new to reloading and need more info on crimping

[spitfire1000001]

i haven't reloaded yet but i have almost everything i need to start reloading for my .243. is crimping necessary? i use my .243 for mainly just shooting but for some hunting. will that make a difference? some info would help a lot. thanks.

 

[dmazur]

The general idea is that for bolt-actions and single shots crimping is optional, as there is no concern of bullet set-back on chambering or in a tubular magazine.

For semi-autos it is recommended, to prevent bullet set-back on the rather violent chambering action that occurs.

For lever-actions I believe it is almost a requirement, to prevent bullet set-back in the tubular magazine on recoil.

Now, if you intend to crimp, the bullet has to have a cannelure or you risk losing accuracy by distorting the bullet.

Unless you're running the .243 in a DPMS, I wouldn't bother with crimping. No advantage, and possible disadvantages.

Neck tension should be sufficient to retain the bullet in normal handling without a crimp. Target or hunting, no need for a crimp. (IMO)

 

[oneounceload]

Semi's and lever guns require the crimp for set back as mentioned. Bolt and single shots - I would neck size only and use the neck tension only to help improve accuracy

 

[Tuckerp229]

The general idea is that for bolt-actions and single shots crimping is optional, as there is no concern of bullet set-back on chambering or in a tubular magazine.

For semi-autos it is recommended, to prevent bullet set-back on the rather violent chambering action that occurs.

For lever-actions I believe it is almost a requirement, to prevent bullet set-back in the tubular magazine on recoil.

Now, if you intend to crimp, the bullet has to have a cannelure or you risk losing accuracy by distorting the bullet.

Not to be contrary but it amazes me the varied experiences in the reloading world. First off I was always told that any weapon loaded with more than one round "could" move the bullet either by recoil or chambering.
Second I was personally unsuccessful reloading a great performing cartridge until I started crimping and particularly with the Lee FCD dies. What I cannot figure out is why various people's experiences are so different. I always guessed that the "engineer type"- you know patient intelligent type- would never make the production errors that a non-engineer guy like me might make. When everything settled out for me with my first Lee FCD, I bought them for all of my reloading and haven't looked back.

 

[BADUNAME37]

Neck tension alone should securely hold the bullet. Neck tension is the normal expanding of brass and subsequent squeezing which occurs when a bullet is seated. It takes quite a bit of pressure to seat a bullet into a resized case (whether it be full-length resized or just neck sized - typically done to always use the ammo in the gun it was fired from before neck sizing). What does not feel like much on a compound-leverage press is actually quite a bit of pressure during seating.

I don't crimp my 22-250's that will be chambered into a bolt action, including into the magazine. But I do place a fairly good crimp on my .223 ammo that will be chambered into a semi-automatic rifle, into 30-round magazines, etc.

From what I've heard and learned over my 30+ years of reloading, there is typically a bit more accuracy achieved when the bullets are NOT crimped.

YMMV

 

[Tuckerp229]

Neck tension alone should securely hold the bullet. Neck tension is the normal expanding of brass and subsequent squeezing which occurs when a bullet is seated. It takes quite a bit of pressure to seat a bullet into a resized case (whether it be full-length resized or just neck sized - typically done to always use the ammo in the gun it was fired from before neck sizing). What does not feel like much on a compound-leverage press is actually quite a bit of pressure during seating.

Very good points..all. Also I don't don't your level of experience. But to crimp or not crimp seems a bit like the "Ford vs. Chevy" arguments-they are "no-win" because depending on ones original method he was taught and subsequent experience tends to yield which side of the equation he comes down on. While searching for anweres one can easily pull up data on both sides of the argument
For instance this guy:
http://www.accuratereloading.com/crimping.html

I don't know him form Adam nor is one test conclusive. Just saying there is no dearth of search results to support both crimping and non-crimping not to mention whether use the Lee FCD or not.

As I said in my previous post, "it amazes me how varied the reloading experience is."
I started with no crimp, had mediocre results, tried the Lee FCD die because of my frustration had much improved results. I became used to these better results and wanted more so I decided to find a way to quantify the crimp pressure and my results improved again.
I don't know what the non-crimpers are doing that works but my hat is off to you all.
Judging by the many, many posts on the net and in the forums this question of "too crimp or not" or the related one "how much crimp" is an area of reloading that could use some more work.

 

[Grumulkin]

I've loaded for a number of semiautos in 308 Winchester, 30/06, 223 and 7.62X39 and haven't found the need to crimp for any of them. In addition, in only one case have I found crimping to improve accuracy.

I would agree though, that if you're going to crimp, the Lee FCD is the best way to do it.

 

[James2]

The only rifle I have ever crimped for is the 30-30 Winchester 94. This because of the tubular magazine.

I don't have any auto loader rifles, nor elephant guns. Types that are often crimped.

Oh, and I have never had a Lee FCD. I wonder how I ever got along without one of those?