Leading!

[noylj]

Question: revolvers have forcing cones. Autos don't, as far as I know (and someone will tell me if I am wrong)
1) You can't find a better powder for lead bullets than Unique. If you are working for low power target loads, AA2 and 213/HP38 work quite well.
2) I don't know if this has been covered, but take your gun to the reloading bench. Disassemble and use the barrel for a case gage.
Make up two inert (no powder or primer) "dummy" rounds. Use them to verify that sized cases drop freely into the chamber. Expand and bell the case (the case ID should be 0.0450±0.001" and the case mouth should be flared enough not to contact the bullet during seating). This is one of several reasons to separate seating from crimping.
Seat the bullet to a COL of 1.270 in both "dummy" rounds. At this point, the case mouth should be flared to the point where the round will not chamber in the barrel. Place the crimp die in the press. Run the "dummy" rounds to the top and screw down the crimp die just until it contact the case. Lower the round and turn the crimp die in about 1/4 turn. Run the "dummy" into the die. Now try to chamber the round. Keep turning the crimp die down in very small increments until the "dummy" will drop into the chamber. Remove case mouth flare/bell from both "dummy" rounds.
The COL may be too long for your chamber, so go back to the seating die and seat the bullet deeper until the round chambers all the way. On a 1911, you use the barrel hood to set headspace. Your barrel may not have any way outside of the gun to judge headspace and chambering. If so, reassemble the gun and place one of the "dummy" rounds in the magazine. Does it fit? If not, adjust the COL until the "dummy" fits in the magazine. This should NOT happen, however.
Put the magazine with the two "dummy" rounds in it, pull back the slide and let it go (do not try and help it, just pull all the way back and release). If the first round doesn't feed or completely chamber, you need to adjust the COL again until you get the "dummy" rounds to feed and chamber. A "normal" COL for my guns and a L-RN bullet has been 1.270-1.260".
After the two dummy rounds feed and chamber, go back and crimp the rounds until there is no longer any sign of case mouth flare/belling. Run your finger down the bullet to the case and you should not feel a sharp transition. If you must measure things, shoot for a case mouth OD of 0.473-0.470".
At this point, all your dies should be set. You can save the "dummy" rounds so you can quickly set up the dies the next time you need to.
Remember, reloading manuals reference the MINIMUM recommended COL.

 

[Jech]

Isn't Melonite just the finish applied to the slide? What I was referring to was the bore...terms I've heard before are things like chromed-steel chro-moly, 4064 steel etc.

 

[918v]

Your OAL is too short. Your bullets are jumping into the throat and shaving lead on the way. The reason is the case is slightly off center in the chamber due to the extractor hook tension. This shaved lead is deposited in the chamber. Increase the OAL to 1.250" so that the front driving band is partially in the throat upon chambering. That will assure the bullet is better aligned with the bore and will not shave on the way in.

 

[LiveLife]

Isn't Melonite just the finish applied to the slide? What I was referring to was the bore...terms I've heard before are things like chromed-steel chro-moly, 4064 steel etc.

Jech, Melonite/Tennifer are not finish applied to the metal, but nitriding salt bath treatment process for the metal that hardens the surface and makes it more corrosion resistant. Final finish you see on the metal is coating that's applied over the metal treatment.

On older holstered PD trade-in Glocks, you'll see that the finish has worn off, but the Tennifer treated metal remains beneath the finish.

As far as I know, both slide and barrel are treated now.

 

[Jech]

Your OAL is too short. Your bullets are jumping into the throat and shaving lead on the way. The reason is the case is slightly off center in the chamber due to the extractor hook tension. This shaved lead is deposited in the chamber. Increase the OAL to 1.250" so that the front driving band is partially in the throat upon chambering. That will assure the bullet is better aligned with the bore and will not shave on the way in.

Now that's a new concept I never would have even put together on my own When it comes to the chamber leading though, I haven't seen it again since I ran out of the MBC 230gr LRN Softball bullets /shrug. I wonder if this extractor claw tension could explain the asymmetrical leading I was seeing on 11/8 though?

I'm worried now that you say 1.245" is too short cause yesterday I hit the range again using the Lee 452-230-TC bullets...this time seated to 1.162" putting the ogive start flush with the case mouth allowing the round to pass the barrel-case-gauge test. They shot like a dream if I ignore the asymmetrical leading pattern. For the record, I used HP-38 charges varying from 3.8gr to 5.3gr and posted results here on CastBoolits.

Now, when I first tested chambering a dummy seated at 1.245", I saw a very distinct ring of lead around the exposed shoulder/side of the bullet just like I used to with the MBC 230gr LRN bullets. This premature headspacing was what prompted me to load those MBCs to 1.228" even though they fed reliably at longer OALs. Eventually I settled on a theory of that shaved ring being forcibly sloughed off when the cartridge was fired then got smashed into the chamber wall by the next round going off.

Would it be advisable then to try an OAL more along the lines of 1.25-1.26" with the TCs even though it won't headspace anywhere near the case mouth?

 

[Jech]

...swabbing the bore with Kroil...running a good tight flannel patch thru would get 95% of the lead on the first pass...apparently the Kroil penetrates the interface of lead-barrel steel, "floats" the lead free.

Another intriguing method I haven't heard of before...I have PB B'laster sitting around that I'll have to give a shot.

Wrapping strands of (magnet tested) kitchen copper scrubbing pad around a tight patch has been a major PITA. Is there really that big of a difference between "name brand" ChoreBoy and other $2.99 generic implementations?

 

[918v]

TC bullets are a different story than RN. In TC bullets, the shank portrudes past the case mouth to a greater degree than the shank of a RN bullet at the same OAL. TC bullets are generally seated to an OAL in the 1.200" range. If you were to seat a TC bullet to an OAL of 1.250", the shank would hit the rifling before the case mouth could bottom out against the chamber. Such a round would not work in a self-loader.

Use your barrel as a gauge. Take it out of the gun and seat the bullet long, say 1.270". Use the crimp die to remove the bell only. Then drop the round into the chamber. Does it drop in freely? Is the case had flush with the end of the barrel hood? If not, then seat the bullet deeper and deeper until it fits.

This method assumes the bullet diameter is smaller than the freebore. If the bullet is the same or larger than the freebore, you will have to seat it extra deep and it will shave lead on the way in. The ideal size for self-loaders is .0005" under.

You should know your chamber dimensions before proceeding further. I had a Wilson CQB whose freebore was .452". As you can imagine, it would not work with commercial cast bullets as they are all typically .452"+. I had to get a Lee die and resize them to .4515". Then they fed beautifully. I used an OAL of 1.250" for both LRN and SWC.

My current 1911's accept .452" bullets without any issues due to their .453" freebore.

 

[DBR]

Another cause of leading if the bullet is too far off the rifling lead (what you are calling the forcing cone) is hot gas escaping by the bullet before it jumps into the rifling. This gas erodes lead off the bullet at the front of the chamber before the bore is sealed.

 

[Jech]

...this time seated to 1.162" putting the ogive start flush with the case mouth allowing the round to pass the barrel-case-gauge test.

My XD has a sub .452" freebore...looks like we're both on the same page now...shorties they will be!

 

[918v]

And you will continue to shave lead. The solution is to resize the bullets, not to seat them shorter.

 

[murf]

agree with 918v. you said the bore was .451. either buy .451 bullets, or resize. you should then be able to set to normal col without leading issue.

murf

 

[Jech]

Wouldn't resizing to .451" contradict one of the fundamental rules of cast bullet shooting? It was my understanding that cast shooters were supposed to load bullets .001" over their slugged bore's diameter to ensure a proper seal.

 

[Jeff H]

Wouldn't resizing to .451" contradict one of the fundamental rules of cast bullet shooting? It was my understanding that cast shooters were supposed to load bullets .001" over their slugged bore's diameter to ensure a proper seal.

+1

I'm not quote following how sizing down will help leading either. I'm open to ideas though.

 

[918v]

Wouldn't resizing to .451" contradict one of the fundamental rules of cast bullet shooting? It was my understanding that cast shooters were supposed to load bullets .001" over their slugged bore's diameter to ensure a proper seal.

Your understanding is correct, however the .001" over figure is not mandatory to achieve a proper seal. First of all, you assume the groove diameter of your barrel is .451" and that may or may not be the case. Many 45 ACP barrels have groove diameters as small as .449". Krieger, for example, cuts a .450" groove diameter in their 45 ACP barrels.

http://www.kriegerbarrels.com/Calibers__Prices-c1246-wp3390.htm

You should slug your barrel before assuming.

I bet your groove diameter is smaller than .451". Even if it were .451", shooting a .451" bullet through a .451" barrel makes for a perfect fit, especially since the bullet is under pressure and obturates whatever imperfections it may encounter.

The .001" over figure is meant as a guide.

 

[Jech]

First of all, you assume the groove diameter of your barrel is .451" and that may or may not be the case...You should slug your barrel before assuming.

Been there, done that, bought the t-shirt...It was hidden in my trademark Oversized Wall'o'Text ><

...My bore is slugging at .4508-.451" so even the freebore catches the lead if the side sticks out at all from the case.

-------------------------------
Speaking now strictly in a hypothetical sense and thus ignoring the sacrilege of smithing inside the bore... I wonder if it would be possible to open up the first 1/16" of the freebore by .0015". This would essentially creat a throat likened to what rifle chambers have, allowing these bullets some extra protrusion from the case mouth.

Again, I'm just thinking out loud here...I don't have the money to do that nor do I have access to the equipment myself.

 

[918v]

So shoot .451"