
noylj wrote:ALL manuals that show a COL are only giving a minimum COL that the data applies to—Lee is just the only one to properly label it such.
COL is ALWAYS dependent on the bullet ogive, the magazine (how long a round it will take and when it releases the round), the feed ramp, and the chamber. Bullet length has a small effect on pressure (note, the whole fear of shorter COL started with an article/ad showing a 9x19 round that produced ~35ksi would produce 60+ ksi if the bullet was pushed into the case 0.25"), but that is all taken care of by ALWAYS going back to the lowest starting load when you start to load a new bullet. You work up a load based on the COL you determine before you start to load.
There is a range of COL that will function in any given gun and the most accurate COL is generally the longest COL that feeds and chambers.
What I assume you hope to achieve by measuring the bullet length is to avoid re-working a load—assuming that as long as the bullet weight is the same and the length of bullet seated in the case is the same, pressures will be the same.
JJ wrote:This isn't rocket surgery. Look at a couple data sets, figure out your min/max charge and COAL. If there is a variance between data sets, split the difference. Start at 10% below max and work up.
Shoot
Each and every publisher will garner different results, as a result if different components and different test apparatus. You will see variation between manuals, and occasionally publishers will make typos (this is why multiple references should be checked). If you are scared to reload based on these small variances, you need to spend some time around an experienced reloader to bolster your skill set and understanding of the process.
Using SR primers in pistol loads is not voodoo. The only difference between SR/Sp primer is cup thickness. SR primers will handle higher pressure. I know some that use SR primers in all their pistol loads, just to limit the amount of different components they need to stock.
noylj wrote:ALL manuals that show a COL are only giving a minimum COL that the data applies to—Lee is just the only one to properly label it such.
Seismic Sam wrote:I would NOT make that assumption. I suspect the max COAL may be coming from the SAAMI blueprint for the cartridge, and the other, shorter one is the length that their cartridges were when they developed the load data. As I said above, the Lee manual is peculiar in that in the actual load data it shows ONLY the MIN COL, and does NOT give you any idea the brand or length of the bullets listed. In other words, the only data they are giving you to cover their own a&& is the minimum length of the cartridge that you should load, so they are protected from somebody seating the bullet too deep and blowing themselves up. With any other manual, they publish MAX COAL and the COAL for each bullet that they developed data for, and the bullet lengths are clearly listed.
John S. wrote:Wait, just looking again at VH 2006 manual, it says starting and Max loads OAL 1.575 in. Although, I just noticed they show a drawing with 1.590 OAL, so, basically, they DO NOT say that 1.575 is Min. COAL and that drawing doesn't show that max COAL is 1.590 in the drawing either. No min COAL, or, Max COAL, just shows the two diff lengths, but, not specifying if it is min. or max. I guess your just supposed to "assume" they mean Min. and Max?
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