308 thick ADI brass!

[in2anity]

I can see dr wiki says 60kpsi for NATO, but my understanding 7.62 NATO ammunition was loaded to a maximum average pressure of 50kpsi back then, with only a proof to 67kpsi. So f4 ball ammo is 50kpsi. And also as Vince discovered, 42gr 08 or 06H under a 147gr aint gonna yield 60kpsi. It'll be around 50kpsi.

[bladeracer]

Yes, they were converted by professionals weren't they, people that would've done the calculations and determined that they would work just fine?

My understanding is they were converted with consideration to the commonwealth 762 NATO ammo available in that era, i.e. 144gr. Not just any 308w available.

I did find a page that says the original L2A2 Ball 144gn made 50,000psi, at 2700fps, but I haven't found a supporting source yet.
https://sites.google.com/site/britmilammo/7-62mm/7-62mm-nato-ball
As current 147gn M80 ball makes 2800fps at 60,000psi I'm wondering if perhaps the Brits simply took their pressure measurements using a different method?

According to this guy https://www.youtube.com/watch?v=sE3WWgyJ3Pw the current F4 Ball is a 43.2gn charge behind a 145.5gn bullet making 2800fps in a 22" barrel, so virtually identical to US M80 Ball, and only 4% hotter than the 1954 stuff.

[bladeracer]

I found proof marks on the early L1A1's are also 20 tons per square-inch, so I think the Brits simply measure their pressures differently.

This page has early proof rounds rated at 27 to 29 tons - around 60,000psi.
https://sites.google.com/site/britmilammo/7-62mm/7-62mm-nato-proof-armour-piercing

I don't believe early British NATO ammo was making 2700fps with only 50,000psi chamber pressure measured according to modern standards.

[Vince24]

In any case, my rifle is a wartime Long Branch, so I will not exceed 43.5, starting from 41.5.

Cheers

My No.4 Mk1* is a 1943 Longbranch.
My standard load with the 150gn bullets is 36gn of AR2206H.
I'm using S&B brass for this rifle. Filled to the top it holds 48.9gn of AR2206H.

Just to avoir any misunderstanding, is yours in 308w as well? That seems a very mild load (but it seems you like those mild loads in 2206H in military rifles )

[Vince24]

Yes, they were converted by professionals weren't they, people that would've done the calculations and determined that they would work just fine?

My understanding is they were converted with consideration to the commonwealth 762 NATO ammo available in that era, i.e. 144gr. Not just any 308w available.

I did find a page that says the original L2A2 Ball 144gn made 50,000psi, at 2700fps, but I haven't found a supporting source yet.
https://sites.google.com/site/britmilammo/7-62mm/7-62mm-nato-ball
As current 147gn M80 ball makes 2800fps at 60,000psi I'm wondering if perhaps the Brits simply took their pressure measurements using a different method?

According to this guy https://www.youtube.com/watch?v=sE3WWgyJ3Pw the current F4 Ball is a 43.2gn charge behind a 145.5gn bullet making 2800fps in a 22" barrel, so virtually identical to US M80 Ball, and only 4% hotter than the 1954 stuff.

ADI 16, that’s my head stamp! But 43.2 grains of which powder??)

[in2anity]

ADI 16, that’s my head stamp! But 43.2 grains of which powder??)

08 probably.

[Vince24]

Yep - although I have heard that ammo makers sometimes blend different powder types together like French winemakers blend different grapes.

[in2anity]

Vince if you look closely, you can see the difference between 06H and 08 - the kernels are slightly coarser with 08. Could you compare your factory to these powders?

[bladeracer]

In any case, my rifle is a wartime Long Branch, so I will not exceed 43.5, starting from 41.5.

Cheers

My No.4 Mk1* is a 1943 Longbranch.
My standard load with the 150gn bullets is 36gn of AR2206H.
I'm using S&B brass for this rifle. Filled to the top it holds 48.9gn of AR2206H.

Just to avoid any misunderstanding, is yours in 308w as well? That seems a very mild load (but it seems you like those mild loads in 2206H in military rifles )

Nope, .303.
I just mentioned it as you can see my charge is about 75% of the total case capacity.
I wouldn't say it's especially mild, but it is significantly easier on the rifle. I think it's around 2350fps.

[bladeracer]

ADI 16, that’s my head stamp! But 43.2 grains of which powder??)

Pull one of your rounds down and dump the powder into a dish.
Tip some AR2206H and AR2208 into dishes and make a visual comparison.
Those are the most likely powders which is about as close as you're going to get, unless you can find a copy of the F4 Ball specification sheet.

Use either powder and develop a load that gives you the same chrono reading as the factory ammo.

But these guys are telling you that this load is 10,000psi higher than your rifle was designed to cope with.

[in2anity]

But these guys are telling you that this load is 10,000psi higher than your rifle was designed to cope with.

I'm not - i think that ammo is around 50kpsi, perhaps a touch more, as i've been saying all along.

[Over The Hill]

I am following this conversation with great interest as I also have a No.4 in 308W which was built for me specifically as a range rifle and in 308 as I already shoot and load this calibre so I didnt need to outlay anything for ammo or loading gear, also I like being a little bit left of mainstream. ADI has load data for the 308 with 150g pills. I am currently using 150g Hornady Soft Point Interlocks with 12g Trailboss for 50M which will be approx 26000 psi and for 100-200M I am loading Speer 150g Soft Point Boat Tail Spitzers with 44g AR2208 which ADI lists at 43600 psi. I dont see any need to load higher as I wouldnt see any noticable improvement using irons and have no desire to increase pressures. I seem to remember reading on another forum that back in the day the Canadian DCRA imposed a weight limit of 155g and even the gunsmith who built my No.4 also said not to use projectiles over 155g whether factory or handloads. I have too many $ invested in this rifle and want it to last my shooting life so I am happy to treat her nice and stick to listed loads where the pressures are published. Note, ADI table is for 24" barrel, std No.4 is 25" so close enough for a good estimate.

[in2anity]

I am loading Speer 150g Soft Point Boat Tail Spitzers with 44g AR2208 which ADI lists at 43600 psi.

That seems like a mistake in the ADI table to me - look at the Nosler loads above, of the same weight. I reckon it's a misprint and should be CUP.

[bladeracer]

But these guys are telling you that this load is 10,000psi higher than your rifle was designed to cope with.

I'm not - i think that ammo is around 50kpsi, perhaps a touch more, as i've been saying all along.

How do you explain it making virtually the same velocity as modern 60,000psi ammo then?

[bladeracer]

I am loading Speer 150g Soft Point Boat Tail Spitzers with 44g AR2208 which ADI lists at 43600 psi.

That seems like a mistake in the ADI table to me - look at the Nosler loads above, of the same weight. I reckon it's a misprint and should be CUP.

I agree, for some reason they're using Copper Units for the starting load and psi for the max load.

Screenshot 2022-09-28 181210.jpg (26.22 KiB) Viewed 2213 times

Screenshot 2022-09-28 181505.jpg (25.84 KiB) Viewed 2213 times

Still not a hot load though.

[bladeracer]

I am following this conversation with great interest as I also have a No.4 in 308W which was built for me specifically as a range rifle and in 308 as I already shoot and load this calibre so I didnt need to outlay anything for ammo or loading gear, also I like being a little bit left of mainstream. ADI has load data for the 308 with 150g pills. I am currently using 150g Hornady Soft Point Interlocks with 12g Trailboss for 50M which will be approx 26000 psi and for 100-200M I am loading Speer 150g Soft Point Boat Tail Spitzers with 44g AR2208 which ADI lists at 43600 psi. I dont see any need to load higher as I wouldnt see any noticable improvement using irons and have no desire to increase pressures. I seem to remember reading on another forum that back in the day the Canadian DCRA imposed a weight limit of 155g and even the gunsmith who built my No.4 also said not to use projectiles over 155g whether factory or handloads. I have too many $ invested in this rifle and want it to last my shooting life so I am happy to treat her nice and stick to listed loads where the pressures are published. Note, ADI table is for 24" barrel, std No.4 is 25" so close enough for a good estimate.

I use 15gn for my TB loads, they are much more enjoyable to shoot than the hotter stuff

I want my milsurps to still be as good as I got them when I pass them on to their next caretaker. Every year more of them are taken out of service by neglect, wear, damage, and external threats like fire, flood, theft, laws, and those that deactivate them for souvenir value. They are not going to be around forever. I don't think we're too far off manufacturers producing replicas of even the rifles we consider pretty common nowadays simply because as the numbers decrease and the prices increase it will become cheaper to buy and shoot replicas than real ones.

[Over The Hill]

I am loading Speer 150g Soft Point Boat Tail Spitzers with 44g AR2208 which ADI lists at 43600 psi.

That seems like a mistake in the ADI table to me - look at the Nosler loads above, of the same weight.

I reckon it's a misprint and should be CUP.

I am not so sure its a misprint
If I look at the ADI table for 150g speer SPBT with max 47.5g AR2208 nis shows pressure of 58400 PSI. If this was in fact a misprint and meant to be 58400 CUP then the pressure in PSI would be well north of SAAMI spec and I doubt that ADI would be publishing recommended loads that exceed SAAMI

In any case for the 44g load I am using whether 43600 psi or 43600 CUP (approx 48200 psi) it is in my opinion still a safe load for the No.4.

[bladeracer]

I am loading Speer 150g Soft Point Boat Tail Spitzers with 44g AR2208 which ADI lists at 43600 psi.

That seems like a mistake in the ADI table to me - look at the Nosler loads above, of the same weight.

I reckon it's a misprint and should be CUP.

I am not so sure its a misprint
If I look at the ADI table for 150g speer SPBT with max 47.5g AR2208 nis shows pressure of 58400 PSI. If this was in fact a misprint and meant to be 58400 CUP then the pressure in PSI would be well north of SAAMI spec and I doubt that ADI would be publishing recommended loads that exceed SAAMI

In any case for the 44g load I am using whether 43600 psi or 43600 CUP (approx 48200 psi) it is in my opinion still a safe load for the No.4.

The start charge is 43,600CUP, not psi, the max charge is 58,400psi. The error is in the use of two different measuring systems but listing both as psi.
SAAMI spec is 60,000psi for .308Win.

[Vince24]

okay, upon request of the estimated audience , i have dismantled one of those ADI rounds.

The only surprise is that it has been super easy with the "inertia hammer" (or however you translate this in English).
Just two blows, easier than with my reloads, I was shocked. Yet my reloads are not crimped.

Anyway.

so the bullet is 145gn as discussed (quite a different shape from the Hornady 3037)

IMG_4403.jpg (64.84 KiB) Viewed 2202 times

And I found 42.9 grains of powder. May have lost a few in the hammer.
As to which powder, well not easy to say, see pictures.

IMG_4402.jpg (131.68 KiB) Viewed 2202 times

From top to bottom you have the ADI powder, some 2206H and then some 2208.

IMG_4404.jpg (121.68 KiB) Viewed 2202 times

It looks like 2206H but not 100% certain.
According to GRT, with that load (43gn 2206H) and that OAL (2.775) with the Hornady bullet, I would be at 52,247 psi.

At the end of the day, my conclusion is that I will try 7 loads from 41.5 to 43.5 grains of 2208 (41.5-42-42.5-42.8-43-43.2-43.5) on an OAL of 2.8' and will settle on the mildest one giving me a good outcome. The maxi load at 43.5gn 2208 should be around 51,437 psi for the smallest of my cases.

Given the number of rifles I have (too many according to wifie), and the quantity of shooting I do practically (not so much), I doubt I will have a chance to stretch the action .

I will let you know the outcome of the testing, but it won't be until January, I have a handful of other (less problematic) rifles on my handloading list before I get to this No4.

Among others a K31 - for which ADI does not even give load data in 2208!!

[bladeracer]

As to which powder, well not easy to say, see pictures.

IMG_4402.jpg

From top to bottom you have the ADI powder, some 2206H and then some 2208.

IMG_4404.jpg

Top and bottom samples look identical to me.

[Vince24]

The ADI father looked like 2206H to me but anyway, it has become purely academical by now.

[in2anity]

The ADI father looked like 2206H to me but anyway, it has become purely academical by now.

With the modern thales fmj, 43gr06H makes a lot more sense to me than 43gr08 - wasn't game to say it before, at risk of conjecture. 43gr08 would be rather anemic.

Looking back through my notes, I found this nugget which I think is pertinent to our discussion, only 42gr but a clue nonetheless:

308w - 42gr 06H under the Hornady 150gr FMJ

150gr_42gr_06h.png (49.19 KiB) Viewed 2174 times

Note the sub-50kpsi pressure, which is the collective idealogy for No4-762s under our combined clubs. Quickload disclaims a 10% margin of error

I did this for a clubmate who had just acquired his first No4-762, and was looking to switch away from AR2208, to reduce the recoil impulse. I tend to run 06H in my Service Rifles; purely for this fact; even my as-issued No4. 08 gets reserved for my Neilson TR, which is so heavy the recoil is moot.

[straightshooter]

Pretty well all of these loading calculators are a flashy interface applied to the Homer Powley ballistic calculations developed in the early 60's.
The illusion of predictable precision in these modern calculators is just that, an illusion.
Trust only data from reputable laboratory tested loads such as ADI/Hodgdon and to have a chance of getting the predicted results one must follow the recipe exactly but the result will still depend on the remaining variable, ones rifle.

[Over The Hill]

I am loading Speer 150g Soft Point Boat Tail Spitzers with 44g AR2208 which ADI lists at 43600 psi.

That seems like a mistake in the ADI table to me - look at the Nosler loads above, of the same weight.

I reckon it's a misprint and should be CUP.

I am not so sure its a misprint
If I look at the ADI table for 150g speer SPBT with max 47.5g AR2208 nis shows pressure of 58400 PSI. If this was in fact a misprint and meant to be 58400 CUP then the pressure in PSI would be well north of SAAMI spec and I doubt that ADI would be publishing recommended loads that exceed SAAMI

In any case for the 44g load I am using whether 43600 psi or 43600 CUP (approx 48200 psi) it is in my opinion still a safe load for the No.4.

The start charge is 43,600CUP, not psi, the max charge is 58,400psi. The error is in the use of two different measuring systems but listing both as psi.
SAAMI spec is 60,000psi for .308Win.

Out of interest I contacted ADI questioning their data in case of misprint. To my pleasant surprise ADI have replied with a letter that states: We can confirm that the data which you are referring to is accurate based on our records.

Full letter text below FYI as it contains some interesting info regards the accuracy of these published tables


Thank you for your enquiry of 28/9/2022 with regard to reloading using ADI Sporting powders.
Please find attached our latest test load data for .308 Winchester.
We can confirm that the data which you are referring to is accurate based on our records.
Owing to the effect of variations within allowable manufacturing tolerances for cartridge components made by different manufacturers, firearm variations and conditions, operating temperatures etc, pressures developed by any given rifle or pistol load can vary significantly from those that apply to our recommended loads. The two loads you are referring to have been generated at different times with different manufacturers component lots and in different barrels so there is likely to be some variation.
We note that there is no ‘rule of thumb’ to convert CUP to PSI so the two loads that you are referring to cannot be directly compared.
Older data and some of the load data supplied by Hodgdon Powder Company has been measured in copper units of pressure (cup), which is mechanically using a copper slug called a “crusher”. The crusher is placed in a fixture over the chamber where a hole passes through the barrel to the chamber. When the cartridge is fired, the resulting gases cause the “crusher” to flatten. The “crusher” is measured and the result is then converted to pressure by comparing to a tarage table. Our more recent data is measure in pounds per square inch (psi) by calibrated Piezoelectric transducers.
Our published test load data is only ever intended to be used a guide and you should always work your loads up using your components and firearm until you find your optimum safe load.
Ensure that you begin your load development at the suggested starting load. Carefully monitor your rifle and cases for signs of excessive pressure like badly flattened primers or difficult bolt lift.
Extreme caution should be taken and loads should be worked up accordingly. Refer to our website at www.adi-powders.com.au or our 10th edition handloaders’ guide for more information, warnings and reloading safety.
We thank you for using ADI Sporting Powders.
Yours sincerely,
ADI Technical Centre

[bladeracer]

Out of interest I contacted ADI questioning their data in case of misprint. To my pleasant surprise ADI have replied with a letter that states: We can confirm that the data which you are referring to is accurate based on our records.

Full letter text below FYI as it contains some interesting info regards the accuracy of these published tables


Thank you for your enquiry of 28/9/2022 with regard to reloading using ADI Sporting powders.
Please find attached our latest test load data for .308 Winchester.
We can confirm that the data which you are referring to is accurate based on our records.
Owing to the effect of variations within allowable manufacturing tolerances for cartridge components made by different manufacturers, firearm variations and conditions, operating temperatures etc, pressures developed by any given rifle or pistol load can vary significantly from those that apply to our recommended loads. The two loads you are referring to have been generated at different times with different manufacturers component lots and in different barrels so there is likely to be some variation.
We note that there is no ‘rule of thumb’ to convert CUP to PSI so the two loads that you are referring to cannot be directly compared.
Older data and some of the load data supplied by Hodgdon Powder Company has been measured in copper units of pressure (cup), which is mechanically using a copper slug called a “crusher”. The crusher is placed in a fixture over the chamber where a hole passes through the barrel to the chamber. When the cartridge is fired, the resulting gases cause the “crusher” to flatten. The “crusher” is measured and the result is then converted to pressure by comparing to a tarage table. Our more recent data is measure in pounds per square inch (psi) by calibrated Piezoelectric transducers.
Our published test load data is only ever intended to be used a guide and you should always work your loads up using your components and firearm until you find your optimum safe load.
Ensure that you begin your load development at the suggested starting load. Carefully monitor your rifle and cases for signs of excessive pressure like badly flattened primers or difficult bolt lift.
Extreme caution should be taken and loads should be worked up accordingly. Refer to our website at http://www.adi-powders.com.au or our 10th edition handloaders’ guide for more information, warnings and reloading safety.
We thank you for using ADI Sporting Powders.
Yours sincerely,
ADI Technical Centre

Disregard it, they are wrong. Anybody that queries the irregularities in their published data gets the same response.

[Vince24]

Pretty well all of these loading calculators are a flashy interface applied to the Homer Powley ballistic calculations developed in the early 60's.
The illusion of predictable precision in these modern calculators is just that, an illusion.
Trust only data from reputable laboratory tested loads such as ADI/Hodgdon and to have a chance of getting the predicted results one must follow the recipe exactly but the result will still depend on the remaining variable, ones rifle.

Hummm I think you should look into GRT, it's free, if you haven't yet. Hopefully things have changed since the 60's.
If anything else, it's a very useful database with the specs of thousands of calibres, projectiles from all manufacturers etc,

If I had only looked into ADI data and raised no question to anybody, I would have prepared rounds from 44 to 47 grains.
Way above what I should be using, pressure-wise.
This is because the ADI data does not know about the reduced capacity of my (ADI, lol) cases.
ADI data does not know the projectile I am using, Not all 150gn projectiles will give you the same pressure!
It does not let me play with seating dept.

A modern reloading software attemps to do all that. And more.

It does not replace the reloading data from the manuals or from ADI, it does not replace your brain, but it's a useful complement to understand what you're doing. Just that. I don't use it for accuracy, only the group on your target can tell you that!

Cheers
Vincent

[in2anity]

It does not replace the reloading data from the manuals or from ADI, it does not replace your brain, but it's a useful complement to understand what you're doing. Just that. I don't use it for accuracy, only the group on your target can tell you that!

It’s fine he’s just being melodramatic. It’s a thang, within NRAA affiliated, and they are some of the best shooters in Oz. Of course nothing beats the real thing, nor across the chrono, but I’ve never seen it worse than 5% error and I’ve concocted all manner of loads for myself and others over many years. When it’s left of field, it starts with software. As you said it’s a valuable complementary tool that just needs treating with an appropriate safety margin

[straightshooter]

in2anity
Not what you think.
I am astounded by the simple mindedness of people who read and accept a result that implies a precision of 5 or more significant figures because it is in an app or on a computer but will ignore a quite visible developers disclaimer of being within 10% accuracy.
That 10% means plus or minus 10% or to express it another way, for example a reading of 2543 could be anywhere between 2289 and 2797 or for that matter a powder weight given as 45 grains could be in error by + - 4.5 grains.
The attentive among you might now see a connection with the admonition to always start load development with a 10% reduced load.
And this does not take into account the users potential cumulative measurement errors in inputs and other mechanical variations.
In classic computer speak GIGO.

[in2anity]

You're astounded are yu SS? Well lucky nobody is forcing you to use ballistic software bud... seems like it's a bit much for you to handle...

Meanwhile, back to the to real world for the rest of us "simple minded" folk; whereby the calculators are a great compliment to the tables, chrono results and generally experience on the mound.

[bladeracer]

I don't see any relevance to these things either, but I can see they might be a useful learning tool when you're starting out. They do sort of teach the relationship between the different aspects of the cartridge, change one thing and you can see what else changes in response. But for actually loading ammo it's not helpful.