Accuracy problem

[Youngeyes]

I now shoot a Shadow target custom shop. I've loaded Acme coated 147 with 3.4 gr N-320 at 1.135 OAL.. It makes power factor with a single digit S/D. The problem is that my groups are 3-3.5 inches at 15 yds. I changed to MG 147 CMJ with 3.65 gr powder. It makes PF but still gets me only a 2.5-3 inch group. I can shoot my Baer 45 and get 1-1.5 groups.This is my first 9mm. Are they just not as accurate as a 45? Is it the fact that my 45 is a Les Baer that makes the diff? The Custom Shop told me that they used factory 115gr ammo for their test shots. Is the 147 gr just too much? Does switching from a 45 to a 9mm have a big learning curve? Does a smaller faster caliber have less room for user error? Is anyone getting 1.5 inch groups? Has anyone else switched calibers and had this problem? Any advice is welcome.

[mro111lland]

My cz75 does not like 147 I use 124 mg can get 2 inches at 40 yards

[45 Raven]

Try some different weight bullets. Don't give up after two bullets of the same weight and only one brand of powder. If you have a CZ Custom Shop Target Shadow, rest assured that it WILL be an accurate pistol unless you were unfortunate enough to get one that has a problem. And if it does have a problem, CZC will make it right.

[JHicks8h]

I have used SNS coated New Round Nose profiled 147s and 135s and produced sub 3" groups at 50yds on a ransom rest utilizing N320 and Ramshot Competition. I ran some hornady 147s in the past that I thought were accurate, however did not own a ransom rest at that time. Your OAL is very similar to what I am running with the SNS bullets. Did you purchase the CZ new? If used I have seen barrels wear out in some instances and even the internally pressed bushing showing signs of wear. Those are generally with significant round counts. I will say I did test some other bullets that would not even stay on paper at 50yds with the same gun. I know you have tried 2 bullet profiles so far, but as others had said, don't give up, these guns are highly accurate.

[JGus]

Shooting 147 SNS roundnose over 3.5 gr Ramshot Comp, OAL 1.125 in my CZ AccuShadow, i can consistently shoot groupings slightly better than my Les Baer Premier II and Concept V in slow freehand or table rest. But with the right load i'm not sure much can outshoot the Accu?

Edited July 12, 2016 by JGus

[kneelingatlas]

Have you slugged your barrel? It's possible you'll get tighter groups with bigger bullets, I've heard of people using as big as 0.358" in 9mm.

[zhunter]

My gun likes .356's a lot more than .355's

Also, your OAL is very long for a CZ barrel unless it was modified. All 3 of my shadows are very accurate, but I load under 1.10"

You just need to get the load dialed in and you are good to go

[cnote]

All my CZ s shot better with 124s regardless of powder. They all also liked short oal better which is easier with the 124 to do safely

Not saying it can't be done with 147, but you tried two good brands and the best powder for 9 out there

[Jollymon32]

Disclaimer: Total reloading noob here

My gun likes .356's a lot more than .355's

Also, your OAL is very long for a CZ barrel unless it was modified. All 3 of my shadows are very accurate, but I load under 1.10"

You just need to get the load dialed in and you are good to go

So, like the OP, my OAL is set to 1.135. I determined this OAL by measuring a commercial round that the CZ shot with no issue; AE 124 gr. At this OAL, the round passes the plunk test, I assume that at even a smaller OAL, the bullet will be even farther back. How does this improve accuracy?

[zhunter]

Disclaimer: Total reloading noob here

My gun likes .356's a lot more than .355's

Also, your OAL is very long for a CZ barrel unless it was modified. All 3 of my shadows are very accurate, but I load under 1.10"

You just need to get the load dialed in and you are good to go

So, like the OP, my OAL is set to 1.135. I determined this OAL by measuring a commercial round that the CZ shot with no issue; AE 124 gr. At this OAL, the round passes the plunk test, I assume that at even a smaller OAL, the bullet will be even farther back. How does this improve accuracy?

d

Is the bullet profile of your commercial round the same as your reload bullet? Probably not. Most of us have gone under 1.10" and not had any problems. I load at 1.095". I found that 125's were easier to not get a case bulge at the shorter OAL too.

147's are longer, are more expensive, and I found had very little impulse difference. YMMV, but an extra 700 per case for the same price is a winner for me

[QuickMick]

weight of bullets is ok, we use 28.6mm OAL - try a 13lb recoil spring.

[JusticeOfToren]

Have you slugged your barrel? It's possible you'll get tighter groups with bigger bullets, I've heard of people using as big as 0.358" in 9mm.

This ^

Some vendors allow you to order different dia bullets. Try some 0.357 first.

[CZ85Combat]

My Shadow likes MG124 JHP's. If I rember this is at 18 yards.

[dlightning]

All my CZ s shot better with 124s regardless of powder. They all also liked short oal better which is easier with the 124 to do safely

Not saying it can't be done with 147, but you tried two good brands and the best powder for 9 out there

I have this exact same experience. Although I did the test at 15 yards bench.

[inspector1999]

I can only add to the others who say my accuracy is great with my CZ SP-01. It is more accurate with .356 diameter bullets and the best weight was 124. I tried blue bullets which were .355, and I was getting 4-5 inch groups at 15 yards. Lighter bullets seemed to have a different point of impact to point of aim, meaning the gun shot way high with 115 at distance.

The OAL was determined by plunk testing, remove your barrel, put a round in the barrel and you should be able to spin the round. Start long and go shorter till it does.

So my recipe ended up being BBI 125 grain, over 3.6 grains of tightgroup at a OAL of 1.10.

Picture is at 25 yards, 5 shot group, the paster X is 2 inch by 2 inches.

Sent from my ASUS_Z00AD using Tapatalk

Edited July 13, 2016 by inspector1999

[Youngeyes]

Thanks for all the great advice. I've ordered some 124 MG bullets. I'm going to try ...

1. 147 MG with an OAL of 1.10

2. retry the coated 147 with the OAL at 1.10

3. 124 MG with OAL of 1.10 and starting at 3.4 Gr N-320

4. increase the powder charge with the 147s. I think the heavier bullets need more pressure and velocity to be accurate.

I'll work from there, changing powder weight and OAL. If I can't get to where I need to be. I'll have the barrel slugged. I may not need to shoot a 1.5 inch group at a match, but I need to have the confidence that I can.

[himurax13]

I have agree with Youngeyes.

Depending on the load, increasing the velocity or changing the OAL can affect long range grouping. Typically though I prefer to load .01, or closer, below the max OAL I can pull off with passing the spin and plunk test.

For 147g I try to maintain a 132 to 137 PF for my loads.

[Youngeyes]

My gun likes .356's a lot more than .355's

Also, your OAL is very long for a CZ barrel unless it was modified. All 3 of my shadows are very accurate, but I load under 1.10"

You just need to get the load dialed in and you are good to go

Good advice. I checked my max OAL. I placed a bullet in a fired case and pushed it into the barrel. The measurement for the 147 coated was 1.132 every time. The 147 MG CMJ was 1.35. It would seem that I'm loading to the max OAL. I've reduced the OAL to 1.10. I'll try the new loads.

[Jollymon32]

So I ran a batch of Xtreme 124's, 4.1 gr N320, with a 1.10 OAL.

Did Not a notice much difference in accuracy.

HOWEVER, I noticed, much to my amazement, a HUGE difference in how dirty the spent case were. My previous 1.149 OAL loads, when shot, left a sooty cartridge behind. The smaller OAL leave a very clean spent case.

Imagine that.

Going to chrono the 1.10 and see what I get.

[CZ85Combat]

with 124gn bullets you will need 3.8-4.2gn of N320 @ 1.090"-1.110" You are looking for about 1050fps CZ's like the bullet going faster.

Edited July 14, 2016 by CZ85Combat

[Youngeyes]

Here are some of my results..

OAL Powder Charge Bullet Avg fps S/D PF

1.10 N-320 3.4gr 124 MG CMJ 980 14 121

1.11 N-320 3.6 147MG CMJ 905 11 133

1.10 N-320 3.7 147MG CMJ 915 7 134

1.10 N-320 3.8 147MG CMJ 920 14 135

The 3.7 gr and 147MG CMJ shot the most accurate and softest recoil. It's still not as accurate as my 45 but will do for now. I'm going to try 4.0 and 4.1 gr to see if it improves accuracy. I'm ordering a 10X bushing to try out.

[MemphisMechanic]

Why is your charge under the 124 lower than the ones beneath the 147s?

The lighter the bullet, the more powder you need to drop for an equivalent power factor. Not less.

Edited July 19, 2016 by MemphisMechanic

[Fantom919]

I hope this isn't too off topic, but is "acceptable accuracy" for all of you?

I've heard 2" at 25 yards standing with no support but that seems impossible for me. Could be my bad eyes or bad ligthing at my in door range but the best I can do is a 4 inch group with my accushadow resting it off my gear bag.

For reference, I used a 124 gr MG jhp under 4.1 gr of tite group at 1.085 oal.

[CZ85Combat]

3.9 gn of N320 with a 147gn bullet is MAX, 4.0gn & 4.1gn is not a good idea.

[Jollymon32]

Youngeyes, With identical powder and primer - but with an Extreme 124 plated bullet - here are my results

N320 3.8 gr - 1.0945 OAL:

Median: 1008

Stnd Dev: 14.69

Average: 1005

PF: 125.68