Crimping gauging 40s&w

[firstater]

I loaded a few of my first cast bullets and found they would not fit flush into the case gauge without a heavy crimp from LFCD which deforms the bullet. Seem to fit the barrel ok so I skipped the FCD and backed out the seating die to see how much crimp I needed to apply for the round to fit in the barrel. The first test round with no crimp fits in barrel fine. I knocked the round on the table pretty good to see if the bullet would seat deeper and it didn't budge. Any reason to apply slight crimp?

I'm using lee 175grain TC

[geargnasher]

Only put enough crimp to straighten out the bellmouth, no more, unless you have to to get them to chamber. Check the case mouth with a micrometer while adjusting the crimp die until there is no bell, then use your chamber as a case gauge. Most of the time here is no need for any kind of a crimp in an automatic since the recoil forces don't pull the boolits like they do in a revolver, but some of the .40s have pretty substantially tapered chambers that require a little swaging at the case mouth to get the loaded round to fit with the fatter cast boolit.

Now, for the advice. You just discovered the worst thing about trying to load cast boolits in a typical .40 with typical standard dies: The boolits get squeezed way undersized, even without the Lee FCD, which as you discovered is the root of all evil with certain calibers. If you try to shoot those boolits, they will likely lead the bore terribly because they will be swaged undersized by the loading and then by the FCD. The solution is to have a larger expander spud made for your Powder Thru Expander die which will expand the brass to about .001-2" under boolit diameter, and about .025" deeper than the boolit seating depth your gun prefers, that way your boolits will still fit the bore AFTER being seated, crimped, and fired out of the cases.

Most other handgun calibers aren't as picky as the 9mm and .40, but tight chambers and really hard brass combined with dies made for jacketed bullets can play hoc with cast.

Gear

[Blammer]

no reason at all to apply any crimp.

[Doby45]

I concur with Gear. I love my custom 401 expander plug.

[geargnasher]

You mean this one?

http://castboolits.gunloads.com/showthread.php?t=93108&highlight=spec+pic+jim

Like post #19?

Me too.

Gear

[fredj338]

no reason at all to apply any crimp.
I'll disagree for semiauto rounds. It's the only way to insure reliable ammo IMO. Leaving any flare is asking for a FT chamber, especially as carbon/lead/lube build up.
IF you are not sizing, your bullet may be too large to allow anything but heavy crimp. Size them to at least 0.402", that should run in any 40.

[noylj]

Back in the old days, when we were casting bullets over the campfire, you simply removed the belling/flaring and you did it by LOOKING at the round. There was no need for a micrometer. You could FEEL the bell if it was still there and you could FEEL the lack of case mouth edge if you went too far.
Also, as part of not measuring things, we also did measure cases and bullets before and after each step using a couple of inert "dummy" rounds to be sure the lead bullets weren't being swaged down and the expander was doing its job. Then, we would order the expander stem and seating stems for our lead bullets (knowing that the dies had not been designed for the bullets we were shooting).
Right now, I am going to need to get a Lee PTE stem about 0.002" larger then the one in my Lee PTE for .40S&W--and the same may be true of the Dillon powder funnel when I go to buy one.
My son will need to order a 0.002" larger expander for his .45ACP Lee PTE due to his .453" bullets being swaged to 0.4505 unevenly. We measured, so we know where the problem is.
Now a days, Hornady is making special PTXs for lead bullets and RCBS has their "Cowboy" dies supposedly designed just for lead bullets.
Now people talk about crimps in terms of micrometer readings and, when they have a problem, they don't think to actually measure what needs to be measured.

[Doby45]

You mean this one?

http://castboolits.gunloads.com/showthread.php?t=93108&highlight=spec+pic+jim

Like post #19?

Me too.

Gear

Thats exactly the one and has changed my 40cal loading completely.. No one should load lead in a 40cal without one. :wink:

[geargnasher]

Back in the old days, when we were casting bullets over the campfire, you simply removed the belling/flaring and you did it by LOOKING at the round. There was no need for a micrometer. You could FEEL the bell if it was still there and you could FEEL the lack of case mouth edge if you went too far.
Also, as part of not measuring things, we also did measure cases and bullets before and after each step using a couple of inert "dummy" rounds to be sure the lead bullets weren't being swaged down and the expander was doing its job. Then, we would order the expander stem and seating stems for our lead bullets (knowing that the dies had not been designed for the bullets we were shooting).
Right now, I am going to need to get a Lee PTE stem about 0.002" larger then the one in my Lee PTE for .40S&W--and the same may be true of the Dillon powder funnel when I go to buy one.
My son will need to order a 0.002" larger expander for his .45ACP Lee PTE due to his .453" bullets being swaged to 0.4505 unevenly. We measured, so we know where the problem is.
Now a days, Hornady is making special PTXs for lead bullets and RCBS has their "Cowboy" dies supposedly designed just for lead bullets.
Now people talk about crimps in terms of micrometer readings and, when they have a problem, they don't think to actually measure what needs to be measured.

I always recommend the micrometer method to newbies, I don't know their ability level when it comes to "feel", but if the case is .474" at the boolit driving bands and .476" at the mouth, that's something we can all understand. If it chambers and fires hundreds of times without a failure or cleaning, it doesn't matter what the measurement was.

I agree 100% about the custom expanders for the Lee PTE dies, I have five custom spuds to date, including an extra-long one for 340 grain boolits in the .45 Colt. They have all but eliminated leading, and have improved accuracy greatly in many of my guns by making case tension more consistent. An oversized spud is not an option on the .40 unless you're using a gas-checked boolit, even then it is a good idea.

Gear

[fredj338]

Back in the old days, when we were casting bullets over the campfire, you simply removed the belling/flaring and you did it by LOOKING at the round. There was no need for a micrometer. You could FEEL the bell if it was still there and you could FEEL the lack of case mouth edge if you went too far.
Also, as part of not measuring things, we also did measure cases and bullets before and after each step using a couple of inert "dummy" rounds to be sure the lead bullets weren't being swaged down and the expander was doing its job. Then, we would order the expander stem and seating stems for our lead bullets (knowing that the dies had not been designed for the bullets we were shooting).
Right now, I am going to need to get a Lee PTE stem about 0.002" larger then the one in my Lee PTE for .40S&W--and the same may be true of the Dillon powder funnel when I go to buy one.
My son will need to order a 0.002" larger expander for his .45ACP Lee PTE due to his .453" bullets being swaged to 0.4505 unevenly. We measured, so we know where the problem is.Now a days, Hornady is making special PTXs for lead bullets and RCBS has their "Cowboy" dies supposedly designed just for lead bullets.
Now people talk about crimps in terms of micrometer readings and, when they have a problem, they don't think to actually measure what needs to be measured.

I have never exp this problem & prefer my expander to be bullet size or 0.0005" smaller. Maybe I am not shooting soft enough bulet to see this?

[geargnasher]

I keep seeing people say that an expander needs to be .002" smaller than the boolit diameter being used, but actually it varies based on a number of factors. I typically use an expander that leaves the expanded case .001-2" smaller than boolit diameter, and to achieve that sometimes the expander has to be larger than boolit diameter. It depends on caliber, case nech thickness, desired boolit tension, boolit hardness, and about a million other things.

I interpreted what Noylj said to be correct, since most .45 ACP expanders are in the .449-.450" range, and gettting one that is .002" larger would be about right for making his cases accept .453" boolits without swaging, yet still have sufficient tension to keep the boolits from being seated deeper in the magazine under recoil (assuming an autoloader and not a revolver).

Gear

[farmer66]

I am a lurker and learner, but this subject has a lot interest to me. I use RCBS dies, and noticed their website lists expander plugs for the Cowboy series. They have .357, .401, .428, .430, .452, and .454 diameter, among others. These should work better than the ones I have for .357, .40 S&W, .44 Mag, and .45ACP. I use 50/50 Pb/WW and water quench, then size to .3585, .402,.432, and .4515 respectively. The expander plugs that came with the dies (1960 vintage or newer) are .3555, .397, .425, and .450.

For less than $7 each, seems a good deal. Anyone with experience using the Cowboy expanders in the old standard die bodies?

Thanks in advance,

Ken

[geargnasher]

Ken, it sounds like you've found the answer for RCBS dies. a .401 expander is perfect for the .40/10mm, .357 might be good too for .38/357, and the .430 should be about right for most .44 Magnum, but the .452 might be a little large. Good thing is it would be easy to turn down to .451 or whatever was desired for the .45s with a drill and sandpaper. The big problem with expanders made for j-words is that you can't make them bigger, but you can make an oversized one fit with a little tweaking if the part is available.

Gear

[songdog53]

Want my 40's crimped to prevent boolit's from being pushed deeper and increasing pressure. Besides on my Dillon isn't like is problem when the down stroke will taper crimp it before kicking it in to tray. Too deep might = kaboom

[sargenv]

Hmm... I guess I'm just an odd duck on this one.. to aid in a smoothly operating Dillon 650, I use the 9mm belling/flaring attachment within the powder measure to open up the mouth of my 40's to seat lead or jacketed bullets.. I size all of my 40 cal bullets to .401" and they seat and shoot fine out of three different firearms (S&W 610, Sig 229, Para P16-40). I cast and shoot a custom long round nose ~185 gr 40 and the Lee 175 truncated cone TL bullet. In fact, I use the 9mm flare/belling attachment for 9mm, 38 super, 38 spl, 357 mag, 40 S&W, and 10 mm. For the 45 if I ever load any, I use the 40 cal flare/belling attachment (Not really a die since it is a replaceable part of the powder measure).

[geargnasher]

Want my 40's crimped to prevent boolit's from being pushed deeper and increasing pressure. Besides on my Dillon isn't like is problem when the down stroke will taper crimp it before kicking it in to tray. Too deep might = kaboom

The crimp ain't what keeps the boolit from getting seated deeper under recoil, it's the case tension and the 'step' in the case, like a cannelure, left by a properly dimensioned expander plug that does that. I haven't seen too many .40 caliber boolit designs with crimp grooves into which you could tuck the mouth of the case. If you're taper-crimping enough so that the crimp alone is keeping the boolit still, you're asking for leading issues.

Gear

[farmer66]

Gearnasher, thanks for the opinion.

A followup to my post #12 above. I measured a few of each of the four calibers with the expander die inserted, and then without. A bit surprised, but all ran .002 to .0025 smaller diameter without the expander die inserted. My .44 had the most interference, a .425 expander with a .432 bullet. I calculate that would result in a .423 internal diameter brass, so this results in .009 interference. I also measured a few .44 neck diameters with the bullet seated, and they suggest the bullet is staying close to .432 diiameter. I use water quenched 50/50 mix, so I assume the brass is yielding to a .430 diameter, then the remaining .002 is the tension holding the bullet.

Other posts for accuracy suggest using lots of tension to get a uniform ignition for a .44 with hot loads. Looks to me like you only get .002 worth of tension, no matter how much you start with. I am thinking that if the bullet is hard enough, the larger expander gives a more uniform bore alignment, hence more accuracy.

I can probably calculate and measure the tension force if any interest, but I think the larger expanders will fix me up in this area.

Thanks for the info,

Ken

[Doby45]

The fact you brought the 44 in makes it apples and oranges. The 44 uses a "roll" crimp and does not rely on neck tension only. Straight wall pistol cases that use a "taper" crimp rely more on the starting neck tension and with M-type dies a "shelf" for the boolit to rest upon.

[farmer66]

Doby45, I agree and use a roll crimp on all the revolvers. After playing with the neck tension, I think the roll crimp is most of the restriction. My plan is to get the larger expander dies, and see how much different the force is to move the bullet using the old and comparing to the new. Do you think they will be the same, or am I overlooking something? I may throw a crimp in to see the effect.
All this is headed towards trying to get my SBH to shoot better. About all I can do is six inches at 50 yards.


Thanks,
Ken

[geargnasher]

Are we talking .44 Magnum or .40 S&W? Like Doby said, apples and oranges.

If you're shooting .44 Magnum loads that are hot enough to break the crimp under recoil, you should probably be using boolits that are hard enough to withstand beign seated in a .009" undersized case without getting squeezed any smaller. That means BHN in the low twenties. You're right to assume that you need case tension on the boolit for good ignition in slower powders. Crimp really doesn't do as much as you think, it's more like the icing on the cake.

The .40 likes hard boolits for top end loads with powders like HS6, BD, and Longshot (near 1150 fps with 175-grainers), but works just fine with boolits in the 12 bhn range with powders in the Unique/Universal/231 range. The key is that the .40 is a shorter case than the .44 Magnum, is thicker, and is MUCH HARDER throughout. The result is that the .40 brass needs an expander that's about the same diameter as the boolit you're shooting with either alloy or your boolits will mysteriously go on a slimming diet when seated and lead the barrel when you shoot them.

Further, you have to understand the essential difference between rimmed revolver cartridges and rimless auto-loader cartridges: In a revolver, recoil PULLS the boolit, in autos the front of the magazine PUSHES the boolit. Think about it.

Gear

[farmer66]

Doby45 and Gear, thanks for the comments, I am learning, so apologize for the hardheaded questions. I am a retired gear engineer, so please have patience. Some things I have come up:

Material is probably 70/30 brass, called C26000.
Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI
when hard. My values will be between the two.
Modulus of Elasticity is 16,000,000 PSI. This means to pull a 1.000 inch long strip to 1.001 inch long induces a 16,000 PSI stress.
So if I pull a 1.000 inch strip to 1.005 inch long, I get about 76,000 PSI, which is the max obtainable. It takes roughly the change from .430 diameter to .432 diameter to get this same effect. I think this agrees well with my readings of .002 difference in the Post #15 above.

I think I am talking myself into anything more than .003 difference in bullet to case inside diameter is a waste and can only aggravate case distortion.

Does any of this make sense? By the way, RCBS says the Cowboy expanders fit in my old 1960 vintage dies, and are sending me a free one. Hard to believe, so I ordered one for all my others.

I would appreciate a few words of wisdom,

Ken

[geargnasher]

If cartridge case mouths are worked until hard from many firings, sizings, and crimpings, they will eventually exceed their elastic limit AND yield limit when stretched over .002 (diameter), or about .006" linear and split like a melon right when you seat the boolit/bullet. Often old brass will split down the middle of the body when fired if it's too hard and been resized too much. Lots of variances in case mouth anneal. I think that there are something like five different tempers from base to mouth of Lapua bottleneck brass.

I usually shoot lead boolits with .001" to .002" case tension (dimensional interference fit), in some cases like the .44 Magnum and slow powders you need all the case tension the brass can give you.

[243winxb]

Great info. I didn't know cartridge brass had so many uses. http://www.olinbrass.com/companies/fineweld/Literature/Documents/Alloy%20C260%20Data%20Sheet.pdf
Doby45 and Gear, thanks for the comments, I am learning, so apologize for the hardheaded questions. I am a retired gear engineer, so please have patience. Some things I have come up:

Material is probably 70/30 brass, called C26000.
Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI
when hard. My values will be between the two.
Modulus of Elasticity is 16,000,000 PSI. This means to pull a 1.000 inch long strip to 1.001 inch long induces a 16,000 PSI stress.
So if I pull a 1.000 inch strip to 1.005 inch long, I get about 76,000 PSI, which is the max obtainable. It takes roughly the change from .430 diameter to .432 diameter to get this same effect. I think this agrees well with my readings of .002 difference in the Post #15 above.

I think I am talking myself into anything more than .003 difference in bullet to case inside diameter is a waste and can only aggravate case distortion.

Does any of this make sense? By the way, RCBS says the Cowboy expanders fit in my old 1960 vintage dies, and are sending me a free one. Hard to believe, so I ordered one for all my others.

I would appreciate a few words of wisdom,

Ken