You must crimp to a 100lbs of bullet pull or else...

[Bang!]

Page 38 and 39 (believe it’s page 57 before current updates) discusses crimping rifle rounds. Chapter 2 with subject of crimping rifle rounds.

Basically:

1. If you don’t firmly crimp then you must load close to lands or you won’t get sufficient start pressure.
2. Factories can’t custom load for your rifle. They make up for it with heavy crimp to ensure sufficient start pressure. They do this because their “very survival depends on it.”
3. You must have 100lbs of bullet pull formed by a firm crimp for good functioning, ignition, velocity, pressure, and accuracy.
4. If your projectile doesn’t have a crimp grove then one should be formed.

Personally; I rarely crimp rifle rounds (especially bolt action), don’t like the idea of forming a crimp groove in match grade projectiles, can’t measure bullet pull or seen where anyone does, a “firm crimp” would have to be measurable to be repeatable, etc...

Sure, crimp for your tube fed magazines (debatable), your hunting rounds your shipping to Africa, your 3 moa autoloaders, but a must for everything?

Would like to see a discussion by the more knowledgeable and experienced folks here on THR to clarify this subject for me and others down the road. Has to be 100lbs of bullet pull to be accurate? To have proper ignition? To have proper velocity? For good functioning? If you don’t have 100lbs of bullet pull you will have problems? Problems that can only be alleviated by the bullet almost touching the rifling?

 

[Bang!]

 

[mcb]

With good case sizing you can probably get 100 lbs of pull with no crimp at all. I have found that over crimping can reduce pull force too. I am very much in the modest crimp camp. I want just enough to keep the bullet from setting back or jumping foward. I have had more problems from over crimping than under-crimping in my experience.

 

[.38 Special]

I am not much of a rifleman, but I have done quite a bit of loading for them, and also spent a few years playing at benchrest competition, way back when. At least for bolt-action rifles, the only time I crimp is for dangerous game rifles. For general-purpose hunting rifles, I doubt crimp matters much one way or another. In my experience, at least, a properly sized neck provides enough tension. I have no idea whether it's a hundred pounds, or a thousand, or ten, but I never have had a problem attributable to crimp or lack thereof. (There was a time I lightly crimped all my .30-'06 hunting rounds into the crimp groove. I couldn't see any difference between the crimped and uncrimped rounds, so stopped bothering.)

I always have thought that using a crimp die to "create a crimping groove" in a bullet was a dumb idea. I do remember the bullet (Speer, IIRC) advertisments with the tagline "If you want to ruin your accuracy, start by ruining your bullet." and I believe that is about right. Certainly, if you want to get a few laughs you could go to a benchrest match and advise the competitors that they need to start crimping their rounds.

 

[Varminterror]

Which book?

 

[PWC]

What is the source you cite?

 

[.38 Special]

It appears to be the Lee manual.

 

[Arkansas Paul]

Never crimped a rifle round that wasn't going in a tubular magazine.
My accuracy is sufficient for my needs so I doubt I ever will.
I don't care where the lands are either. I load to the bullet manufacturer's recommended OAL and go from there.

I'm not a target shooter however. I just hunt. I do care about accuracy though, and usually don't have any trouble getting a load dialed in.

 

[jmorris]

You couldn't get 100 lbs of resistance with some cases unless you soldered the bullet in place.

 

[FROGO207]

Nice advertising for the Lee FCD. He can spin it well. As far as accuracy I personally find crimping in my bullets hurts accuracy in MY rifles. Do your own test and make your decision at the results. I do crimp in a rifle with a tubular magazine, just enough to prevent setback though.

Rember crimping is done for several reasons. Not necessarily for max accuracy.

 

[Varminterror]

Which book?

It appears to be the Lee manual.

Nice advertising for the Lee FCD. He can spin it well.

Well done gents. Made it too easy!

 

[walterelm]

Well .... it would be interesting to hear from somebody who is actually crimping rifle bullets .... and not just in lever actions ...

 

[mcb]

I crimp both my 300 BO and my 450 Bushmaster. It's only a few thousands under nominal case mouth diameter. Keeps from setting bullet back into cases when feed in ARs.

 

[Varminterror]

I’ve crimped in bottleneck rifle rounds for various supposed advantages and requirements. I’ve never found it to be advantageous for accuracy, and almost always detrimental.

 

[jmorris]

Special and costly tools are available to measure both the point at which the rifling starts and the corresponding point on the bullets ogive of the loaded round.

I actually have extras of the special and costly tools he is talking about, that I will sell cheap.

$20 each shipped...





Odd that would come from Lee when their own manuals have conflicting information.

 

[Grumulkin]

I would be happy to crimp if I had found it improved accuracy. The ONLY cartridges in which I found crimping improved accuracy was in a low pressure 45 Colt load. I have to crimp 460 Smith & Wesson Magnum loads to be shot in a revolver to prevent bullets from moving under recoil bit in a single shot pistol I don't crimp them and accuracy is great.

I do crimp some rifle cartridges with more than average recoil (458 Lott, 378 Weatherby, etc.) but I don't know if it improves accuracy. The 378 Weatherby with crimped in Barnes bullets does well under 1 MOA but I don't know if that's because of the crimping.

Handloading is all about experimentation (within safe limits) and finding out what works for you so by all means try crimping if you like.

 

[M1key]

Some guy on THR here showed improved accuracy with his bolt rifles in 223, 270 and 308 before and after crimping. In his case anyway, crimping improved accuracy. Since I shoot reloaded rounds in bolt rifles and autoloaders, I go ahead and crimp all of them. I am perfectly happy with the results. I hate over-thinking this stuff. I'd rather spend it in the field or on the range.

M

 

[jaguarxk120]

Down load a copy of Earl Naramore's book "Principles and Practice of
Loading Ammunition"
Read the section on crimping bullets, you will find that is where
many "experts" get their information!

 

[Bang!]

Sorry, Lee Second Edition.

 

[PWC]

40 years ago, I used to go shoot, pick up after myself, go home and reload. Spent time relaxing with my Lyman #45 manual and reloading. Follow die and powder mfgr's instructions to make good sage ammo.

Then along comes the I'net....can't just use powder balance, gotta have a scale that is accurate to .XXXXX ($$$), can't just set up and drop from Lyman 55. Seat out to the lands, don't seat to the lands; turn the necks or not, bump shoulder, don't bump, some say you can't anyway; need a new trimmer, bulge buster or small base dies, swagger....can't use pocket knife to remove crimp or snall screwdriver to clean out.......

Roloading has become such a complicated process, trying to keep up with all the nuances, that sometimes it doesn't seem like fun anymore. My guns are capable of more accuracy than me. I shoot and reload for enjoyment and relaxation. I'm going to eliminate any unnecessary steps that may cause xtra stress. Kinda like Joey and Rory sang about, "You Gotta Go Back"

 

[whm1974]

I have limited experience with reloading and certainly no expert, but 100lbs of crimping really sounds awful high to me... Perhaps aside from Magnum level cartridges and even that looks to be rather high...

The only ammo reloading I even done is with .38 Special so what do I know???

 

[.38 Special]

40 years ago, I used to go shoot, pick up after myself, go home and reload. Spent time relaxing with my Lyman #45 manual and reloading. Follow die and powder mfgr's instructions to make good sage ammo.

Then along comes the I'net....can't just use powder balance, gotta have a scale that is accurate to .XXXXX ($$$), can't just set up and drop from Lyman 55. Seat out to the lands, don't seat to the lands; turn the necks or not, bump shoulder, don't bump, some say you can't anyway; need a new trimmer, bulge buster or small base dies, swagger....

Roloading has become such a complicated process, trying to keep up with all the nuances, that sometimes it doesn't seem like fun anymore. My guns are capable of more accuracy than me. I shoot and reload for enjoyment and relaxation. I'm going to eliminate any unnecessary steps that may cause xtra stress. Kinda like Joey and Rory sang about, "You Gotta Go Back"

I've gone through three stages of loading so far. The first was straight out of the book, squeezing things together to form a cartridge that would go bang. The second was the experimental phase, trying out every conceivable thing hoping to arrive at some sort of handloading Nirvana. The third - and probably final - was to start out with a concrete goal ("I want this bullet to fly at this speed and group into this size at this range") and then do what it takes to achieve it. Mostly I've found that my goals were achieved decades before I was born and all that is necessary to duplicate them is to do what Skeeter and Elmer and O'Connor said to.

 

[.38 Special]

The only ammo reloading I even done is with .38 Special so what do I know???

For the record, I have never done any reloading with whm1974.

 

[jmorris]

40 years ago, I used to...

Roloading has become such a complicated process, trying to keep up with all the nuances, that sometimes it doesn't seem like fun anymore.

Yep, I still grab a cane pole every now and then to fish 6 ft from where I am sitting and remember the good old days, maybe teach a younger how to cook popcorn over a campfire and call a hot dog on a stick a good dinner. Life has a way of making things complicated, reloading does too. It’s a long path from making something that safely goes “bang” to quit looking for anything better, for some folks.

 

[forty_caliber]

Fascinating specification...100# of crimping force. How is one supposed to measure that? I use a Lee FCD for 30-30 but, taper crimp other rifle rounds. I've found that just a hint of taper crimp actually improves accuracy for me but I'm only applying enough to help get even neck tension from cartridge to cartridge in a given run. It's easy to over do it.

One aspect of this is that I own both semi-auto and Bolt rifles in the same caliber. I don't load for one rifle differently than the other rifle and need each cartridge to be usable in either.

The idea behind this is to create about the same neck tension--> even pressures from burning propellent --> even muzzle velocity -->more consistent point of impact. This has worked well enough for me over the years and is how I was taught to do it.

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