To crimp or not to crimp - What a question!

[the count]

I got the factory crimp die for each pistol caliber I reload, 9mm, 38 SPL, 45 LC, 45 ACP.

The old timers at the range keep telling me there is no need to put a crimp on these rounds as they head space on the case mouth. Is this true? Just wasting my time? On the other hand I keep hearing how 'great' the factory crimp is...

 

[BeerSleeper]

I don't understand what good the FCD is for auto pistol rounds. The "factory" rounds I buy at walmart have no crimp on them...

 

[cfullgraf]

Back in the days (1980 or so) when all dies came with roll crimps, a roll crimp was not to be put on a case for a semi-auto pistol. Actually, today as well, roll crimps are not suitable for pistol cartridges.

The process was to barely bell the case so that there essentially was no bell left when the bullet was seated. No crimping needed. But, the potential for case damage or bullet shaving was increased.

Properly set, a roll crimp can remove the belling ro pistol cases, unless all the cases are the same length, the "crimp" can be variable.

In those days, companies started to offer separate taper crimp dies.

Now a days, taper crimps are the norm in pistol dies.

You don't want to leave excess belling on your pistol cases and belling the cases to minimal dimensions is a pain. So, bell the case for reliable loading and use a taper crimp to remove it.

So, the old guys are technically correct but in my opinion, technology has passed them by.

 

[buck460XVR]

I got the factory crimp die for each pistol caliber I reload, 9mm, 38 SPL, 45 LC, 45 ACP.

The old timers at the range keep telling me there is no need to put a crimp on these rounds as they head space on the case mouth. Is this true? Just wasting my time? On the other hand I keep hearing how 'great' the factory crimp is...

The .38SPL and .45 LC, DO NOT head space on the case mouth. If you have die sets for the calibers you are reloading, you probably already have the correct crimp die in the set. For revolvers and cannelured bullets you use a roll crimp. For pistol and bullets with no cannelure, you use a taper crimp. A roll crimp locks into the cannelure and prevents the bullet from movement either from recoil or from tension in a tubular magazine. The taper crimp used on pistol rounds basically just takes the bell/flare off the case mouth to assist in feeding and chambering.

 

[Vern Humphrey]

I got the factory crimp die for each pistol caliber I reload, 9mm, 38 SPL, 45 LC, 45 ACP.

The old timers at the range keep telling me there is no need to put a crimp on these rounds as they head space on the case mouth. Is this true? Just wasting my time? On the other hand I keep hearing how 'great' the factory crimp is...

You have to slightly flare the case mouth to load each of those cartridges, and the flare must be ironed out to get proper feeding in 9mm and .45 ACP. A taper crimp is what you need there.

The revolver cartridges also need crimp to keep the bullets from creeping during recoil and to get proper combustion. You can use taper crimps in those cartridges, too -- using your 9mm taper crimp for .38 Special and your .45 ACP crimp for .45 Colt.

You may, however, find a roll crimp works best for your revolver loads,

 

[Bula]

It was my understanding that revolver calibers roll crimp, auto calibers taper crimp. You do need to remove the belling on auto rounds for reliable feeding. I also roll crimp all my revo loads (how heavy the crimp is determined buy how heavy the load). What i did do, was knock out the carbide rings on all my Lee FCD in pistol calibers. I think the old timers are saying you don't need to post resize with that carbide ring. I agree with that, but I crimp'em all.

 

[Walkalong]

A slight taper crimp on auto cases that headspace on the case mouth. For revolver rounds that headspace on the rim, a roll crimp is standard, with some applications using a taper crimp.

I do not believe in post sizing rounds, but many folks use the FCD. I prefer to crimp normally without post sizing.

 

[PapaG]

You might not think your wallyworld cases have no crimp but they are taper crimped.....barely discernable.
Anyone who tells you that the 45 Colt and 38 special headspace on the case mouth has no business telling you anything. They need a crimp to burn the powder correctly and to prevent the bullets pulling forward under recoil

 

[Steve C]

The "factory" rounds I buy at walmart have no crimp on them

You'd better check your rounds closely again. I've never seen a factory round that isn't crimped.

Crimp serves 2 main purposes, one is to keep the bullet in place during recoil. Important with mostly magnum revolver cartridges and heavy bullets. This prevents the bullets from pulling out and tieing up the cylinder.

The second function is to prevent bullet set back, mostly for semi auto pistol cartridges that get the bullet nose pushed into a feed ramp by the action as they're stripped from the magazine.

Crimp is also useful in holding the bullet tight in place allowing for more pressure to build up. Important with some loads and powders, notably slow pistol ball powders like H110 and W296.

How much crimp you need (if any) depends upon your load, the bullet and brass you are using and if you are likely to experience any of the problems described previously. If the bullet fits tightly then no crimp may be needed but to say that you never should crimp is nonsense as would be saying you always need to crimp.

Personally I like the Lee FC dies for semi auto rands and for rifle calibers that will be fired in military semi auto's. The revolver FC dies work fine as does crimping using the seating die so I don't see any big advantage to them for the .38 spl/.357 mag or .45 LC other than if you want to crimp in a separate operation and have a progressive press.

Best thing about the Lee FC dies for handguns is that you are assured that the ammo run through them are no greater dimensionally than maximum SAAMI spec and the crimp is does not reduce the case neck below minimum SAAMI dimensions. Some people comment that the FC dies size the case and bullet but unless the OD diameter of the case area holding the bullet is larger than max SAAMI no sizing will take place. It will however iron out any bulged spots in the round and assure the round will chamber.

 

[1SOW]

The term "crimp" sometimes means different things from different folks.

As others have said, in straight wall cases a 'tapered crimp' is necessary to remove the case mouth bell put in by the seating die. Many want just enough taper crimp to take out the bell and form it back to the bullet. Others believe a little tighter yet gives higher pressures and tighter groups (45acp bullseye shooters).

With 9mm I like .376-ish after taper crimp. Saami spec is .380 (corrected later) if memory serves.

You do need to remove the bell back to 'at least' SAAMI specs and then to fit properly in your chamber.

Hope this makes sense.

 

[gamestalker]

Crimping revolver rounds is an absolute and can get you in trouble if your not. Gases blowing back will dislodge revolver rounds from the mouth which can get dangerous. If a bullet jumps out of the mouth a fired round can ignite the powder charge, thus causing a very explosive situation!

 

[murf]

if you have the factory crimp die, use it. handgun rounds with a rim headspace on the rim. those without a rim headspace on the case mouth. the directions included with the die sets wil help you with the crimping step.

murf

 

[GLOOB]

Your seating die can do the same crimp as the FCD.

The FCD's reason for existing is to post-size the round. The fact that it also does a crimp can be thought of as a bonus.

The post-sizing is basically there to make sure your reloads will chamber. When the bullet is seated, it stretches the neck to a larger diameter, hence the "coke bottle" effect. If the bullet is out of spec, being too large or deformed, it might not chamber. The FCD squishes the bullet and neck back down to SAAMI specs. It's basically a failsafe die, to catch abnormal rounds. Think of it as a chamber check, except the failures get fixed in the process.

So the question "to crimp, or not to crimp" really has nothing to do with your FCD's. The question, there, is "to post-size, or not to post-size."

 

[ArchAngelCD]

If you are using Lee Factory Crimp dies you have the correct type of crimp for the round you're loading. The Lee Factory Crimp Dies for the .38 Special and .45 Colt are roll crimp Dies whereas the 9mm and .45 Auto Factory Crimp Dies apply a taper crimp. Like said above, the seating dies will do the same as the FCD but I like to apply the crimp in a separate operation. Unless you're doing something wrong the Lee FCD will not post-size a round. Something has gone very wrong if that happens and I've never had it happen to any round I've loaded.

 

[BeerSleeper]

I think Gloob's explanation makes a lot of sense. I don't have a FCD, and I've not yet had a reload fail to chamber, so I don't think I have a burning need to go out and get one just yet.

I still have a hard time thinking of a taper crimp as a "crimp", when it's really just removing the bell. I had always thought of a crimp as a roll crimp, and a taper crimp as just "de-belling". Same idea, I was just thinking of it in different terms.

 

[cfullgraf]

I still have a hard time thinking of a taper crimp as a "crimp", when it's really just removing the bell. I had always thought of a crimp as a roll crimp, and a taper crimp as just "de-belling". Same idea, I was just thinking of it in different terms.

You are probably correct. Since the crimping, whether roll or taper, happens at the same point of the reloading cycle the name crimp stuck for the taper crimp.

Kind of like Lee's Factory Crimp Die does more than crimping but does not reflect that in it's name.

By the way, the original poster was asking about crimping auto pistol rounds that headspace on the case mouth.

 

[Walkalong]

The OP mentions both type rounds. Ones that need a taper crimp and ones that need a roll crimp.

The FCD's reason for existing is to post-size the round. The fact that it also does a crimp can be thought of as a bonus.

Yep. The FCD for pistols does two different things.

It crimps, just like any other crimp die, but also uses a carbide ring to squish any over sized (diameter only) round into submission.

I prefer to make my rounds to where the post sizing is not needed, and use normal crimp dies. Lee makes those as well if you prefer Lee.

There is one good use for the FCD, and that is for reloaders making tons of rounds for IDPA (or similar) matches using lead bullets and mixed brass where some might be a hair over sized. The FCD assures that round will chamber and not screw up their match. Many prefer this to checking all those rounds in a gauge (or their chamber). They do not need fine accuracy, only acceptable accuracy. 100% function is more important.

 

[LiveLife]

I prefer to make my rounds to where the post sizing is not needed, and use normal crimp dies. Lee makes those as well if you prefer Lee.

There is one good use for the FCD, and that is for reloaders making tons of rounds for IDPA (or similar) matches using lead bullets and mixed brass where some might be a hair over sized. The FCD assures that round will chamber and not screw up their match. Many prefer this to checking all those rounds in a gauge (or their chamber). They do not need fine accuracy, only acceptable accuracy. 100% function is more important.

This comment is for semi-auto pistol reloading, not revolver/rifle. +1 to what Walkalong posted. In recent years, I have come across some inconsistent brass quality and case wall thickness variations.

One batch of new lot once-fired PMC 40S&W brass was found to be softer and the cases were crushing/bulging ever so slightly when I was seating the bullet. These chambered fine in 40S&W Glock and M&P barrels, but failed to chamber fully in tight Lone Wolf barrels. I did not have the same problem with other head stamp cases. I tried increasing the case neck flare, but it did not help. This is one of those rare situations where FCD is perfect for. Post sizing with FCD would restore the finished round's dimensions so the round dropped freely into the tight Lone Wolf barrels.

If you reload for most semi-auto pistols, you'll notice a factory round will "rattle" in looser chambers like Glocks. But if "bulged" reloaded rounds were chambered in tighter factory or aftermarket barrels, they may not chamber fully.

I still adjust all of my dies (without the FCD) so they chamber freely even in tight Lone Wolf barrels. FCD is a cheap insurance to have on hand in case you run into problem like this.

 

[cfullgraf]

The OP mentions both type rounds. Ones that need a taper crimp and ones that need a roll crimp.

Oops, I stand corrected. i was focusing on the comment about headspacing on the case mouth which 38 Special and 45 Colt do not do.

 

[Walkalong]

This comment is for semi-auto pistol reloading, not revolver/rifle

Yes. I should have clarified.

 

[gearjammer-2000]

I learned from a very painful experience that not only do you have to crimp revolver loads but you have to FIRMLY crimp revolver loads.
A mishap with a .44 involving bullet creep and a trip to the hospital taught my that, after a 3 week recovery I then proceeded to go out to the bench and crank down the crimp die and recrimp all my .44 reloads and NEVER again will I put such a light crimp on any round.

 

[BigBob3006]

The Count,

Yes/no.

Let me explain. Pistol cartridges, those fired in a semi-auto pistol do head space on the lip of the case. I load my .45 ACP so the cases head space on the bullet and the use a light taper crimp.
Revolver cases head space on the down side of the rim of a case when the cartridge is in the chamber. I prefer a light roll crimp on revolver cartridges and cases to be fired in a lever action rifle if the bullet has a crimp groove or cannelure

The magnum cases should have more crimp.

The old timers who shot the .38 Special in target matches seldom ever used a crimp on their cases. Those cases held mild loads and lasted for almost ever. I know one old timer who went to new cases because he has lost to many cases. The old f**t forgot to pick up his cases sometimes.