FloridaFlier
Member
On bullets with no cannelure (think Berry's), I sometimes wonder how deep to seat the bullet. Usually, the advice is to find something in a loading manual of the same weight and composition. Sometimes, that doesn't work very well.
Today, I am loading .44 Specials. The 240gr Berry's RNFP plated bullets are 0.655" long, while the 240gr Berry's lead SWC bullet is 0.730" long, and has a cannelure. The difference is 0.075", yet Berry's suggests using lead bullet data for their plated bullets. I'm thinking that to get the same power, I should load the plated bullets 0.075" shorter COAL than the lead bullets, which would provide the same volume in the case after the bullet is seated. There is a lot of room for adjustment on the Berry's bullet before it begins to taper.
To press the point, even on bullets with a cannelure, if my bullet has its cannelure in a different place than the cannelure in the manual's bullet, I'll have a different COAL if I crimp at the cannelure (which I would do).
We know that seating depth affects case volume, which affects maximum pressure, even with the same powder charge. I have no interest in testing loads beyond the published limitations, but have no real way of measuring internal pressure.
Bottom line, if you can't find a similar shape and composition bullet in the manuals, how do you decide on COAL/seating depth?
Or am I over-thinking this question?
Sorry, I just noticed that there are similar posts here on the forum. 'Deja vu all over again'. As Rosanne Roseannadana used to say "Nevermind". -Pete
Today, I am loading .44 Specials. The 240gr Berry's RNFP plated bullets are 0.655" long, while the 240gr Berry's lead SWC bullet is 0.730" long, and has a cannelure. The difference is 0.075", yet Berry's suggests using lead bullet data for their plated bullets. I'm thinking that to get the same power, I should load the plated bullets 0.075" shorter COAL than the lead bullets, which would provide the same volume in the case after the bullet is seated. There is a lot of room for adjustment on the Berry's bullet before it begins to taper.
To press the point, even on bullets with a cannelure, if my bullet has its cannelure in a different place than the cannelure in the manual's bullet, I'll have a different COAL if I crimp at the cannelure (which I would do).
We know that seating depth affects case volume, which affects maximum pressure, even with the same powder charge. I have no interest in testing loads beyond the published limitations, but have no real way of measuring internal pressure.
Bottom line, if you can't find a similar shape and composition bullet in the manuals, how do you decide on COAL/seating depth?
Or am I over-thinking this question?
Sorry, I just noticed that there are similar posts here on the forum. 'Deja vu all over again'. As Rosanne Roseannadana used to say "Nevermind". -Pete
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