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Re: Crimped Bullets are more accurate bullets

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16 September 2004, 12:02
dan belisle
Re: Crimped Bullets are more accurate bullets
Well, I crimped according to Lee's instructions. I had some left over loads from the Hornady series (when I got too much velocity/pressure signs I stopped) that I pulled apart, and I don't recll seeing any marks on the bullet (aside from the collet marks from pulling). So I guess that would be lightly. - Dan
15 September 2004, 03:34
NorHunter
Greetings fellow shooters
If i understand this tread right, i must get a crimp-die and try it to find out if i get better presicion on my 300wm.

There is no correct answer then ?

BTW: Is Redding Comp. kit with wolfram bushings a good solution ?
15 September 2004, 04:50
JustC
I use bushing dies for ALL loading be it benchrest or hunting. By simply using a smaller bushing,..you increase neck tension (same principle as a crimp) but you don't intrude on the jacket of the bullet because the bearing surface is being gripped by the entire neck area which contacts it instead of a small area which is "clamped" to the jacket near the mouth of the case. The use of bushings in correct sizes yields IMHO the best results.
15 September 2004, 06:26
Matt_E
I have tried the Lee FC die in a couple of rifles in 223 and 22-250 and found it decreased accuracy in my case.
15 September 2004, 06:21
Swede44mag
I don't crimp my rifle bullets anymore I havent found them to be any more accurate. The more the case necks are worked the shorter the life this would include crimping IMHO.
15 September 2004, 10:25
<eldeguello>
Quote:

OK, I've said it before, I'm new and sometimes one just doesn't know enough to argue. A guy made the statement to me that he crimps all of his centerfire rifle ammo because crimped rounds are more accurate due to the milliseconds between ignition and release of the bullet. He says those milliseconds allow the gases to build up inside the case???

Those milliseconds also allow your hold to move! If not, why bother with speedlocks??
16 September 2004, 16:26
Ricochet
I crimp 'em right into uncannelured bullets. The die makes its own cannelure, in a very similar manner to the way the bullet makers make cannelures. It's a smaller, shallower cannelure than the ones the bullet makers roll into bullet jackets. Custom fit to the crimped-in case mouth.
17 September 2004, 06:48
Born to Hunt
Hot Core,

I read the instructions on my RCBS dies last night. I'll give it a shot. I can't load any for a day or two...I'm waiting for a shipment of supplies!
17 September 2004, 09:07
djpaintles
The only die that you should use on an UnCannelured bullet is the Lee. An RCBS or other die can seriously bulge a shoulder and ruin a case if you try and use them for crimping w/o a cannelure..........DJ
17 September 2004, 15:19
Ricochet
Quote:

The only die that you should use on an UnCannelured bullet is the Lee. An RCBS or other die can seriously bulge a shoulder and ruin a case if you try and use them for crimping w/o a cannelure..........DJ

Yes. I was of course speaking of the Lee Factory Crimp Die, but should have been more explicit.
17 September 2004, 12:28
Hot Core
Hey Born to Hunt, As I mentioned before, I don't normally crimp my rifle ammo, but I do have a couple of rifles and revolvers where I do crimp.

By the way, I believe "DJ" has given you some good advice about only using the Roll Crimp on bullets that have a cannelure. What he posted makes sense to me, but I've never tried crimping a non-cannelured bullet.

If you are using a bullet with a cannelure and you do decide to Roll Crimp, I can recommend you do the following things:

1. Make sure your cases are all trimmed to the same length. Then very lightly chamfer and deburr the Casemouth.

2. Initially set-up your Seating Die to Seat the Bullets "without crimping". The Casemouth should align with the center of the cannelure or with the Bullet just slightly deeper. But it should not be Seated so deep that you can not see where the cannelure starts closest to the Bullet Tip.

3. Do the crimping as a separate step. Be sure to back the Seating Stem up out of the way so it can't once again make contact with the Bullet.

4. Adjust the Seating Die so it only Roll Crimps so the outer edge of the casemouth is Rolled into the cannelure.

You can overdo the Roll Crimp as DJ mentioned even with a cannelure. If you do, you will will find the case impossible to chamber. Then it is time to pull the Bullet, dump the powder, remove the Primer Punch, Resize the case, put the powder back in and return to Step #2 above.

---

Lots of good folks with good advice helping you in this thread. Some of this stuff depends on the actual Bullet, cartridge and type of rifle you are loading for. So, it would help all the folks if you mentioned what you are Loading for and the specific Bullet.

Best of luck to you.
15 September 2004, 15:05
Ricochet
Quote:

Quote:

Those milliseconds also allow your hold to move! If not, why bother with speedlocks??

In this case, you're talking about microseconds, not milliseconds. Holding the bullet back for the pressure to rise will raise the entire pressure curve, and the muzzle velocity will rise a bit. You probably end up with less bullet dwell time in the gun after ignition. If the crimps are quite uniform in their release pressure, ballistic uniformity will improve. I think most of the poor results that have caused some to think crimps are inherently detrimental result from inconsistent crimps, as you'll surely get from using the typical roll crimp dies.