Having problems with leading in new pistol

[tomme boy]

OK I had this listed down in the pistol forum but not much going on to help there. So I am moving it up here.




I have been looking to get a new pistol for a while now. I used to have a CZ75B a few years ago. I loved that pistol. Today I was at a local store to see if they had any powder. I walked over to where the pistols were at and seen a polymer pistol that looked like the cz75. I picked it up and looked it over. It felt very good in the hand. It is a little thinner than the cz in the grip. Had a 16 round magazine. It comes apart the same as the cz. Trigger feels ok. It is the same SA/DA trigger. The barrel and the recoil guide rod is hard chrome plated. It should last a very long time.

I had to have it. $315 out the door. It is imported by EAA from Turkey and is the SAR Arms. I won't be able to get out to shoot it for a few days. When I got home, I slugged the barrel and it measured 0.3557" Perfect! I am going to try the Lee 120 TC with 3.7grs of Bullseye. I am going to try the 0.357" sizer first. That should seal the bore up.

Here is a pic of it next to a Browning Hi Power for size.

http://img.photobucket.com/albums/v21/tommeboy/101_0360_zpse7734f75.jpg (http://smg.photobucket.com/user/tommeboy/media/101_0360_zpse7734f75.jpg.html)

http://img.photobucket.com/albums/v21/tommeboy/101_0361_zps59224ad8.jpg (http://smg.photobucket.com/user/tommeboy/media/101_0361_zps59224ad8.jpg.html)

http://img.photobucket.com/albums/v21/tommeboy/101_0358_zps7df55a1c.jpg (http://smg.photobucket.com/user/tommeboy/media/101_0358_zps7df55a1c.jpg.html)


(Second part)

Well I took it out for a very quick run today. I fired two mags through it and it functioned perfect. Shot a little low at 10 yards. Grouped pretty good.

Now the bad. It leaded up the barrel a little on the two mags. It cleaned up fairly quick, but it was leaded. I pulled a couple of rounds apart and they were still sized at 0.357" so the cases are not sizing them down when seating them. My alloy runs about 17 for hardness. I water drop all of my boolits. It is easier for me to water drop them. Does anyone think maybe soften them up a little might help? Or maybe up the powder charge a little because of them being hard? The lube I am using is NRA 50/50. I have other powders to try as well. 231, imr7625, tightgroup, red dot, unique, hs6.

(Third part)

Well I went out today and shot off a little over 100 rounds. I first shot 50 rounds with 3.9 grs. of imr7625. They shot ok. I used mixed brass for this test. It was mainly for function. The boolits were sized 0.358" this time also. I also backed off the crimp a little as the rounds just fall into the chamber. I think I could use a 0.359" if I had to. The round still fit loose in the chamber. It still leaded a little. It is all the way down the bore.

The second test was to check the 3.7 grs. if bullseye again with all WIN cases. These were sized at 0.357" but a little softer lead. I kept 32 rds in a 2.5" circle at 12 yards. This was just resting my hand on the bench. The leading stayed the same. It never got any worse. I ended up shooting 16 rounds of jacketed through it to wipe out the barrel and maybe break any edges. I don't think they will with the hard chrome bore. But it can't hurt.

Anyone have any ideas???????

[MtGun44]

I always use air cooled wwts for 9mm, Lee 356-120-TC at .357 or lately .358. Never had any
leading in many different 9mms. Bore may be very large. Possibly need to smooth up the
barrel with a few hundred jbullets, too.

Bill

[chris in va]

17 is way too hard. Even so my water dropped wheelweights will lead the barrel some. No worries, it doesn't hurt a thing. I can put 300 downrange without problems.

[myg30]

Tom, Congrads on the new pistol. Im no expert but as Bill mentioned you might want to break in the bbl.
I would stay with one lead mix like plain coww's first. Try to use a mix that you can use for all your pistol shooting and make it easy on yourself.
You slugged the bbl and its .3557 so the mic says. Stick with .002 over bore. Don't change the lead mix or size yet.
Now you can vary powder charges from low to mid or max range. See which charges prove the least leading.
Next you can work up load with another powder, start low and work up see if leading gets better or worse.
Try to stay with a powder you use in other pistols, keep it easy on yourself if possible. Trial n error.
If you don't have any luck then change 1 thing only and start over with load work ups.

At the bottom of the page in the Cast bullet notes, I think there was an article on bbl leading and the possible causes depending on where the leading takes place in the bbl. Also, I personally do not shoot FMJ's over a leaded bbl to clean it. There is lots of different reading on the subject. In my mind, it presses the lead into the lands more.
Start with a CLEAN bbl. If a patch on a tight bore brush comes out dirty then the bbl is dirty ! Remove ALL copper and lead before you start!

I hope your able to find the trouble, after all "There is no miracle load" ! Be safe, don't get frustrated and only vary one thing at a time.


Mike

[tomme boy]

I tried the 0.358's and they still leaded. The second test was with a softer alloy. It was about 12 brinell. The bore measures 0.3557" but the chamber seems really big. The cartridge wiggles in the chamber. I am seating these boolits at 1.065" as this is where it just touches the throat. It has a tapered throat about 1/4 inch long.

One thing I am wondering about. With the chamber being loose, does anyone else think that it cause the boolit to start off center and might be shaving the boolit as it starts? Or should I try to jam the boolit in the throat?

How much if any break in will there be with a hard chrome bore?

[detox]

Or should I try to jam the boolit in the throat?


Sounds logical.

[geargnasher]

I tried the 0.358's and they still leaded. The second test was with a softer alloy. It was about 12 brinell. The bore measures 0.3557" but the chamber seems really big. The cartridge wiggles in the chamber. I am seating these boolits at 1.065" as this is where it just touches the throat. It has a tapered throat about 1/4 inch long.

One thing I am wondering about. With the chamber being loose, does anyone else think that it cause the boolit to start off center and might be shaving the boolit as it starts? Or should I try to jam the boolit in the throat?

How much if any break in will there be with a hard chrome bore?

I think you're shaving. Make a pound cast and see what the throat entrance measures, if it even HAS a throat. If it doesn't, that can be fixed. I battled the same thing with a .38 Super with a tight, match chamber and a sharp step at the end of the throat taper. That's right, the end of the throat, where the taper was supposed to blend with the bore/groove. It leaded from end to end. I lapped out the second step and no more leading. Yours is probably shaving at the end of the chamber where the throat begins.

Gear

[RobS]

I have a SAR K2 45 auto (actually have had two) and the chrome bore hasn't been an issue at all with lead boolits. I did work the throat over though as it was very short and tight on both of the K2's that I had. My Springfield XD tactical 45 was similar with a tight throat and the only way I could get it to work with no shaving of the boolit was to either crimp the boolit over the front drive band and crimp it so the boolit would funnel easier into the bore or later on I worked on the throat of that auto too. Figuring out your chamber/throat dimensions will tell you what is going on.

[tomme boy]

Gear, it is tapered. It is quite long for most pistols I have seen. I just loaded up some more with a OAL of 1.10" Any longer and the grease grove is showing. So the front drive band is all the way into the throat now. I know it can go a little larger on the size as it still wiggles a little in the chamber. Not as much as before. It is supposed to be really cold tomorrow but I might still take a ride to the range and just shoot out the window a few mags just to see if they lead.

I'm thinking gas is leaking around the boolit before it seals with the shorter OAL. I must have done something wrong on the measurement for the OAL earlier. Now I can seat them out farther.

[Silverboolit]

Would a heavier boolit, say 140ish grain be a little longer? If it is, it may be pushed a little farther ito the barrel and still be in the case.

What I have done is to take a dowel and push into the end of the barrel with the slide closed, no casing, and make a mark at the end of the barrel. Then , I take a boolit and seat into the barrel as far as it will go, hold it there, take the same dowel and make another mark. This gives a pretty close over all length of the round, measured between the two marks.

[tomme boy]

Well it is still leading. I got it cleaned up. I used a mini magnifying glass to peek into the chamber. The throat is really rough. It looks like tiny little pits all the way around. I am wondering if firelapping will work? I have never done this, so I know nothing about it. Anyone have any boolits with the lapping compound I could get?

[RobS]

Fire lapping could help. I did a friends HiPoint to clean up the bore but most of my firelapping as been on revolvers. All you need is a some 320 grit lapping compound and two pieces of metal to roll the slightly over sized lead bullet in to embed the grit. I use a wheeler set but you can get just the 320 grit which I need to do myself as I'm almost out of the 320. Also Clover from Loctite makes different grit lapping compounds as well and you may find at a machine shop locally that might have some.

I've worked on throats of auto pistols with an 11 degree lap that comes with the revolver forcing cone setup. I just turned down the lap diameter to just fit into the chamber of whatever caliber I'm working with. I've done this on a few different 45 auto's as well as a 40 S&W Lonewolf barrel.

[geargnasher]

I've used lead laps before to good effect, mount the boolit on a cleaning rod and turn with a drill and file to the right taper. Be careful not to scratch the chamber. Putting grit in the throat with a q-tip and inserting a clean, dry lap helps.

Gear