Shadow 2 problem - Sometimes it keyholes?

[Pew-Shadow2-Pew]

Dear CZ enthusiasts,

I recently have a problem with my CZ Shadow 2 and I can't find a solution to the problem.

While shooting I see that sometimes without any regularity a bullet hole looks like a keyhole. I make my own ammunition and use 145gn CP HP from L.O.S. for training. For gunpowder I use 4.0 grain Lovex D032. This has always worked well and I have not had this problem before.

I also checked the barrel and didn't see anything strange. The weapon is completely standard apart from a 12lb recoil spring from CGW I fired about 30,000 rounds with the gun

Anyone know what could be the problem or know a solution?

Thanks!

[M1A4ME]

The 147's (hollowpoints and lead - well, lead were 140 grain) I'd loaded up for my M&P had keyhole issues in my P09, CZ85, P01, etc.  Too slow for the CZ's barrel twist?  I added some powder (and changed powder as all my AA#5 was long gone) and eliminated the keyhole issues with some additional velocity (which increases the buller spin rpm, which makes it more stable - I read.)

[Wobbly]

Too slow for the CZ's barrel twist?  I added some powder (and changed powder as all my AA#5 was long gone) and eliminated the keyhole issues with some additional velocity (which increases the bullet spin rpm, which makes it more stable - I read.)

He's right. Number 1 cause of keyholing is not enough velocity.

[Pew-Shadow2-Pew]

I will up the gunpowder and see if it will solve the problem!

Thank you guys!

[Andres B]

 Slovenian bullets and czech gunpowder, huh? Bet ya are from old comblock:)
 4,0 grains D032 looks pretty heavy for 145 grain bullet. How much PF it gives?
 I use LOS 145 RN bullets and 3,3 grains of same powder. Gives 128-129PF.
 Alsa Pro bullets are better IMHO.

[tdogg]

Yeah, looking at published load data that is well over max load already.  Do you have a chrono?  What is your velocity?

I'm going to guess that these bullets are undersized or something.  What is the diameter of these bullets?  Have you slugged your barrel to determine the groove diameter?

Cheers,
Toby

[Pew-Shadow2-Pew]

@Andres B
For competition I use Alsa Pro bullets. These are definitely better.
I get the following data with the chrono:
V: 930.4
PF: 136
Dv: 13

@tdogg
The label says the diameter is .356. I measured ten. These were all .355
Where did you find the load data? I did not slugged my barrel.

[timmy75]

I use this load for LOS bullets:
130PF from Shadow 2. Super soft shooting load.

LOS 145gr FP copper plated, 3,3gr N320, 27,3mm COL
LOS 145gr RN copper plated, 3,3gr N320, 28,5mm COL

if there is no N320 around, than add ~20% more Lovex. But much better with N320

[Pew-Shadow2-Pew]

@timmy75
If my calculations are correct, you end up at 3.96gr. I used 4.0gr.
Unfortunately the load looks like it is not working out because it keyholes.

I now made a batch with 4.2gr and it runs smooth. Next monday i can check if it stil has the same problem. I got this batch with some discount otherwise i wouldn't have bought hp.

Unfortunately I cant get N320 at the moment. But I can get almost every type of Lovex.

[tdogg]

I get the following data with the chrono:
V: 930.4
PF: 136
Dv: 13

@tdogg
The label says the diameter is .356. I measured ten. These were all .355
Where did you find the load data? I did not slugged my barrel.

I just googled the powder and looked at the reloading guide.  I have to admit I'm not familiar at all with this brand of powder.  https://shootersworldpowder.com/reloading-guide/

Not knowing anything about your bullet, oal, or gun for that matter makes this a futile endeavor.  The closest thing listed is a fmj 140gr and it states maximum is 3.2gr with a velocity of 984 fps.

Cheers,
Toby



Sent from my motorola edge (2022) using Tapatalk

[Andres B]

 Same load data from manufacturers web page https://explosia.cz/app/uploads/2019/07/EXPLOSIA_reloading2019_en_new.pdf
 My loads came out like this, shot from S1, Caldwell chrono.
 140 gn Alsa Pro FMJ RN bullet (made in Czech Republic), 3,6 gn Lovex D032, OAL 29,5 mm  916 fps, 128,4 PF
 145 gn LOS RN (made in Slovenia), 3,3 gn Lovex D032, OAL 28,5, 887 fps, 128 PF
 147 gn Ares (made in Slovakia) painted RN bullets (not the best IMHO) 3,1 gn Lovex D032, 888-ish fps, 129-ish PF. Will not buy them anymore, so who cares.
 D032 should be in the same ballpark with VV N320 tho.
 And I cannot imagine, what causes such different outcome from the same powder. S2 barrel is a smidge longer also- so speed should be more.
 Dunno- maybe your barrel is clogged or something:) Good ole bronze brush scrubbin' and CLP soakin' never hurts.

[noylj]

If it actually keyholes (many confuse an oval hole for keyholing), it is almost always a bullet too small for your barrel’s preference. Try 0.356 and 0.357” bullets. If using plated bullets, be sure they are 0.001” over measured groove diameter—just like lead bullets.
The second cause can be a damaged muzzle where escaping cases come out at one point and mess up bullet flight. The last cause might be a barrel with too slow twist rate, but I’ve never seen this.