rclark

As I am curious kind of guy, I wanted to see the affect of seating the bullet to different depths but use the same bullet, powder, and primer. The forums are rampent with 'worry' over seating depth and careful OAL measurements .... Anyway ....

Here are the results for .45 Colt :

41.54mm OAL, 7.0g Red Dot, 255g SWC, CCI-300, 901fps, 30 SD, 125 ES, 15 shots
40.41mm OAL, 7.0g Red Dot, 255g SWC, CCI-300, 933fps, 12 SD, 38 ES, 15 shots
38.73mm OAL, 7.0g Red Dot, 255g SWC, CCI-300, 965fps, 11 SD, 44 ES, 15 shots
38.73mm OAL, 6.0g Red Dot, 255g SWC, CCI-300, 862fps, 13 SD, 32 ES, 15 shots

41.54mm is very bottom of crimp groove
40.41mm is very top of crimp groove
38.73mm is very top of the driving band

You can draw you own conclusions here .... but as you see in .45 Colt the seating depth isn't going to blow up your revolver if you just crimp somewhere in the crimp groove . Also, the deeper you seat the bullet the better your consistency.

Here is an article that is similar to this line of testing : Thoughts on Improving Revolver Loads

dagger dog

I always wondered why some obsess over COL especially with cast bullets, the manufactuer has done all the homework and has set the crimp cannelure on the bullet to give the best performance.

Thanks for the link and the chrono data!

hollombj

Some of us "obsess" as you put it because we bought bullets without a crimp groove and want to use them up!

TMD

On a low pressure cartridge such as the .45 LC a few thousands of an inch won't make much of a difference. Higher pressure cartridges such as 9mm and .40 S&W operate at over double the pressure of the .45lc and have much less case volume to work with. On calibers like these that same few thousands of an inch can cause dangerous pressure spikes.

rclark

If using the non crimp groove bullets in .45 Colt, .44Mag, .44Spec (high case volume) it really isn't a big deal where you seat 'em .... as long as not 'really' deep (tip peeking out of the case), or barely in the case where you can wiggle the bullet. You can 'eyeball' it (looks about right) in these cartridges without pressure worries is my conclusion at this point. That is why I ran the test.... FWIW....

Yep. I agree. Should have added that to my post about low case volume cartridges. Going to test some .45ACP and peanut .357 at some point here for kicks too. I don't have anything to shoot the .40S&W or the little 9mm (nor do I ever plan to)....

I'd like to get my hands on that table mentioned in the article I posted above, as it sounds like some of the groundwork that I am doing ... has already been done .... Comforting though to 'confirm' it yourself.... and fun!

BTW, as always, if working on the high pressure bleeding 'edge' ... work up ANY loads if changing seating depths, primers, powders, cases....

Sr40ken

great info!!!! Thanks for the research!

Temmi

Good test

Thanks


Snake