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Crimping

Posted: Mon Nov 21, 2011 9:12 am
by Tokimini
I was at a range a couple of weeks ago and a guy shooting next to me (who sounded very knowledgable) said he noticed a sizable fireball at the muzzle when I shot and it could be adversely affecting my accuracy because my powder was not burning completely in the barrel. I don't load over max and use two of the most common powders for 204, 8208XBR and Reloder 10X. I have two questions.
First, was the guy correct, and second if he is right, would crimping the bullet delay its release from the brass long enough to allow a more complete powder burn.

Re: Crimping

Posted: Mon Nov 21, 2011 9:49 am
by Rick in Oregon
In some cases, that is correct, but it's usually taken for granted that CF rifle calibers do not need to be crimped if shot in bolt or single shot rifles with powder of the correct burning rate for the caliber and bullet in question.

One case comes to mind is the Hornet case. Many crimp this case as the powder volume is slight, the neck walls are very thin (don't offer much tension) and just the primer ignition will move the bullet out of the case prior to the powder igniting. But if proper bullet tension is empoyed in bottleneck rifle cases, crimping is not only unnecessary, but will weaken the case mouth over time and damage the bullet ever so slightly if not cannelured.

Just ask yourself this question: How many BR shooters crimp their cases? Not a single one that I'm aware of, and these guys shoot bugholes virtually every day.

You don't mention what barrel length you have, but if shorter than 22", most factory loads will leave a good muzzle flame. Just check your bullet tension, it's most likely that simple. Usually around .002" press-fit is enough, so if you're not using bushing dies, check to see what a sized and expanded case neck I.D. is....the bullet is .204", and most dies will give a neck I.D. of around .200", which is plenty of bullet grip/tension (.004").

Remember, we're NOT talking about handgun ammunition here, revolver or pistol. Now if you're loading for the AR platform, this does not apply, as most will agree that fodder intended for autoloaders should usually be crimped.

Re: Crimping

Posted: Mon Nov 21, 2011 11:13 am
by Tokimini
Thanks Rick. I'll check the case neck ID. I don't know what my barrel length is off hand, but my gun is a standard Remington 700 SPS.