No.4 300 Winchester Magnum Test

[Andy]

Interesting project and I'll be watching for results, but my experience in these things is that many sceptics will remain unconvinced, as solid evidence is rarely sufficient for them to cease clinging to their beliefs. I did some proof testing of a Carcano a while back (posted here) and the "fact" that it's a weak and dangerous action remains a fixture of gun folklore.

You'll go to all that trouble and expense, fire 100 max loads through it and it will remain intact, but it will still be considered unsafe for conversion to 300 Win Mag.

Why not leave it in 303 Brit, and load up full cases of progressively faster powder under the 174 gr bullet (e.g. start with 4350 and work down to 4198)? I could not get the Carcano to come apart with a full case of Unique, but the cartridge did come apart.

[ireload2]

If you know anyone that has an Oehler 43 you could have transducers mounted on both sides of the receiver and on the barrel. This would permit comparing the reaction of the receiver and barrel to the firing loads.
I would like to see how many reloads you can get out of .... say 5 new cartridge cases when chambered in the new round of your choice.
I think a .300 RUM with the rim rebated to match the .303's diameter would be a more interesting test.

[jmoore]

Feel free to run whatever tests you care to do!

300WM was chosen as a rather large incremental step up using factory and known reloads. I'm not worried about overpressure experiments, rather its a question of whether the action is suitable for 7.62x51 usage in a general sense. (I'm well convinced, obviously, as I not only shoot L42a1s but 2a1s as well!) Even when I worked for a firearms mfg. we had no access to strain gages, but I have used them at the "institute" many moons ago. If anyone knows how to lay hands on such equipment w/o spending a fortune, I'll jump on board. (No research grants from this forum are there?)

If the action holds up to standard loads, then I'll try some oiled cases. Pressures will remain "standard", however!


BTW and ETA- Another reason for 300WM is that I've 60-80 factory rounds already and no rifle. Brass is easy to come by, and I can borrow some reloading dies. 300WSM- 20rds maybe and no brass. Other calibers- Nadda! If someone wants to contribute 100rds factory ammo and reloading dies in the caliber of their choice, I will certainly consider it. Just making do, and all...

[bearhunter]

Andy, Parker Ackley, who was a very decent fellow by the way, did several blow up tests on many different service rifles. The Carcano was one of them. He was amazed at how strong the action really was. It was stronger than the P17 and Springfield 03 actions. The only reason the cartridge was loaded to the pressures and velocities the Italians chose is just that, they chose to keep it mild for several reasons, the SD was very high and the wear and tear on both the rifle and soldier was less. The Austrians, through Steyr, built many Carcanos in 8x57JS. I have one of those and if I recall, so do you.

As far as using progressively faster powders goes, many moons back, when we were more adventurous, we replayed one of Ackley's experiments. We rechambered a 6.5 Arisaka carbine ($5) that was in less than fair condition to 30-06 in the original 6.5 barrel. We just jumped directly to his final test. Loaded the 30-06 cartridge with 150gr fmj over as much 2400 powder as we could stuff into the case. We tied the rifle to a logging truck tire and let her go. There was a bunch of smoke and flame, out of every nook and cranny. The stock was split and shattered as well BUT the action held together. The bolt wouldn't open, even with a hammer and some brass from the case had flowed around the bolt head and out the gas vents.
We had to mount the rifle in a lathe and cut back the barrel shoulder to get the barrel off. The really amazing thing about the whole thing is that the action was still sound. It didn't set back the lugs or ways and didn't stretch the action. The bolt was fine. In fact that action is still in use to this day as a 308Win. The other gent involved in the experiment was so impressed that he used the action to build up a hunting rifle.

I know, an old story and others besides myself have done the same thing but I think it's appropriate in this case.

Personally I'm quite interested to see how this will pan out, with the Lee Enfield.

[jmoore]

Barrel off! Good grief!!!

Finally gave up and cut a ring up against the receiver to roughly 1" dia...

Barrel promptly unscrewed w/ just finger pressure. Threads OK, no distortion, penetrating oil all over 'em.

Now: The cobble-ing commences.

(ETA This is what you get after I've been up for 23 hrs. Oy.)

[ireload2]

As long as the brass used is in good condition it will just stretch with the action. Nothing much will happen, even with oiled cases. However if they are reloaded look for the cases to give it up quickly.

Feel free to run whatever tests you care to do!

300WM was chosen as a rather large incremental step up using factory and known reloads. I'm not worried about overpressure experiments, rather its a question of whether the action is suitable for 7.62x51 usage in a general sense. (I'm well convinced, obviously, as I not only shoot L42a1s but 2a1s as well!) Even when I worked for a firearms mfg. we had no access to strain gages, but I have used them at the "institute" many moons ago. If anyone knows how to lay hands on such equipment w/o spending a fortune, I'll jump on board. (No research grants from this forum are there?)

If the action holds up to standard loads, then I'll try some oiled cases. Pressures will remain "standard", however!


BTW and ETA- Another reason for 300WM is that I've 60-80 factory rounds already and no rifle. Brass is easy to come by, and I can borrow some reloading dies. 300WSM- 20rds maybe and no brass. Other calibers- Nadda! If someone wants to contribute 100rds factory ammo and reloading dies in the caliber of their choice, I will certainly consider it. Just making do, and all...

[bearhunter]

delete

[ireload2]

I have read it several times including the predicted failure modes.
I was just going on record that the 300 Win Mag with factory ammo will prove nothing except that the #4 will withstand the firing just fine. The #4 is plenty strong enough to last as many rounds as you can afford.
The only thing that fails is the brass when it is reloaded....

[jmoore]

It's a really ugly 30-06 as of this afternoon. Now to install enough parts to get it in firing order, and do a quick test next week. Hopefully!. Then, reamer rental time.

Bolt heads all fail the "overturn" test right now, going to sort that as well.

[Surpmil]

JM, you're wasting your time. PO Ackley already did the destruction tests a long time ago.

They tell nothing relevant to this "debate".

Why don't you get a nice 1950s No4 Mk2 and strip off the wood, set it up in a fixed rest with remote trigger release, arrange a garden hose to spray a mist of water over the bolt and magazine and fire off as much .303 as you care to waste?

You can check the HS with HS gauges and feeler gauges at the start and after every 10 or 100 rounds.

Having done that, you can proceed to do the same in 7.62mm.

My guess is you'll waste a lot of ammo and determine nothing, but if you want a relevant project, that would be it IMO.

Two scans from the Textbook of Small Arms 1929. I think they speak for themselves, but the obvious conclusion is that could the base of the cartridge be made strong enough, and the blowing out of gasses through the primer holes be prevented, rifles could be fired without any kind of breech block or bolt at all, assuming there is no grease or oil present in the chamber. I notice that there is no reference in the Textbook of Small Arms 19129, at least not that I have seen, to any such issues surrounding the presence of water in the chamber.

If anyone else has noticed such references in their reading I would like to hear the details.