Barrel as a Case Gauge?

[geargnasher]

http://castboolits.gunloads.com/show...ght=.40+Doby45

If you want to shortcut, just read the posts by me, CBRick, and Doby45. It's all there.

Gear

[stainless1911]

Im reading that thread now.

I slugged the barrel by driving an as cast bullet (didn't have pure lead) through the barrel. I started at the muzzle, and it cut a little lead ring. Just as soon as the ring detatched from the lead, the slug slid down the barrel with very little effort, I was able to push it the rest of the way through by hand.

[geargnasher]

I don't remember if it was mentioned in that thread or one of the other ones by Gun Nut on the same subject, but Doby and I both had JimInPhx make longer and fatter expander plugs for the Lee Powder-Through-Expander dies that we use, that ended up solving the majority of our leading problems with the .40. Correct alloy for the pressures we used and correct lube for the velocity/pressure range you choose to load for will take care of the rest.

As for overall length (seating depth), I think THX and Gohon about covered it. I like to headspace the Lee 175 TC boolit on the rifling in my .40 M&P, just leaving about .002-3" between the case head and the barrel hood if you put a straight edge perpendicular to the case across the hood. Not all chambers will allow you to do this, requiring headspacing on the case mouth or extractor claw due to magazine or feeding limitations and/or longer throat/leade/ball seats (whatever you want to call it).

Gear

[stainless1911]

there is so much that is going on all at once, and I don't know what I am doing. Im so confused and frustrated that Im just about to just give up. I think Im going to can this casting thing until I can get someone to actually come over and show me how to set this stuff up. I can see why so few people reload.

[thx997303]

Don't give up. You just have to follow through and do it methodically.

First, you need to slug your bore twice. Once from the muzzle, all the way through.

Then slug it again, from the chamber, and only halfway through.

Compare the two diameters, and report on your findings.

Then, take a boolit sized .001-.002" over groove diameter.

Flare the mouth on your case just enough to accept the base of the boolit.

Seat and crimp the boolit in the case. Then pull the boolit using a kinetic puller or whatever you have.

Measure the boolit and report on that.

Take note of whether or not your expander will expand the case enough to accept the boolit base.

This is where to start, and you will likely find your problem using these steps.

Let us know.

[stainless1911]

Thanks for the encouragement.

I'll slug the bore after dinner.

Can the OAL be greater than the 1.135 max that I have read about? the only way to get the base of the bullet to line up with the picture on the first page of this thread is to set it at around 1.160

[MGySgt]

I am going to start a heated debate here - BUT

In my humble opinion a lot of your problems are with the Lee Dies. Experienced reloaders can make them work, but I hate them.

I use to use Lyman exclusively and never had a problem with bullet fit due to thier M die.

I think that Lyman makes the best dies for a new reloader. Their Cast Boolit books are greeat and should be required read.

I have my flak jacket on folks!

[thx997303]

If the longer OAL will fit in your magazine as well as your chamber, then you can load them longer.

I would test their feeding characteristics as well.

[stainless1911]

ok, I have a digital caliper, it reads .xxx then there is a little 5 that shows up sometimes.

slugged muzzle first, : .4005
slugged half way from rear, : .401 to .4015
Pulled bullet, hammer puller : .400

Out of Lee push through sizer, : .4015 sometimes .402

[MtGun44]

Remember tha calipers are only accurate to +/-.001.

If you can check a factory bullet near that size, of a known diameter, to see
how much yours might be off. Really , you need a micrometer accurate
to +/- 0.0001, which are availalbe for under $50, sometimes way under.

Bill

[stainless1911]

sigh.

I have a factory bullet, it measured .399.

I now have no idea how big anything is.

[stainless1911]

I tried to learn how to read a micrometer once, then bought a digital caliper, and Im having enough trouble measuring to the thousanth with that!

[geargnasher]

OK, first off, while digital calipers aren't really accurate enough for fitting boolits, they ARE usually close enough as comparators.

.399 is about normal for jacketed factory bullets, that's one reason your expander is too small for cast!!!!!!!! Copper bullets don't have to be as airtight in the bore ("obturate" is the term for achieving complete bore seal from breech to muzzle with a cast boolit) and therefore are usually at or just below standard groove diameter.

While your calipers might not be accurate enough to tell what's going on between the two barrel slugs (you might or might not have a taper or restriction in there), they are most certainly telling you that your sized boolits are getting swaged down .0015" to .0020", and this is BAD NEWS. This is almost certainly the cause of your problems.

If you measure a sized case outside diameter just below the case mouth (rotate the case to make sure it's round and giving an accurate measurement), then seat a boolit in it and measure again, then add .0015" to the seated-boolit measurement, you'll get an idea of the total amount the brass has to expand to accomodate the boolit. If the difference between the two measurements is more than .002" (and I'll bet you a pound of wheel weights it is LOTS more, like .005") then the brass is having to be stretched too much by the boolit and the boolit is getting squeezed. .002" case tension (interference fit between boolit and inside diameter of the case "neck") is more than enough to hold the boolit under recoil.

One more thing to check, take the expander out of the expander die and measure it. You want an expander that extends down into the case about 20-50 thousandths below where the boolit base will be seated, and for the .40 you want it to be about .001" under or maybe right at boolit diameter. When the expander is forced into the case it should stretch the brass and make way for the boolit as well as flare the mouth slightly. The brass will spring back slightly after the expander is withdrawn, so it is a balancing act.

You must understand that most factory reloading die sets aren't designed for cast boolits and often leave the brass too tight for our softer boolits. You will need to get a larger and longer expander spud made, or buy a Lyman "M" expander die that's about .400", and make sure it's long enough to expand the case all the way to just past where the base is seated. If you don't do this, your problems with leading won't go away.

I'll post a link in a minute to a thread where you can see a dimensional drawing of a proper .40 S&W expander plug for the Lee PTE die, if you have a good local machinist, maybe he can make you one.

One more thing, if you want, I can mail you a handfull of pre-expanded, decapped .40 cases to load up with your .4015" boolits so you can see what difference it makes.

Gear

[Gohon]

slugged muzzle first, : .4005
slugged half way from rear, : .401 to .4015
Pulled bullet, hammer puller : .400
Out of Lee push through sizer, : .4015 sometimes .402

Stainless, it appears to me and as others have stated, that your expander is undersized. Just seating the bullet is sizing the base down .001-.0015 below bore diameter according to your readings. Leading is going to be pretty much guaranteed. Even if your set of calipers are not that accurate, they are still showing a problem. Personally if your gun feeds, goes into battery and fires reliable, I wouldn't worry about COAL all that much at this point.

[geargnasher]

CRUD. The thread with Doby's and my pics is gone from the testing forum, and I think it was Doby who actually posted the .40 pic, cuz it ain't in my attachments. Anywhoo, I think the expander part was .350" or somewhere therebouts, and .400 in diameter. We had it designed for the Lee 175 TC boolit seated to about 1.118" COAL, yours may need to be different based upon how far the boolit goes down in the case.

Try to measure that for me and I'll double check to see if my expander is long enough to do the job for your seating depth, or maybe it's too long and I can run it in partway and you can finish flaring the mouth with your dies. Lemme know.

Gear

[fredj338]

I can almost guarantee that the LFCD, the 4th die, is the culprit. They tend to size the lead bullet down along w/ the case. Size the bullet to 0.401", run them along @ 900fps, ww alloy is fine, seat & taper crimp only, toss the LFCD in the trash or sell it to someone that uses jacketed bullets, it's just not needed to make reliable, accurate ammo.
OAL has nothing to do with leading. Your leading is a bullet fit problem, alloy problem, powder problem, lube problem or a combo of all variables. So eliminate variables one at a time starting w/ proper bullet fit.

[stainless1911]

Try to measure that for me and I'll double check to see if my expander is long enough to do the job for your seating depth, or maybe it's too long and I can run it in partway and you can finish flaring the mouth with your dies. Lemme know.
Gear

You want the OAL, or how far the boolet goes into the case? I assume the latter.

Im getting around .350

empty sized case, just below case mouth, : .418
Bullet seated, measured just below mouth : .422

the diameter of the expander in the powder through die is : .397
it only goes into the sized casemouth about .115 before it starts to flare it.

I put a sized case through the expander die, then seated and then removed a boolet. It measured .401 and once, I got a .4015. The boolet was shiny below the lube groove, but not above it.

Above the lube groove I got .4015 and .402

[stainless1911]

.
OAL has nothing to do with leading..

Im certain the problem is bullet fit as well. I was concerned with the OAL thinking that if the boolet was too far from the rifling, that it would skid, and contribute to the leading.

[stainless1911]

Is this the die you referred me to?

http://www.midwayusa.com/viewproduct...tnumber=568862

[stainless1911]

CRUD. The thread with Doby's and my pics is gone from the testing forum, and I think it was Doby who actually posted the .40 pic, cuz it ain't in my attachments. Anywhoo, I think the expander part was .350" or somewhere therebouts, and .400 in diameter. We had it designed for the Lee 175 TC boolit seated to about 1.118" COAL, yours may need to be different based upon how far the boolit goes down in the case.

Try to measure that for me and I'll double check to see if my expander is long enough to do the job for your seating depth, or maybe it's too long and I can run it in partway and you can finish flaring the mouth with your dies. Lemme know.

Gear

I THINK this might have been what you were looking for, post # 19?

http://castboolits.gunloads.com/show...ander+lee+plug