If I am using a powder like AA #9, do I need a particularly heavy crimp on 10mm rounds?

I know in 44 magnum loads, a heavy crimp is needed with #9 and similar powders to allow full ignition of the powder.

Should I be giving the crimp die an extra half turn or so down?

Thanks

Tight bullet fit is need however your taper crimp should be the same for all of your 10mm ammo.  The full seating of the bullet to it's proper depth without any crimp being applied should be done.  Afterwards in a separate step you can apply the taper crimp, to squeeze the casing closed, back against the bullet to finish.  This will provide the best bullet tension in the semi auto cases.

For the 10mm, my finished crimp measurement at the very edge of the case mouth usually measures 0.4215" to 0.4220".  You should see a slight shine on the very edge of the case mouth, where the casing makes contact with the tapered portion inside of the crimp die.

Hope this helps! 

BTW, Yetiman welcome to the forum, hope you find it to be everything you need and then some.

Shadow nailed it.  in a autoloading case like 10mm you aren't wanting to "roll" the case mouth like you would on a rimmed round.  Just iron out the flare you put in to ease seating.

Thanks for the input. So far. i have loaded 100 rounds (all the new Starline brass I could find at first was a bag of 100 at Cabela's). The brown truck dropped a thousand more off two days ago.

I measured some of what i loaded so far and they measure .421" - .422", so I guess i am there.

I am using Dillon dies now, and have a Lee carbide FCD on the way.

i just wasn't sure how sensitive the 10mm was on crimp.

Will you be using the LEE FCD as a pass through sizer die?  It works well for that operation...

With all the info above, I still also use the "Push" test to see if tight enough while slowly adding taper... ( during first setup )

Make a round, measure it, then push it against the bench with some good force.... If they stay the same length after push , the taper is set well.

Quote from: The_Shadow on March 27 2015 09:02:24 PM MDT
Will you be using the LEE FCD as a pass through sizer die?  It works well for that operation...

Just curious... do you pass through size everything?

I only run range pick-up or "Glocked" brass in 40 S&W through my G-Rx.  Never any that has run through my Tanfo Match (10mm).

I have a Lee FCD. I've never used it for pass through sizing. I assume this operation is used to remove any bulge from the case head.?. How does one do a pass through resizing? Are any modifications or special equipment needed?

Charlie_Zulu, it does help to run everything through the Pass-through die before regular sizing and depriming just to be sure and it gives another chance to visually inspect the brass.  I use my LEE FCD as my pass-through die and run 10mm / 40S&W / 357Sig / 9x25Dillon after each use.  This them to fully fit the cartridge case gauge and any tighter chambered barrel insuring 100% reliability with feeding and full in battery lockup.

joshuamalezi, It was easy for me because I had a bullet push pin from a Lee bullet sizer kit that I use to push the brass into and up into the LEE FCD with it guts removed and positioned higher up on the press to take advantage of the top of the stroke leverage.

Here is a link to the pass through discussion http://10mm-firearms.com/reloading-10mm-ammo/pass-thru-sizing-using-lee-fcd/

Quote from: tommac919 on March 28 2015 06:38:17 AM MDT
With all the info above, I still also use the "Push" test to see if tight enough while slowly adding taper... ( during first setup )

Make a round, measure it, then push it against the bench with some good force.... If they stay the same length after push , the taper is set well.

This is not exactly correct.  The taper crimp will have virtually no influence on bullet retention unless excessive crimp is applied to the point of ruining neck tension. Neck tension (or bullet hold) occurs with the sizing die. There's it's nothing that can be done with the taper crimp die to materially affect bullet hold except to mess it up by over doing it.

Your test of pushing the bullet against the bench is a good one. But it can be done after seating, with the flair still remaining. If tension is good-to-go, set the crimp die to just close up the flair so that it keplunks into the gage our chamber.

If there is setback, there isn't anything that can be corrected with a taper or FCD. The ID of the sizer is wrong, relative to the brass thickness; or the brass is work hardened and is springing back after passing through the sizer.  Again, neither of those problems can be corrected with a crimp die for auto loading service cartridges.

Unfortunately, even manufacturers get this wrong and state that their crimp die will increase bullet hold.

To the OP's question:

As far as Accurate no. 9, it does like a high bullet pull. My best velocities and High/low velocity spreads come with squeaky clean new brass. I re-size those to bump down the ID of the cases. Clean smooth brass gives a lot of grip on the bullet. It is common for me to see high/low spreads of less than 10 for five shot strings by using this method. I really like Accurate no. 9.

Quote from: The_Shadow on March 28 2015 11:00:05 AM MDT
Charlie_Zulu, it does help to run everything through the Pass-through die before regular sizing and depriming just to be sure and it gives another chance to visually inspect the brass.  I use my LEE FCD as my pass-through die and run 10mm / 40S&W / 357Sig / 9x25Dillon after each use.  This them to fully fit the cartridge case gauge and any tighter chambered barrel insuring 100% reliability with feeding and full in battery lockup.

joshuamalezi, It was easy for me because I had a bullet push pin from a Lee bullet sizer kit that I use to push the brass into and up into the LEE FCD with it guts removed and positioned higher up on the press to take advantage of the top of the stroke leverage.

Here is a link to the pass through discussion http://10mm-firearms.com/reloading-10mm-ammo/pass-thru-sizing-using-lee-fcd/

You have been a strong proponent of pass through sizing.  Curious if you've had issues with resized cases not passing a gage. My experience had been that my ammo passes the gage virtually 100%. Even after max effort ammo shot with Glock barrels. The exception is when very clean brass has high friction, when going through the carbide ring, and I get some galling. I started using Hornady One Shot about a year ago, and the galling issue is gone. Highly recommend this. So much smoother in the sizer - especially with 5 cases going on the progressive. So much easier to feel the other steps that are going on when there is less drag through the sizer. Another occasional issue is work hardened case mouth that won't fully close. Those are shot in Glocks then tossed.

But I otherwise see no issue with the bottom of the case not getting sized. With the volume that I shoot sometimes, and my VERY busy schedule, pass through sizing would add a big step. Thankfully it has been a non-issue. FWIW, both of my 40 bore sizing dies are RCBS. My shellholders and shell plate are RCBS too.

taterhead nailed it on the crimp dies for taper crimp.  Lee FCD is great for pass through sizingin 10mm, but not much else IMHO.

I love a FCD for my bottleneck rifle rounds with cast bullets.  It really put a good roll into that crimp.  But for taper, not so much.

Taterhead, I too use the RCBS 10mm dies for 10 and 40S&W and they do a great job, but as I started getting "The so called GLOCKED brass" I did see a few that did fit most chambers but did not pass the case gauge.  In my Storm Lake 40S&W barrel I did have some show the slightest hold out of battery where a slight push on the slide sent them home.  Also as the chamber got fouled with soot it would get worst...

The pass-through system help with everything 10mm / 40S&W / 357Sig / 9x25Dillon, this restored the brass to a better state and actually improved primer pockets and case rims as it made them uniform in roundness.

Yes it was adding an extra step, but in my opinion it was well worth the troubles.  I usually sit at the table and pass through size every thing and toss in a big jug and place a piece of paper stating they were pass-through sized.

Quote from: The_Shadow on March 28 2015 06:04:09 PM MDT
Taterhead, I too use the RCBS 10mm dies for 10 and 40S&W and they do a great job, but as I started getting "The so called GLOCKED brass" I did see a few that did fit most chambers but did not pass the case gauge.  In my Storm Lake 40S&W barrel I did have some show the slightest hold out of battery where a slight push on the slide sent them home.  Also as the chamber got fouled with soot it would get worst...

The pass-through system help with everything 10mm / 40S&W / 357Sig / 9x25Dillon, this restored the brass to a better state and actually improved primer pockets and case rims as it made them uniform in roundness.

Yes it was adding an extra step, but in my opinion it was well worth the troubles.  I usually sit at the table and pass through size every thing and toss in a big jug and place a piece of paper stating they were pass-through sized.

It is funny, since I am the kind of guy that looks for an excuse to "need" to buy a reloading tool. You might say that I have been guilty of looking for a solution to a problem I really didn't have. I, on more than one occasion, had the G-Rx die in my cart with the mouse pointer hovering above the "submit order" button. I talked myself out of it since my cases gage just fine. It sounds like you've run into issues here and there, so I can see the logic in what you're doing.