seating coated lead bullets

S

Shadow9mm

New member
First time with lead bullets. 9mm, .356, with the grease groove. I meant to get without the groove, oops. I'm doing some learning and have a few questions.

Do they NEED to be crimped? never crimped 9mm before

they do need flare to seat so do I need to crimp to close the case mouth back up?

The bullet has a shoulder/taper before the grease bands. should this be showing? I would assume it would need to to be able to crimp.

Will the shoulder cause any feeding issues, like a SWC?

With the bullet diameter being smaller until the grease rings, it should not have any plunk (ogive hitting lands) issue right? will this cause any accuracy issues as it could be "jumping" farther. I know this is taken into consideration with rifles, but from my understanding with handguns, as long as it was not hitting it is fine.


Did a few seating tests, need a touch more flare. first 3 tries. last one was not too bad but needs just a bit more.

Seated, 1.127
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Pulled, 1st, 2nd, 3rd try, still need a touch more flare
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You'll have to flare more than jacketed because cast are made .001 larger. And yes, you'll need to crimp, but just enough to remove the flare. Most I know will crimp just enough to bring the case mouth back to saami spec, or maybe a half thou under. Remember, 9mm, and practically all straight wall semi auto cartridges headspace off the case mouth, so that dimension is very important. You don't want it rolled in

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Two types of crimp,

Taper Crimp (for 9mm and the like for semi auto) roll crimp for straight wall cases and in particular magnums.

A good taper crimp for 9mm. You do not want that bullet to move when it cycles up and through the feed ramp.
 
RC20 said:
Two types of crimp,

Taper Crimp (for 9mm and the like for semi auto) roll crimp for straight wall cases and in particular magnums.

A good taper crimp for 9mm. You do not want that bullet to move when it cycles up and through the feed ramp.
Click to expand...
ok, my hornady seater has a taper crimp. put a case in and ran he die down till it touched. added 1/4 turn. seems to be a light crimp. drops into my round gauge fine.
 
You don't want to hard of ANY crimp on a cartridge that headspaces off the mouth. Roll, taper, doesn't matter. That diameter/dimension is critical. Bring it back to spec, maybe a TOUCH under. That's IT. too hard a taper crimp will roll the edge over too

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measured the case mouths .

SAAMI spec, max 0.380

resized unloaded .0376
resized, flared before loading, 0.3815

loaded, FMJ, no crimp 0.376
loaded, lead, crimp 0.376
 
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1) Flare MORE. more rounds are ruined by not flaring enough than cases are ruined from too much flare.
2) Bullets must be as square on the case as possible and the seating stem really need to fit the bullet. I often order custom seating stems and ask that the seater not touch the bullet meplat/nose and only contact as low on the ogive as possible. Note the marks on the bullets from your seater.
3) Taper crimp is ONLY to remove the flare. It is NOT to crimp in the bullet.
4) I find that coated bullets are slightly less accurate than std lead bullets and groove or non-groove makes no difference. Some people like no-groove as they gain a couple of mils of internal length and others prefer groove as they gain mils of bearing surface. The casting companies LOVE no-groove as they fall out of the mold so much easier...
5) Did you measure your actual groove diameter of your barrel and order bullets that were at least 0.001" larger?
 
noylj said:
1) Flare MORE. more rounds are ruined by not flaring enough than cases are ruined from too much flare.
2) Bullets must be as square on the case as possible and the seating stem really need to fit the bullet. I often order custom seating stems and ask that the seater not touch the bullet meplat/nose and only contact as low on the ogive as possible. Note the marks on the bullets from your seater.
3) Taper crimp is ONLY to remove the flare. It is NOT to crimp in the bullet.
4) I find that coated bullets are slightly less accurate than std lead bullets and groove or non-groove makes no difference. Some people like no-groove as they gain a couple of mils of internal length and others prefer groove as they gain mils of bearing surface. The casting companies LOVE no-groove as they fall out of the mold so much easier...
5) Did you measure your actual groove diameter of your barrel and order bullets that were at least 0.001" larger?
Click to expand...
I did not measure until after I ordered. both guns are measuring between .3550 and .3555 between a couple measurements, depending on how i position them and how much pressure I apply. so these will be .0005 larger than the bore. not ideal. I probably need to order 0.357 in the future.
 
Flare is important but should a case be expanded to .001"-.002" less than the bullet diameter to reduce swaging? Brass case walls vary by brand.
 
1) Flare MORE. more rounds are ruined by not flaring enough than cases are ruined from too much flare.
2) Bullets must be as square on the case as possible and the seating stem really need to fit the bullet. I often order custom seating stems and ask that the seater not touch the bullet meplat/nose and only contact as low on the ogive as possible. Note the marks on the bullets from your seater.
3) Taper crimp is ONLY to remove the flare. It is NOT to crimp in the bullet.
4) I find that coated bullets are slightly less accurate than std lead bullets and groove or non-groove makes no difference. Some people like no-groove as they gain a couple of mils of internal length and others prefer groove as they gain mils of bearing surface. The casting companies LOVE no-groove as they fall out of the mold so much easier...
5) Did you measure your actual groove diameter of your barrel and order bullets that were at least 0.001" larger?
Click to expand...

This. All of it. Especially the flare more part. And proper size. In your case the .356 will probably shoot ok. .357 would be safe and may shoot better, but .356 is probably fine.
 
I do think it would be hard to taper crimp a 9mm or the like from working.

Gauges would be a help. Sierra recommends a firm taper crimp which is what I do and have had not problems (I am no expert on that head space)

I do know that I got 45 GAP (god awfull projecti9) in a 45 ACP (yea I did not know there was something stupid like GAP out there (and yes, you should read labels and I did screw up but who in their right mind would do a SHORTER 45 ACP? - yea, only Glock).

It fired, no issues, no damage, would not cycle.

I think the bigger issue is you drive the bullet back and wind up with a pressure spike but that is a take/view/opinion and not from anything that says that specifically.

Shorter or not it fired just fine. I don't begin to recommend it.

Kind of puts the mouth head space in some perspective though.

My guess is the extractor held the case and let the firing pin work.

Not that I want to find out but I have seen head space issue on rifles that won't fire as its too great, dents a primer but the case is moving and does not get a firing smack.
 
If any crimping is done with typical straight pistol cases,it should be taper vs roll crimping. 9mm,45 ACP,etc dies typically taper crimp. 357,44 mag,etc revolver dies typically roll crimp.

Crimping semi-auto pistol cartridges is done primarily to resist set back .
The benefit of crimping regarding bullet retention is controversial. I was firmly convinced crimping was good. Debate here on TFL lead me to research the subject.
I have not done any scientific research. Some searching and reading on the web have caused me to concede there may not be benefit to crimping beyond removing bell. The loudest voices on forums indicated crimping may be detrimental. Of course,loudest is not necessarilly "more correct" Its not an absolute conclusion,IMO.

Regarding crimping cartridges that headspace on the case mouth: Do not think in terms of roll crimping. Some loading data will give a "Crimp Dimension" You set your crimp so you measure that diameter at the case mouth . It allows plenty of square case mouth for definite headspacing.Its just a non-issue.
A rule of thumb starting point for setting taper crimp dia I took from a magazine article is twice the case mouth wall thickness,plus your bullet diameter ... (which would be zero bell,zero crimp) minus .003 or .004, which would be .0015 to .002 crimp per side. That leaves the rest of the .010+ case wall for headspace.

Once again,its a controversial topic. Zero bell,zero crimp might work as well as a light crimp,or even better. I cannot say for sure.

A taper crimp would generally be .002 or less per side. Over doing it is detrimental.
 
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Got it fixed thanks. The flare with my hornady die just gave the mouth a bell and the bullet kept trying to tip over. I got a Lyman M-die, as well as the lee universal flare with custom inserts from NOE that are similar to the m-die. They are sitting in and staying straight during loading now. thanks.
 
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