Question for 10mm reloaders using revolver only

[Encoreman]

Hi all, I load 10mm for my S&W 610 revo only. I don't own nor plan on getting a bottom feeder in 10mm. That said I was thinking today and yes that can be dangerous, but would there be a problem to load COAL to 1.275 or even 1.300 using Hornady 180gr. XTP/HP bullets? I am assuming it would lower the pressure wouldn't it? I know that 40S&W is sensitive to OAL. All input is appreciated, even those scolding me for thinking. Thanks Mac

 

[sparkyv]

Nope. Not at all a problem, and yes the pressure will be reduced. In fact I've considered "long loading" my M610 so I can add in some extra powder to get the velocity up. I've also been considering converting mine to 10mm Mag. That N-frame can take quite a bit. Not for the inexperienced reloader.

 

[noylj]

COL doesn't effect pressure by much. A few hundred psi to maybe 2000 psi depending.
When you change COL, re-work load.
Are you saying you want increase COL simply to lower pressure? This will decrease velocity; however, it will be only by a small amount. It will also reduce total bullet/case tension holding the bullet in the case. So, with only a taper crimp, you could be increasing the odds of the bullet coming out of the case and jamming the cylinder.
Just be aware.

 

[Bfh_auto]

COL doesn't effect pressure by much. A few hundred psi to maybe 2000 psi depending.
When you change COL, re-work load.
Are you saying you want increase COL simply to lower pressure? This will decrease velocity; however, it will be only by a small amount. It will also reduce total bullet/case tension holding the bullet in the case. So, with only a taper crimp, you could be increasing the odds of the bullet coming out of the case and jamming the cylinder.
Just be aware.

According to multiple reloading manuals. A .020 change in seating depth can raise pressure to 50,000 psi in 9mm.
This being a 10mm the larger case capacity will be less affected by the seating depth. But it will still be substantial.

I agree that he is risking bullet jump by doing this. One locked up revolver taught me a lesson on seating really long.

 

[scotty]

I also have a 610 as my only 10mm. When I shoot .40, I use the same ammo as my autoloaders. With 10mm, I see no problem with loading it long as long as its shorter than the cylinder. Of course, all the factors that noylj mentioned apply.

 

[Encoreman]

Are you saying you want increase COL simply to lower pressure?

No, one reason was I think a 1.250" 10mm looks stupid for one thing. I just figured a pressure decrease couldn't be a bad thing. I was also thinking the closer I could get the bullet to the barrel it would be a shorter jump. Why would the bullet jump, if it is crimped into place? The Hornady XTP's are plenty long enough, there is at least 1/4" or more just guessing not at my loading bench. Thanks for the replies gentlemen. Mac

 

[CoalCrackerAl]

Ummmmmmmmmmmmmmm reduce the load. Less pressure then.

 

[robert4301]

Lowering pressure by loading longer will tend to decrease powder burn efficiency, especially with slower powders. Seating depth tuning with mid-speed powders like BE 86 and Unique can be interesting and fun.

 

[CZ9shooter]

I am currently experimenting with a 200gr XTP load at 1.350". So far it shoots great out of my Blackhawk with the little bit of working up I have done indoors. It'll be interesting to see the effects on chrono numbers once the weather gets better around here.

I think I might be seeing some bullet creep due to recoil at higher charge levels, but I have not yet confirmed with a caliper.

 

[noylj]

Playing with COL for accuracy makes some sense.
I know that in all my pistols that the longest COL that feeds and chambers tends to be very slightly more accurate,
Others report that a 0.015" jump, or such, is most accurate.