Ammo help for 9mm...poor groups

Hi folks,

I'm a little bummed about the accuracy of my new gun and hope you accuracy experts can help me out.  I purchased it used and the original smith was Mike LaRocca. 
http://www.laroccagunworks.com/

I don't know much about him but he has a good reputation.  It's not a bullseye gun...but I like my guns to shoot better than it is.   Today I got a 2 1/2" group from a rest at 25 yards.  That's about the best I've had.  With other ammo I usually have a couple of flyers extending the group to 5".

Anyway, I brought the gun to Ed Masaki yesterday and he said is was very well made, barrel fit good, bushing good, slide to frame good, he liked the 3 lb trigger with a slight roll.  He said it was a well made gun and he's the type of guy who will be honest if something isn't to his liking. 



Ammo used in this 2.5" group above was American Eagle 115gr FMJ.

I've also used CCI aluminum cased 115 grain ammo and those produced the worst groups.  That ammo is very accurate in my other guns.
I also tried a 124 gr. lead round nose with 4 gr of Bullseye powder that did better but not stellar...maybe 3 inches.


It has a non ramped Kart barrel.  I think the twist is 1:16 but I'm not certain.




I'm going to order the caliber conversion for 9mm so I can start testing some loads.  Is a 1 inch group at 25 yards too much to ask for this barrel?  I would appreciate any advice you guys have on where to start with accurate loads for this barrel. 


I've been playing around with my 1970 Clark Hardball over the last couple of weeks and getting decent groups.  The group on the right is 1 1/2".  I'm sure it would be tighter with a ransom rest.  Sweet old gun.

Thank you very much for your help,
Dave

I would believe that the gun would give you groups of 1" or less from 25 yards with the right ammo.  It's just a matter of experimenting.  For factory ammo, I always had the best accuracy with Winchester White Box or PMC.  
For reloads, I have never used anything but Hornady 115 FMJ and Power Pistol.

I shoot either Zero 115 JHP-C or Hornady 115 XTP with 5.0 gr Power Pistol, or 5.0 gr Vitavouri N-330, or 4.5 gr Vitavouri N-320 LOA 1.105  out of a KKM with 1:32 twist will shoot 1-1.5" at 50yd.  I would think that one of these loads would shoot in your gun.

Sorry for the second post on this subject but if you want to buy ammo you can get loaded 9mm in 115 gr JHP or FMJ from Zero or Atlanta Arms & Ammo.  Atlanta makes ammo for the AMU as well as other competition shooting sports look at the ammo descriptions.

Have you contacted the gunsmith that built it?  Since you have his website, phone number and email, that would have been my first choice.  Most gunsmiths I know, at least those that build BE pistols, will provide a suggested load.

The barrel twist rate is important in 9mm. My Baretta will do under 3" at 50 yds for 10 shots with a KKM 1in 32" barrel.

Thank you all for the replies.  Where do you guys buy the Zero bullets?  They look out of stock every place I look. 

Good idea on contacting the gunsmith.  I don't know why I didn't think of that.

Thanks,
Dave

zero is sold to the public thru Rose distributing, you can google and find them.

Thanks.  Each time I've visited their site over the last couple of months everything has been out of stock.  I figured you guys had a line on another supplier.  Thanks,
Dave

http://www.starreloaders.com/edhall/92loadinfo.html

Try this. I've seen several master g'smiths' targets that show it's potential.

and, I found this on Bob Marvels website...



"1.384
30 rounds
115 XTP HP
6.1 Power Pistol
1.120 OAL"

With a 1:16 twist, you may do better with a heavier (longer) bullet.

I appreciate the help very much. 
 
Any suggestions for the 147 grain bullets? 

Thank you,
Dave

I shoot a lot of 147gr. The group on my avatar was shot with 5.1 gr of power pistol behind a hornady 147gr RNBT.Case o.a.l. is 1.152. The boat tail bullet just seems to work a little better for me.And as a plus the extra weight bullet and recoil keeps the pistol functioning well with the extra weight of the dot on the slide.
Len

Thank you for the detailed load data Len. 
Dave

I too am certain the issue lies with the ammo. How did your reloads perform in different guns? There are a lot of loads listed on the internet by AMU shooters. Of course you should start out with all matched cases and weight matched bullets as always.

Thank you.  I did not test the 124 grain lead ammo in any other guns.  The Blazer ammo that I was shooting gets close to one hole groups at 25 yards with my other guns. 
I ordered some Zero 147 grain round nose today and will test that soon.  Take care,
Dave

147 GR BULLET LOAD. THESE ARE FOR FMJ OT JHP NOT FOR LEAD.
4.0GR WSF
4.2 GR VV330
JIM P

Thanks for the tip Jim.  I loaded up my Zero 147's this evening and hope to test mid week.  I shot some 147 American Eagles and the groups were much better.  147's are the ticket. 
Dave

It's been about 6 weeks since I first posted.  I've been working hard on this 9mm load and I'm making progress. 

I'm new to reloading and started with the .45.  My first loads with .45 worked great. 

9mm wasn't so easy and I had quite a few things to sort out.  I'm getting there.

Thanks for the advice.

Dave

Looks like you got it with that load.

Of course we'd love to get that at 50...

Makes me start reconsidering my practice of sticking with 115s as my "standard" load.

Me too!

Thank you.  I would have been happy to stick with the 115s but the groups were 5 to 6 inches.  

Hopefully there is still room for improvement with a better powder and bullet.  
Dave

It seems that the KKR barrels lots of smiths use for highly accurate 9mm's are very slow twist barrels (1:32 I think).  The faster twist barrels that come in our pistols as standard may be over-spinning the 115gr bullets.  The longer, and hence heavier, a bullet is in a given caliber the more spin it needs to stabilize.  Hence the faster twist barrels may well work better with 147's than 115's.  The down side is more recoil impulse with the 147's.

at the risk of censure for mentioning a long arm, but don't you use a slower twist for heavier bullets  (1 in 7 for 77gr .223)?

I believe that's true also...