Group analysis from the LR Experts

[kjd]

Not knocking the 308 Gary, just saying if I'm getting 308 velocities for 20gr more powder I may as well have gotten one of them.
I'll try more 72gr loads and go up to 73gr should I try even hotter if there are no pressure signs?

[Glenn]

Yes!

Went to 74.5 with no pressure but groups opened up!

Glenn

[aaronraad]

What made you start off at 67gr of AR2213SC?

Looking at the ADI manual for the 175gr & 180gr and AR2213SC I'd have started with their minimum of 69gr and worked from there. I'd be ignoring the Nosler E-tip results given they are a monolithic projectile as the other two projectiles are closer representatives of the A-Max.

You might also find the 175gr A-Max is a little slower than most of the other cup and core projectiles of the same weight as it has much longer bearing surface. A slower powder might help but more than likely you'll run out of case capacity before getting anywhere near maximum pressure.

Once you do find maximum pressure with a particular powder it becomes much easier to considered your other powder options and make educated estimates at a starting load and increments. Velocities can be a little distracting. Are you looking to do any ladder type testing at 200 to 300y after the first stage of load development?

[justjeff]

Hi Keith,

I would look at going up another series of half grain tests, you neglected to tell us the conditions when you shot the test. Was there a significant or variable cross wind? For my LR bench gun, the 72 gr load is the sort of thing I look for. The total lack of vertical tells me that you are right on a node for the combination. I would expect there to be anothoer node around 74 - 75 gr, whether your brass will live with it remains to be seen. If it won't, and you want to stick to 2213, then go back to the 72gr load and play with seating depths, you may tighten it up a bit more.
If it were my rifle, I would also look at 2217, as it has better fill density and lower flame temp, which will help with barrel life, which can be improtant with the 300 Win Mag. The version I shoot has a .380 long neck, which also helps.
In reality, the 300 Win Mag will give you better results for the heavier pills, where slow powders and large volumes let the pressure build slower, resulting in better velocity v pressure.
Just my experience, but I would avoid RE22 if you think you will fire a number of rounds in a short time, as in the bench guns it seems to produce extreme carbon fouling, with 2213 not far behind. Not an issue I know for a hunting gun which might only fire a shot or two between cleans, but just my experience.

Good luck,

Jeff

[Tony Z]

Keith you have found your low node at 69.5 grains. Like Jeff said you are at least 5 grains from where the powder becomes efficient and reaches pressure and the next node. The question is will the brass make it there and how long will it last? My 308 5R runs over 2800 fps with the 175s and Lapua cases running Re15 with no loss of primer pockets and virtually no sizing required. Remington or Winchester brass in a 300 WM won't last long and probably won't reach the next node. Lapua and RWS will.

What I can't tell from the pics is the rise in POI but at about 75 to 76 grains of SC there will be a sudden elevation shift, the bore will be less fouled with carbon and the recoil will be more heart felt. That is about where it all gets going. My own experience with the 300WM in heaps of guns is that the 175-190 grain pills node with SC is 77 grains. If memory serves, Stuart Elliot ran a 300 WM with 77 grains of SC and a 185 Lapua to win a whole heap of Fly matches. Pretty much a known formula. I think Rinso ran something very similar. Both ran Lapua cases. If you can't get there then the 308 is the choice and why so many go there. Unfortunately the books don't tell the whole story of pressure, accuracy and brass quality.

[MISSED]

Thank you Tony

[kjd]

Thanks for the great advice fellas.

Conditions were a slight breeze. Though when I shot the 72gr load it went still and mirage appeared which could be why I botched the group!

[aaronraad]

Thanks for the great advice fellas.

Conditions were a slight breeze. Though when I shot the 72gr load it went still and mirage appeared which could be why I botched the group!

Nothing wrong with the 72gr group unless you keep getting unexplained horizontal. Don't throw the baby out with the bathwater...as they say.

[kjd]

Thanks for the great advice fellas.

Conditions were a slight breeze. Though when I shot the 72gr load it went still and mirage appeared which could be why I botched the group!

Nothing wrong with the 72gr group unless you keep getting unexplained horizontal. Don't throw the baby out with the bathwater...as they say.

Still need a bit more velocity!

[aaronraad]

Thanks for the great advice fellas.

Conditions were a slight breeze. Though when I shot the 72gr load it went still and mirage appeared which could be why I botched the group!

Nothing wrong with the 72gr group unless you keep getting unexplained horizontal. Don't throw the baby out with the bathwater...as they say.

Still need a bit more velocity!

Still room to move from what I can interpret for the 300WM on the ADI manual on-line; but you still have to make judgement on pressure levels with the information you have. I don't have to live with the risk...unless I'm on the bench beside you at the local range.

If you didn't have a chronograph, what load development process would you use?

[kjd]

Thanks for the great advice fellas.

Conditions were a slight breeze. Though when I shot the 72gr load it went still and mirage appeared which could be why I botched the group!

Nothing wrong with the 72gr group unless you keep getting unexplained horizontal. Don't throw the baby out with the bathwater...as they say.

Still need a bit more velocity!

Still room to move from what I can interpret for the 300WM on the ADI manual on-line; but you still have to make judgement on pressure levels with the information you have. I don't have to live with the risk...unless I'm on the bench beside you at the local range.

If you didn't have a chronograph, what load development process would you use?

Mate I think you are right, I'm probably going to go half grains up to at least 74gr, I'm not getting any flattening of the primers bolt lift is still really easy and extraction is not an issue so there is definitely more room for powder in the case.

If I didn't have a chrony I probably would have just settled on 70gr and never really wrung out the performance that is still available.

I'm a lazy reloader haha.

[aaronraad]

Mate I think you are right, I'm probably going to go half grains up to at least 74gr, I'm not getting any flattening of the primers bolt lift is still really easy and extraction is not an issue so there is definitely more room for powder in the case.

If I didn't have a chrony I probably would have just settled on 70gr and never really wrung out the performance that is still available.

I'm a lazy reloader haha.

I still like to look for the pressure signs you mention above, especially in bolt actions with factory chambers and tolerances. Historically, I found my loads near or over the ADI maximum range and it's only been the more recent ADI versions of their manual where I settled on a load within their min to max range. Some cartridges really don't perform at efficient levels until that last 2grs.

Reloaders do come unstuck though when their chosen load is riding right on the working pressure limit of one of the components. There are definitely more custom actions and tight chambers than ever before, maybe not percentage wise but definitely in terms of overall volume. These bespoke bolt action rifles can do a good job of hiding the common pressure signs we're told to look, feel and measure for. Chronographs and pressure (strain-gain) systems make an excellent double check.

Adding a custom 'long' bolt handle can give the false impression that bolt lift is still 'easy'...I can't wait to read the post that says, "I found the bolt lift on my Tikka T3 was getting stiff, so I fitted this long tactical version. All good now, but these new primers must be soft, they keep smearing all over the case head???" ...for some reason I keep reading that with a kiwi accent in my head...

[kjd]

haha very true mate. I still have the factory bolt handle attached and haven't noticed any pressure signs, the primers look the same across the varying charge weights no appreciable differences were detected in regards to pressure and I have been watching them. I'm still a grain under max for a 180gr load and my projectiles are 178gr so theres probably some more room there especially as seeing the 175GR SMK's go up to 76 or so grains.

[Seddo]

I run 2225 through one of mine and will be using 2217 through the new one. Those velocity's are terrible, I'm running 208's out at 2945 with mine but they have longer barrels.

What length are you loading them too? Mine are all loaded to max AI mag length.

[kjd]

3.360" which is the max length of a tikka mag mate!