Thread: bolt failure P14

Originally Posted by Cordite

And what about pics of the first (penultimate!) case fired? Any clues from that?

will try to get pics tomorrow, all my gear still at dads place. we actually looked at the cases and thought they were fine. will tag you when i put pics up.

Originally Posted by Tankd

The Rifle seems to be operating in the range of pressures it can hold ? . That being the 276 enfield and 30-06 , and there where a lot of 30-06 fired out of P17's .
So what the question is what happened to the case ? . Because it all seems to point to what Gundoc has said with maybe some sort of case failure / maybe oversized / oil on case / something which contributed as a catalyst . With age cracking just behind the bolt ?????.
So is there any pictures of the case ? .

i use imperial sizeing wax on cases then ultrasonic clean and air dry before i load them, clean primer pockets etc, loaded rounds are stored in mtm case. the case that was in the barrel apart from no arse end had no splits and no signs of gas blowing past the neck. will try get fresh pics up tomorrow.

For my 5 pence worth find that ADI have reduced their min-max loads by quite a bit over the last 30 plus years, I use their max load as starting load if I'm using different cases or projectiles from the norm, never struck a problem and most my loads are 3-4 grains above what they now class max in their reloading data, this is with medium - larger case capacities. Don't know what has happened here, go buy a lotto, you had luck on your side.

Originally Posted by tetawa

For my 5 pence worth find that ADI have reduced their min-max loads by quite a bit over the last 30 plus years, I use their max load as starting load if I'm using different cases or projectiles from the norm, never struck a problem and most my loads are 3-4 grains above what they now class max in their reloading data, this is with medium - larger case capacities. Don't know what has happened here, go buy a lotto, you had luck on your side.

yeah bloody lucky, hows TK these days. bloody interesting QL data. im eyeing up a sauer 100 in 300WM. need to move some other toys to achieve it thou. will sell the 3006AI with timmney trigger and dies as wont need it with 300WM may even sell the 6.5/06 but thats a maybe.

I use AR2213SC in a 26" barrel with the my .30/06 and the powder difference between hot but no pressure signs on the case to primers falling out is bugger all. I am running 167 grain Lapua Scenars at 2950 fps, good extraction and no pressure signs. 3030 fps gives popped primers and stiff extraction. The powder difference is 0.5 grains. The action is a Winchester M17 with a Vulcan match barrel, and accuracy is about 0.5 MOA. Clearly AR2213SC pressure spikes badly when the maximum load is exceeded by even a small amount. When the load is right, and the barrel is long enough to burn it, the pressure is good, the bore stays clean, and the mean deviation is low. I am happy with my load and will stick with it but as I am changing projectiles to 168 Sierra HPBT I will back off a grain and work back up, 0.1 grain increments and over my chrono until I hopefully get to 2950 fps again.

Greetings All,
First Zimmer I found the Quickload data interesting, if a little startling and appreciate the notes on reliability. I also would like to state that I am not having a go at anyone, just trying to put a little more info out for those that feel a little bewildered like myself. I note that the Quickload predictions are close to the data that Hodgdon provides for the 129 grain Interlock and wonder how or if they have allowed for the relative hardness of the Barnes projectile. Hodgdon also provides data for the Nosler 130 grain Accubond but cuts the load over 2 grains to 59.2 grains of AR2213SC. Nosler goes even further to 57.5 grains of the same powder. Barnes does not even list AR2213SC with the 127 grain LRX BT perhaps feeling that the powder is just too fast for the cartridge. Barnes did get over 3,100 feet per second with AR2225 (Retumbo).
All of the above is intended to show that the .264 Win Mag although capable of decent performance is cranky to load. Even Winchester struggled with high pressures in the 1950's when the cartridge was in development. Their answer was a two diameter projectile which solved the pressure problem but created an accuracy one. Due to Remington currently chambering the .264 in their Sendero we are lucky to have at least three sources of piezo pressure tested data available even though they don't agree on much.
Quickload like most predictive models used for all sorts of things is based on model created to match observed data. The loads do not come directly from actual test data. Something to remember.
Based on a number of articles in Handloader traditional methods for estimating pressure like bolt lift, primer appearance, ejector marks etc are unreliable often resulting in pressures around 70,000 PSI. A number of domesticated wild cats from the 80"s failed in the market due to velocities needing to be reduced to meet pressure limits. Remember the 7 mm STW? Hopefully I have not added to an already perplexing subject.
Grandpamac.