Mine is similar. but with 24" barrel. Do you think IMR3031 is still the best option? I was planning on working up loads with this powder but wanted your input on the diff barrel length. Thanks for any advice.
Hello, thanks for the tutorial! You specifically say to use a fired but not resized case to determine max case volume in grains of H2O. I'm using a semi automatic.308 so I full length resized my brass, do you still recommend fired but not resized case volume for my reloads?
Yes - you need the fired and unsized volume as this is the space the case occupies as the powder is burning. In actual fact, the case does elastically contract slightly after firing, but there is not much you can do about that. Once you have your volume, of course then continue to resize as normal - you just need the figure for the calculations.
Hi John. The manual and the in-program help are at odds with each other with the manual claiming "bring water even to end of case neck" and the bubble help claiming "data is in grains of water at case mouth overflow" which would have a convex bubble of water showing at the top. I find the latter is more accurate in factory chambers, but the former may be better in very tight custom chambers.
Hello I have a question about the H2o case fill. At what temperature are the case and water for this measurement. Temperature has a effect on mass measurement. Great video.
Hi - the manual just says room temperature. I wouldn't sweat the difference - water density at 2°c is 0.999 g/cm3 and at 25°c it is 0.997 g/cm3, If you take something like a .223 case which holds about 30 grain of water (1.94 gram) then the mass temperature variation between 5 and 25°c is only 0.004 grams or 0.062 grains. You will have a better set of scales than me if you can detect that! :) Brass does of course expand and contract with temperature change, but again (without going into more math) the changes are too subtle to detect.
I very much appreciate this video... even though it is 2 years old! :) I have been thinking of buy this program but what has stopped me is while I am absolutely sure the math is good the program itself seems old school. I mean it looks like it is a Win95 or even older program running in like a compatible Win7/Vista mode. And like you had problems with the icons that also seems old. Showing both imperial and metric at same time confuses more. Aren't they going to update this? (data is)
Hi and Thx for your tutorial. why do you choose 115% case capacity in your powder parameters. were you ever able to fill powder up to 115% in a case? just wondering. Thanks.
Hi, I use 115% simply as it is about the maximum powder volume you can fit in the case (without the bullet) and still compress the charge. This very much depends on the powder though. In reality, these highly compressed loads are rarely the most accurate.
Where did you get the idea to make a convex "bubble" of water for weighing? I'm fairly certain the geometry of the program uses water level with the mouth and not convex or concave.
@@anthonykaiser974 That’s probably the word he wanted. Lines on a pipette or beaker are adjusted to accommodate a meniscus. A balance/“scale” is not. The water should be as flat as possible and is easily achieved with any rifle caliber I’ve ever used. I’ve done this many times. If it’s overfilled it’s a dome/convex; if it’s under filled it looks like a meniscus/“concave”.
