Crimping rifle rounds

[utvolsfan77]

Hey guys, do any of you taper crimp your bottleneck rifle cartridges? If so, what are the advantages of doing so?

I have Lee die sets for all of my calibers (.22-250, .243, .270, .270WSM, .308, ,30-06, and 300 WinMag), including the Lee Factory crimp dies.

If I don't use the crimp die, will neck tension be enough to hold bullets in bolt guns?

 

[jaguarxk120]

Neck tension is OK. You do not need to crimp any rifle shell.

 

[TimSr]

I have never been able to successfully crimp a loose fitting bullet in a rifle cartridge to where it is held any better, and increasing the crimp almost always resulted in shoving the neck back into the cartridge for a bulging shoulder. Haven't done it decades.

 

[straight-shooter]

Semi-auto Yes, Bolt action No.

 

[Grumulkin]

1. You should not need to crimp the bullets for any of the cartridges you mentioned.

2. I have needed to tighten up necks a few times and the Lee Factory Crimp Die works well for that.

3. There are bottle necked cartridges that require a crimp.

4. I've loaded for a number of semi autos and usually didn't need to crimp.

 

[morcey2]

If you don't have proper neck tension, crimping isn't going to help. That said, I crimp loads for several of my rifles but they all have a common characteristic: They're all milsurp rifles with (relatively) huge neck clearance and long throats. I worked up loads both ways and let the gun tell me what it likes. I have one gun in particular that shoots 1" groups all day crimped, but doesn't do less than 2" uncrimped. I've got a couple of others that improve, but not that much, and a couple more that don't like crimped loads at all.

If you have a commercial gun with an average chamber, you probably won't notice a difference with a crimp and it might degrade accuracy. The one constant with crimping is that you will work the brass more so if you don't get a noticeable improvement in accuracy, it's usually better to leave it uncrimped.

Matt

 

[OYE]

Crimping

Bolt actions don't particularly need crimped, but sometimes they do. Sometimes the Lee factory crimp die will tighten up groups some, sometimes not. We have a couple of 30/06
it did help a little with. One is a lighter weight 20 inch barrel that we shoot heavier bullets in. Since the rounds in the magazine were denting the front of the magazine well (which we were able to remedy, somewhat), we were more comfortable using the Lee FCD. Since it shrank the groups a little and added about 25 fps (which really isn't worth talking about) we felt like it was worth our while. Another consideration we had was bullet setback while on horseback. We had never noticed it on rifle shells but we have experienced that with loose 44 mag shells with a heavy roll crimp being carried in a leather pouch in a saddle bag (which we stopped doing). So we just figured it was a possibility with uncrimped rifle shells, even though we typically don't carry those loose either.

Since you already have the die, it will be simple enough to see if there is any added benefit.

We should mention that we trim those rounds each time and haven't experienced any reduced case life (split necks etc) before we retire the brass.
OYE

 

[Ifishsum]

I never crimp for bolt actions, no need whatsoever IMO. I tried a FCD years ago in a few different rifles, with no noticeable improvement in accuracy whatsoever. I don't usually crimp for semi-autos either but I do make sure I have good neck tension. IF the bulllet I'm using has a cannelure AND i am seating to that cannelure, I might give a light roll crimp because it looks more finished to me. I always crimp for lever actions with a tube magazine. Otherwise pretty much never. Taper crimping with no cannelure (such as a match bullet) won't do much unless you're also deforming the bullet jacket, and that can never improve accuracy IMHO.

 

[joem1945]

The only time I crimped .223 was when I was using surplus powder and I couldn't get the FPS exactly where I needed it . Took some time but eventually I had a slight crimp to increase the vel to where I wanted it.

 

[gamestalker]

I've never crimped a bottle neck in my entire 30 + yrs. of reloading, tubular magazines aside.

Take a resized case, seat a bullet in it, then using all the muscle you got, try to get it to move, crimping is not necessary.

GS

 

[Walkalong]

I use a light to medium roll crimp .30-30 and .35 Remington for my lever guns. I lightly taper crimp 55 Gr FMJ .223/5.56 for informal plinking. A light to medium roll crimp will work if the cannelures have any depth and are consistently placed on the bullet.

 

[BigBore45]

I do not crimp rifle rounds. Never had any problems not crimping them.

 

[Grumulkin]

If you don't have proper neck tension, crimping isn't going to help.

There have be instances in my reloading experience where not only was neck tension inadequate but crimping not only helped but yea, even cured the problem. Of course, I was using a Lee Factory Crimp Die; I doubt the usual taper crimp or roll crimp die would have helped.

Bolt actions don't particularly need crimped. Sometimes the Lee factory crimp die will tighten up groups some, sometimes not.

If you try loading for a 458 Lott, a 378 Weatherby Magnum or a 460 Weatherby Magnum without crimping, I believe that notwithstanding excellent neck tension you will find the bullets in the cartridges in the magazine will be rammed into case neck a lot further than you placed them to begin with.

I do agree with your statement regarding the Lee Factory Crimp Die; sometimes they help accuracy and sometimes they don't. I've never had them hurt accuracy though.

It's really simple; if the bullets move under recoil you need to crimp and if they don't you don't.

 

[carbine85]

Reloading manuals usually talk about crimping and they are typically written by experts. It really depends on the gun you are shooting. I would read the manuals and decide from there.
It isn't always needed but it isn't necessarily a waste of time either.
Lyman and Lee address it in there manuals.

 

[OYE]

It's really simple; if the bullets move under recoil you need to crimp and if they don't you don't.

Would have to agree with that. So we added the disclaimer to our previous post. We did hint about setback under recoil possibly being an issue later in the post. OYE

 

[oldreloader]

I load for 223, 25-06, 30-30, 35 Rem, 300 RUM. I only crimp 30-30, 35 Rem and 300 RUM. I never crimp standard rifle cartridges unless they might go in a tubular magazine or are heavy recoil magnums

 

[ArchAngelCD]

I use a Lee factory crimp die on some of my rifle rounds. I'm really not sure why I do but when I tested crimp and no crimp there was no difference at all.

Is a crimp necessary for bolt action rifle cartridges, no.

 

[jmorris]

If you don't have proper neck tension, crimping isn't going to help.

This, more often than not, is the case. The brass will be forced onto the bullet to the point it deforms the lead and/or copper then will "spring" back (while the bullet itself does not) making it even worse.


In some cases crimping into a cannelure even with good neck tension will help, like a heavy recoiling tube magazine fed rifle.

Like everything, just depends.

 

[Walkalong]

If it's a proper cannelure with some depth to it, it can certainly help. Crappy cannelures with no depth to them don't work so well.

But yes, you must have good neck tension. No amount of "crimp" will overcome poor neck tension.

 

[steve4102]

Hey guys, do any of you taper crimp your bottleneck rifle cartridges? If so, what are the advantages of doing so?

I have Lee die sets for all of my calibers (.22-250, .243, .270, .270WSM, .308, ,30-06, and 300 WinMag), including the Lee Factory crimp dies.

If I don't use the crimp die, will neck tension be enough to hold bullets in bolt guns?

To answer your question, Yes, neck tension will secure the bullet in a bolt action.

Now for your "terminology".

The Lee Factory Crimp die is NOT a "taper" crimp die. It is a collet type crimp and is a one of a kind design.

Taper crimping is an entirely different animal than crimping with the Lee Factory Crimp die.

You asked what advantages there are to a "taper" crimp. In my opinion, none. But as stated the LFCD is not a taper crimp.

Is there advantages to using the LFCD, IMO yes, especially in Semi-autos. In my experience the LFCD not only helps secure the bullet it improves accuracy. So, give it a try and see if it helps with accuracy, if not, leave it in the drawer as it is Not required.

 

[Horsemany]

As long as we're talking terminology taper crimps are not used on bottle neck cases. Roll crimp or Lee final crimp die would be the choices. Most rifle seater dies have a roll crimp built in and are employed by lowering the die body.

 

[Walkalong]

You can actually get a proper taper crimp die for .223, maybe others, dunno. It isn't the norm though, as bottle necked rifle calibers generally come with roll crimp capability for crimping into a cannelure. I have tried it both ways in .223.

And no, the FCD for rifles is not a taper crimp. A stab crimp may be a good way to describe it. Anyway, it uses a collet to press the case mouth straight in from the side. Some factory ammo has the same kind of crimp.

 

[Potatohead]

I'd say if your neck tension is not good enough before crimping, something aint right.

And just an fyi, you'll get flamed in a hurry here if you say crimping = help with neck tension, at least in the semi auto pistol world.

 

[steve4102]

And just an fyi, you'll get flamed in a hurry here if you say crimping = help with neck tension, at least in the semi auto pistol world.

True dat.

Thing is, most of those that do the "flaming" have never tried the Lee factory Crimp die.

From Sierra. Flame away.

Neck Tension

When we stop to consider the vigorous (read, downright violent) chambering cycle a loaded round endures in a Service Rifle, it becomes pretty clear it suffers abuse that would never happen in a bolt-action. This is simply the nature of the beast. It needs to be dealt with since there is no way around it.

There are two distinctly different forces that need to be considered: those that force the bullet deeper into the case, and those that pull it out of the case. When the round is stripped from the magazine and launched up the feed ramp, any resistance encountered by the bullet risks having it set back deeper into the case. Due to the abrupt stop the cartridge makes when the shoulder slams to a halt against the chamber, inertia dictates that the bullet will continue to move forward. This is exactly the same principle a kinetic bullet puller operates on, and it works within a chamber as well. Some years ago, we decided to examine this phenomenon more closely. During tests here at Sierra’s range, we chambered a variety of factory Match ammunition in an AR-15 rifle. This ammunition was from one of the most popular brands in use today, loaded with Sierra’s 69 grain MatchKing bullet. To conduct the test, we chambered individual rounds by inserting them into the magazines and manually releasing the bolt. We then repeated the tests by loading two rounds into the magazine, chambering and firing the first, and then extracting and measuring the second round. This eliminated any potential variation caused by the difference between a bolt that had been released from an open position (first round in the magazine) and those subsequent rounds that were chambered by the normal semi-automatic operation of the rifle. Measuring the rounds before chambering and then re-measuring after they were carefully extracted resulted in an average increase of three thousandths (0.003") of forward bullet movement. Some individual rounds showed up to seven thousandths (0.007") movement. Please bear in mind that these results were with factory ammunition, normally having a higher bullet pull than handloaded ammunition.

To counteract this tendency, the semi-auto shooter is left with basically two options: applying a crimp or increasing neck tension.

http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm

 

[Sunray]

You do not need to crimp any rifle cartridge except those with heavy recoil or those used in a tube mag lever action. Otherwise, crimping isn't needed for rifle cartridges, semi-auto's included.
The semi auto pistol world is a different place.