Thread: Pushing 308 to 300WM speeds.

Just goes to show, primers and brass aren’t always a good indication of pressure signs. Pretty amazing but also bloody dangerous considering they didn’t get a sticky bolt even way way above the pressure maximum for the cartridge.


https://youtu.be/uXkmcpk7Brc?si=fHSwc-BghGkyYBHQ

That's impressive, a little crazy but impressive all the same.

Im not into reloadig but that was impressive.A well built 308 thats for sure matching a 300wm.

Those 300wm speeds are definitely low. Is there a hand loader on this forum that doesn’t get over 3000fps with that weight pill?
Still it’s impressive velocities. As they say often, don’t try this at home. That entire setup is way over spec.

Greetings All,
I have seen this happen before. Load worked up gazing at primers and such based on some extra hot loads for a wildcat rifle, no longer published. No "pressure signs" but the cases looked fine but were stuffed with expanded primer pockets. One of the reasons I work up loads using the chronograph. We have mostly heard the wails of "but there no pressure signs" over a now defunct rifle or buggered cases.
Regards Grandpamac.

Originally Posted by grandpamac

Greetings All,
I have seen this happen before. Load worked up gazing at primers and such based on some extra hot loads for a wildcat rifle, no longer published. No "pressure signs" but the cases looked fine but were stuffed with expanded primer pockets. One of the reasons I work up loads using the chronograph. We have mostly heard the wails of "but there no pressure signs" over a now defunct rifle or buggered cases.
Regards Grandpamac.

Noone is suggesting you should work up to these sort of speeds or pressure, just showing what could be done with heavily over spec builds with custom minute tolerance chamber reaming and the right brass/primer combination.
Not at all in the video was it suggested that anyone should try this, in fact it was heavily advised repeatedly that you don't.
Cool video, but yeah nah not advocates for over pressure loads.

Originally Posted by dannyb

Noone is suggesting you should work up to these sort of speeds or pressure, just showing what could be done with heavily over spec builds with custom minute tolerance chamber reaming and the right brass/primer combination.
Not at all in the video was it suggested that anyone should try this, in fact it was heavily advised repeatedly that you don't.
Cool video, but yeah nah not advocates for over pressure loads.

Greetings @dannyb,
I did note on the video that they were using velocity to validate or correct pressure same as I do. The difference is that I use pressure tested data for the cartridge rather than Quickload which I don't have. I also spotted that they were using Alpha cases with small rifle primers. First I have heard of Alpha which I assume is a premium brand and likely harder in the head than your average brass so there is a big variable. Their point and mine was looking at case heads and primers to divine pressure is worse than worthless for working up loads and only reliable data is worth using validated by the chronograph.
Some handloaders still rely on the old and worthless pressure signs and it is them that are likely to come unstuck.
Regards Grandpamac.

Sorry if my reply sounded preachy, it wasn't intended

Originally Posted by dannyb

Sorry if my reply sounded preachy, it wasn't intended

No problem. Sometimes my brain gets ahead of my fingers so my meaning is not clear. I had not watched the vid so went back and watched most of it, something I likely should have done first.
I have found the chronograph absolutely essential in handloading and found the continued reliance on pressure signs by some frustrating. Hopefully the arrival of the Garmin chronographs, reasonably affordable and easy to use will change that. At a price of under $1,200.00 or about a that of a half decent scope more will make the change. My 35P cost $850.00 ( a decent rifle and scope then) over 30 years ago when few had chronographs. I rang up a friend and told him I had bought one. He rang back a short time later to check he hadn't dreamed it.
Regards Grandpamac.

well seen as though I appear to use old and worthless methods I shall reply in kind...if your not hot rodding and trying to get silly speed by stoking up cartridges above what manuals say is ok...you DONT NEED AN EXPENSIVE BIT OF KIT to tell you it goes bang and hits what its aiming at,and does so safely.

Not sure it was a responsible thing of him to post. You just know there's going to be someone that ignores the warnings, takes it out of context, and decides they should try to unleash their off-the-shelf 308's inner magnum.

Originally Posted by Micky Duck

well seen as though I appear to use old and worthless methods I shall reply in kind...if your not hot rodding and trying to get silly speed by stoking up cartridges above what manuals say is ok...you DONT NEED AN EXPENSIVE BIT OF KIT to tell you it goes bang and hits what its aiming at,and does so safely.

Well said @Micky Duck,
From reading your posts including the above you are not the type of person to work up from max. You start low and work up to a medium level that works for you (and would work for everyone else as well if truth be known). For you the handloading is a prelude to the main event of hunting. For some of us older chaps the handloading is the main event garnished with a bit of target shooting plus the odd armed grandpa walk seldom requiring any loud noises to be made or anything heavy to be carried.
Best Regards Grandpamac.

Originally Posted by Pommy

Not sure it was a responsible thing of him to post. You just know there's going to be someone that ignores the warnings, takes it out of context, and decides they should try to unleash their off-the-shelf 308's inner magnum.

Kinda agree, but they were very very clear a lot of precision work went into this and it wasn't just a slap together and load her up as much as you can.
They also gave multiple warnings on not to try this at home, what more can you do ?
Posted or not there will always be someone who thinks they are invincible and that book max is only a guideline for sheep.
I have a friend like this and I refuse to shoot his loads or rifles, and yes I have told him multiple times I think he's playing with fire

there is/was a new type of case being bandied around about a year ago..special forces round in 6.8mm ??? has steel head and brass body to withstand much higher pressure than normal. the technology is there to do the high pressure thing,Ive always thought a thick walled case was a feasable idea,sort of take the belt on likes of 7mm magnum all the way from head to shoulder to enclose the bit that stretches /gives out.

@grandpamac

Have a look at gordons reloading tool, if you are missing quickload. Its a free (and better!) alternative