| Gerard |
| (.224 member) |
| 14/02/10 04:01 AM |
Re: I Read All Of The OSR Thread, Time For The Machine Shop!
|
eagle27,
Quote:I considered that after I posted. In fairness, the test I did included only copper drive band monos and standard lead core bullets. I did not include any type of brass mono or copper banded bullets. Maybe that would be a good one to do. Consider however that a finite amount of heat is generated by the combustion process and that some heat is generated by friction as the bullet is accelerated down the bore. A bullet with good thermal conductivity must carry more heat away with it than a lead core bullet. The bottom line is that there are too many variables and only testing with a variety of bullet types will tell the story. Otherwise we are guessing. I can only attest to the experiment I conducted.
monos may actually absorb more heat from the combustion and then pass this through the barrel wall via the point of contact
JabaiHunter,
Quote:
Bullet makers offer no proof OSR is not possible with their bullets, just the same as owners of DRs with OSR are accused of offering no proof because they can't photograph or measure it.
This is true. So we have to fall back on history and experience to make the judgement call until something better comes along.
I am not sure that everything that is visible can be dimensionally measured. This will weigh and measure dimensionally exactly the same as This. Similarly, I have seen a single piece of steel develop a red cast in the blued finish, with use, due to the particular hardness and temper at that point. Dimensionally there is no change but visually there is.
I have no doubt that OSR exists and, at this stage, the evidence is inconclusive. We do not know if it is caused by a particular type of bullet or whether it may be a particular type of rifle or manufacturing problem that causes it.
But if we have to make that judgement call, how do we do it at this point?
We know that rifles used only with lead core bullets have OSR. We know that rifles that have seen use with some conventional monos have it. I know that, since we have seen drive band monos in use in doubles, the combination of drive band bullet and double has not produced a rifle with OSR. That is the last 14 years. The other way of preventing OSR in a rifle that does not have it, is to not shoot the rifle at all.
Based on the history of what we know at this point, there are therefore two ways of being reasonably sure that a double will not develop OSR.