First time with lead bullets

[GLOOB]

So Berry's was out of stock at my fav store, for awhile. Being impatient, I bought some MBC 125 gr small ball bullets for loading 9mm. BH 18, diameter .356".

I know all the issues with lead bullets. Will be using a LW barrel, at first. But one thing that seems to be under contention is pressure.

For instance: using HP38 behind a 124 gr plated or jacketed bullet, I need about 4.4 gr to burn clean and reliably cycle my pistols. That's the starting load for jacketed bullets, per Hogdon, so that makes sense.

Now, if I use the starting load for lead, 3.9gr HP38 (same exact listed velocity), then can I expect this to cycle my pistols?

I'm assuming lead bullets INCREASE pressure, because they're bigger (meaning they must deform more as they hit the rifling AND seal better) and because the coefficient of friction is higher (although I dunno how lube affects this). Thus, 3.9 gr powder with a lead bullet will push the action harder and burn cleaner than 3.9 gr powder using a jacketed bullet?

BTW, I have Win Auto Comp, HP38, and Unique on hand. So if anyone has suggestions for the best powder using these bullets, have at it. I'm all ears. Esp if anyone has worked up a load that works well out of a stock G19, I hope to be able to achieve that, since I was a bit overzealous on this first order.

 

[Waywatcher]

I think you'll do well with the starting load of HP38; work it up until satisfied.

The general rule of thumb is that lead bullets decrease pressure, by the way.

 

[straight-shooter]

The biggest factor to prevent leading is to insure the bullet is .001 to .002 over your bore size to begin with. With this and the proper lube your golden.

 

[GLOOB]

K, then. Haven't micc'ed my barrel, but I think LW is supposed to be good for lead.

Waywatcher:
The data seems to suggest pressure goes up, in this case.

125 GR. xxx LCN Hodgdon HP-38 .356" 1.125" 3.9 1009 25,700 CUP 4.4 1086 31,200 CUP
125 GR. SIE FMJ Hodgdon HP-38 .355" 1.090" 4.4 1009 24,600 CUP 4.8 1088 28,800 CUP

 

[smurf hunter]

Another way to think of it, it takes more pressure to move lead at the same velocity.

Also, an overcharge is considerably less dangerous with lead.

 

[murf]

the .001" increased bullet diameter is probably why the lead bullet shows a higher pressure. run your load over a chrony and compare velocities to the book to make sure your pressure is ok. fwiw

murf

 

[Hondo 60]

velocity & pressure do NOT correlate.

Just because you're firing 50fps less than what the load says in your manual does NOT mean your pressure is an equal number less than what the manual says.

Please be careful.

 

[suzukisam]

lead swages more easily and move down the barrel with less friction because it is softer... I just reduce my favorite jacketed harges a little for my lead charges(assuming the fit into the data) like for example my 9mm charge for jacketed with blue dot is around 7.0 for a 124 jhp.. my lead load is about 6.2.. and they make nice target rounds

 

[Jeff H]

move down the barrel with less friction because it is softer

The hardness of lead has nothing to do with its friction against steel. Friction is measured by the coefficient of friction of two metals sliding against one another and copper-steel has a lower coeff of friction than lead-steel so copper and steel slide easier against one another.

 

[LiveLife]

Now, if I use the starting load for lead, 3.9gr HP38 (same exact listed velocity), then can I expect this to cycle my pistols?

Haven't micc'ed my barrel, but I think LW is supposed to be good for lead.

9mm Lone Wolf barrel bores are .355" and have low land rifling for less leakage around the bullet/land/groove space.

MBC 125 gr Smallball has more "rounded" nose profile than the traditional more "pointed" nose - this design allows for greater bearing surface of the bullet base for better stabilization and shorter OAL to feed better in some pistols like XD/XDm.

I have tested the bullet from 1.125" OAL down to 1.08" OAL and it fed/chambered fine in factory Glock and LW barrels. Depending on the OAL used, 3.9 gr starting load will cycle the Glocks. I usually load at 1.10"-1.12" OAL using 4.1-4.3 gr of W231/HP38.

 

[suzukisam]

The hardness of lead has nothing to do with its friction against steel. Friction is measured by the coefficient of friction of two metals sliding against one another and copper-steel has a lower coeff of friction than lead-steel so copper and steel slide easier against one another.

okay... but because lead bullets are softer and swage easier into the barrel they create less back pressure, and therefore conform to barrel shape by "deforming" more than a hard jacketed bullet. again creating less pressure..

 

[GLOOB]

Regardless of which theory you subscribe to and leaving pressure totally out of the discussion, my takeaway here is that with lead you can achieve equivalent velocity, recoil, and slide movement, with less powder. Sound about right? Else, all this "lead swages easier, has less friction, goes faster" theory* is moot if the super-lead load at lower charge doesn't cycle your gun.

My MBC 125 ball reloads chamber in my LW barrel all the way out to 1.145" compared with 1.125" of Hogdon's guide. This is the longest I could seat while covering the lube groove. So I upped my starting load to 4.1gr. I'm hoping the closer to the rifling, the less leading I will get. I'll post here if I have any problems when I finally get to shoot them.

*Personally, I tend towards the belief that lead has more friction. This causes a more complete burn of the powder, hence the greater efficiency. It's like when you have a light reload that doesn't quite cycle your gun. Then you seat the bullets deeper, and voila, they work. I do think the peak pressure could be lower. Lead could get more velocity out of the powder because of the higher friction and pressure that it maintains on it's way down the barrel. Same way a compound bow can shoot faster than a long bow, even when the longbow has a much higher peak pressure. I could be wrong.

 

[LiveLife]

my takeaway here is that with lead you can achieve equivalent velocity, recoil, and slide movement, with less powder. Sound about right?

Yes. The reason for requiring less powder charge to achieve similar pressure/velocities has more to do with larger diameter of the lead bullet and softer "malleability" of lead alloy.

With .355" diameter hard jacketed bullet shot in .355" bore Lone Wolf barrel, when the powder ignites, there will be some bumping of the bullet base (especially for FMJ RN with exposed lead base), but the hard jacketing won't completely "mold" to the land/groove rifling and some hot gas will leak around the bullet in the space between the bullet jacketing/land/groove space reducing the chamber pressure and velocity.

With .356" diameter lead bullet shot in the .355" bore barrel, when the powder ignites, bumping of the bullet base will tightly mold the softer lead bullet against the land/groove rifling and less hot gas will leak around the bullet increasing the chamber pressure and velocity. If the bullet alloy hardness/powder charge won't bump the bullet base enough, hot gas will leak around the lead bullet and resulting gas cutting will erode the bullet base, causing lead smearing at the chamber end of the barrel.

The reason why most jacketed bullets require more powder charge is due to the smaller diameter and leakage of hot gas around the bullet.

My MBC 125 ball reloads chamber in my LW barrel all the way out to 1.145" compared with 1.125" of Hogdon's guide. This is the longest I could seat while covering the lube groove. So I upped my starting load to 4.1gr. I'm hoping the closer to the rifling, the less leading I will get. I'll post here if I have any problems when I finally get to shoot them.

Although I value the longer OAL to engage the rifling sooner, I think most will recommend the .001" larger sizing and proper bumping of the lead bullet base (obturation) the primary concern when shooting lead bullets. For me, I consider longer OAL to mean engaging the rifling sooner for more consistent chamber pressure generation for more consistent shot groups. Just with proper bullet to barrel fit and powder charge, you can get "enough chamber pressure" but that may not be consistent. Longer OAL will increase this "enough chamber pressure" to be more consistent.