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GENERAL => CZ Gunsmithing => Topic started by: Cujo99 on November 27, 2019, 10:02:17 AM

Title: Errant first shot_ P09_9mm
Post by: Cujo99 on November 27, 2019, 10:02:17 AM
I have a somewhat new to me CZ P09 in 9mm, late 2015 build, fairly stock except 18# hammer spring, lighter trigger return spring, light firing pin block spring. (only things polished are the FPB, trigger pin, & hammer pin)

This thing is a Jeckel & Hyde deal-- thing loads & ejects great, good even smooth trigger pull, seems to have a decant barrel to slide lock up.

Problem is: first shot goes about 4" high & 2" left (darn near always), then other 9 following shots  go into well under 2" group at 25 yards (rested on sand bag).

Next day it repeats,  first shot goes about 4" (+/-) high & 2" (+/-) left (darn near always), then next 9 following shots  go into well under 2" group at 25 yards (rested).

Barrel lock-up looks good (best I can see & feel anyhow), I have tried using slide lock & slingshot first round chambering with no apparent difference in the wild first shot.

----(all above  test shooting done single action)---


I have been shooting handguns for well over 50 years & have seen a 'number' of gun accuracy  problems in that time but all have been visible & fixable. I seem to be missing something on this one as everything looks OK.

As a controller (to sort of rule ME out) I have shot my P07 (9mm) & P07 .40 first off the same sand bag (multiple times) with all rounds going into a decent group then quickly followed that up with my P09 & still show the same first shot high left. 

I have a coupel of shooting partners & have had them shoot the gun but they do not shoot small enough groups at 25 yards to determine anything.

I sort of points to a first round barrel lock-up issue but I sure can't see, feel, or measure it.

I guess my basic question is: has anyone seen a similar errant first shot with the CZ P09 before & if so any idea what was causing it?

Thanks_



Title: Re: Errant first shot_ P09_9mm
Post by: M1A4ME on November 27, 2019, 03:09:18 PM
Nope.  Neither of mine do that.

Just for grins/giggles have you tried.
1.  loading a 5 round magazine to see if #1 does the same thing as in a 10 round magazine and 2 through 5 do the same thing as the 2 through 10 in a ten round magazine?

2.  Do some dry firing first, before you shoot for groups?

3.  Chamber that first round, then manually eject it and see if you get a 1 off 8 in the same group pattern?

4.  When unloaded, but with slide forward, can you move the barrel around in the slide up front or push the chamber end around in the slide at the ejection port?
Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 27, 2019, 03:33:17 PM
1.  loading a 5 round magazine to see if #1 does the same thing as in a 10 round magazine and 2 through 5 do the same thing as the 2 through 10 in a ten round magazine?-- I have tried 3 rounds, fist one goes high left & other 2 go in target center close to each other.

2.  Do some dry firing first, before you shoot for groups?--I haven't dry fired first but have used a different gun first then switched to this gun, made no difference  

3.  Chamber that first round, then manually eject it and see if you get a 1 off 8 in the same group pattern?-- I haven't tried this (I will try it) but I have manually ejected the first round a few times to look for bullet damage (there was none)

4.  When unloaded, but with slide forward, can you move the barrel around in the slide up front or push the chamber end around in the slide at the ejection port?-- No, barrel locks up tight & looks to be the same height in the slide as after firing a few rounds.
Title: Re: Errant first shot_ P09_9mm
Post by: Grendel on November 27, 2019, 04:30:38 PM
I have to say: 'It's probably you'.

Anticipating recoil.
Title: Re: Errant first shot_ P09_9mm
Post by: GeneticallySwiss on November 27, 2019, 04:32:56 PM
So these first, errant shots are always cold bore shots?


GS
Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 27, 2019, 05:16:09 PM


Quote
So these first, errant shots are always cold bore shots?

Yes, always cold bore, at least as far as I know.  (good point)

I guess I better put the first shot & following shots over my chronograph to see if the first shot stands out as far as velocity is concerned.

I usually don't clean my guns until I store but will sometimes run a patch/jag/brush  through the bore at 500 rounds or so. This gun only has about 700 rounds through it (since I got it), I cleaned it after buying (previous owner only put 20 rounds through it). I did a quick bore clean  at around 500 rounds. Barrel looked good (no lead or copper at last cleaning).

One thing that I forgot to mention above is: this P 09 likes 115 bullets better than 124 or 147. I usually shoot 147 but had to switch to 115 in this gun to get groups under 2" at 25 yards (except first shot). But this is just a quick observation as I didn't do any load work-ups for 147 in this gun, just shot what I have worked up for my other CZ's.   

Title: Re: Errant first shot_ P09_9mm
Post by: M1A4ME on November 27, 2019, 07:52:32 PM
The only other thing I can offer is a change in grip between the first shot and the rest.  If you change they position/grip, grip force, move your finger position on the trigger, it can affect POI.  I've seen it the most with a rifle but it can do it with a pistol, too.

I chuckled when I saw your comment about 115 grain shooting so good.

I haven't found a good shooting 147 grain load yet for my CZ 9MM pistols.

On the other hand, the 115's are awesome.

I've not really messed with 124's in a 9.  Mostly used them in .357 SIG.  I'm about to experiment with 124's though as a certain M&P I bought awhile back seems to prefer that Winchester 124 grain FMJ NATO load (for smaller groups) over everything else.  The same ammo that starts to make the M&P look like it knows what it's doing doesn't do nearly as well in my P01 (haven't shot any in the P09 or CZ85 yet.)
Title: Re: Errant first shot_ P09_9mm
Post by: DOC 1500 on November 27, 2019, 11:10:19 PM


2.  Do some dry firing first, before you shoot for groups?--I haven't dry fired first but have used a different gun first then switched to this gun, made no difference  

In this statement are you saying that with a different gun you put them 4 inches high and 2 in left also ?
If that is the case then it's you not to gun.
Title: Re: Errant first shot_ P09_9mm
Post by: Joe L on November 28, 2019, 06:12:14 AM
With gun unloaded and magazine out, hold the front end of the slide in a vise, gun level and horizontal, normal shooting orientation.  Insert a 1/4" aluminum or brass rod in to the barrel to use as a lever and try to wiggle the barrel up and down as felt at the chamber end.  You can put a dial indicator on the chamber end of the barrel to measure any movement.  I've seen up to 0.008" movement at the chamber end produce the same first shot results.  (Note--I am NOT a gunsmith!) 

Compare measurement with this gun to one that shoots well.  Any significant difference, try a different front block in the frame is all I know to suggest. 

If you can't change the front block, use the heaviest recoil spring that will still cycle with your ammo and sling shot the slide very carefully--do not follow or ride the slide at all, release it from the full recoil position when chambering the first round, and do so with the gun level, not aimed up. 

Hope you get it fixed or figured out.  The only CZ I have that is a little loose is a P-10C.  Good enough for a service gun still, but not good enough for a bullseye match.  All the rest are bullseye match quality lock ups:  P-10F, P-10S, P-07, two P-09's.

Joe
Title: Re: Errant first shot_ P09_9mm
Post by: rdcinhou on November 28, 2019, 06:19:32 AM
I'm curious...are you taking your first shot DA and then SA thereafter?

Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 28, 2019, 08:12:40 AM

Quote
2.  Do some dry firing first, before you shoot for groups?--I haven't dry fired first but have used a different gun first then switched to this gun, made no difference


Quote
In this statement are you saying that with a different gun you put them 4 inches high and 2 in left also ?
If that is the case then it's you not to gun.

No, in that statement  I am saying that (IF)  I shoot a different  gun  first  (my P07 9mm or my P07 .40) all the bullets from those guns go POI to POA (or within 2" or so at 25 yards) , with no decisive first shot variance.

 On all my other CZ guns, Shadow, coupel of  CZ 75's, SP 01 couple of P 07's none have that first shot high left. Only my P 09 shows the high left first shot. 

I get the same high left first shot shooting off-hand as shooting off a solid sand bag only the sand bag shots are easier to define as the main group is smaller & less ragged.

Even the factory target that came with the P 09 gun shows one shot high left but not neatly as high left as I am getting, plus I can't say if the high left on the factory target was 1st shot.

I am a long time pistol shooter so can usually call my shots as I track my sights when the shot breaks.

If I break a bad shot (it happens) I can usually call where that shot is going to be on the target before I use my glass  or walk down to look at the target.





Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 28, 2019, 08:16:39 AM
Quote
  I'm curious...are you taking your first shot DA and then SA thereafter?

No, as I mentioned in my first post all shots are single action.
Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 28, 2019, 08:35:40 AM
With gun unloaded and magazine out, hold the front end of the slide in a vise, gun level and horizontal, normal shooting orientation.  Insert a 1/4" aluminum or brass rod in to the barrel to use as a lever and try to wiggle the barrel up and down as felt at the chamber end.  You can put a dial indicator on the chamber end of the barrel to measure any movement.  I've seen up to 0.008" movement at the chamber end produce the same first shot results.  (Note--I am NOT a gunsmith!) 

Compare measurement with this gun to one that shoots well.  Any significant difference, try a different front block in the frame is all I know to suggest. 

If you can't change the front block, use the heaviest recoil spring that will still cycle with your ammo and sling shot the slide very carefully--do not follow or ride the slide at all, release it from the full recoil position when chambering the first round, and do so with the gun level, not aimed up. 

Hope you get it fixed or figured out.  The only CZ I have that is a little loose is a P-10C.  Good enough for a service gun still, but not good enough for a bullseye match.  All the rest are bullseye match quality lock ups:  P-10F, P-10S, P-07, two P-09's.

Good thought, I have used a fiberglass rod (round tent stake) to basically do what you suggested when I was first looking for the problem but that rod had a lot of compliancy so I was just basically looking for a loose lock-up.   (I couldn't really find any loose lock up but I was only looking for major movement not a few thousandths of movement).

I have a long brass .38 range rod (I will have to see if it will fit the 9mm bore), I do have a short brass 9mm range rod but it is way too short to put a proper bending mode on the barrel.

I guess I will have to make a longer brass 9mm range rod (I should have one anyhow so I will do that after this weekend when  all the family leaves me alone)

I have tried different ways of chambering the first round with slingshot, slide release, gentle release (follow) with holding the gun level (shooting orientation)  & also holding muzzle-up with no discernable difference in first shot out-of-group.

I made up some dummy rounds with brand new brass yesterday that I am going to use to  hand chamber a round then use my depth mike to compare barrel lock-up height in the slide to barrel height after firing a live round  (I have looked at this many times & it looks the same but as of yet I haven't precision measured it).
Title: Re: Errant first shot_ P09_9mm
Post by: rdcinhou on November 28, 2019, 11:23:05 AM
Quote
  I'm curious...are you taking your first shot DA and then SA thereafter?

No, as I mentioned in my first post all shots are single action.

My apologies for not picking up on that.

Another thought...when you "rack" your 1st round do you let the recoil spring "slingshot" the round into battery or do you push the slide forward by hand?

Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 28, 2019, 11:44:57 AM

Quote
 
Another thought...when you "rack" your 1st round do you let the recoil spring "slingshot" the round into battery or do you push the slide forward by hand?

Yes, yes, & yes-- I have tried all ways-- easy, slingshot, slide release, gun level, gun pointed up, gun pointed down with no change in first round impact. 
Title: Re: Errant first shot_ P09_9mm
Post by: M1A4ME on November 28, 2019, 12:00:38 PM
Have you shot it left handed (weak hand) or with both hands?

Have you tried shooting that first shot, putting the pistol down on the bench, picking it up, firing shot #2, laying down, picking it up for shot #3 and continuing that for the remaining 7 shots?

Going back to that change in grip/trigger finger placement on that pistol.
Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 28, 2019, 12:18:48 PM
Have you shot it left handed (weak hand) or with both hands?-- Both hands, strong hand make no difference.

Have you tried shooting that first shot, putting the pistol down on the bench, picking it up, firing shot #2, laying down, picking it up for shot #3 and continuing that for the remaining 7 shots?-- Not exactly but have shot first shot, laid gun down to go look at target, then picked gun back up & continued through remainder of magazine.

Going back to that change in grip/trigger finger placement on that pistol.-- No, I change nothing, I use the same grip & finger placement on all my CZ's, this P09 is the only one with the errant first round, all other CZ's (many) don't show any first round issues.

Title: Re: Errant first shot_ P09_9mm
Post by: SI VIS PACEM PARRABELLUM on November 28, 2019, 12:48:04 PM
These guns are all service grade but the great thing about CZ's is they tend have fantastic accuracy by design sometimes much better than guns costing 2-3 times as much but that doesn't mean EVERY gun they make will be a tack driver and there are bound to be some from time to time that just are not as accurate as others.
In the grand scheme of things accuracy even off by that much @25 yds. is still acceptable by service standards.
All that said there is certainly the possibility of a slight lock-up issue or even a temp related issue. I'd shoot the first round and let the gun completely cool back to ambient temperature then fire follow up rounds in the same manner and see how it behaves. If every round fired from a cool barrel lands off from the intended poa/poi then I'd think the barrel is the problem and it's maybe temperature related. How does the gun perform at more normal defensive ranges?
Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 28, 2019, 01:50:41 PM
These guns are all service grade but the great thing about CZ's is they tend have fantastic accuracy by design sometimes much better than guns costing 2-3 times as much but that doesn't mean EVERY gun they make will be a tack driver and there are bound to be some from time to time that just are not as accurate as others.
In the grand scheme of things accuracy even off by that much @25 yds. is still acceptable by service standards.
All that said there is certainly the possibility of a slight lock-up issue or even a temp related issue. I'd shoot the first round and let the gun completely cool back to ambient temperature then fire follow up rounds in the same manner and see how it behaves. If every round fired from a cool barrel lands off from the intended poa/poi then I'd think the barrel is the problem and it's maybe temperature related. How does the gun perform at more normal defensive ranges?


That is within my normal defensive range practice distance & that kind of first shot accuracy in not acceptable as it precludes a  first shot headshot from safe cover. My other CZ guns don't do this.

I do keep thinking about the barrel being the possible problem. I am going to see if the P09 barrel will fit my P07 with decent lock-up, if so that should point to, or eliminate the barrel.
Title: Re: Errant first shot_ P09_9mm
Post by: eastman on November 28, 2019, 04:22:07 PM
any chance of borrowing a P-09 upper locally and trying that on your frame?
Title: Re: Errant first shot_ P09_9mm
Post by: SI VIS PACEM PARRABELLUM on November 28, 2019, 06:05:11 PM
These guns are all service grade but the great thing about CZ's is they tend have fantastic accuracy by design sometimes much better than guns costing 2-3 times as much but that doesn't mean EVERY gun they make will be a tack driver and there are bound to be some from time to time that just are not as accurate as others.
In the grand scheme of things accuracy even off by that much @25 yds. is still acceptable by service standards.
All that said there is certainly the possibility of a slight lock-up issue or even a temp related issue. I'd shoot the first round and let the gun completely cool back to ambient temperature then fire follow up rounds in the same manner and see how it behaves. If every round fired from a cool barrel lands off from the intended poa/poi then I'd think the barrel is the problem and it's maybe temperature related. How does the gun perform at more normal defensive ranges?


That is within my normal defensive range practice distance & that kind of first shot accuracy in not acceptable as it precludes a  first shot headshot from safe cover. My other CZ guns don't do this.

I do keep thinking about the barrel being the possible problem. I am going to see if the P09 barrel will fit my P07 with decent lock-up, if so that should point to, or eliminate the barrel.

Well by military or law enforcement standards that's good accuracy at 25 yds since they won't be teaching head shots at that distance but I get it that you want consistency from the gun. I would want it better as well. I replaced a Sig M11 A1 barrel recently because it would fail to eject about once every 400 rounds. New barrel with over 2000 rounds and no failures. I like things that run 100% too.
Title: Re: Errant first shot_ P09_9mm
Post by: Walt Sherrill on November 28, 2019, 09:10:51 PM
Cujo99:  I didn't see it mentioned -- maybe I just read past it  -- but are you starting from hammer down or from cocked & locked? 

The DA/SA transition can be a killer with some guns, and while you seem to have taken steps to move things along, it may take something very simple to make that first shot hit closer to where you want it to hit.   

That  something may be little more than a lighter hammer spring (but one that still ignites the primers.)   I infer that you aren't having this type of problem with others guns,  It MAY be the gun and not the shooter -- particularly if the trigger on your P-09 is different than most of your other guns.

If you're doing a DA first shot, you may be having to position your trigger finger on the trigger in a way that is great for the following shots but not for the first shot. (CZ typically have LONG DA trigger pulls). 

If you're doing DA first shots, try shooting only FIRST shots and see how you do -- i.e., decock before each shot.  And keep doing it until you find your shots hitting where you want.   Then switch back to DA/SA and see if you've lost that wandering first whot.
Title: Re: Errant first shot_ P09_9mm
Post by: Steve Menegon on November 29, 2019, 01:02:32 AM
Are the primer strikes on the first shot the same as the follow up shots?8
Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 30, 2019, 09:32:09 AM
Cujo99:  I didn't see it mentioned -- maybe I just read past it  -- but are you starting from hammer down or from cocked & locked? 

You read past it twice as it was stated in 2 different posts.
Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 30, 2019, 09:45:13 AM
Are the primer strikes on the first shot the same as the follow up shots?8

Best I can tell they all look the same, I even put some red sharpie on the 1st round so I could tell it from the others. They all have nice deep firing pin indents.

All shots in the magazine passed my go-to ignition integrity  test (I do this on any gun that I have worked on &  intend to carry).
That is to load a full  magazine with CCI 450 primed rounds. Those 450 primers are thick & hard so it takes a real  good strong firing pin hit to ignite them.
 My first test magazine of CCI 450  primed rounds all fired double action.
 My second  test magazine of CCI 450  primed rounds all fired single action. (this is a very difficult test to pass in double action with a lighter hammer spring in a hammer fired gun)

Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on November 30, 2019, 10:02:13 AM
I think I am making some progress (hopefully)___

Yesterday morning I took my digital caliper out to my range then measured slide to barrel hood depth after a manual slide drop then after first fired round. I got some discrepancy in the measurements with manual dropped slide showing .005"-.006" difference. (caliper isn't the best tool for this measurement though)

So with a little more investigation it looked like the slide face where the rear of the round slides up was fairly rough. So I lightly sanded then polished that slide face (not mirror as I didn't want to remove much metal) just tidied up the rough surface a bit).

My grandson was visiting (he loves to shoot) & I have a bunch of old NATO 9mm (real strong stuff) so I let him shoot about 350 rounds of that hot stuff (he loves it, I hate it myself).

This morning I shot one magazine of rounds off a sand bag & they all seemed to go into  the same group (sort of as it was pretty ragged group but just under 2" @25 yards. Unfortunately I don't know where the first shot went in the group but it definitely wasn't way high left.

This was just a sample of one magazine so time will tell but it sort of looks promising anyhow. 

 

Title: Re: Errant first shot_ P09_9mm
Post by: Walt Sherrill on November 30, 2019, 02:27:56 PM
Quote from: Cujo99
You read past it twice as it was stated in 2 different posts.

My apologies.   (There was almost 50 posts in this discussion, and I was late to the game, and obviously missed your comment in the first post -- and the restatement later.)  I kept looking for other, meatier comments.

I've experienced a pretty consistent difference in points of impact between a manually chambered first shot and the action-chambered following rounds with a number of different guns, but generally attributed at least some (maybe most) of the observed differences to the shooter (me) and my inability to always master the DA/SA transition.  I've never experienced that with SA starts, so probably wasn't reading as closely as I should have read.

You've apparently found (and may have corrected, if only by shooting more potent NATO ammo, and bit of judicious sanding) a subtle imperfection in the action (slide/barrel fit maybe in the breech face) made obvious when manually chambering the first round.  It seems that the difference in force by the closing slide wasdifferent enough to affect lockup.   It may be that your sanding and the hotter NATO rounds helped smooth up the imperfection(s).
Title: Re: Errant first shot_ P09_9mm
Post by: DOC 1500 on December 01, 2019, 12:40:43 PM
I think I am making some progress (hopefully)___

So with a little more investigation it looked like the slide face where the rear of the round slides up was fairly rough. So I lightly sanded then polished that slide face (not mirror as I didn't want to remove much metal) just tidied up the rough surface a bit).

Correct me if I'm wrong, but I believe you're talking about the bottom side of the firing pin Channel that rubs on the next round in the magazine.
That area should always be stoned and Polished to a mirror finish. If not done just causes a lot of resistance to the slide, and in this case enough resistance that the slide does not lock up properly.
Title: Re: Errant first shot_ P09_9mm
Post by: GeneticallySwiss on December 01, 2019, 03:48:51 PM
I think I am making some progress (hopefully)___

Yesterday morning I took my digital caliper out to my range then measured slide to barrel hood depth after a manual slide drop then after first fired round. I got some discrepancy in the measurements with manual dropped slide showing .005"-.006" difference. (caliper isn't the best tool for this measurement though)

So with a little more investigation it looked like the slide face where the rear of the round slides up was fairly rough. So I lightly sanded then polished that slide face (not mirror as I didn't want to remove much metal) just tidied up the rough surface a bit).

My grandson was visiting (he loves to shoot) & I have a bunch of old NATO 9mm (real strong stuff) so I let him shoot about 350 rounds of that hot stuff (he loves it, I hate it myself).

This morning I shot one magazine of rounds off a sand bag & they all seemed to go into  the same group (sort of as it was pretty ragged group but just under 2" @25 yards. Unfortunately I don't know where the first shot went in the group but it definitely wasn't way high left.

This was just a sample of one magazine so time will tell but it sort of looks promising anyhow.


Cujo,

While I’m happy you are finding improvements, it does seem curious to me why such a “fix”, as described, would have cured an anomaly that occurred only on your first round fired.

So it’s always the first round?  If this is so let’s think about this.  What is different about anyones first shot?

This assumes there has been no changes to the firearm, ammunition or significant change in shooting position/stance from first shot to follow on shots.

Weapon

- Cold bore (previously discussed)
- Chambering procedure is vastly different than follow on shots

Shooter

- First shot CAN be a flyer (potential, and slight flinch anticipating recoil), I have experienced this, then I settle in
- shooting position (again, getting settled in)
- Some external influence

Other than the above, I got nothing.  Good luck.


GS
Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on December 01, 2019, 04:23:16 PM
Quote
- Chambering procedure is vastly different than follow on shots

I don't shoot on Sunday's so nothing to report today.

It seems to be pointing to  - Chambering procedure is vastly different than follow on shots  but this hasn't been confirmed yet. Will do another test string tomorrow if weather holds.

I have been shooting for well over 50 years so  know full well what a flinch feels like & what it can do to a shot, but after all these years I have learned to  track my sights so know where my sight is at on the target at shot break.  I can almost always call a miss or out of group shot before even looking at the target.

I am getting almost the exact same out-of-group on first shot shooting off-hand as I do  when gun is sand bagged down tight (this alone points to gun not shooter).

I have also shot my P07 9mm & P07 .40 prior to shooting this P09 & I get no first shot flier with either of those so again this points away from shooter involvement.

I shoot every day except Sunday's (weather permitting) so it shouldn't take long to see if the breach face polishing helped the problem.

 

     
Title: Re: Errant first shot_ P09_9mm
Post by: Cujo99 on December 01, 2019, 04:35:46 PM
Quote
Correct me if I'm wrong, but I believe you're talking about the bottom side of the firing pin Channel that rubs on the next round in the magazine.
That area should always be stoned and Polished to a mirror finish. If not done just causes a lot of resistance to the slide, and in this case enough resistance that the slide does not lock up properly.

I was referring to the breech face (should have said so)  but I did also lightly break the sharp edge on the front & rear of that bar that runs along the bottom side of the firing pin channel  as it was leaving a slight line on the next round in the magazine.  I did the rear corner also to allow a smoother hammer cock during recoil (I usually do this on all my CZ's) I just hadn't got around to doing this one yet.

We'll see what happens when I get out on my range tomorrow as I would like to confirm improvement.

I have other shooting commitments that come first so those have priority.