C.O.A.L for 9mm

rocknbrock · May 4, 2008, 05:18 PM

I'm currently using Vitavhouri N340 powder and 115gr JHP's from Montana Gold (meant to copy the xtp jhp's from Horndady). Vitavhouri (downloaded data from their website) gives a range of 5.2-5.9 grns and a C.O.L. of 1.142. I used 5.6grn in my loads. Until recently I fired these with my xd-9 with great results. However I just bought a CZ P-01 and noticed that at that C.O.L. of 1.142 the bullets don't fully seat in the barrel chamber as it seems the bullets hit the rifling before the case mouth seats. I found the same powder and similar bullet in my Lymans 48th editition with the C.O.L at 1.090 and 4.5-5.0 grains. I made a few mock up rounds with no powder or primer at this C.O.L. and it seats perfectly in the chamber and loads from the magazine ok. I'm wondering why such a difference in the C.O.L. between the two resources and If I should just toss the aprox 200 loads I have left from my previous COL and Powder charge. It is adviseable to put them back in my press and seat the bullet to the 1.090 COL with the larger charge or am I taking to big a risk on that since the powder load is so much greater? Thanks in advance for your input.

JDG · May 4, 2008, 05:29 PM

I'll guess 1.100 would be safe, that were I load my 115gr hps, for my CZs

rocknbrock · May 4, 2008, 05:43 PM

What powder and grns do you use?

totalloser · May 4, 2008, 06:07 PM

I use a similar powder charge with no 5 and a 124 grain fmjhp (longer bullet both from weight, and the hollow point) at 1.110". I use 5.6 (hot load beware!) and it had plenty of space to not cause a compressed load. When you squish the powder with the bullet, that's when the pressure REALLY spikes. If in doubt, I would measure the length of bullet into the case and the depth of the powder to verify you aren't compressing the powder. I kinda doubt you are even close with a 115 grain bullet.

I have heard this story before with CZ's 75s. I think the rifling starts sooner on most of them. FANTASTIC gun, though. Best of 92f combined with the best of the High Power.

CrustyFN · May 4, 2008, 08:52 PM

My experience with CZ's is they have a short throat. I have had to load some FP's at 1.035 to get them to chamber in my CZ 75BD Police.
Rusty

JDG · May 5, 2008, 04:44 PM

Quote:

What powder and grns do you use?

I load 5.5gr Power pistol, 115gr Zero hps, 1160fps

rocknbrock · May 9, 2008, 05:23 PM

Went with 1.1 COL and 5.2 grns of n340 and worked well. Thanks for the input everyone!

swmike · May 13, 2008, 08:18 PM

Vihtavouri likes real long COL's for some of their powders. I load VV3N37 and they spec 1.142" using a 124gr JHP. If follow this my CZ won't go into battery. I have to shorten the cases to 1.125" which works great in both my CZ75 SP-01 Tac and my Sig P-229.

If you want to find the longest COL that your pistol will accept, take a case that has been trimmed to .750" (Design Std for this round). Insert a bullet in the unloaded case leaving it extra long, drop it into the chamber and press in until the case mouth engages the front of the chamber (where it headspaces). Remove the bullet/case assy and measure. Subtract .005" from this measurement (for freebore) and THAT is the longest round (using that bullet) that will fit. Then make sure it will fit in your magazine. If so, it probably will be very accurate as well as the bullet is not wobbling around in the chamber a lot before it engages the rifling.

Beware of MINIMUM COL's as they are there to prevent extreme case pressures by squeezing the charge too much.

May 4, 2008, 05:18 PM	#1
rocknbrock Junior Member Join Date: May 4, 2008 Posts: 3	C.O.A.L for 9mm I'm currently using Vitavhouri N340 powder and 115gr JHP's from Montana Gold (meant to copy the xtp jhp's from Horndady). Vitavhouri (downloaded data from their website) gives a range of 5.2-5.9 grns and a C.O.L. of 1.142. I used 5.6grn in my loads. Until recently I fired these with my xd-9 with great results. However I just bought a CZ P-01 and noticed that at that C.O.L. of 1.142 the bullets don't fully seat in the barrel chamber as it seems the bullets hit the rifling before the case mouth seats. I found the same powder and similar bullet in my Lymans 48th editition with the C.O.L at 1.090 and 4.5-5.0 grains. I made a few mock up rounds with no powder or primer at this C.O.L. and it seats perfectly in the chamber and loads from the magazine ok. I'm wondering why such a difference in the C.O.L. between the two resources and If I should just toss the aprox 200 loads I have left from my previous COL and Powder charge. It is adviseable to put them back in my press and seat the bullet to the 1.090 COL with the larger charge or am I taking to big a risk on that since the powder load is so much greater? Thanks in advance for your input.

May 4, 2008, 05:43 PM	#3
rocknbrock Junior Member Join Date: May 4, 2008 Posts: 3	Ok What powder and grns do you use?

May 9, 2008, 05:23 PM	#7
rocknbrock Junior Member Join Date: May 4, 2008 Posts: 3	Thanks. Went with 1.1 COL and 5.2 grns of n340 and worked well. Thanks for the input everyone!

May 4, 2008, 05:29 PM	#2
JDG Senior Member Join Date: November 28, 2005 Location: West Michigan Posts: 673	I'll guess 1.100 would be safe, that were I load my 115gr hps, for my CZs

May 4, 2008, 06:07 PM	#4
totalloser Senior Member Join Date: October 20, 2007 Location: Fort Bragg, CA Posts: 679	I use a similar powder charge with no 5 and a 124 grain fmjhp (longer bullet both from weight, and the hollow point) at 1.110". I use 5.6 (hot load beware!) and it had plenty of space to not cause a compressed load. When you squish the powder with the bullet, that's when the pressure REALLY spikes. If in doubt, I would measure the length of bullet into the case and the depth of the powder to verify you aren't compressing the powder. I kinda doubt you are even close with a 115 grain bullet. I have heard this story before with CZ's 75s. I think the rifling starts sooner on most of them. FANTASTIC gun, though. Best of 92f combined with the best of the High Power.

May 4, 2008, 08:52 PM	#5
CrustyFN Senior Member Join Date: June 4, 2006 Location: West Virginia Posts: 2,258	My experience with CZ's is they have a short throat. I have had to load some FP's at 1.035 to get them to chamber in my CZ 75BD Police. Rusty

May 13, 2008, 08:18 PM	#8
swmike Senior Member Join Date: June 25, 2005 Location: Marysville, WA Posts: 670	Vihtavouri likes real long COL's for some of their powders. I load VV3N37 and they spec 1.142" using a 124gr JHP. If follow this my CZ won't go into battery. I have to shorten the cases to 1.125" which works great in both my CZ75 SP-01 Tac and my Sig P-229. If you want to find the longest COL that your pistol will accept, take a case that has been trimmed to .750" (Design Std for this round). Insert a bullet in the unloaded case leaving it extra long, drop it into the chamber and press in until the case mouth engages the front of the chamber (where it headspaces). Remove the bullet/case assy and measure. Subtract .005" from this measurement (for freebore) and THAT is the longest round (using that bullet) that will fit. Then make sure it will fit in your magazine. If so, it probably will be very accurate as well as the bullet is not wobbling around in the chamber a lot before it engages the rifling. Beware of MINIMUM COL's as they are there to prevent extreme case pressures by squeezing the charge too much.