Originally Posted by greydog
Originally Posted by Ackman
Originally Posted by greydog

So here is how the test will work: I will chamber for the standard 223 and will load with a powder which requires near 100% loading density. I'll gauge pressure by miking the solid head of the case. I think everyone can agree that, once the solid head shows any expansion, it is safe to say the maximum has been reached. In fact, it can be said that the pressure is slightly excessive if primer pockets become loose with repeated reloading. After establishing and chronographing the top load, I will load and fire one case 10 times to measure case stretching. I'll do this with the 40 grain bullets. I will also work up a load of similar pressure using a 52 grain bullet for those who might be interested. I will not work up a heavy bullet load since this barrel won't stablize it anyway.
I will also work up a load using a powder which will not quite reach max pressures even when solidly compressed. This will produce the situation where the AI is most likely to shine.
After this is done, I'll rechamber to 223 AI and do it over again. The barrel will be set back approx 1/4 turn (.016") so the barrel will be that much shorter. This may reduce velocities by as much as .75 (75/100ths)fps.
As I said, this will take some time. I have other rifles to finish and test as well. GD



You're unclear about this. Obviously watch pressure, but equal pressure doesn't matter. It's about speed at best accuracy, not about the maximum. Just look for the most accurate load with each chambering and record velocity. That's it. AI cartridges like to be pushed and shoot really well on the topend, std cartridges may/may not.

Look, it's not that hard. You're making this into a lot more than it needs to be. Find the most accurate .223 load for that barrel and velocity will be whatever it is. Rechamber to .223AI with the exact SAME web and neck dia, and EXACT SAME throat. With the SAME powder and brass, go up 'til you find best accuracy fireforming. Do the same with formed cases. I'd be using 50 gr bullets.

You're wanting to prove that all the people who shoot these things and get more velocity really don't know as much as you. You won't. You'll find that you really don't know squat about this stuff.


No, this IS about maximum velocities because that is the question which was asked. The accuracy I obtain from this old barrel is immaterial since, when I'm done, the barrel will be scrap anyway. I'm doing this to illuminate what appears to be a dark shadow aroung the 'fire. I will test things in such a way that variables are minimized if not eliminated all together. While testing for velocity, I will also be able to test for case stretching and the requirement (or not) for trimming. These are things that I would expect that people would like to see quantified. I've done a lot of testing like this before and have a pretty good idea of what's required to maintain validity. Mind you, most such testing I did about 25 years ago so maybe things have changed in the interim. If so, I will get to learn something as will any other open minded individual who cares to do so.
By the way, also in my spare time, I am testing the performance improvement realized with the 303 Epps. This is an improved cartridge which substantially increases powder capacity so should make serious gains in performance as well. The amazing thing with this test, so far, has been the velocity levels I have reached with the standard 303 with no indication of excessive pressure (This in a strong action, mind you; the pressure would most definitely be excessive in a Lee Enfield) 174 grain bullets at 2720 is pretty impressive for the old war horse.
One real advantage to the Epps cartridge is that one may chamber a strong actioned rifle for the Epps and make it impossible to inadvertently fired a hot load in his Lee Enfield. The same would be true with the 30/40 Improved. You don't want to be shooting a hot load through a fine old Krag. GD


No you really don't get it. And if accuracy isn't in the equation your test will be meaningless. Load workup is done by shooting groups.....you've done that, right? Max velocity is irrelevant without if it's not the most accurate. It's about actual working field loads hitting what's in the crosshairs. Once more.....AI cartridges are accurate at full power where others have to be backed off. This isn't difficult, are you too friggin' stupid to understand?

But the 303 Epps? One of the most popular rounds out there. Everybody shoots those things. Way to go.