Printable View
As were on the subject (not regarding old posts etc) but regarding Metals, I,ve just ordered the book below in the link, more of an interest thing but may help when I start studying again (my old notes from my apprenticeship I cant read or decipher) just wonder if anyone has it on their bookshelf ?
Handbook of Metal Treatments and Testing: Amazon.co.uk: R.B. Ross: Books
If you really start on the metallurgy trail, be ready for the looooooong haul, believe me! Even the Mech Eng Uni courses 'do' the subject, in real terms, as you learn when you're out in the real big bad world, it's no more than glossing over. In fact it's a degree in its own right
On the down side, I find that while many of them soon become PHd's/Doctors, they get a bit nerdish/blinkered. Only my take on things
No its not a start on the Metallurgy trail, in my job our Certificates are never deemed to match or are equal to anything shore based although we study the same subjects such as Maths, Applied Mechanics, Heat etc, and only some shore based Companies recognize Merchant Navy Qualifications, so thought I,d look at a degree with the Open University.Quote:
Originally Posted by Peter Laidler
I,ll be sticking to Engineering (may have an advantage with this) this would give me an exemption for My Cheif Engineers (part A) and provide with me with more points such as the 15 I,m short of, for NZ and automatic selection.
I think I mentioned it before but looked at it a while back and sent off all my qualifications I had, to see if I could get a few credits, must admit after serving a 4 year apprenticeship (a proper one), 23 years at sea with qualifications in the subjects above, being Corgi Registered (now Gas Safe), several heating qualifications and a few shooting medals I thought I may get a few, they come back with my credits, Dear Mr.........your credits for the above= 0
What got my back up at the time if I went to one of the many evening Lectures available for adult learning (all subjects), I could get around 2 credits for each one.
So thought about the old saying " If you cant beat them Join them"
So thought about the old saying " If you cant beat them Join them"
Or,,,, Kick in the door and start blasting!,,,,,,, just sayin
To the NSA, I'm only kidding
I have read in two books (one by skennerton) that the indian 2a1(7.62) receivers were made from EN36A steel !!!!!! not trying to say Peter is wrong in anyway(but have we all been misinformed ??) anyway I have machined up lots of parts for machinery using this steel and had it casehardened, (i used to work for 23 years in one of the largest automotive plants in the southern hemisphere as a toolmaker) and found this steel was also used the in the Australian automatic arms SAR which went into the rifle trials against the styer aug F88 the manufacturer used en36A steel case hardened to a depth of 0.010" at 56 to 59 rockwel hardness (how do I know what they used? well I rang the guy who made the AAA rifles)
please feel free to comment as I would like to see these books proved wrong, and if so ill be selling my 2A1
The first test is simple. Just look at some of them and guess what........... They are based on old converted No1 rifle bodies! Another is that if the old No1 in .303" is proofed at 18.5 tons and the 7.62 at 19 tons.......... (I know it not quite that simple in this respect but it does illustrate the point) and 3........ do you want me to go on?
"the old No1 in .303" is proofed at 18.5 tons and the 7.62 at 19 tons...."
Here's another thing:
Has anyone looked at the throating of a 2A1?
If the barrel is throated like a bench-rest rifle, with the ogive of the bullet touching or actually engaged in the lands, you can expect a fairly "sharp" pressure-curve rise time and high "peak" pressure. You can also expect VERY consistent propellant combustion and thus muzzle velocities.
IF the barrel is throated with a bit of "free-bore", then the PEAK pressure will be lower and the "dwell-time" of that lower pressure will be a bit longer than otherwise. The free-bore allows the bullet to start to move virtually as the primer ignites and before the main propellant has really got going.
Early (and "easy") movement of the bullet effectively increased the volume in which the main charge starts its burn. More volume means less starting pressure and a lower peak pressure. NC powders burn faster the more they are contained, so, a bit of "extra space" effectively slows down the initial burn rate.
It's a bit like the difference between being whacked with ball-pein hammer vs. a rubber mallet.
Has anyone with a "mint" 2A1 ever tried to do a casting of the chamber and leade/throat of the barrel?
So, given the rather rapid burn rate of good-old Cordite, a bit of freebore may not be a bad thing in a .303 chambering. With the larger quantity of slower-burning, granulated nitrocellulose propellants in the 7.62 NATO cartridge in a SMLE action, some freebore would be a fairly good precaution.
Hmmm I have never seen one built on a 303 action body, but it does not surprise me in the least, I had a real good look at mine and it does appear to have a new 2a1 action, also the cut out for the magazine in the action is of a different shape to my Lithgow 303, getting back to throats, lots of surplus rifles have deep throats, and you are probably correct as I have tested lots of loads in military chambers and found that you can load more powder into a rifle with a long throatQuote:
Originally Posted by Peter Laidler
Thank you Peter, that's all I was looking for!Quote:
Your last sentence is yet another myth 303guy.
muffett.2008, may I enquire the date of that document, please?
Back to metallurgists again.... I'm not having a go at them (?) as a profession - but in my dealings with them, most recently during a xxxx-xxx trial you always got the impression that if something was built DOWN to a price as opposed to built UP to a spec for maintainability, then they'd be responsible. Just my take on things.
I remember saying about a piece of fabricated crap that it was beyond any sort of repair. In fact beyond any salvation. One of them just commented that '...... Peter, it's got an xx life. Bin it and get another at that price' But in the meantime the XXXX-XXX was out of action awaiting another feed shute. Metallurgists