.300 Win Mag 200gr Maximum Velocity (with SOMCHEM S385 Powder)

[SlushPuppy]

For the 200gr Accubonds, I bumped up the S365 to 64gr, now I'm grouping nicely at 2800 ft/sec. The 180gr AB still working properly with 66gr of S365, running at 3000 ft/s . All this in PMP cases, must say, they are not the most consistently weighing bunch. Getting 100 Hornady Cases to see if I can get better accuracy.

 

[SlushPuppy]

So, a lot of load work done this past weekend.

I changed to Hornady Cases with average internal volume of 90gr H2O, yes I tested all 100 cases I bought new.

With the 200gr Accubonds, I worked my way up with S 365, I am now using 66.5gr and pushing the bullets at average 2900 ft/sec, 100m Grouping Attached below (the 10cent coin is 21mm in diameter).

No signs of excess pressure.

The 180gr gave me a hard time grouping at 3150 ft/s using 70gr S365, so I'm backing up the load to 68.5 which should yield around 2970 ft/s Average. I believe they will group nicely at this velocity.

Will send another update after this weekend's run.

 

[Desperatezulu]

Good grouping!

I don't want to rain on your parade but you are playing with fire.... Literally! Your loads look they are well over max pressure, other than your last 180gr load @ 2970f/s.

I still don't get why you're chasing the last word in speed - wear and tear on your components will be much higher than intended by the designer, assuming you manage to avoid a catastrophe. At the very least you're probably going to start seeing signs of case head separation within a few reloadings.

 

[ChrisG]

Thanks for all the info peeps.

The reason I'm considering a "Higher" Velocity Load, and not just settling for a more Practical (worry free) 2500ft/s is because of the shot distances in the areas I hunt.

250 meter+ shots are not uncommon on some big game (an Eland this time), thus I'm looking for that extra advantage in Trajectory and Bullet Energy by using a "Higher" Velocity Load.

This must of course still be a safe load with proper accuracy in my new Howa .300 Win Mag (24" Barrel).

So for the load, I'm using PMP Casings (used once before), proper Magnum Primers, SOMCHEM S385 Powder, and Nosler Accubond 200gr Bullets.

I will share my results here once I start testing the loads.

Every time I start thinking I need to push my rifles a little bit faster, I consult a ballistics calculator and get a little perpective.
I used the worst possible choice of bullet for this. a 200 grain Round Nose. B.C. .241. If you use your accubond, the numbers would not be significantly better but retain velocity would be higher for performance on game. Even if you load a 200 grainer to 2600 FPS (seems quite doable even with mild RSA powders), sight it in for 200 yards (2.5 inches high at 100) you are only about 12 inches low at 300 yards and 36 inches low at 400. Boosting your velocity even to 3000fps you gain about 25 yards. It doesn't really seem worth it for all the wear and tear on your rifle, brass and throat, not to mention your shoulder. I thinkn you are right in the ballpark for about what a .300 mag is supposed to do without going to a .30-378 Weatherby or something equally as fire-breathing.

The major advantage to faster burning powders in the tremendous decrease in muzzle blast and flash. The original max charge you listed for SomChem is rather light for the .300's capacity, which makes me think it is a faster powder. Slower powders haven't dropped off the pressure spike by the time the bullet leaves the barrel. This means the all the gas produced by the cartridge is under a high enough pressure, and is still hot enough to ignite the residual gases produced by the powder when they contact the atmosphere. This produces the fireball that blinds people in low light when most game is active, and produces a deafening blast (shockwave actually). Not really what you want in a hunting rifle, if it can be avoided. Longer barrels mitigate this somewhat. I don't know how much this helps the OP but I am of the opinion that your original load was just fine if you can get it to shoot decently!

 

[SlushPuppy]

Good grouping!

I don't want to rain on your parade but you are playing with fire.... Literally! Your loads look they are well over max pressure, other than your last 180gr load @ 2970f/s.

I still don't get why you're chasing the last word in speed - wear and tear on your components will be much higher than intended by the designer, assuming you manage to avoid a catastrophe. At the very least you're probably going to start seeing signs of case head separation within a few reloadings.

I don't stare myself blind against QuickLoad Pmax Results. I use it as a guideline only, I have found it to give correct and incorrect results.

I'm able to increase the charge because the cases have a larger internal capacity than the PMP cases used earlier.

Work your way up from light loads using chrony, and keep a close eye on ANY pressure signs, even the slightest primer cratering can already tell that pressure is becoming a problem with a particular load, and then back off you load.

Always inspect your cases before reloading them, looking for deformations and problems areas. Chuck them if they look suspect. Only reload the strong cases.

I am crosschecking my loads with old timers that have been reloading 300 win mags for many years, my loads may not be in check with QuickLoad Software Results, but it is in check with real word practical results.

Other than that, my Howa was bought as a workhorse rifle, and I don't mind some extra wear on the barrel. If its gets worn out a few years earlier than another, then so it is, time for a upgrade then.

 

[ChrisG]

I don't stare myself blind against QuickLoad Pmax Results. I use it as a guideline only, I have found it to give correct and incorrect results.

I'm able to increase the charge because the cases have a larger internal capacity than the PMP cases used earlier.

Work your way up from light loads using chrony, and keep a close eye on ANY pressure signs, even the slightest primer cratering can already tell that pressure is becoming a problem with a particular load, and then back off you load.

Always inspect your cases before reloading them, looking for deformations and problems areas. Chuck them if they look suspect. Only reload the strong cases.

I am crosschecking my loads with old timers that have been reloading 300 win mags for many years, my loads may not be in check with QuickLoad Software Results, but it is in check with real word practical results.

Other than that, my Howa was bought as a workhorse rifle, and I don't mind some extra wear on the barrel. If its gets worn out a few years earlier than another, then so it is, time for a upgrade then.

I would say for the most part that this is a pretty good method. The only thing I have witnessed is that some rifles and brass don't even START to give you any pressure signs at all until you are at close to 80,000psi. I don't ever go above max with any brass because the extra 50fps isn't worth it in my opinion.

It is a lot of money to do it yourself, but if you can find someone who has a setup, strain gauges will give you exact pressures and then you will really know where you are at. The Chronograph is also good at telling you this, but sometimes weird things happen. 80,000psi can obturate a bullet so much that it increases the friction between the bullet and barrel, effectively slowing it down. People report that an increase in powder charge brought about a decrease in velocity when they are up to max. This is a major sign that something is seriously wrong with the load. However, they assume it is safe due to the fact that the primers look fine and the brass ejects without a problem... food for thought.

Your groups look great btw!

 

[ChrisG]

So, a lot of load work done this past weekend.

I changed to Hornady Cases with average internal volume of 90gr H2O, yes I tested all 100 cases I bought new.

With the 200gr Accubonds, I worked my way up with S 365, I am now using 66.5gr and pushing the bullets at average 2900 ft/sec, 100m Grouping Attached below (the 10cent coin is 21mm in diameter).

No signs of excess pressure.

The 180gr gave me a hard time grouping at 3150 ft/s using 70gr S365, so I'm backing up the load to 68.5 which should yield around 2970 ft/s Average. I believe they will group nicely at this velocity.

Will send another update after this weekend's run.

View attachment 154113

Just out of curiosity, why don't you want to use the 180 accubond? It seems to me that it shoots really well and I doubt there is an Eland alive that could take a 180 through the pump and keep walking. If you are worried about oblique shots, Barnes TSX or TTSX are fantastic penetrators!

 

[PHOENIX PHIL]

Just out of curiosity, why don't you want to use the 180 accubond? It seems to me that it shoots really well and I doubt there is an Eland alive that could take a 180 through the pump and keep walking. If you are worried about oblique shots, Barnes TSX or TTSX are fantastic penetrators!

If I had a safe load pushing a 200gr bullet at 2900fps versus a safe load for a 180gr bullet at 2970fps and accuracy was the same..........the choice is easily the 200gr load. The increased BC will easily compensate for the mere 70fps difference and you'll have the momentum increase.

 

[ChrisG]

If I had a safe load pushing a 200gr bullet at 2900fps versus a safe load for a 180gr bullet at 2970fps and accuracy was the same..........the choice is easily the 200gr load. The increased BC will easily compensate for the mere 70fps difference and you'll have the momentum increase.

Right, I understand that it is possible given the data that we have here. But the original OP was inquiring about ways to get 2900 out of a .300 with 200 grain bullets. I wouldn't want to recommend anything unsafe and after looking at SomChem's Load data, I don't know as it is easily possible. All of their loads with 200 grain bullets top out maxed at about 2700-2725fps as seen here: http://www.somchemreload.com/search?c=8&f=121

My point was, If he could easily get 2900 out of a 180 (which it appears is pretty easy) but could only safely get 2650 or 2700 out of the 200 why he didn't just go with the 180. His data seems a bit hot. 66.5 grains isn't a little bit over max. It is 3 whole grains over published max and even if he isn't seeing any signs of excess pressure, without at least a strain gauge, there would be no way of knowing. Thats why I was wondering if it wasn't more prudent to go with the lighter bullet. I get the impression that RSA doesn't have the nigh infinite choice of powders that are privileged to have here in the states. That was all I was wondering. I hate to see anyone blow themselves up looking for a 1" flatter trajectory.

 

[PHOENIX PHIL]

Right, I understand that it is possible given the data that we have here. But the original OP was inquiring about ways to get 2900 out of a .300 with 200 grain bullets. I wouldn't want to recommend anything unsafe and after looking at SomChem's Load data, I don't know as it is easily possible. All of their loads with 200 grain bullets top out maxed at about 2700-2725fps as seen here: http://www.somchemreload.com/search?c=8&f=121

My point was, If he could easily get 2900 out of a 180 (which it appears is pretty easy) but could only safely get 2650 or 2700 out of the 200 why he didn't just go with the 180. His data seems a bit hot. Thats why I was wondering if it wasn't more prudent to go with the lighter bullet. I get the impression that RSA doesn't have the nigh infinite choice of powders that are privileged to have here in the states. That was all.

Yeah I can't comment to the SomChem powder haven't looked at it so I'll have to take your word on that. 2900fps with 200gr with powders we have wouldn't surprise me. I get 2850fps with 200gr bullets using H4831. Based on what I've read I could do better as far as velocity goes, but I was fine with that velocity as the load is quite accurate.

 

[ChrisG]

Yeah I can't comment to the SomChem powder haven't looked at it so I'll have to take your word on that. 2900 fps with 200gr with powders we have wouldn't surprise me. I get 2850 fps with 200gr bullets using H4831. Based on what I've read I could do better as far as velocity goes, but I was fine with that velocity as the load is quite accurate.

I was just saying that he should probably stay on the established safe reservation and not wander off into the frontier too far. That's how you end up with things like this:

Or at the very least, heavy wear and stress on the rifle and brass.

And like I said, I doubt if an Eland will just shrug off a good hit with a 180 grain bullet that was safely loaded vs. a 200 grain that was loaded to the gills.

 

[PHOENIX PHIL]

I was just saying that he should probably stay on the established safe reservation and not wander off into the frontier too far. Thats how you end up with things like this:

Or at the very least, heavy wear and stress on the rifle and brass.

And like I said, I doubt if an Eland will just shrug off a good hit with a 180 grain bullet that was safely loaded vs. a 200 grain that was loaded to the gills.

Wow, that looks like the result of putting pistol powder versus rifle powder in the cases. Point taken, was not dismissing your caution at all.

 

[ChrisG]

Wow, that looks like the result of putting pistol powder versus rifle powder in the cases. Point taken, was not dismissing your caution at all.

I read the story a while ago and I think this guy was loading the rifle hot for long distance silhouette and he had been for a long time. Springfield said that the barrel had stress fractures in it from all the abuse and finally catastophically failed. Just because it doesn't blow up on the first round, or the 1000th, doesn't mean you're not beating the gun to death.

 

[PHOENIX PHIL]

I read the story a while ago and I think this guy was loading the rifle hot for long distance silhouette and he had been for a long time. Springfield said that the barrel had stress fractures in it from all the abuse and finally catastophically failed. Just because it doesn't blow up on the first round, or the 1000th, doesn't mean you're not beating the gun to death.

I could buy that.

 

[SlushPuppy]

Maximum Pressure for the 300 Win Mag:
CIP = 62,000 psi (4,300 bar)
SAAMI = 64,000 psi (4,400 bar)

Using my load data in QuickLoad, I get 62442 psi (4305 bar), so I'm just over CIP, and under SAAMI (screenshot attached).

The only reason that the Pmax is given in red (and message DO NOT USE THIS LOAD) is because the Pmax (MAP) threshold is set to 62336 by default under the cartridge selection. If you change it to 64000 psi, then it changes to purple, and the "DO NOT USE THIS LOAD" message disappears.

This just an Application with thresholds and messages set based on predetermined metrics, NOT the holy grail of reloading. If QL says my loads are at Max Pressure, and my cases show no signs of excess pressure, I don't see a problem.

The published data from Somchem uses PMP Cartridges with internal volume of as low as 85gr H2O. I tested this myself, I have 100 PMP cases. Very durable due to thick sidewalls, but also very limited and varying internal capacities.

I attached the Somchem Data for the 300 win mag. You can run these different loads through QL, and will quickly see 60 000 psi is not uncommon, I found as high as 63 000 psi and this is Factory Ammo, made according to pressure specs for the 300 win mag.

So, if my 62442 psi (442 psi over CIP spec) is a problem, then:

If you're buying factory ammo, you have no way of actually knowing how hot that load is, thus shooting your favorite factory ammo for many years might blow up your rifle like that extreme case with the springfield because it was loaded at Pmax of your rifle???

Nah, doesn't make sense.

 

[Roan]

Be very careful with quick load and RSA components.

Have gotten some very dodgy info from it.

Rather be safe than sorry!

Few FPS isn't worth you or your rifle getting smashed.

 

[Alchemist]

Your QL data as posted indicates a speed of 2830 f/s and not 2900 f/s as per earlier post. You need to calibrate for your setup by changing the Burn rate so your speed indicated shows 2900 f/s. ( Measured speed as per your post )
When adjusting the Burnrate correctly, you will see that your pressure jumps to 71, 000 psi, 15 % higher than p Max. You are in very dangerous territory. You should back off to at least 2800 f/s just to equal p Max.

 

[ChrisG]

Maximum Pressure for the 300 Win Mag:
CIP = 62,000 psi (4,300 bar)
SAAMI = 64,000 psi (4,400 bar)

Using my load data in QuickLoad, I get 62442 psi (4305 bar), so I'm just over CIP, and under SAAMI (screenshot attached).

The only reason that the Pmax is given in red (and message DO NOT USE THIS LOAD) is because the Pmax (MAP) threshold is set to 62336 by default under the cartridge selection. If you change it to 64000 psi, then it changes to purple, and the "DO NOT USE THIS LOAD" message disappears.

This just an Application with thresholds and messages set based on predetermined metrics, NOT the holy grail of reloading. If QL says my loads are at Max Pressure, and my cases show no signs of excess pressure, I don't see a problem.

The published data from Somchem uses PMP Cartridges with internal volume of as low as 85gr H2O. I tested this myself, I have 100 PMP cases. Very durable due to thick sidewalls, but also very limited and varying internal capacities.

I attached the Somchem Data for the 300 win mag. You can run these different loads through QL, and will quickly see 60 000 psi is not uncommon, I found as high as 63 000 psi and this is Factory Ammo, made according to pressure specs for the 300 win mag.

So, if my 62442 psi (442 psi over CIP spec) is a problem, then:

If you're buying factory ammo, you have no way of actually knowing how hot that load is, thus shooting your favorite factory ammo for many years might blow up your rifle like that extreme case with the springfield because it was loaded at Pmax of your rifle???

Nah, doesn't make sense.
View attachment 154167 View attachment 154168

Factory loaded ammunition goes through rigorous testing, well beyond the capabilities on the average reloader. You would need several hundred thousand dollars worth of equipment just to match the tests that most factory loaded fodder goes through just to make it to the shelf. Even smaller companies like Grizzly and Buffalo Bore at least use strain gauges. Do ammo companies make mistakes? you bet. But I can guarantee they don't just use a computer program to run simulations and then assume they are in safe territory. They also design their cartridges with a measure of safety and they are tested at minimum spec, so that, odds are, your rifle has a bigger chamber, throat and barrel than the factory testing apparatus. Also keep in mind, they are always using brand new brass with the internal dimensions about as consistent as they will ever be for the maker.

Ammo Factories also has access to, what we in the States call "Commercial" or "Canister" powder. These are powders designed for a very specific application and are generally not easily available to your average reloader because most of the time, they must be purchased in large quantities, and/or are made specifically to a manufacturer's specs for a particular round. Some have even speculated that the way that loaders like Hornady get their "superformance" loads is by using a duplex charge of powder. A slower powder to get things moving and a faster one on top of it to give you a long smooth pressure curve. long pressure curves=high velocity. They call it "blended." I would almost gaurantee you that even the hottest loads you can buy, if you strain gauge tested them, would be below SAAMI max by a bit. Usually manufacturers get their velocity by playing with pressure curve times, rather than pressure itself. A load with a quick spike to 64,000psi that dips down quick will not produce anywhere near the velocity of a gentle, long curve at 55,000psi. The latter will appear to be so much more pressure because of the blast, flash (sans alkali coating) and recoil. But it doesn't. Ammo companies don't like lawsuits so as much as they can, they try to mitigate that risk.

Please know that we are not dogging you just to dog you. There is a lot of collective knowledge on this thread alone and number of people who are probably much more adept than I am at loading have stated concerns about the load.

My point was: It is completely unnecessary. Plug your numbers into a ballistics calculator and I think you'll find that 200 fps makes so little difference in trajectory even at 400 yards, that the wear and tear on your rifle is not worth it. I would rather have my gun shoot 4" lower and last for 10,000 rounds than replace the barrel at 3,000 because I wanted that little bit more. Now if you are shooting 1000 yard targets, 200 fps makes a world of difference and it is worthwhile pursuing, but not for a 350-400 yard hunting load. My $.02

 

[SlushPuppy]

Thanks for everyone's input so far.

I have surely learned a few things, although a lot of speculation and theoretical analysis was shared as well.

None the less, I'm not that ignorant, for this weekend I will back off the loads a bit on the 180grains as well as the 200grains to see how they group and record speeds etc..

Will share practical experience again next week.

You guys really scared the #$%^ out of me with that Springfield

 

[Clayton]

I can introduce you to a gentleman that "knew what he was doing". For years he'd loaded his Weatherby Mark V, 7mm Mag to the max. And then one morning about 35 years ago in West Texas Jim squeezed off a round that sent the bullet down the barrel and the bolt out the back of the action. His face is still horribly disfigured, his right eye is still there (sort of) but doesn't see anything, and there is an odd looking crease down the right side of his skull. No one knows what was the cause, but everyone knows what the effect was. The incident ended his desire to hunt or shoot.

Just a cautionary tale that I keep in the back of my mind every time I start to reload because you see, I too think "I know what I'm doing".