Cx4 Range report 2 - update
It's been a few weeks since I did that Cx4 range report, and I've got some more information to share.
First, I've done the DIY mod to the hammer to bring down the trigger pull from ~10 lbs to ~5-6 lbs. It worked beautifully and I am very, very happy with the results. Information sources: http://www.berettaforum.net/vb/showthread.php?t=16675&highlight=CX4+trigger and http://gulfcoastgunforum.com/showthread.php?17606-DIY-Beretta-CX4-Storm-Trigger-Job
Second, if you're going to put a barrel shroud like I did, make sure you put some protection in between the shroud and the barrel. I hadn't and found six weeks later surface discolorations on the barrel where it contacted the shroud. I suspect it's caused by some kind of reaction between different metals, but what do I know? Anyhow, I cleaned that up, added a generous coating of Froglube CLP and re-installed the shroud. I'll remove it in October and see if anything new happened.
Third, I got rid of that cheap $50 Remington rest you saw on the first range report and replaced it by a Cadwell rest (model "The Rock") that cost twice as much. And it's proved itself to be worth every dollar, ten times better than the Remington crap: very stable, no wobble at all.
So I went back to the 50 yards range to shoot my remaining CCI Blazer Brass 115gr FMJ and Blazer Aluminum 115gr FMJ, along with some Geco 124gr FMJ ammo. As with my first test, for each ammunition type I shot groups of 20 rounds (but twice this time), hand guard on the Cadwell rest and stock on a sandbag, scope at 4x mag. Temperature was light fog with no wind (no problem, I had anti-fog bullets). To calculate the group sizes, I discarded the two outermost flyers of each group and measured the effective size on the remaining 18 holes.
I know, it's not the standard 5-holes method, but I like it because it lets me select the top 90% of the shots (18/20). if I was looking at 5-holes and discarding flyers, I'd select 80% of the hits only and would never know whether the flyer was my fault's or the ammo's. I think I get better "averaging" effect with 20 rounds on one target.
So here are today's results:
And since pictures are usually required, this is what that last group looks like: twenty little 9mm holes:
Conclusions:
1. It's likely that part of the reason for the large 7.8 MOA group size for the Blazer Brass group 1 is that this was the first shoot I did for the test. It had not two, but three flyers. Without these, the group would have been 6.0 MOA. Perhaps I should have shot some practice groups beforehand to warm up.
2. Since getting the Sierra Papa aftermarket triggers is just about impossible at this time, the DIY adjustment on the hammer is very much worth doing. Just don't over-file the wee thing or you'll be making your gun potentially unsafe and needing a replacement hammer.
3. I'm not buying any more budget ammo, I'd rather shoot quality stuff less often. It's senseless to try improving my shooting technique with cheap ammo: I can't trust what the groupings tell me. Is that flyer caused by a flinch or a trigger jerk, or or is it the ammo that had a QC hiccup?
4. Now that I definitely proved that the Cx4 can make 3 MOA, my personal holy grail for commercial 9mm FMJ will be doing consistent 2 MOA.
VIVA LA CONTESSA!
It's been a few weeks since I did that Cx4 range report, and I've got some more information to share.
First, I've done the DIY mod to the hammer to bring down the trigger pull from ~10 lbs to ~5-6 lbs. It worked beautifully and I am very, very happy with the results. Information sources: http://www.berettaforum.net/vb/showthread.php?t=16675&highlight=CX4+trigger and http://gulfcoastgunforum.com/showthread.php?17606-DIY-Beretta-CX4-Storm-Trigger-Job
Second, if you're going to put a barrel shroud like I did, make sure you put some protection in between the shroud and the barrel. I hadn't and found six weeks later surface discolorations on the barrel where it contacted the shroud. I suspect it's caused by some kind of reaction between different metals, but what do I know? Anyhow, I cleaned that up, added a generous coating of Froglube CLP and re-installed the shroud. I'll remove it in October and see if anything new happened.
Third, I got rid of that cheap $50 Remington rest you saw on the first range report and replaced it by a Cadwell rest (model "The Rock") that cost twice as much. And it's proved itself to be worth every dollar, ten times better than the Remington crap: very stable, no wobble at all.
So I went back to the 50 yards range to shoot my remaining CCI Blazer Brass 115gr FMJ and Blazer Aluminum 115gr FMJ, along with some Geco 124gr FMJ ammo. As with my first test, for each ammunition type I shot groups of 20 rounds (but twice this time), hand guard on the Cadwell rest and stock on a sandbag, scope at 4x mag. Temperature was light fog with no wind (no problem, I had anti-fog bullets). To calculate the group sizes, I discarded the two outermost flyers of each group and measured the effective size on the remaining 18 holes.
I know, it's not the standard 5-holes method, but I like it because it lets me select the top 90% of the shots (18/20). if I was looking at 5-holes and discarding flyers, I'd select 80% of the hits only and would never know whether the flyer was my fault's or the ammo's. I think I get better "averaging" effect with 20 rounds on one target.
So here are today's results:
| CCI Blazer Brass 115gr FMJ - Group 1 | 3.9" | 7.8 MOA |
| CCI Blazer Aluminum 115gr FMJ - Group 1 | 2.8" | 5.6 MOA |
| Geco 124gr FMJ - Group 1 | 1.8" | 3.6 MOA |
| CCI Blazer Brass 115gr FMJ - Group 2 | 2.1" | 4.2 MOA |
| CCI Blazer Aluminum 115gr FMJ - Group 2 | 2.1" | 4.2 MOA |
| Geco 124gr FMJ - Group 2 | 1.4" | 2.8 MOA |
And since pictures are usually required, this is what that last group looks like: twenty little 9mm holes:
Conclusions:
1. It's likely that part of the reason for the large 7.8 MOA group size for the Blazer Brass group 1 is that this was the first shoot I did for the test. It had not two, but three flyers. Without these, the group would have been 6.0 MOA. Perhaps I should have shot some practice groups beforehand to warm up.
2. Since getting the Sierra Papa aftermarket triggers is just about impossible at this time, the DIY adjustment on the hammer is very much worth doing. Just don't over-file the wee thing or you'll be making your gun potentially unsafe and needing a replacement hammer.
3. I'm not buying any more budget ammo, I'd rather shoot quality stuff less often. It's senseless to try improving my shooting technique with cheap ammo: I can't trust what the groupings tell me. Is that flyer caused by a flinch or a trigger jerk, or or is it the ammo that had a QC hiccup?
4. Now that I definitely proved that the Cx4 can make 3 MOA, my personal holy grail for commercial 9mm FMJ will be doing consistent 2 MOA.
VIVA LA CONTESSA!
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