Walther PPQ Polygonial Rifling and the Cure for Leading

[robertbank]

Some here might own a Walther PPQ's and have experienced leading in the pistol's polygonal barrels. Today I went out to the range with 100 rds of GC'd 356402 Lyman bullets cast from WW alloy. After 100 rds the barrel was as clean as a new baby's bottom. There was no powder residue, nothing, just a sparkling barrel. Naked bullets would have started the leading process in the first 1/4" of the barrel. I size my bullets for my 9MM guns .357. I used GC;s made from pop (soda) cans and beer cans. The GC's are made on Pat Marlin dies for PB bullets.

I suspect this would also be the case for Glock barrels but I don't own a Glock so I cannot comment.

I shoot a lot of practice rounds each year and shooting lead bullets is much cheaper than buying Commercial Lead /FMJ or plated bullets.

I am waiting in an Accurate mold for my 10MM GP-100. I am hoping the GC idea will work for that application as well.

Take Care

Bob

[Sasquatch-1]

I have a PPQ-M2. I have had it for a couple of years now. I shoot range scrap lead through it and have never experienced leading. You may be pushing the bullet too fast causing it to drag across the rifling before it catches.

You may also want to check with the Glock shooters. Maybe a couple will chime in.

[ioon44]

I have several Walther PPQ pistols with polygonal barrels and use alloy running around 11BHN with Hi-Tek coating sized .002" to .003" over what the bore slugs, fit is king.

I shoot many thousands of rounds a year in IDPA & USPSA matches without any leading or any other problems.

As for Glock barrels they are not a true polygonal barrel, but I never had a leading problem with shooting Hi-Tek coating sized .002" to .003" over in the Glocks I own.

[robertbank]

Coated bullets are a different kettle of fish. We are using lead bullets sized .357 lubed not coated.

Velocity is 1100 - 1150 using 125 gr lubed lead bullets. I have at least seven othe 9MM guns who experience no leading at that velocity. I don't believe the bullets are skidding. Since the bullets with GC's don;t lead the barrels I am going with that. They are water quenched from the mold. The cartridges run around 1400 fps when shot from my 9MM Carbines.

Take Care

Bob

[fecmech]

Bob--Shot the same bullet in my Khar 9mm at factory velocities with hard lubes. I got minor streak leading that did not accumulate and 25 yd bench groups in the 2-3" range. Bullets sized .357 and I use a Lyman M die for expanding. I'm too lazy to GC pistol boolits!

[robertbank]

Bob--Shot the same bullet in my Khar 9mm at factory velocities with hard lubes. I got minor streak leading that did not accumulate and 25 yd bench groups in the 2-3" range. Bullets sized .357 and I use a Lyman M die for expanding. I'm too lazy to GC pistol boolits!

My 356402 Lyman is a plain base bullet as you know. I bought a Pat Marlin GC maker for plain base bullets. I use pop can aluminum. I use the checks on some of my 38Caliber PB bullets destined for my .357. From reading here I should experience a slight improvement inaccuracy with my PCC's at distance with the GC base. I have been very happy with the results using the GC bulles in my GP-100 as well. The bullets there are sized .358.

Take Care
Bob

[Good Cheer]

Used Lyman #358345 in a polygonal bore in the 80's.
Never had a problem with it.

[FergusonTO35]

I think the gas check helps the rather slippery polygonal rifling grip the boolit better.

[Bigslug]

I have a PPQ-M2. I have had it for a couple of years now. I shoot range scrap lead through it and have never experienced leading. You may be pushing the bullet too fast causing it to drag across the rifling before it catches.

You may also want to check with the Glock shooters. Maybe a couple will chime in.

Chiming in. The stickied "Setting Up for Boolits in a New 9mm" thread at the top of this subforum has my Glock adventures recorded on pages 5 and 6: https://castboolits.gunloads.com/showthread.php?121607-Setting-up-for-boolits-in-a-new-9mm

The short version is I pin gauged and slugged a decent handful of 9mm's and couldn't really see anything internally on the Glocks that made me feel they needed to be treated any differently - learn your gun's internals, size and lube accordingly (.357 and tumble lube working full spectrum for me), and work to avoid the dimensional pitfalls such as bullet seating downsizing your bullets smaller than desired. This is all covered in that thread.

But I've got plain bases running well in both poly and Marksman Glock barrels with no grievances after getting past the initial 9mm learning hurdles.