagree, I want to understand it rather than simply be told to obey it...

The fact is 60% is a number plucked out of the sky, it does not relate to an actual safety issue. Going down to 58% or 50% or 40% does not exponentially increase the risk of an anomaly.