I was helping a couple of freinds at the range the other day and with under maximum loads of 4831 and 180 accbonds the one rifle was averaging close to 3100 FPS. His partner was only getting about 50fps more with a 300 Weatherby using factory Federal 180's.

Is this common or was it just the individual gun and load combination?

I was only getting about 3000 ft/sec with Hornady 165 grain SST bullets over a pretty stout load of IMR4350 in my 300WSM. Some barrels are just faster than others, even with equal lengths, and I have never heard any reason why. I looked and 3100 is almost encroaching on 30-378Wby velocity with 180 grainers. I wonder if the chronograph is giving accurate measurements?

We have no way of knowing what pressure that rifle is running without testing it. Inspecting primers and feeling bolt lift and all of the usual stuff is necessary, but can mask what is really going on.

The freebore and ease with which bullets engrave, bearing surface etc. can also affect velocity and pressure.

The reality is that generally if you are getting much over the book maximum you may well be running over the pressure that the book was based on (but you may not). Not all books are running max pressures for that caliber and not all say how he data was tested. Some run pressure tests in pressure barrels at max pressures, or close to it, and shoot for velocity in a factory rifle which may be a lot slower if the system has loose dimensions and will be below max pressure. If you match that velocity you may still be under pressure.

Sierra No 5 lists 2950 fps as the max with a 180gr in a 24" Mod70 and 3000fps with some other powders. I'd guess 3100 fps is hot, but as I said, how do we know? Why do you say these were "maximum loads"? What created that impression? Prsssure signs or the data in the book? Or just this guy's heaviest loads?

quote:

Originally posted by specneeds:
I was helping a couple of freinds at the range the other day and with under maximum loads of 4831 and 180 accbonds the one rifle was averaging close to 3100 FPS. His partner was only getting about 50fps more with a 300 Weatherby using factory Federal 180's.

Is this common or was it just the individual gun and load combination?

30" barrel?

Well no, 3100 fps with 180 grain bullets in a 300WSM is not common, but it could happen.

I have loaded ammo for 6 different rifles chambered in 300 WSM and none of them achieved 3100 fps with 180 grain bullets using SAFE, PUBLISHED loads.

However, 3050 fps was common so that is not that much difference.

I commonly get better than 3100 fps when using 168 grain Barnes TSX bullets, however.

And, lets face it, there are "fast" and "slow" barrels. Like a fool I sold a 300 Winchester Magnum that would readily shoot faster than my 300 Weatherby rifle when using 180 grain bullets. (both 24 inch barrels)

So tell your buddy to take good care of that rifle and never sell it. I sure wish I had that 300 Win Mag back. (Like a fool, I sold it to help finance an elk hunting trip)

It's not uncommon at all, and sounds about right.
I'm getting 3,160 with 180s in my .300 Win Mag. and have heard by many that the WSM is only about 50-60 FPS behind it with handloads.

I observed several loads in the 3070-80 range and a couple over 3100 saw the cases and they did not show any obvious pressure signs and he indicated he was under book maximum. The recoil was not bad at all but I wasn't that impressed with accuracy about 1.5 inches at 100 yards with 3 shots. Not that that wont work as an elk hunting load - I just couldn't get over how fast it was leaving the barrel out of that stubby case.

Factory ballistics are always being questioned....and I believe anything said ....within reason....

Frankly I don't see the .300 WSM as anything more than a glorified .30-06 and normally the .300 Weatherby as something slightly more than that.

There's a lot of "talk" in the shooting world.....walk is what one measures....

Even if only loaded to 100 fps over a 30-06 with the same bullets, it would be at less pressure and in a short action, making the rifle shorter and lighter. These are all good things.

I would not say it's common. I load for a buddies Browning 300wsm and we get 2,950fps with published max loads and 180gr bullets.

On the other hand, another buddy has a Sako and a custom by Hart Bros, both in 300win. With the exact same load in both rifles, the Sako gives 2,950fps and the Hart was 3,175fps. Not pressure signs detected in the Hart at all.

Back in the 1970's, with a 180 grain Sierra and a load of H4831, 3100 fps in a 300 Winchester Magnum, with a 24" barrel is what everybody judged a 180 velocity at that time. If the WSM is the equal to the 300 Mag, it should do it!!

Jerry

The WSM case is both thick at the head and very hard. It has to be made that way to withstand the pressures which boost velocity in a smaller case to near that of a larger case. A result of this thick/hard case is that pressure signs don't show up until somewhat higher pressures are reached. So yes, it's possible to reach 3100 fps with a .300 WSM and a 180 grain bullet, but the absolute pressures will be higher than most people would be comfortable with.

In the field of interior ballistics there are no free lunches. Less case capacity requires higher pressure to achieve the same velocity with the same bore and projectile. There is nothing about the WSM, other than the hard/thick case which masks pressure signs, that mitigates this relationship of case capacity to pressure and velocity.

Incidentally, I've seen .300 WSM factory loads loaded to pressures high enough that they would cause frozen bolts in a factory SAAMI chamber. In the meantime, the factories will barely load a lot of other modern calibers warm enough to fully fill out the shoulders when fired. But I guess they have little financial stake in selling rifles in long-established calibers.

quote:

Originally posted by Stonecreek:
The WSM case is both thick at the head and very hard. It has to be made that way to withstand the pressures which boost velocity in a smaller case to near that of a larger case. A result of this thick/hard case is that pressure signs don't show up until somewhat higher pressures are reached. So yes, it's possible to reach 3100 fps with a .300 WSM and a 180 grain bullet, but the absolute pressures will be higher than most people would be comfortable with.

In the field of interior ballistics there are no free lunches. Less case capacity requires higher pressure to achieve the same velocity with the same bore and projectile. There is nothing about the WSM, other than the hard/thick case which masks pressure signs, that mitigates this relationship of case capacity to pressure and velocity.

Incidentally, I've seen .300 WSM factory loads loaded to pressures high enough that they would cause frozen bolts in a factory SAAMI chamber. In the meantime, the factories will barely load a lot of other modern calibers warm enough to fully fill out the shoulders when fired. But I guess they have little financial stake in selling rifles in long-established calibers.

Have to agree 100%.
I wiil also add that before the WSM's came along, especially the 300, velocity listings for the 300WinMag and 180gr pills were around 3060-3080 fps, but when the 300WSM arrived the listed velocities magically dropped to equal the new cartridge. I've always wondered how this could be so, and what the gunwriters were touting about the cartridge running 10% less powder but matching 300WinMag velocities. I am still yet to see a 300WSM match the velocities of my 300WinMag, 3190fps/180gr Accubond and 3090fps/200gr Accubond, out of a 26" barrel which is what most WSM's are running in factory form.

Cheers.

Stonecreek thanks for the good info but as skeptical as I am about companies with profit motives and attorneys trying to limit liability isn't it more likely Winchester is comfortable with hotter loads knowing there are only modern safe firearms chambered in 300 wsm?


I tend to load near a cartridges potential as do many hand loaders but I'd be more conservative loading for strange rifles that might be old and worn out.

specneds: In the early days of the 300 Winchester Magnum, many were built upon 98 Mausers, Springfield, and of course the massive 17 Enfield. All of these are capable of withstanding any pressures the 300 could generate. Handloaders were still sending 180's downrange @ 3100fps, with no problems whats so ever. Of course after the cartridge became avilable in Remingtons and Winchester commercial actions, most of these went to the happy hunting grounds. However, if one came to me, and was built properly, I'd shoot the blazes out of it. Here's a little WSSM story. A young friend of mine was looking for a hypo 22, and the older guys were shooting Swifts and 22-250's, so he went for the WSSM. When we started to wring it out, he had really tough "bolt lift" with factory rounds. The accuracy was acceptable for factory stuff, so he couldn't wait to try handloads. Same problem! It was suggested he back it off a bit, until the hard bolt went away, he explained he couldn't do that, as then the Swift et al, would beat him for sure. I post this, as I find many owners of WSM'S etc, have the same mind set.

Jerry

FWIW: SAAMI specs. max pressure for 300/270WSM is 65K.
Maxine for 300 Win. Mag. is 64k.

I own both a 300 and 270 WSMs. I have shot factory ammo in the 270 WSM only and I currently handload to the upper limits for both. I have never once had a "sticky-hard to lift" bolt on either one after firing. I will get extractor marks on the Winchester brass before that happens. I have had hard to close bolts on resized cases that had convexed shaped faces after being fired.

I have never measured the head thickness on either a 300 WSM or a 300 Win. Mag. but I will remedy that this weekend. I seriously doubt the WSM case is thicker or harder. In fact I believe it is too thin, by design, in it's cross section for the extra width of the case walls that it has over the Win. Mag case. This is why the case face can become convexed on top end loads. None the less, this problem is easliy solved by full-length resizing using a good old fashion cast steel O-shaped press that will cam over. I. E.; RCBS ,Lyman, etc.
This little matter has been discussed and cussed here several times befoe.
The theory behind the good performance of the WSM cases has always been the fact that the primer is igniting a wider powder column as compared to it's standard belted cousins. This ideology seems to hold a hell of a lot of water, as can be read by many comments in Hornady's reloading manuals. I fail to see where Hornady would have a dog in the fight for any pros or cons for the WSM line. But I'm sure someone here will dream one up.
As far as factory ammo being anemic for non-WSM ammo, apparently some of our members have never fired some of the higher-end Hornady or Federal stuff. A few years back I ran some Hornady custom ammo through a 270 Win. (Not WSM). Although I don't put much stock in flattened primers, i have to say that I have never seen primers that were flattened and flowing like these were. Extractor marks out the wazoo. I saw some Federal ammo recently that appeared the same.
Just my observations gentlemen.

quote:

The WSM case is both thick at the head and very hard. It has to be made that way to withstand the pressures which boost velocity in a smaller case to near that of a larger case. A result of this thick/hard case is that pressure signs don't show up until somewhat higher pressures are reached. So yes, it's possible to reach 3100 fps with a .300 WSM and a 180 grain bullet, but the absolute pressures will be higher than most people would be comfortable with.
.

Well I did some measuring this weekend and just as I suspected, the above statement was not true and in fact was just the opposite.
Since I do not own any .300 magnums other than a WSM, I measured 5 randomly selected .338 Winchester Magnum cases (Max. SAAMI pressure 64K) and 5 randomly selected .300 WSM cases (Max. pressure 65K). The .338 has the same peak SAAMI pressures as the .300 Winchester Mag.
All were Winchester brass with the .338s having been fired once and the WSM cases fired five times at what I would suspect to be peak pressures since I load both at the top end.
By the way the primer pockets are all still nice and snug as I Full-Length resized and primed them for the sixth time.
I measured the cases with a dial caliper, first by measuring the over-all length of the case. Then I ran the caliper blade inside the case mouth down to the head while keeping the blade against the inside of the neck.
The (5 each) .338WM. Case heads averaged .2036" in thickness. Thinnest=.2015" & thickest=.2055".
The (5 each) .300 WSM cases averaged .2009" in head thickness. Thinnest=.1975" & thickest=.205".

The five randomly selected WSM cases were .0027" THINNER than the .338 Winchester Magnum cases.

By the way, if I am not mistaken, I believe the good-ole .270 Winchester also has a maximum SAAMI pressure of the much dreaded and feared 65k range.

rae59: I am glad you took the time to measure inspect and post your fidings. I also don't have a dog in this fight, if there is a fight. I like to know the facts. I don't necessarily believe all the data posted by the ammo makers, and cetainly don't put all my stock in any one reloading publication. If you shoot alot, and I do, you begin to realize the more you shoot the less things are written in stone.

As to the 270 Winchester, I have 2, a Model 70 with a 24" barrel, and a Sendero with a 26" barrel. Velocities are between 3125 fps and 3300 fps depending on the rifle. No blot lift "click" or primers flowing around the bolt face. I agree with you the 270 is loaded up there. I personally believe you'll see signs of over pressure, long before you are faced with an action failure.

Regards

Jerry

quote:

Originally posted by Rae59:

The (5 each) .338WM. Case heads averaged .2036" in thickness. Thinnest=.2015" & thickest=.2055".
The (5 each) .300 WSM cases averaged .2009" in head thickness. Thinnest=.1975" & thickest=.205".

The five randomly selected WSM cases were .0027" THINNER than the .338 Winchester Magnum cases.

All cases made for large rifle primers are all very similar in the distance from the outer face of the case head to the inner face. This is not the measurement to which anyone is referring when characterizing a case as having a "thick" head; rather, it is the walls near the base of the case head which are made thicker (and harder) in order to withstand more pressure. It is at this point, just aft of the pressure ring where the case is unsupported by the chamber walls, that the case is most subject to failure from excess pressure and where cases intended for very high pressure are made thicker. You can only view this thicker wall if the case is sectioned. If you want to bother to section some WSM cases I think you'll find them substantially thicker than most other centerfire cases at this point. It is much more difficult to measure the hardness of the case head, but I have no doubt that the heads of the WSM series are as hard or harder than typical brass.

S-Creek, My apologizes for not understanding the definiton of the term that you presented.
You are correct in saying that the case walls (body) of the WSM cases are thicker than say a 30-06/308 case althought I am not certain of any belted cases. And I am sure this thickness increase extends all the way down to the case head.
I should have mentioned this in my previous post but didn't think of it until later.
I found this out to be true some time back. I use my 300 WSM F-L die to neck size 30-06 cases for use with lead casted bullets that I paper patch (sort of) with masking tape and then gas check. These 30-06 cases that are neck sized with the WSM die will not hold a conventional .308 diameter bullet. The bullet will fall to the bottom of the case. But it is ideal for the my patched bullet as it will not damage the paper tape that I use while seating the bullet.
But.....
I also believe that the case walls are thicker by design due to basic engineering 101 rather than any super dooper pressures that the WSM line is immagined to operate at as proven by the SAAMI max. pressure specs. I have encountered.
Anytime a pressure vessel diameter is increased, and the cartridge case is a pressure vessel, then one of three things must be done. 1. internal pressure must be reduced, or 2. wall thickness increased, or 3. a stronger material (not necessarily harder) must be used or any combination of the three. As you have stated, you believe two of three have been done and I do know you are correct about the thicker case walls at least compared to a 30-06 or 308 case.
I also know that the brass that I am currently using does not show any indication of being harder than anything else I am using of the same brand...Winchester, which is harder and thinner in any chambering than any Remington or Federal brass I have used.

For my own saticfacton, I think I can get access to a Rockwell hardness testing kit and even maybe a techy, to possibly see the hardness difference between the WSM cases and any other magnum case of the same brand. I will be more than glad to post any results of that testing if and when it happens.

As far as the actions locking up that you said you have seen, I am not doubting that you saw it or them. But I have also seen a Saur action destroyed, if I remember correctly, in a .243 Winchester
chambering by a 243 case that was supposedly loaded with a pistol/shotgun powder by accident.
The old addage "believe nothing that you hear and only half of what you see" comes to mind.
I am not trying to pick a fight here but merely trying to present what I have experienced or know to be true.

quote:

Originally posted by Stonecreek:
It is much more difficult to measure the hardness of the case head, but I have no doubt that the heads of the WSM series are as hard or harder than typical brass.

As hard or harder?
There is no doubt that the cases "are as a hard" as anything else but I would like to know what makes you think the WSM brass is harder?
Inquiring minds would like to know... To paraphrase someone here once.

quote:

Originally posted by Jerry Eden:
rae59: I am glad you took the time to measure inspect and post your fidings. I also don't have a dog in this fight, if there is a fight. I like to know the facts. I don't necessarily believe all the data posted by the ammo makers, and cetainly don't put all my stock in any one reloading publication. If you shoot alot, and I do, you begin to realize the more you shoot the less things are written in stone.

As to the 270 Winchester, I have 2, a Model 70 with a 24" barrel, and a Sendero with a 26" barrel. Velocities are between 3125 fps and 3300 fps depending on the rifle. No blot lift "click" or primers flowing around the bolt face. I agree with you the 270 is loaded up there. I personally believe you'll see signs of over pressure, long before you are faced with an action failure.

Regards

Jerry

Jerry, thanks for your post.
I agree with you on the action failure part but we must add "as long as one follows safe practices of load development in a modern American action".
You have to think "disclaimer" with all of the slimy lawyers out there these days.

Im getting 2825fps with 200gr accubonds out of my 300 wsm its a tikka and has alot of free bore. I forget what i was getting with 190's

Rae59: Your 243 story is one that has a very sad ending, but continues today, as people do not pay proper attention to components and loading tecnique. I know of a Remington 700, that was "laid wide open" barrel downrange 10 yards, and a stock in several pieces, because the owner filed the case, a 30-06 up with #2400. When he was asked, at the local gunshop, why he used #2400, he said and I quote, "well it said rifle powder on the can". Praise God, he wasn't even scratched. And on it goes.

Jerry

It is interesting that the WSSM/WSM has a reputation, in some rifles of chamber difficulties. The 22 WSSM of which I spoke earlier was sent back to Winchester, but never seemed to be right anyway. Also, I haven't seen that rifle, or heard my young friend speak of it, in a couple years.

Jerry

quote:

Originally posted by specneeds:
I was helping a couple of freinds at the range the other day and with under maximum loads of 4831 and 180 accbonds the one rifle was averaging close to 3100 FPS. His partner was only getting about 50fps more with a 300 Weatherby using factory Federal 180's.

Is this common or was it just the individual gun and load combination?

I would say it is probably uncommon but not unheard of. My best loads of 65.5 gr RL-17 with 180 gr. Barnes TTSX averages 3080 fps which appears similar to what you are seeing. Air temp and barrel/chamber temps also influence velocity. I have seen +40 fps in a single shooting session with hot barrel compared to a cool one.

Building a database for all your range shooting and including as many conditions as possible will help explain many changes in what you see for accuracy, velocity, implied pressures, etc.