Light Crimp? Heavy Crimp for 9mm???

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marathonrunner

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Guys, I am a newbe at reloading. I don't know what most are doing with crimping.

1. Do I need light or heavy crimp for 9mm? Also,

2. There does not seem to be any data for Alliant powder for pistol. I am also using Bayou bullets. They are lead round nose that are covered with polymere. Been told to use lead cast data. What do you guys recommend?

3. I didn't know but I have different 9mm brass I picked up fromi range floor. Will that really make a huge difference in accuracy?

4. Is it better to go with maximum OAL or take an average of premium factory ballistic tip like critical defense? I figure I would measure 20 rounds of factory and then choose the middle ground for OAL. Is that good?
 
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Do I need light or heavy crimp for 9mm? Also,
Click to expand...

For any case that head spaces off the mouth of the case, you only want to close the flare.

Your neck tension is what holds the bullet securely. So minimize the flare (I either use a Lyman M die, or only flare about 0.0015" for jacked and 0.002" for lead). I use a taper crimp die and only close the flare. You can verify with calipers. And if you expand too much, you can never regain the bullet retention by crimping. Just my experience.

I load to the maximum OAL, but in many cases I have to bump up the powder charge to offset the increase in case capacity. Unless limited by the bullet contacting the lands, I load everything at the SAAMI max of 1.169". Some conical nose lead bullets have to be much shorter.
 
If you have not done so, suggest you get a couple of good loading manuals and read the first chapters carefully, the ones before the loading tables.
Lyman has an excellent manual for cast loads.

I use pickup brass from the range routinely; just have to inspect carefully.
 
Most certainly light to no crimp for 9mm. I'm finding bullet type makes a difference as well. As Jepp2 mentioned, 9mm headspaces on the mouth so your load, pistol and even brand of brass will dictate how much crimp you can or need to apply. Sorry but trial and error in your particular pistol is the answer. Hey - it's part of the fun. Good luck!
 
I bought Lyman's and I really love this manual. Hornady was awful. I don't know how you can use no crimp, with recoil heard that will cause bullet to fall out. I have never seated a bullet but correct me if I am wrong, are you supposed to just set the bullet on top of the brass and if it sits without falling over or slanting is that good enough? Will crimping cause the OAL to shorten? Will it move the bullet more inside the case?
 
Consult your manuals. Most if not all semi auto use a TAPER crimp. Most if not all dies that seat also taper crimp (read the instructions) You can crimp with a separate die.

The crimp of a semi auto is primarily used to remove the flare made to seat the bullet.

Neck Tension is what holds the bullet. Read the manual.

How are most rifle bullets held in place?? They are not flared and not crimped unless some used in semi autos.

COL is discussed in the manuals and setting up of the dies.
 
marathonrunner said:
I bought Lyman's and I really love this manual. Hornady was awful. I don't know how you can use no crimp, with recoil heard that will cause bullet to fall out. I have never seated a bullet but correct me if I am wrong, are you supposed to just set the bullet on top of the brass and if it sits without falling over or slanting is that good enough? Will crimping cause the OAL to shorten? Will it move the bullet more inside the case?
Click to expand...

You ave a lot to learn & have handicapped yourself a bit by using bullets that you can't find good data with. Yes, use lead bullet data if you can find it. Barring that, use starting jacketed data & work up.
As always, oal is bullet & gun specific, the oal must fit your gun, there is no standard. Measuring factory doesn't help much not the identical bullet. Dummy round, remove the bbl, adjust till it fits.
A taper crimp, what the 9mm uses, can not hold the bullet in place unless grossly applied. Proper neck tension does that. The crimp just finishes the reloading process. Crimping shouldn't affect oal, done with dies properly adjusted. As noted, reread your manual, all this is covered.
 
First, stop reloading and buy some manuals and read them before preceeding. Mark them up with high lighters. Make notes in them. Suggest you start with Lymans 49th edition Reloading Handbook, then read Lee 2nd edition, then Sierra V 7th printing, then Hornady 9th edition. At the same time, watch all of Bill Morgan you tube vids even if you have a different press (search Bill Morgan Hornady then start on vid 1). He also goes thru bullets, etc. Never take a forum response as Gospel. Always compare forum information against the reloading manuals. In those manuals, you will find a lot of mysteries solved. It will also make the hobby more enjoyable. Download from the reloading press manufacturers, sizer, expander, saeter, crimp pfd's and read each of them. Suffice it to say, you need bullet diameter plus twice the case thickness for your crimp. For that you need a caliper and a standard to ensure your calipers are accurate. Buy a standard on ebay for $15 and go to Harbor Freight and find a couple digital calipers that read accurately to the .001." I have Hornady dial calipers and the Harbor Freight that read just as accurate as the expensive calipers (.001). If you are using a Lee FCD, read the instructions that came with it. They mention 1/2 turn for light taper crimp.
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List the bullet used, the grains of powder, and the OAL.
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One of the important things to pay attention to in the manuals is about primers and keeping primer tubes clean of primer dust.
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Another point: People will decap a good primer on a bent casing and re-use it. This is not something a person new to reloading wants to do. I will not do so. I go start the lawn mower and rev the engine and fire the round (empty of powder and bullet of course). When you insert a primer you are also priming the primer so to speak. Read the manuals. Lee makes a good point about hotter primers (ie Federal).
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At any rate, slow down and read the manuals first. Safety is a big part of the hobby.
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Always wear eye pro!!!
 
marathonrunner said:
Guys, I am a newbe at reloading. I don't know what most are doing with crimping.

1. Do I need light or heavy crimp for 9mm? Also,

2. There does not seem to be any data for Alliant powder for pistol. I am also using Bayou bullets. They are lead round nose that are covered with polymere. Been told to use lead cast data. What do you guys recommend?

3. I didn't know but I have different 9mm brass I picked up fromi range floor. Will that really make a huge difference in accuracy?

4. Is it better to go with maximum OAL or take an average of premium factory ballistic tip like critical defense? I figure I would measure 20 rounds of factory and then choose the middle ground for OAL. Is that good?
Click to expand...

No data for Alliant powder? Go to their site and they have reloading info for all calibers. Get a good reloading manual or better yet get two. Nearly all reloading manuals will have data for 9mm. Lyman's 'Cast Reloading Manual' is exclusively lead data. Their '49th Reloading Manual' has data for both lead and jacketed.

You can go with medium to max OAL but don't go too short as that will raise pressures like crazy.

9mm only needs a TAPER crimp, don't cinch down the bullet, just take the flare off the mouths of the cases. As pointed out before, the 9mm headspace position is held by the mouth of the case against a lip in the chamber. Doing a 'plunk test' with a barrel or gauge will tell if everything is ok.

Mixed brass isn't a big deal unless you're trying to be a marksman or compete in tournaments.
 
If you're going to load lead bullets I highly recommend buying the Lyman 4th Edition Cast Bullet Handbook. Lyman Cast Bullet Handbook: 4th Edition Book It is not a reprint of the lead data in the Lyman 49th Edition Reloading Manual, it contains load data for Lyman molds and molds from other companies. (for the first time ever) Lyman Reloading Handbook: 49th Edition Reloading Manual If you bought both you would not be wasting money, it's not a duplicate.

Like already said, case neck tension holds the bullet in place, not crimp. In semi-auto ammo you crimp to remove the flare you added to aid in starting the bullet. Use just enough crimp to remove the bell.

Alliant has plenty of load data for handgun loads. It's a good source to use for crosschecking the data in your manual/manuals. I trust the powder companies for load data. Alliant Powder - Reloader's Guide

Read up, make some test rounds with no powder and primers for practice to be sure they fit in your barrel and then have at it!

Good luck and keep us updated on how your ammo shoots...
 
The bullet material determines how much grip the taper crimp used on semi auto cartridges will have. Jacketed bullets provide a better grip for the crimp than lead bullets with plated being somewhere in the middle. Lead and plated bullets usually have more neck tension as they are usually .356" in diameter or .001" greater in diameter than jacketed bullets at .355".

At a minimum you need enough taper crimp to remove the case mouth belling. If the bullet exhibits set back when chambered and extracted then more crimp is likely needed. An easy test is to push the bullet into the edge of the bench with thumb pressure and see if it remains in place. How much crimp needed should be determined with a little trial and error. Increase the crimp a bit and check the bullet for movement as described previously, repeat as necessary. Don't use more crimp than is needed to hold the bullet in place. All jacketed factory ammo is crimped at the case mouth. Examine a factory round to get an idea of how much crimp to use if loading jacketed bullets.

One advantage of the Lee FC die is that you can not over crimp the round as the die will only reduce the neck diameter no further than SAAMI minimum diameter.
 
wow you all are great! I can tell most here work at gun stores...lol....but everybody here answered questions that my Lyman manual did not and Lee dies failed to make clear. I have so far gotten to the point where all my cases are now clean as I use ultrasonic. I got it now all resized, I now have a primer pocket cleaner that I plan on doing to all cases. Then I will run them through ultrasonic one more time to clean then start flaring the cases. My only other question is how much do I flare? Manual says just enough so the bullet sits. Also said to flare as little as possible to maximize case. So how do I determine that?
 
Case life & 9mm shouldn't be in the same sentence, there's countless 1000's of them laying around.

You want to flare your case mouth so that the base of the bullet starts in the case. It will do you no good to shave lead off of a $.07 bullet making it useless to save the case life of a $.02 piece of brass.

I have used a 3/1000ths taper crimp on everything I've loaded when using a taper crimp for the different pistol calibers. To find out how much you taper crimping anything you need:
A set of dial calipers
The dimensions of the case

The front edge of the case dimension is what your looking for, the 9mm is .380". You crimp should measure .377", use a set of dial calipers to measure the very front edge of where the brass meets the bullet.

Something to think about:
When a revolver reload has a crimp that fails the bullet will jump forward binding the cylinder from turning (bullet nose hits yoke/frame). As irritating as it is no one gets hurt unless your in the middle of a gunfight. Hence test your ammo/firearm combo.
When a reload for a semi-auto has crimp failure the bullet does what's know as setback. The bullet will actually go deeper into the case. The bullet "setback" could affect the feeding of the firearm but the major concern is high pressure. The more/deeper the bullet is set into the case, the less case capacity there is. Less case capacity + same powder charge ='s more pressure.

It seems that 99% of the time I read about a firearm going kaboom it has to do with:
titegroup powder
9mm reloads
40s&w reloads
bluedot powder

I don't know what firearm you plan on using these reloads in but I've owned several different 9mm's over the decades (anything from s&w 39's to 1911's chambered in 9mm). When I reloaded for them I always tried to leave the oal/bullet long in the case & tested for function. And never did fullhouse loads, the case capacity of the 9mm is sooooo small it doesn't take much for bad things to happen real quick.

Awhile back there was an excellent post in this forum where a guy sent an e-mail to a major powder mfg. He asked about the 9mm & pressure differences with a bullets seating depth/setback. He posted the e-mail responce he got back, it was a real eye opener!!!! The e-mail stated the pressure of their p+ 9mm loads were around 35,000psi, safe & well within the limits of that caliber. When they moved the bullet 30/1000ths deeper (setback from too light of a crimp) the pressures spiked & were well over the SAAMI max pressure of 38,500psi.

I would be in your best interests to do a little research & verify the case dimensions of the 9mm along with buying a good dial caliper & some factory ammo to measure to see what they're doing. You can get away with a light/little/no crimp with low pressure cases like the 38spl/44spl/45acp. But you're asking for trouble if you try to do the same thing with the 9mm.

be safe
 
crimp

Forrest r said:
Case life & 9mm shouldn't be in the same sentence, there's countless 1000's of them laying around.

You want to flare your case mouth so that the base of the bullet starts in the case. It will do you no good to shave lead off of a $.07 bullet making it useless to save the case life of a $.02 piece of brass.

I have used a 3/1000ths taper crimp on everything I've loaded when using a taper crimp for the different pistol calibers. To find out how much you taper crimping anything you need:
A set of dial calipers
The dimensions of the case

The front edge of the case dimension is what your looking for, the 9mm is .380". You crimp should measure .377", use a set of dial calipers to measure the very front edge of where the brass meets the bullet.

Something to think about:
When a revolver reload has a crimp that fails the bullet will jump forward binding the cylinder from turning (bullet nose hits yoke/frame). As irritating as it is no one gets hurt unless your in the middle of a gunfight. Hence test your ammo/firearm combo.
When a reload for a semi-auto has crimp failure the bullet does what's know as setback. The bullet will actually go deeper into the case. The bullet "setback" could affect the feeding of the firearm but the major concern is high pressure. The more/deeper the bullet is set into the case, the less case capacity there is. Less case capacity + same powder charge ='s more pressure.

It seems that 99% of the time I read about a firearm going kaboom it has to do with:
titegroup powder
9mm reloads
40s&w reloads
bluedot powder

I don't know what firearm you plan on using these reloads in but I've owned several different 9mm's over the decades (anything from s&w 39's to 1911's chambered in 9mm). When I reloaded for them I always tried to leave the oal/bullet long in the case & tested for function. And never did fullhouse loads, the case capacity of the 9mm is sooooo small it doesn't take much for bad things to happen real quick.

Awhile back there was an excellent post in this forum where a guy sent an e-mail to a major powder mfg. He asked about the 9mm & pressure differences with a bullets seating depth/setback. He posted the e-mail responce he got back, it was a real eye opener!!!! The e-mail stated the pressure of their p+ 9mm loads were around 35,000psi, safe & well within the limits of that caliber. When they moved the bullet 30/1000ths deeper (setback from too light of a crimp) the pressures spiked & were well over the SAAMI max pressure of 38,500psi.

I would be in your best interests to do a little research & verify the case dimensions of the 9mm along with buying a good dial caliper & some factory ammo to measure to see what they're doing. You can get away with a light/little/no crimp with low pressure cases like the 38spl/44spl/45acp. But you're asking for trouble if you try to do the same thing with the 9mm.

be safe
Click to expand...

So maybe I should do a heavy crimp to be safe I think. Is there any drawback to a heavier crimp? I do have calipers and will match the factory stuff. I am a bit confused as to what you mean by shaving off the bullet by flaring the brass. Are you saying to use as little flare as possible or more?
 
marathonrunner said:
So maybe I should do a heavy crimp to be safe I think. Is there any drawback to a heavier crimp? I do have calipers and will match the factory stuff. I am a bit confused as to what you mean by shaving off the bullet by flaring the brass. Are you saying to use as little flare as possible or more?
Click to expand...

Crimp does NOT prevent bullet setback!!! Neck tension is what securely holds the bullet, not crimp!

Yes, there is a drawback to too much crimp. Brass is elastic, the bullet is not. Crimp squeezes the bullet down, while the elastic brass case will spring back. This reduces neck tension, making setback problems worse.

Yes, use as little flare as possible, just enough that you don't shave bullets. Excessive flare reduces neck tension. Crimp will NOT restore it.

How much crimp? This depends on your choice of brass, bullets, and firearm.

This how I do it:

Strip the gun, remove the barrel. Make a dummy round, no powder or primer, with NO crimp. Drop dummy round into breech. Does it freely chamber, and then drop out again (the plunk test)? If not, apply a TINY amount of crimp and repeat. When it passes the plunk test, STOP. You are done.

I don't load 9mm, but I went through this when I started loading .45 auto. My biggest sources of problems were too much crimp and RP brass.
 
Crimping reduces the diameter of the case to hold the bullet in. Since the 9mm headspaces on the case mouth that is a bad idea. It is not that people work at gunshops it is that shooting is inherently dangerous. Reloading your own makes it more so and handicapping yourself by only getting knowledge from youtube videos or the like leaves one with less than 5 fingers on a hand.
 
marathonrunner said:
...I now have a primer pocket cleaner that I plan on doing to all cases. ...
Click to expand...

Just so you know, cleaning primer pockets is really not necessary for pistol calibers like 9mm. I've never done it for 1000's of reloads that have worked just fine for both 9mm and 45 ACP.
 
No heavy crimp, like said above that can cause problems. Just apply enough crimp to iron out the bell/flare you applied to aid in seating the bullet. If you apply too much crimp you can cause the bullet not to headspace correctly.

I agree, I have never cleaned a handgun case primer pocket and don't think I ever will.

Don't over think this, just load up 10 or so rounds and shoot them! (relax, it will be fine!)
 
A lot to think about when starting out, isn't there? As far as crimp goes, for a 9 mm that headspaces on the case mouth, it might be helpful to forget the term crimp altogether, and think of it as simply removing the flare you put in to get the bullet started. If your case is properly sized to begin with, the tension of the case will hold the bullet in place.
 
A 3/1000ths crimp is not a heavy crimp by any means. That's 1 & 1/2 1000ths per side for those who have a hard time with math. Heck ask any bullseye shooter that uses powder puff loads in a 45acp 1911 what crimp to use & you'll get the same boring answer, .469 to .470. And yes a 45acp case is .473. If you want to put little or no crimp on a high pressure small case capacity round like the 9mm, knock yourself out. But you might consider asking any of the people who make print reloading manuals via email or phone what they think about reloading 9mm's without any crimp because the french guy from the internet told you that a crimp isn't necessary.

Take a look at any 9mm jacketed bullet out there that has a cannalure. If you would bother to take the time & measure the indent called a cannalure (you know the thing with lines where the bullet mfg's want you to to crimp the bullet at) you will find its 2 to 3/1000ths deep compared to the body of the bullet. Gee the guys with no crimp must have a gap in their ammo.

If you taper crimp correctly only the end of the case (the last 1/16th of an inch) has the taper crimp. Any more than that it starts swaging the bullet smaller.

Take a little time & go thru some of the 9mm range brass you have laying around & look for a crimp line in the center of the brass. That's there to stop bullet setback!!! They are using that center crimp in allot of p+ 9mm ammo anymore. The "famous neck tension will hold" only goes so far. The taper crimp can only be so deep before it causes problems. So the ammo mfg's came up with the solution of putting a crimp in the brass right below the base of the bullet to prevent setback.

A simple test:
Load a round with no crimp/only neck tension. Set it on a table & push on the head of the bullet with your thumb. Then do the same thing with a 3/1000ths taper crimp.

As far as letting the barrel be your guide in telling you what you need. That's for the bullets oal not the taper crimp. There's soooooo much differences in the 9mm barrels out there between the different mfg's it's scary. It's extremely common for 9mm reloaders to use the expander plug from a 38/357 die to expand their 9mm brass. Another huge trend is the use of .357 & .358 diameter bullets in the 9mm's to stop leading from cast bullets. You know that slug/measure/size bullets to the correct diameter thing. Don't you find it odd that someone can stuff a bullet 3/1000ths bigger (9mm ='s .355/bullet .358) in a 9mm case & it will still headspace correctly.

You really should call a couple people like alliant, hodgdon, speer, hornady along with the people who mfg'd the reloading dies you're using & tell them you've been told not to crimp your 9mm reloads. You will get an answer from the people who make/do this for a living & have done so for a couple of decades anyway.
 
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