New 75B. Shoots Great But Ammo Issue?

[Wiley]

 My new 75B arrived last week and I?m quite pleased with it. The trigger is smooth and my eyes have no problem seeing the fiber optic front sight (thanks to CZ Custom). 

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Saturday after a light cleaning I grabbed three part boxes of miscellaneous 9mm ammo and went to the range. First was 45 rounds of ?Independence? 115 Gr. FMJ, then 30 rounds of Aguila 117 Gr. JHP, all of which functioned perfectly. Third was Winchester white box Nato 124 Gr. FMJ but the 8th round didn?t fire because the slide didn?t completely close. The cartridge appeared to not completely seat. I pulled that round out, reinserted the magazine and the slide fed the next round. I shot that one but again the slide failed to completely close. Took the slide off and barrel out but couldn?t see anything amiss so I tried again with the other two brands. Same problem now with both of them so at that point I put it away.
 Cleaning the barrel back at home I saw the likely culprit fall out. It looks to be a sliver from the end of a brass casing, or maybe off one of the bullets, but it appears more brass than copper. Anyway I believe I found my problem but I don?t understand the cause? Hopefully just a fluke because I?ve never had a problem with this Winchester ammo in any other pistol. I?ve heard of some guns having issues with Aguila so next time I?ll not use it and see what happens.
 The pistol itself is wonderful to shoot in every way. It feels and points naturally, the recoil is well absorbed by the weight and low bore axis, and every shot went in the black!

 


    Here?s a pic of the shaving.

[1SOW]

First thing I would do is a test for bullet contact with the rifling and or case sizing issues.
Remove the bbl, hold it chamber up and drop in 4 or 5 of the JHP cartridges one at a time.  They should fall in with an audible clink and seat on the case mouth.  After they "drop" in,  push on the case head to make sure they are firmly seated;  then try to turn them by hand .  If the bullet sidewall is contacting the cone or rifling it'll be too tight to turn by hand.
Repeat with the other bullets.
CZ has a short chamber and with conical nose bullets, FP or HP noses sometimes the OALs are too long for the chamber.  Cases not sized properly might also cause failures to feed.

Hope this makes sense.   

[Wiley]

Thanks, 1Sow. I just did this again checking 6 each of the three different brands. All fell with the same "clunk" to the same place and they all turn freely even while pressing them in hard. I can see no reason why it would do this again with these cartridges? I'm going to the range again tomorrow and I'll take the remaining three boxes, and a couple more boxes of white box NATO, and see if this happens again. Hopefully it was a fluke round.

[Hognutz]

Wiley, you old coyote you. I found you over here.. Been talkin' to you on the Sig forum..(Hawgster)

Glad to see that you got to shoot the new 75. I'm sure that is was a fluke and would bet that it was an ammo issue rather that a gun issue.
Keep us posted..

Nice looking pistol, my friend...

Mike

[Wiley]

Wiley, you old coyote you. I found you over here.. Been talkin' to you on the Sig forum..(Hawgster)

Glad to see that you to shoot the new 75. I'm sure that is was a fluke and would bet that it was an ammo issue rather that a gun issue.
Keep us posted..

Nice looking pistol, my friend...

Mike

LOL this is a good place to be while you're waiting on your new 75BD to arrive, Mike.   And thanks for the complement!

 This morning I took along a P7 in case the 75 "acted up" again but I'm pleased to say the 75 preformed faultlessly. I used up the remaining 3 part boxes, another box of Winchester NATO, and a 100 round box of white box w/o a hitch. I really like the fiber optic front sight and it?s spot on accurate. After I let the Kimber person beside me shoot a magazine through it (15 of 16 in the black with a bullseye) he handed it back smiling saying ?someone?s done something to that trigger, I like it?. I do too, this one?s a keeper!

[Hognutz]

Glad to hear that your range session went witout a hitch.. I'm sure that failure to go into battery was just one of those things that happen when you don't want/expect them to, with range ammo.

I am so stoked over my purchase. I am not sure when I will get it. As of yesterday, he didn't have one (75 BD) on the premises. They are coming this week or next. I am so glad to hear that you like the fiber optic sight. I have never had one on a pistol, but know that my eyes will be delighted..I sure hope so, anyway. I went with the trigger job, as well as the full length rubber grips.. Did I tell you I am stoked!!

Well, continued good luck with your new 75B, and keep me in the loop on the range sessions.

Mike

[Wiley]

....I am so glad to hear that you like the fiber optic sight. I have never had one on a pistol, but know that my eyes will be delighted..I sure hope so, anyway. I went with the trigger job, as well as the full length rubber grips.. Did I tell you I am stoked!!

Did you get front only or a new rear as well? To be honest after I made the decision to get the front only F/O sight I was a little worried that I'd like it with the stock rear since I'd never seen stock sights. Now that I have it I really like this combo though. The rear is a light colored two dot so the red optic front really contrasts nicely. I may order a set of those nice rubber grips for mine. You made a good decision letting them do a trigger job.
 

[1SOW]

Wiley, I've never experienced or read of a shaving like you showed.

I'm glad it ran 100% this last time.  Keep shooting it to break it in.  It'll get better as build rd count.

[Hognutz]

I went with the front sight only. I really have no clue what the rear sight looks like, so I am really in the same boat that you were in. Again, I am glad to hear your satisfied with the sights. To be totally honest, I have never even held a CZ of any kind. I bought this pistol on 100% heresay. And it was all good. Talk about a leap of faith!!

It has been a long time since I have been this excited about a new gun..Crazy stuff..

I have a brand new S&W M&P Shield downstairs that I have not had time to shoot yet. I waited 5 1/2 months to get it (got it last week) and I am more stoked about the 75..The anticipation is all part of the deal..Fun game to play..Expensive, but fun..

[Wiley]

I went with the front sight only. I really have no clue what the rear sight looks like, so I am really in the same boat that you were in. ....

I decided to start a new topic showing what the sights look like.