Velocity of 9mm lead bullets

[Hi-Power Jack]

I just bought 5,000 115 gr lead bullets from

Moyers in Pennsylvania, loaded a few to

1110 - 1140 fps with about 5 gr of WW231

(old powder from 15 years ago), and it

seems to run fine loaded out to 1.10" in my

Browning Hi-Power (stock), but wondering

If I shoot 5,000 of these, will this lead my

barrel badly?

Should I back off on the velocity a little, and

practice with 1,000 fps and then shoot 1,100

fps in matches to make Minor?

Can I go higher, and run it to 1,200 fps?

What's best way to keep leading out of a barrel?

Thanks,

Jack

[Jman]

Jack,

Experts will soon chime in but in the meantime...

Bore leading is due mainly from unsized bullets that don't fully engage the

barrels rifling. These bullets foul bores regardless of velocity. Now you factor in

bullet hardness and powder. Softer alloys leave more behind. Fast and hot

burning powders melt the base and create lots of leading. So their you go.

Best case scenarios.

* Correct bullet to bore dimensions.

* High quality hard cast bullets.

* Medium speed powder. Unique is excellent for lead bullets.

Jim

[revchuck]

Jack - There are a lot of things aside from velocity that influence leading.

The most important thing is pressure. With commercial hard-cast bullets, low pressure loads will cause leading at the chamber end of the barrel, so I wouldn't mess with lower velocity loads unless you're getting leading at the other end. Too much velocity and/or poor quality or inadequate lube will cause leading toward the muzzle.

Also important is size. My experience is that .356 often works, and .357 is better. My next order for lead 9x19 bullets will be .357. .355 is right for jacketed bullets - period.

Lead bullets will foul more than jacketed - it's just part of shooting them. You have to monitor your gun to determine how it reacts. Shoot a hundred and check your barrel and see if it's leading, and if so, where. Then adjust your load if necessary. Once you've got it where it shoots well and is as good as possible in terms of leading, stop adjusting and load all of them.

[rhyrlik]

If everything else fits, soft lead generally should be used at 900 FPS or less. Hard lead can be used up to 1300 FPS. After that, you need a gas check.

The mechanics of leading are as follows:

Upon chambering, the bullet sits partially in the throat/ freebore. Let's just call it the throat (the part of the barrel between the chamber and the rifled bore). Upon ignition, hot gasses accelerate to 7000+ FPS, hit the bullet, and push it forward. The bullet moves forward until it encounters the leade (the part of the rifling that tapers down toward the throat). The bullet slows as it hits this obstruction.

The bullet then obturates (grows in diameter) due to the pressure of the gasses pushing on it from behind and the leade pushing on it from the front. You want the bullet to obturate the throat completely, else the gasses will overtake it and gas-cut it's shank, depositing molecular lead ahead of the bullet in the bore. Soft lead obturates the throat at a lower pressure than hard lead, therefore hard lead requires a closer fit to the throat. The prolem with that is the closer the bullet diameter to the throat, the harder it is for the round to chamber. Imagine trying to insert a piston into an engine block at the same speed your slide cycles.

9mm throats range from .356" to .360+"

With this in mind, understand that with some 9mm chambers there is absolutely nothing you can do to stop leading. You cannot obturate a soft lead bullet anymore than .003" at pistol pressures. Hard lead won't obturate more than .001".

You simply cannot use .360" bullets. They are to fat to slip into the case while the case slips into the seater die. My Redding seater die will not allow .358" bullets to seat. Sadly, that is the ideal bullet diameter for Sig P226 chambers. Beretta 92's have .357" throats, so .356" bullets are just about perfect.

I bet your bullets measure .356" in diameter. I have no idea how big Hipower throats are. But if they are any larger than .357", you will see leading. Commercial bullets are cast hard. They won't obturate more than .001". If your throat is .358", you will have .001" of gap for the gasses to slip through. If your throat measures .360", you'll have .003" of gap.

FYI, Bar-Sto 9mm barrels have .357" throats. This is from the horses mouth, I asked. They are a great addition to any factory gun. They don't lead.

[Rabe]

Based on what you have shot so far, are you getting leading in your barrel?

Your current load makes minor so there should not be any reason to load to a higher

velocity unless you are looking for faster reaction on poppers.

As other posts have said there are many variables that will determine your max velocity without

leading, not to mention how smooth your bore is.

If your worry is about cleaning the barrel after a shooting session, you could always end your session with some jacketed bullets which normally will clean out any leading.

Edited August 19, 2008 by Rabe

[anachronism]

9mm throats range from .356" to .360+"

With this in mind, understand that with some 9mm chambers there is absolutely nothing you can do to stop leading. You cannot obturate a soft lead bullet anymore than .003" at pistol pressures. Hard lead won't obturate more than .001".

You simply cannot use .360" bullets. They are to fat to slip into the case while the case slips into the seater die. My Redding seater die will not allow .358" bullets to seat. Sadly, that is the ideal bullet diameter for Sig P226 chambers. Beretta 92's have .357" throats, so .356" bullets are just about perfect.

Try picking up a set of 38 S&W (not Special) dies & using that seater. A 9mm Makarov seater may work too, and may be easier to find. My Hornady Durachrome dies will seat .358s in 9mm cases.

My apologies for the hijack.

[rhyrlik]

That's a good idea... those 38 S&W dies.