.44 Slugfest

[125JHP]

A couple weeks back, I found about 500 .44 240gr LRN cast bullets under my bench and decided to load them up to see how various loads would perform in my stable of 44's. Working up the load and the chrony results is another story...

While cleaning the little pigsters I noticed a couple had considerable leading after not all that many shots. I only shot 15 test loads (6.5 to 7.0 Unique) out of my snub and it was heavily leaded. I shot about 35 rounds -they were a little hotter at 7.5gr Unique and it wasn't leaded quite as bad, but still noticeable. The 4" and 6 1/2" had fired about 50 loads each all the way up to 10gr Unique and only showed a very slight amount of leading.

My initial conclusion was that the additional pressure in the hotter loads is expanding the lead to seal the throat/forcing cone enough to prevent the lead deposits but the light loads isn't. I don't know the hardness of the lead but it scratches like wheel weight and has the common hard blue lube commercial producers use-however since I also have a box of unsized castings, I either got them from a neighbor or garage sale somewhere along the trail. Anyway, I don't think they are hard-cast.

This of course lead me to wonder just exactly what sizes are my throats and bores... which lead to... slugging my chambers and bores. The results were interesting and have prompted additional questions which I hope some of you can provide additional insight on.

First, so everyone starts on the same page, here was my process...
All guns were cleaned, lightly oiled and bores and chambers were mopped to remove any excess oil. Tools assembled included hardwood dowels, verier caliper, 0-1" .0001 micrometer, both sized and unsized lead bullets from the test box, felt cloth to clean the mic between readings, magnet to hold cylinder retaining screw, latex gloves to avoid lead contact, pen & notepad, etc.

Steps included:
1. Pick 6 bullets, wipe with clean rag and use sharpie to put an ID number on bullet base.
2. Measure each bullet in 2 places around dia. with mic. Take.xxxx measurement across both drive bands, exclude base edge due to possibility of deformities.
Clean mic surfaces with felt cloth between measurements. Note range of tolerance, & average (repeat measurements if results vary more than .0002). Note gun, bullet ID & value.
3. Remove cylinder (secure screw w/ magnet) and use sharpie to mark reference dots on #1 and #2 chambers.
4. Insert bullet #1 into Chamber #1 and if required, tap it thru with wood dowel, repeat for all chambers.
5. Measure each throat-sized bullet 2x as above and notate gun, cyl # & values.
6.Tap one throat-sized bullet completely thru the barrel from the muzzle with wood dowel. (use bullet cushion cloth at recoil shield to avoid damage to bullet.)
7. Mark & ID the bullet for later bore measurement. Because of the 5 grooves, I will have to work up a method of measuring the bullets, I don't know if I will get V blocks or try the pop can wrap method.

In the remaining cylinders, even Unsized bullets either fell thru or slide out with light finger pressure. the largest dia unsized bullet was .4318 so I reason that the chamber throats have to be around .43175".

Next I slugged the bores from the muzzle. I tried measuring the bullets, but couldn't get a consistent reading. However, since it took a lot more force to pound them through the bore than the chambers I think I can safely assume the throat-sized bullets are significantly larger than the bore.

I am disappointed with the amount of leading and initially figured that the charge wasn't doing enough to expand the bullet in the forcing cone. However 850fps seems pretty decent for 44 SPL, so now I'm not so sure it's the load and want to see what size the forcing cone is compared to the throats.

I would like to start casting my own but not if I have to scrub lead like this session. I am a little reluctant to bump the charge up to 7.5gr as I'm not sure if the L frame can handle it on a regular basis.I may have to use jackets.

I'm not sure how to get a good forcing cone measurement since I cant easily tap (hammer) a bullet in from the frame side and cant get a mic or caliper squared up in the cylinder opening either. I probably could pour a cerrosafe cast of the forcing cone but was hoping for a more permanent record sample.

• How would you measure the forcing cone?
• What would be reasonable forcing cone figures to look for and where along the cone ?
• What are acceptable figures for cylinder throats, Bores, lands etc.?
• Would it be beneficial to have the throats opened up? To what size?

Do you see any other issues to consider?

Any ideas or comments are welcome

 

[Skip Sackett]

The easiest way to measure a 5 sided bore is to wrap the slugged bullet with a .001" feeler guage. After getting a measurement, subtract .002" from your reading.

Measuring the forcing cone? Never heard of that one. Recutting one, polishing one, yeah, heard of that.

Personally, the problem is that you are not casting your own, and have no idea what you are dealing with for alloy in the ones you have. Neither do you know what the lube is. It may just be axle grease mixed with paraffin, like blue crayons. There are much better lubes out there.

One forum member told of some really accurate M29s. If memory serves me, they were the DX Classics, don't trust me on that one though. Seems that they had smaller throats than bores and shot like a house a fire! Some of the most accurate 44Mag revolvers that Smith ever put out and went totally against conventional wisdom. I'm just repeating what he said. No personal experience with it.

I know this, copper fouling can wreak havoc with lead bullets. If you had one that shot only jacketed stuff, use some good copper solvent and get that stuff out of there. You may not even see it, it can still be there.

Then, go with some known commodities. Get bullets that are sized to be .001" to .002" bigger than your throats and that are in the 12BHN range, no harder. Have them lubed with a good bullet lube, I prefer anything White Label Lube makes, although, there are others out there.

As for the forcing cone, um, yeah, well, never done anything with mine on any gun I've owned and I have pushed the envelope on a lot of magnum loads, both 357 and 44, 45ACP and even some super 45 Colt loads, all with lead bullets, and if I followed the above rule about size and minimum hardness, I found I can drive them as hard or as soft as I want to with NO leading, none.

Hope this helps AND, this has to be one of the best reports I have ever read on the forum for someone trying to figure out what is going on with his firearms. With this kind of diligence, you are going to find your answer.

 

[125JHP]

as a follow up...

Thank you Skip, I'm honored for your kind words.

As a follow-up to my earlier posts, I searched the web and read all I could on leading problems. I have come to the conclusion (been convinced) that the cylinder throats are the critical element in the issue and that for a modern S&W I can usually ignore measuring the bore and forcing cone.

As mentioned above, while measuring the throats on some of my guns, the bullets fell right through, indicating they were larger than the un-sized castings I was using. This left a lot of uncertainty as to how big these throats actually are.

What I ended up doing was grabbing the box of un-sized bullets and started dropping them thru the cylinders until one stuck without protruding out the face. I filled all the cylinders that way, thus finding bullets that could be forced thru the throats and measured.

I discovered that one pistil has throats that range from .431 to .433 and that others have numbers between .4315 and .4335

Now that I know this, what options are there? (all Q's in the context of avoiding leading at 44 spl velocities).
Custom molds are out of the question unless I find cheap ones at a sale and dremmel them out myself.

What would be a good size to use?
Just how close to the throat size should the bullet be?
If undersized is acceptable .... by how much?
What size mold would be needed? I would then think that a larger mold could be coupled with different sizing dies to custom fit the boolits to each gun.
Would it work to load un-sized bullets with alox for lube (as long as they chamber that is)?

I'm more interested in solving the leading as I can bump the charge in the magnum and probably get a seal that way.

As I measured around each bullet, I noticed that even though they were tap-forced thru the throat, they still weren't round. Most measured .430 at one point across the bands and increased upward to .4335 at 90 degrees,as I rotated it- indicating they are oval - is this normal? I took the highest value indicated- is this a valid throat measurement?

Does lead "spring back" after leaving the compressed state of the throat? even by .0001 ? If so then my throats might not be as large as I think.

What are y'alls thoughts?

 

[Larry from Bend]

A couple weeks back, I found about 500 .44 240gr LRN cast bullets under my bench and decided to load them up to see how various loads would perform in my stable of 44's. Working up the load and the chrony results is another story...

While cleaning the little pigsters I noticed a couple had considerable leading after not all that many shots. I only shot 15 test loads (6.5 to 7.0 Unique) out of my 696 and it was heavily leaded. I shot about 35 rounds from the 3" 624 but they were a little hotter at 7.5gr Unique and it wasn't leaded quite as bad, but still noticeable. The 4" and 6 1/2" 629's had fired about 50 loads each all the way up to 10gr Unique and only showed a very slight amount of leading.

My initial conclusion was that the additional pressure in the hotter loads is expanding the lead to seal the throat/forcing cone enough to prevent the lead deposits but the light loads isn't. I don't know the hardness of the lead but it scratches like wheel weight and has the common hard blue lube commercial producers use-however since I also have a box of unsized castings, I either got them from a neighbor or garage sale somewhere along the trail. Anyway, I don't think they are hard-cast.

This of course lead me to wonder just exactly what sizes are my throats and bores... which lead to... slugging my chambers and bores. The results were interesting and have prompted additional questions which I hope some of you can provide additional insight on.

First, so everyone starts on the same page, here was my process...
All guns were cleaned, lightly oiled and bores and chambers were mopped to remove any excess oil. Tools assembled included hardwood dowels, verier caliper, 0-1" .0001 micrometer, both sized and unsized lead bullets from the test box, felt cloth to clean the mic between readings, magnet to hold cylinder retaining screw, latex gloves to avoid lead contact, pen & notepad, etc.

Steps for each gun included:
1. Pick 6 bullets, wipe with clean rag and use sharpie to put an ID number on bullet base.
2. Measure each bullet in 2 places around dia. with mic. Take.xxxx measurement across both drive bands, exclude base edge due to possibility of deformities.
Clean mic surfaces with felt cloth between measurements. Note range of tolerance, & average (repeat measurements if results vary more than .0002). Note gun, bullet ID & value.
3. Remove cylinder (secure screw w/ magnet) and use sharpie to mark reference dots on #1 and #2 chambers.
4. Insert bullet #1 into Chamber #1 and if required, tap it thru with wood dowel, repeat for all chambers.
5. Measure each throat-sized bullet 2x as above and notate gun, cyl # & values.
6.Tap one throat-sized bullet completely thru the barrel from the muzzle with wood dowel. (use bullet cushion cloth at recoil shield to avoid damage to bullet.)
7. Mark & ID the bullet for later bore measurement. Because of the 5 grooves, I will have to work up a method of measuring the bullets, I don't know if I will get V blocks or try the pop can wrap method.

I did the above procedure on 7 different guns (696_3", 624_3", 629-4_4", 629-1_6", 629-4_6.5", 29-3_6" & 29-3_8 3/8"). On 5 of them the bullets fell freely or slid easily thru the chamber throats but had to be lightly tapped thru on the 696 and the 4" 629.

Here are the figures by gun/cylinder.
696_3" Sized bullet- #1-.4297, #2-.4297 , #3-.4295 ,#4-.4295- ,#5-.4296
Bullet after Throat sizing- #1-.4293, #2-.4293, #3-.4291, #4-.4293, #5-.4293

629-4_4" Sized bullet- #1-.4295, #2-.4304, #3-.4294, #4-.4305, #5-.4295, #6-.4304
Bullet after Throat sizing- #1-.4293, #2-.4293, #3-.4293, #4-.4295 ,#5-.4294 ,#6-.4293

In the remaining 5 cylinders, even Unsized bullets either fell thru or slide out with light finger pressure. the largest dia unsized bullet was .4318 so I reason that the chamber throats have to be around .43175".

Next I slugged the bores from the muzzle. I tried measuring the bullets, but couldn't get a consistent reading. However, since it took a lot more force to pound them through the bore than the chambers I think I can safely assume the throat-sized bullets are significantly larger than the bore even in the 696.

I am disappointed with the amount of leading in the 696 and initially figured that the charge wasn't doing enough to expand the bullet in the forcing cone. However 850fps seems pretty decent for 44 SPL, so now I'm not so sure it's the load and want to see what size the forcing cone is compared to the throats.

I would like to start casting my own but not if I have to scrub lead like this session. I am a little reluctant to bump the charge up to 7.5gr in the 696 as I'm not sure if the L frame can handle it on a regular basis.I may have to use jackets in the 696.

I'm not sure how to get a good forcing cone measurement since I cant easily tap (hammer) a bullet in from the frame side and cant get a mic or caliper squared up in the cylinder opening either. I probably could pour a cerrosafe cast of the forcing cone but was hoping for a more permanent record sample.

• How would you measure the forcing cone?
• What would be reasonable forcing cone figures to look for and where along the cone ?
• What are acceptable figures for cylinder throats, Bores, lands etc.?
• Would it be beneficial to have the throats opened up on the 696 & 629 4" ? To what size?

Do you see any other issues to consider?

Any ideas or comments are welcome
Thanks
Al

I'll just add this. I've seen harder bullets lead when than softer bullets didn't--- in the same gun and loading recipe. It takes about 21,000 psi to obturate a 15 BNH bullet. If your bullets are wheel weight hard (say BNH 15) they may not be obturating. This could surely cause leading. I've never slugged my cylinders/bores in my 29 or 629s so can't help there.

 

[358156hp]

You should use pure lead for slugging throats and bores. Alloys with antimony have a bit of "memory", and although they will size down a bit, the will try to return to their original diameter. They won't make it all the way, but they will differ from the bore dimension they were forced through. Many S&W 44s seem to have large cylinder throats. My 629-2 runs between .4315 to a hair over .432. I had to buy it a custom mould, which still annoys me, but the mould was about the cost of 2 boxes of factory ammo, so I'll get over it. If you want to shoot lead in the 696, consider Hornady swaged lead bullets. They might just do what you're looking for.

 

[MMA10mm]

Now you see how difficult it is for the ammo factories. Your struggling a little loading for several guns. Imagine if your ammo had to be safe, accurate and without problems in tens of thousands of guns!!

You really have a couple solutions available.

First, you can rent a throat reamer and get all the chamber throats up to as close to one standard size as possible. (Looks like in your case that's going to be around .432".). Then, that's the only size you have to worry about, and given decent forcing cones (which can also be fixed by a reasonably skilled home gunsmith), the bullets will swage down to your smaller (by then - after reaming the throats) bore diameters, as should happen.

Second choice is to use a soft enough bullet with just the right pressure load so that after it squeezes through the tight chamber throats, the bullet is re-obturated into the barrel's forcing cone. This requires some significant trial-and-error, and forces you to use specific load combinations (little-to-no flexibility) based on the bullet alloy available and/or what velocity/power-level you're trying to achieve.

I concur with the others above as well. This is a fine example of giving appropriate information and working through a problem yourself until getting to a point it was time to ask for clarification. Great post.