KKM 9mm 1-18 vs 1-32 twist

Hello everyone!

I noticed KKM website shows AMU using 1-18 and 1-32 twist for 9mm. What twist rate is better for 50 yard accuracy? I’m sure they both shoot great. I know the loads for the 1-32, but not for the 1-18. I heard Atlanta Arms made a new 9mm 110 jhp and the company Accuracy X is using the 1-18 twist with that ammo. I look forward to your responses.  Thanks! 

I had KC build a 1-32 twist 9MM for me, very accurate (<1.25@50yd) with either a 115gr Hornady HAP or XTP bullet but you have to push it at 1,100fps with about 5.0gr of VVN340 or 5.2-5.4 of WSF.

The 9MM's recoil was too sharp for me after carpal tunnel surgery so I had KC convert it to .38 Super with a 1-10 fast twist barrel.  Very soft shooting with a 147gr lead BBFP (from Magnus or Dardus), 2.8gr of WST it's a 1.75" @50yd gun and with a hotter round (147gr JHP)  it's <1.5" @50yd.
- Dave

Dronning what barrel did KC use for the 10 twist?
Jon

Jon Eulette wrote:Dronning what barrel did KC use for the 10 twist?
Jon

Jon, 
It's a Clark.  
I initially had major leading issues with .356 bullets had to go with .357.  Leading went away and accuracy was more than good enough with the .357.  I slugged the barrel at both chamber and muzzle and it was .3555. At some point I am going to run about 1K rounds of 147gr JHP through it and retry the .356 bullets again.

- Dave

Nothing but a guess on my part at this time.  But I'm going to say that the 1-18 barrel will outshoot the 1-32.  Still going to have to drive it a bit faster for the 1-18 but I don't think you'll have to drive it as fast as the 1-32.  Of course this is for jacketed ammo.

THE ORIGINAL S&W PP9's WERE 1-17.75 AND WERE VERY ACCURATE WITH 147GR BULLETS. THE 147 GR LOAD WAS ALSO VERY MILD COMPARED TO THE 115GR LOAD YOU NEED FOR THE 1-32 BBL.
147GR LOAD FOR THE S&W WERE AS FOLLOWS;

147GR HORNADY XTP
OAL 1.142
4.2 VV330 (BEST) FED SP
4.0 WSF    (2ND) WIN SP
NEW BRASS AT 50YDS
USED BRASS SHORT WITH THE HORNADY 147 FMJ BULK

P.S. THE 147GR XTP IS A BOAT TAIL BULLET

Thank you Sir!

OH YEA, THE XTP's ARE .356 ACCORDING TO THEIR WEB SITE. JP

The 952 is 1:18.75 and it shoots very well with the 115gr and 147gr XTP. Will also shoot the 147gr L-FP from Magnus well but does not like lighter lead bullets.

https://www.bullseyeforum.net/t5192-the-good-not-so-good-and-the-ugly-9mm-range-test?highlight=the+good

dronning wrote:I had KC build a 1-32 twist 9MM for me, very accurate (<1.25@50yd) with either a 115gr Hornady HAP or XTP bullet but you have to push it at 1,100fps with about 5.0gr of VVN340 or 5.2-5.4 WST.

The 9MM's recoil was too sharp for me after carpal tunnel surgery so I had KC convert it to .38 Super with a 1-10 fast twist barrel.  Very soft shooting with a 147gr lead BBFP (from Magnus or Dardus), 2.8gr of WST it's a 1.75" @50yd gun and with a hotter round (147gr JHP)  it's <1.5" @50yd.
- Dave

I would be careful using WST and 9mm over 5 gns, Winchester does not list loads for 9mm owing to pressure issues in 9mm cases. I have loaded 9mm up to 4.2 gns WST with no pressure signs.

rich.tullo wrote:

dronning wrote:I had KC build a 1-32 twist 9MM for me, very accurate (<1.25@50yd) with either a 115gr Hornady HAP or XTP bullet but you have to push it at 1,100fps with about 5.0gr of VVN340 or 5.2-5.4 WST. < Changed to WSF in original post.  I use WST in the .38 Super

I would be careful using WST and 9mm over 5 gns, Winchester does not list loads for 9mm owing to pressure issues in 9mm cases. I have loaded 9mm up to 4.2 gns WST with no pressure signs.

Thanks I wasn't sure what you were talking about then I re-read my post it should have said  I use 5.2-5.4 of WSF in the 9MM I made the change above.

WOW and that is why you double check what someone posts about load data before you try it.

Thanks for the catch!
- Dave

+1 on driving them fast with a 1-32 barrel.  And forget about 147 gr. bullets.  They go sideways in the slow twist.

i'm guessing here.. that when the CMP allowed for any safe ammo people went to the 1-18 for the 147bullet instead of the 1-32 with the 115-124

JIMPGOV wrote:OH YEA, THE XTP's ARE .356 ACCORDING TO THEIR WEB SITE. JP

The only one I see that is .356" is the 125 HAP. The 9mms are .355".

https://www.hornady.com/bullets/handgun/#!/

Chris Miceli wrote:i'm guessing here.. that when the CMP allowed for any safe ammo people went to the 1-18 for the 147bullet instead of the 1-32 with the 115-124

I don't think that happened. I think the 32 twist barrel came to be because of the FMJ requirement but after the ammo rule change the big change was teams and civilians started to use JHP, 115XTP bullets instead FMJ's. Maybe someone with inside knowledge can speak to what big team shooters are using now?  I haven't heard about a big change to 16-18" twist barrels and using 147's in the 92F, but i'm certainly not in any loop to hear of such changes. Maybe now that is happening but not right after the rule change. It wouldn't surprise me that select teams are changing everything over since Uncle Sugar is paying for everything..

I believe the XHD barrels are 16" twist or faster and that stock barrel was used with 115gr Atlanta Arms ammo by one AMU shooter to do well at Perry and set a Bianchi Cup record.

The older XDM factory barrels came with a 1-16 the new ones are 1-10

Yep, and they shoot 115's JHP just fine.

NEW S&W M&P 2.0 IS 1-10 ALSO. JP

S148 wrote:

JIMPGOV wrote:OH YEA, THE XTP's ARE .356 ACCORDING TO THEIR WEB SITE. JP

The only one I see that is .356" is the 125 HAP. The 9mms are .355".

https://www.hornady.com/bullets/handgun/#!/

I ordered 100 .356 125 HAP's to  try against my .355 115 HAP's in my RO and 986. The RO is 1:16 and the 986 1:10.   I see in Handgunner the 986 is now a 2 inch barrel....ugh!  Bad timing here as the weather has been very winter-like for the last 2 weeks so my range sessions will be few and far between until spring.

rich.tullo wrote:

dronning wrote:I had KC build a 1-32 twist 9MM for me, very accurate (<1.25@50yd) with either a 115gr Hornady HAP or XTP bullet but you have to push it at 1,100fps with about 5.0gr of VVN340 or 5.2-5.4 WST.

The 9MM's recoil was too sharp for me after carpal tunnel surgery so I had KC convert it to .38 Super with a 1-10 fast twist barrel.  Very soft shooting with a 147gr lead BBFP (from Magnus or Dardus), 2.8gr of WST it's a 1.75" @50yd gun and with a hotter round (147gr JHP)  it's <1.5" @50yd.
- Dave

I would be careful using WST and 9mm over 5 gns, Winchester does not list loads for 9mm owing to pressure issues in 9mm cases. I have loaded 9mm up to 4.2 gns WST with no pressure signs.

The load data for Winchester is on Hodgedons site, Hodgedon has been the US distributor for Winchester powders since about 2006. http://www.hodgdonreloading.com/data/pistol, They have data for Cast, and jacketed 9x19 loads. 

I would agree that you need to be careful with pressures at the high end of the loads with WSF. Both my company and a major ammo manufacturer used to use WSF in production ammo manufacturing. It's fine if you are loading to Minor power factor for USPSA style. The key caviot being that you brass sort by headstamp, especially on the high end of the load as case volume changes quiet a bit through the range of mfgs and various lots. There have been plenty of failed cases due to over pressure from mindlessly using WSF with mixed headstamps.

PLEASE note I made a correction!  I use 5.4gr of WSF NOT WST in my 9mm, I use 2.8gr of WST in my .38 Super.

- Dave

I have never thought to use WST in the 9mm, have been using WSF exclusively but I read on some other forums is is a fantastic choice for light 9mm loads as well. I'm going to work up some loads this winter. Always great to consolidate powders.

To anyone that has a ransom rest and free time: I have been shooting 3.5 WSF with a 147gr XTP/plated hollowpoints and it has been an excellent short line load. May require a lighter recoil spring in some 1911's but in all my guns it cycles fine with stock springs. It seems to be able to hold the 10 ring nicely, but I am curious how well it does @25 out of a rest. All pistols tested with the load had 1:16 or 1:18 barrels, YRMV. I would assume 1:10 would be even better for such a slow load.