S&W Shield 40 Leading/Tumbling Issues

[Dvdmacdaddy]

Is this what I need to use in my LEE powder through die?

[Burnt Fingers]

Is this what I need to use in my LEE powder through die?

No, that's for the Lee Universal Expanding die. It's a solid plug.

[JBinMN]

And I do not think that one pictured in the last 2 posts is the correct size from how you described your slug from your bbl. at .4015".

On the NOE plugs, the bigger number first is the "stepped portion" of the plug that does the flare of the case, the 2nd number is the size of the expander plug to form the case to fit the boolit.

{As in .404 x .400 (P) Exp. Plug - .404 is the wider step of the plug that will form the flare, & the .400 is the smaller diameter of the plug for expanding to boolit diameter.

You want the second number to be about .001 below the size you actually want you boolit to be once it is seated & then crimped( I suggest taper crimp, btw in a separate step from seating, but some folks don't taper crimp & some roll on some rounds even though they are for "pistols" & not revolvers, as well as seat & crimp at the same time. Your choice...)

Another way to know that your boolit won't be swaged down is to use the 2nd number so that you can push the boolit in(seat) with your thumb to about the last crimp groove not easily, but with a little bit of force. This will allow some case tension to hold the bullet in, so recoil, etc, doesn't change boolit position.("set back" usually, rather than moving outwards.) Be sure to check this possibility of setback by taking the completed round, measuring OAL & then pushing the boolit end against your bench to see if it moves in & then check the OAL again. If it has changed you need to readjust your expander die &/or plug, your crimp die, or both until you cannot more the boolit by pushing as described.

Note that different types of boolits types & mnfrs , as well as jacketed do not all sit in the case the same & and the expander plug you use should be checked to make sure it is compatible with the projectile used. That way you are not expanding deeper or shorter than you would like & possibly cause issues for yourself.

One last thing about the NOE plugs. If I am not mistaken, the (P) is to designate that the expander plug is a shorter one for (P)istols, and no (P) for rifle exp. plugs. Another thing to consider is that some of the rifle plugs can be used for pistols as well. So, be sure to check both lists, rifle & pistol to try to find what you need. If there is a need for a custom one you can call them or email & ask them about making one for you as well.

Hope I helped & G'Luck!


P.S. - That image & plug being shown is not the one you would want for your 40 cal as it is too small an expander for your goal size of .4023 -.403 (based on your measurement of the slug you mentioned earlier in the topic), just in case you thought it was. I reckon you just used it as an example, but I thought I should mention it just in case. The closest that they show for either pistol or rifle is the .404 x .400 (P) Exp. Plug
[PEP-404x400] as far as what I saw there. You may have to talk to them about a plug for you if you choose to use their product(s) Once again, G'Luck!

[DougGuy]

Leading and tumbling like that can only mean one thing, boolits too small. I would look at pulling a few from each batch and mic'ing them to see if you are swaging them when they are being loaded.

[JBinMN]

Leading and tumbling like that can only mean one thing, boolits too small. I would look at pulling a few from each batch and mic'ing them to see if you are swaging them when they are being loaded.

You may have missed it... See post#16 by the OP.

[Walks]

Is there an after market bbl available ?

I have a Wolf bbl for both my Glocks, use the Lee 40-170-TC or the RCBS #40-180-RF. I cast of Linotype for a reliable feed. Still use the same RCBS dies I bought in 1992. Use a C&H taper crimp die to just kiss the case mouth closed. The Linotype is the std alloy for all my auto-loading cartridges. It's what worked for my DAD in every Surplus pistol available after WW2. So it's what I use. I know most will disagree with that, but too bad.

I will however be trying some PC'd bullets cast of a softer alloy soon.

[Dvdmacdaddy]

I have a 9mm aftermarket barrel by Alpha Wolf for it for plinking and some practice.

[Dvdmacdaddy]

Last night I casted 10 bullets marked which cavity they came from. Let the mold cool then took handles off cleaned the mold well with Bar Keepers Friend and 0000 steel wool. Then took some polishing compound and used the casted bullets to polish the inside of the cavities. Then cleaned the molds well with dawn and hot water, reattached the handles, sprayed the cavities and mold face with brake parts cleaner, lightly smoked the mold with a match. Casted 10 more bullets and measured with micrometer. The OOR situation is just about gone, .0005 OOR . Now to cast more, PC and wait on my M Die to arrive to test. In the mean time lapping my .401 sizing die to .402 (going to test for leading at .402 before lapping to .403).


In taking the mold handles off the Allen screw that held one side on was not secured all the way. So I’m wondering if that combined with smoke buildup was my OOR issue.

[DougGuy]

In the mean time lapping my .401 sizing die to .402 (going to test for leading at .402 before lapping to .403).

OP you really need to know what diameter your throat is in the barrel, there is freebore in there and if you lap the sizing die larger than the freebore, ammo will not chamber.

You may have missed it... See post#16 by the OP.

You are correct sir...

[Dvdmacdaddy]

OP you really need to know what diameter your throat is in the barrel, there is freebore in there and if you lap the sizing die larger than the freebore, ammo will not chamber.



You are correct sir...

I got my chamber casting material in the mail today, hopefully have time to cast it tomorrow.

[DougGuy]

You also have to allow for springback, for instance a Lee .452" sizer, will only let a .4515" Z minus pin go through it. If you lap it to .402" and you have freebore that is .402" there will be interference b/c you have to stop short of the desired diameter so the boolit will be the desired size, -after- passing through the sizer.

[cwlongshot]

Recipt says you should have boolets Saturday!

Good luck!

CW

I got my chamber casting material in the mail today, hopefully have time to cast it tomorrow.

[Dvdmacdaddy]

Recipt says you should have boolets Saturday!

Good luck!

CW

Awesome just in time.

I have to have the micrometer back to him Sunday. So trying to get as much done with it while I can.

I was able to get my chamber cast done and the throat was .404", I also went ahead and re-slugged the barrel (to measure using the micrometer), which came out to .400". It was much easier to get a measurement using the micrometer vs calipers. I can now see how my measurements have been off using calipers, time to invest in a micrometer.

Any suggestions on micrometers under $50 (momma is gonna flip at that price too for a "bullet tool" as she would say). I priced the ones I am borrowing and they are $150, way outta my price range.

[Burnt Fingers]

I've found my Harbor Freight micrometer works just fine for my needs.

[DougGuy]

Any suggestions on micrometers under $50

Ebay is your friend. I got all my mics, calipers, pin gages, dial indicators, dial bore gauges from ebay, you can get used in excellent condition name brand high quality well made tooling for the same money you pay for new in the box Asian made garbage.

I paid $39 for my Mitutoyo Micrometer No. 193-211 In Original Hard Case 0 - 1" .0001" free shipping. This is a great mic for the buck!

I would highly recommend investing in a heavy mic base so it holds the mic for you and you have both hands free to hold the object being measured, and to turn the thimble.

I was able to get my chamber cast done and the throat was .404"

I am of a mind to question this one, and not saying you are doing anything wrong, but after throating dozens of barrels, I am looking at the line at the end of the freebore where the rifling leade-ins begin to pick up. The Freebore in the throat, is the smooth parallel part just behind this line. From what I see, the difference in that line and the grooves is not significant enough to be .002" in height. It looks like only a couple of tenths of one thousandth. If there was .004" difference between the freebore and the groove, meaning a step of .002" on both sides, that line would look like a trench! It would look like this HUGE ring in the barrel, and that one just doesn't look like there is more than half a thousandth difference and that's stretching it. I have done a LOT of these, and I have seen this line, it's not a tool mark, it is where the 1.5 degree angle picks up. I think it's smaller than .404"

[Dvdmacdaddy]

Ebay is your friend. I got all my mics, calipers, pin gages, dial indicators, dial bore gauges from ebay, you can get used in excellent condition name brand high quality well made tooling for the same money you pay for new in the box Asian made garbage.

I paid $39 for my Mitutoyo Micrometer No. 193-211 In Original Hard Case 0 - 1" .0001" free shipping. This is a great mic for the buck!

I would highly recommend investing in a heavy mic base so it holds the mic for you and you have both hands free to hold the object being measured, and to turn the thimble.



I am of a mind to question this one, and not saying you are doing anything wrong, but after throating dozens of barrels, I am looking at the line at the end of the freebore where the rifling leade-ins begin to pick up. The Freebore in the throat, is the smooth parallel part just behind this line. From what I see, the difference in that line and the grooves is not significant enough to be .002" in height. It looks like only a couple of tenths of one thousandth. If there was .004" difference between the freebore and the groove, meaning a step of .002" on both sides, that line would look like a trench! It would look like this HUGE ring in the barrel, and that one just doesn't look like there is more than half a thousandth difference and that's stretching it. I have done a LOT of these, and I have seen this line, it's not a tool mark, it is where the 1.5 degree angle picks up. I think it's smaller than .404"

Thanks for the heads up about ebay. Just bought the same mic for $40.

I remeasured the casting and still same numbers. Going to cast the chamber again and see if I get the same results.

[DougGuy]

If that freebore really is .404" and also you had boolits swaged down by the case, so you add the difference in .398" and .404" which is .006" divided by 2 is .003" on each side of the boolit, this would be plenty enough room for some serious gas cutting, so here is yet a 3rd factor contributing to an undersized boolit causing leading and tumbling.

Otoh, if you have alloy soft enough to swage the boolit down in the case, it may be soft enough to obturate and seal that .404" throat as it leaves the case mouth. The 40 is a high pressure cartridge, it certainly generates enough pressure to bump up a soft alloy. This is also another trick in getting the boolit to fit the throat, letting the pressure of firing do it for you.

[Dvdmacdaddy]

If that freebore really is .404" and also you had boolits swaged down by the case, so you add the difference in .398" and .404" which is .006" divided by 2 is .003" on each side of the boolit, this would be plenty enough room for some serious gas cutting, so here is yet a 3rd factor contributing to an undersized boolit causing leading and tumbling.

Otoh, if you have alloy soft enough to swage the boolit down in the case, it may be soft enough to obturate and seal that .404" throat as it leaves the case mouth. The 40 is a high pressure cartridge, it certainly generates enough pressure to bump up a soft alloy. This is also another trick in getting the boolit to fit the throat, letting the pressure of firing do it for you.

Best I can tell until my alloy analysis comes back is my alloy is about 9-10 BH. The thought of using a mini-lathe to make a hollow base into the bullet has crossed my mind, but very reluctant to attempt.

[DougGuy]

That should be soft enough to obturate, so being that it is leading and tumbling I would say it is not obturating enough to seal in the freebore and that gas cutting is very much one of the culprits here. Going to have to be a larger boolit. You just have to know when to stop lapping the sizing die!

[Dvdmacdaddy]

I am of a mind to question this one, and not saying you are doing anything wrong, but after throating dozens of barrels, I am looking at the line at the end of the freebore where the rifling leade-ins begin to pick up. The Freebore in the throat, is the smooth parallel part just behind this line. From what I see, the difference in that line and the grooves is not significant enough to be .002" in height. It looks like only a couple of tenths of one thousandth. If there was .004" difference between the freebore and the groove, meaning a step of .002" on both sides, that line would look like a trench! It would look like this HUGE ring in the barrel, and that one just doesn't look like there is more than half a thousandth difference and that's stretching it. I have done a LOT of these, and I have seen this line, it's not a tool mark, it is where the 1.5 degree angle picks up. I think it's smaller than .404"

I have been reading up on chamber casting and have a question. How much does Cerrosafe shrink when its cooled? And would it make that much difference in measuring the throat diameter? I'm wondering of slugging the throat would get me a better measurement.