Terry,

I tested pressure on some 300 WSM Winchester PowerPoints here the other day using the Oehler 43 and also PressureTrace, both read identical and indicated 2990 fps and 56,000 psi for that ammo.

I wonder what lot# you got and if they were the same.

I seen some new 300 SAUM Remington ammo with the new Coreloct Ultra bullet, a friend had some at the range and they were hot or the brass was CRAP. It was extruding the rim into the offset slot the extractor lays in on the 700's boltface, where it's not supported next to the ejector side. The brass was ruined, no way the rims would fit into a shellholder without filing them all round again. I've never seen factory ammo do this, ever.

I'll try and remember to look up that lot # tonight, and send it to you.

It sounds like you have an obvious case of too tight a chamber. If factory ammo won't function in your rifle it's far more likely that the problem is with your rifle than the ammo. If the browning fired cases won't chamber in your rifle before sizing it obviously has a longer headspace. And if you can't size cases down far enough with standard dies that's another strong indicator of a tight chamber.
I recommend that you try something like a RCBS Precision Case Micrometer for the 300 WSM to see if a fired case from your gun is too short of headspace. You could also use it to check your land depth. I think they are about $30-40 now.
Good Luck............DJ

Hey Hot Core and Terry,I'm not trying to be cute but it sounds like it's going to take more than a patient grasshopper to have factory ammo work in that chamber, unless of course the ammo was at falt.Terry ,have you fired any other ammo,factory or near max. reloads? Do the primers have any pressure indications at all? I guess I have a problem accepting that a chamber is within acceptable limits, although on the small side, and have the result you had with factory ammo. I'm not saying it can't happen but it sure would surprise me if that were the case. Roger

Hey Terry, Hang in there. Everything you are describing sounds like a small change in the height of the Shell Holder and Seating Depth (which you both recognized) which can be easily compensated for.

If your chamber was at the opposite extreme, it might work as well as the tight one will, but they can be a real pain.

Sit back and think about how nice it is to have that SAAMI MINIMUM Chamber.

Patience Grasshopper - patience!

Good luck to you.

Had some "warm" factory as well. Found the cheapo Win ammo is very inconsistant to put it politely. Short throat too, no fear of running out of space in the mag. Velocities matched posted data, no wonder with that ammo. My loads match top velocities without trouble but my overall length is a little shorter than max col listed, never checked the fodder lengths. Maybe that had something to do with the pressure signs.

I finally got around to putting a 300 WSM barrel on a Rem 700 action. The case head fits the bolt face well, as the bolt has a SAKO extractor on it.

Installed the barrel, and test fired a Winchester factory 180 gr Power Point in it.

Could hardly get the bolt open, pressure was so high that the ejector button was visable on the case head.

I thought I would try a few reloads of lower pressure.So I took some once fired cases, that had been fired in a Browning rifle, and proceeded to FL size them in Hornady FL dies.

Soon found out that I could not push the case far enough into the die to size it enough.

I then found an old RCBS shell holder and tried that, now it will work, but barely.

Seems the Hornady Shell holder is too high, and needs grinding down by about .015.

Moral of the story, either the shell holder is too high, or the die has been drilled too deep.

I checked the throat on the barrel, thinking it was too short. It does show about .090 of throat, and not knowing the SAAMI specs, don't know if that is too short or not.

Too me it is, but I don't know yet. I have a throater, so it is not a problem to lengthen it if need be.

So far, this project has not been fun.

Did you check to see how much neck release you have/had with the factory stuff? It will give you much higher pressures than a tight chamber if inadequate.

Yes, I did check the neck clearance, and it was fine.

Will try and get out this weekend, and test several loads I have in Winchester and Federal ammo I have on hand.

After that, then I can see what direction to go.

It may be the WW factory loads. I had a new Savage 12fvss show hard bolt lift and very high velocity, 3223 fps, with the 150 gr Power Point loads in a 270 WSM.

Tell us how the Federal loads work.

I use and love my 300WSM so I'm not flaming it but I agree that some of the Win. factory ammo is too hot. I witnessed a guy at the range shooting a new BAR in 300WSM with Win. factory Supreme 180 gr. Failsafes blowing primers and getting extractor brass flow. I feel this may have been a combo of the slick nickel brass , hard failsafe bullet, gas autoloader and Winchester ball powder which is not known for being very friendly on hot days. Any cartridge can be overloaded, this is no flame of the short mag.

Question Terry. When you chambered your rifle, did you polish the chamber to a high shine? So to speak. If so, this cause the brass to push back and swell the cases too much. This will cause the brass to lengthen during the burning process and once the pressure is gone the case puts tension on the face of the bolt. Thus causing it to be hard to extract. I have seen this before on a 6x284 rifle I put together. Once i figured out that the chamber was too slick and had nothing to grip against during the peak preasure time, I too 240 grit emoray paper and ruffed it up at little. This may not be your problem, but it may be something to consider.