Polygonal Rifling In Pistols
- Thread starter Glenfilthie
- Start date
I witnessed a Glock barrel so badly fouled with lead that it was starting to peel away from the polygonal "grooves" in thin ribbons. The owner thought there was something wrong with the barrel steel. I asked him when the last time he had cleaned it was and he just gave me a blank stare as if to say "what's cleaning". Hopefully he discovered what it was before the kaboom.
Hard cast bullets are not always the answer. The .45acp is a low pressure cartridge and as such really doesm't need a hard cast bullet. Most leading is caused by gas cutting due to under sized bullets, to hard a lube or skidding when lead bullets are driven to fast for the caliber. Too soft or to hard and you can get leading.
Take Care
Ok, so I shot 10 rounds of 230gr RN, BRNL of 14.5 sized to .453 loaded with 5.3gr 231 out of my HK45. I stopped after 10 and striped him down to check for leading and it was quite bad for the first 1" in the barrel and then disappeared abruptly. Leading was only evident on about 1/2 of the diameter of the barrel though. It was bad enough that I didn't want to chance shooting any more. Any suggestions? Charge too high? Harder or softer lead needed? Bullet sizing incorrect? Cycling was strong and so was brass ejection. Should I be focusing on my charge/powder selection or should I be looking for harder/softer lead? I could drop my charge by .3grs 231 to 5.0grs but I wouldn't want to go any lower than that as cycling may be an issue.
I use lead bullets almost exclusively in my Glocks. When I return home from a shoot with any gun, I squirt some Wipeout or G96 in the barrel and them give it a couple of passes with a stainless steel brush. This wipes out the lead fouling if any.
I have not noticed that the Glocks have picked any more lead than the other makes, but they get cleaned after every shoot and there is no problem using cast lead bullets in them.
if you are lazy, shoot your last target with jacketed ammo. That should vaporize the lead deposits, if any.
I have not noticed that the Glocks have picked any more lead than the other makes, but they get cleaned after every shoot and there is no problem using cast lead bullets in them.
if you are lazy, shoot your last target with jacketed ammo. That should vaporize the lead deposits, if any.
Your load is ok. Are you casting your own bullets, if so are you using a hard or soft lube? The .45acp is not a high pressure cartridge so bullets cast from wheelweights with a Brintnell rating of around 8 10 should be hard enough. You might want to try sizing the bullets .452.
Your load should be generationg around 840 FPS.
To clean the lead out wrap some strands of 100% copper chor boy around a cleaning brush. The lead will be out in a few strokes.
Take Care
Bob
Except for Glock.
And Ruger, there wouldn't be enough room, left.
No, unfortunately I don't cast my own but I do have a local source. Not sure what sizing dies he has available or the lube he uses. Looks like more experimenting is needed because there is no way I would continue shooting with my barrel looking like that after only 10 rounds. I'm not saying that it was unsafe and that I couldn't have fired another 90 or 200 rounds without problems....it's just was a surprise for me to see that amount of leading that quickly. That being said my experience with lead is very limited as I have been reloading plated stuff in my semi autos for many years now. One thing I do know is that in my Wilson or Sig P220 there is no leading so that speaks volumes to me about shooting lead in polygonal barrels. There is some trial and error to it.....
Cocked&Locked
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sounds like the bullets are undersize (or over taper crimped) and too hard to boot. The biggest problem with purchasing cast bullets these days is that they are too damn hard. Unless your running them at full out magnum speeds, softer will usually shoot more accurate and with less leading. You only need hard ones for auto's that really slam the bullet off the chamber roof on loading like 1911's. Commercial cast bullets made the rifling in my 625 revolver disappear in 50 rounds (and what a pig that was to clean out). I found a caster who will do a soft alloy for me, and wow, no leading at all and better accuracy too boot.
If your leading ahead of the chamber, possibly a heavier load might kick the hard bullet up in size at the base and seal it up better. Or it may make it worse, you need to experiment. Try different powders too, some smoke much more with the lube off cast bullets, some hardly at all.
If your leading ahead of the chamber, possibly a heavier load might kick the hard bullet up in size at the base and seal it up better. Or it may make it worse, you need to experiment. Try different powders too, some smoke much more with the lube off cast bullets, some hardly at all.
Cocked&Locked aside from the handgun bullets, in the main, being to hard most commercial casr bullets are bevel based, How they ar expected to bump up enough to provide additional sealing eludes me but I could be wrong. Then again I am not a deciples of the effects of obuturation either. The need for haerdness in a bullet is driven by the pressure range the cartridge lives in, and to a lessor extent the velocity the bullet it is driven. For most common handgun cartridges there is little need for hard cast bullets as you know. Using hard cast bullets with hard lube in a low pressure round like .38spl or .45acp is a recipe for leading in most barrels due to gas cutting. Undersized bullets for the barrel will lead up a barrel very quickly nno matter their hardness.
Take Care
Bob
Take Care
Bob
I'm thinking that is what I have.....gas cutting. The leading was only evident in 1/2 the diameter of the barrel...and only about 1" in length in the first 1-2" of the barrel ahead of the chamber. I might try some softer lead and see what happens.
For those of us who use store-bought cast bullets, one possible fix to decrease leading is to tumble lube them in liquid Alox (Dralox from Dragon Bullet Lube is the same thing at a lower cost than the Lee product) to supplement the hard lube found on most commercial bullets. Put a batch of bullets in a suitable container, add a very small amount of Alox, and shake the container around until the lube is evenly distributed. Spread the bullets out on wax paper and allow to dry for 24 hours.
The only downside is that the bullets will be a bit sticky to the touch.
The only downside is that the bullets will be a bit sticky to the touch.
Your experience is pretty common...don't ask. If you haven't done so have a 'smith cut your forcing cone from what likely is 5 degrees to 11 if you are shooting revolver. Too, if you are using a revolver make sure your cylinder throats are .358 for the .38spl/.357mag and .452 for the .45acp. If they are less than those diameters you are going to get gas cutting and lilely aren't getting the accuracy your handgun is capable of.
If you are experiencing leading in your pistol you might try slower or faster powders. Some say you can reduce the gas cutting by going to a slower powder. Others say go to a faster powder. Does the words witch craft come to mind. I suspect much depends on the gun. My Norinco 1911's with Dlask barrels don't lead in the first 1/2" since I started casting air cooled bullets. My .40 cal Tanfoglio with it's polygonial rifling has never shown any leading...ever using soft lubes and hard cast bullets.
At one time I sized my 9mm bullets .356. Not anymore! I found sizing them .357 eliminated leading completely provided the bullets were hardened by water quenching. For me soft bullets in the 9mm can be a recipe for leading in some guns....mine in particular.
tjhaile idea to use liquid alox certainly can't hurt.
Take Care
Bob
If you are experiencing leading in your pistol you might try slower or faster powders. Some say you can reduce the gas cutting by going to a slower powder. Others say go to a faster powder. Does the words witch craft come to mind. I suspect much depends on the gun. My Norinco 1911's with Dlask barrels don't lead in the first 1/2" since I started casting air cooled bullets. My .40 cal Tanfoglio with it's polygonial rifling has never shown any leading...ever using soft lubes and hard cast bullets.
At one time I sized my 9mm bullets .356. Not anymore! I found sizing them .357 eliminated leading completely provided the bullets were hardened by water quenching. For me soft bullets in the 9mm can be a recipe for leading in some guns....mine in particular.
tjhaile idea to use liquid alox certainly can't hurt.
Take Care
Bob
