Roll crimp or taper crimp?
- Thread starter Bill M.
- Start date
- Status
Depends on the powder and what you are using them for.
Slow burning powders and heavy loads usually have more than a taper crimp just to complete the powder burn, though I never deemed it necessary with magnum loads. If you want to play around, go ahead and try it, but you may lose some accuracy and might also spike your pressure.
More information on your load, bullet type and seating depth would be required to give you a better answer.
Slow burning powders and heavy loads usually have more than a taper crimp just to complete the powder burn, though I never deemed it necessary with magnum loads. If you want to play around, go ahead and try it, but you may lose some accuracy and might also spike your pressure.
More information on your load, bullet type and seating depth would be required to give you a better answer.
Charlie98
Member
He beat me to it.
I use a taper crimp in .41 when I am loading my mid-range load with Unique, I use a roller when I load W296 or IMR4227.
There is proof positive right there!
Charlie98
Member
I mentioned using a roller for W296 and IMR4227... two slower powders. W296 in particular needs that heavy crimp to help kickstart the burn process (along with, typically, a Magnum primer.) I tried it with a taper crimp, just to see, and it did not work well... dirty, and crazy SD numbers.
FROGO207
Member
If it works well now why change? As long as you have no bullet movment and clean burn keep'em the same. Taper crimping will prolong case life usually. You could try roll crimping to see if your accuracy changes though.
Palladan44
Member
- Joined
- Nov 7, 2020
- Messages
- 1,904
The necessity to do "heavy" Roll crimps is over-rated in my opinion, and I keep hearing the same thing over and over again from literally dozens of different people, and I got to wondering if theyre all just starting to repeat one another. I beg the question whether a roll crimp, light or heavy is even required at all.....
So, I tested it out.
I'm speaking to it having an effect on how WW-296 (arguably the most "roll crimp required!" powder there is) burns and the result on end product. I understand in a tube magazine to prevent bullet setback, fine and dandy. But ive found that good case tension in pistol rounds like 357 and 44 Mag, prevents this anyways. Use a slight roll crimp for insurance, fine and dandy.
If you're shooting heavy loads especially in a light weight or short barreled revolver, bullet pull/creep under recoil can occur, ive seen it. But only in bullets that don't have a cannlure. If the bullets have a cannelure, a medium taper crimp on the cannelure has been sufficient to prevent bullet pull/creep in every load ive ever shot in 357 or 44 mag, from hot to not. Snubbies, 4 inchers you name it.
As for ignition and consistency, I've found the exact same ballistics in WW-296 loads in 357 and 44 Magnum whether there's a good taper crimp or a roll crimp. Velocities the same, accuracy the same. Cleanliness/unburnt powder the same.
I'm not sure if the dimensions of my resizing dies allow for excellent neck tension where these variables are diminished compared to some others out there? I'm always thinking that with too much roll crimp, the lead is swaged down and as the brass springs back a little bit, the lead core/jacket stays swaged down, effectively reducing all the good case tension you created in step 3.
Roll crimps must be done carefully and with the right die. I've seen them flubbed up.
Do em right, just do em light?
So, I tested it out.
I'm speaking to it having an effect on how WW-296 (arguably the most "roll crimp required!" powder there is) burns and the result on end product. I understand in a tube magazine to prevent bullet setback, fine and dandy. But ive found that good case tension in pistol rounds like 357 and 44 Mag, prevents this anyways. Use a slight roll crimp for insurance, fine and dandy.
If you're shooting heavy loads especially in a light weight or short barreled revolver, bullet pull/creep under recoil can occur, ive seen it. But only in bullets that don't have a cannlure. If the bullets have a cannelure, a medium taper crimp on the cannelure has been sufficient to prevent bullet pull/creep in every load ive ever shot in 357 or 44 mag, from hot to not. Snubbies, 4 inchers you name it.
As for ignition and consistency, I've found the exact same ballistics in WW-296 loads in 357 and 44 Magnum whether there's a good taper crimp or a roll crimp. Velocities the same, accuracy the same. Cleanliness/unburnt powder the same.
I'm not sure if the dimensions of my resizing dies allow for excellent neck tension where these variables are diminished compared to some others out there? I'm always thinking that with too much roll crimp, the lead is swaged down and as the brass springs back a little bit, the lead core/jacket stays swaged down, effectively reducing all the good case tension you created in step 3.
Roll crimps must be done carefully and with the right die. I've seen them flubbed up.
Do em right, just do em light?
Had a pound of W296 for about 20 years finely used it for 300 Blackout. Same with 4227, I just shoot paper and don't have a reason to shoot heavy loads. But your are right any magnum powder is going to require a heavy crimp.
I started using taper crimp on 38/357 because of my Thompson Center contender and encore then just started using it for the rest of my revolver loads brass don't crack as much.
Zendude
Member
Would a roll crimp damage the coating on the bullet, sort of like it might on a copper plated bullet?
Not if done properly; if it was me I would trim the cases I was using for the coated bullets. Is that a painful process yes.
Last edited:
Riomouse911
Member
Don’t gorilla-crimp the plated or coated bullets and you’ll be just fine. I load .41 Special and .41 Magnum loads with coated and plated bullets and I use a minimal roll crimp for them.
Stay safe.
Blue68f100
Member
If your have a concern that the bullet is moving, do a test. Measure your OAL on one, load the cylinder up with the measured cartridge last to shoot. After all shot except the measured one, remove it and check to see if it moved. Then you will can make a valid decision.
Thanks for all the answers. No, I have no concern that the bullet is moving. I saw a picture of some similar bullets and they were loaded with a good bit of roll crimp. I am loading a very light charges of Titegroup, Clays, or HP 38. Everything seems fine. I will stick to the light taper crimp. I do have a Redding profile crimp die if that would be better. But so far have only used it on jacketed bullets. Not many of which I load or shoot in this gun.
gwpercle
Member
I let the bullet call the crimp . My 41 magnum is my Avatar , model 58 S&W .
If the bullet has a crimp groove I roll crimp into it . You get a better burn with a roll crimp and heavy loads of 2400 or H110 and other slow powders .
If the bullet is smooth sided , no crimp groove or cannelure , it gets a taper crimp and I usually load those with medium to fast burning powders .
Usually the taper crimp will hold if the bullet is not over 215 grs. and the powder is something like Unique or Acc #5 .
Double check that recoil doesn't pull the bullet when firing ... if not enough crimp the bullets will slowly walk out ...shoot 5 and measure #6 !
Gary
If the bullet has a crimp groove I roll crimp into it . You get a better burn with a roll crimp and heavy loads of 2400 or H110 and other slow powders .
If the bullet is smooth sided , no crimp groove or cannelure , it gets a taper crimp and I usually load those with medium to fast burning powders .
Usually the taper crimp will hold if the bullet is not over 215 grs. and the powder is something like Unique or Acc #5 .
Double check that recoil doesn't pull the bullet when firing ... if not enough crimp the bullets will slowly walk out ...shoot 5 and measure #6 !
Gary
Otto
Member
- Joined
- May 14, 2007
- Messages
- 2,357
Redding’s profile die incorporates a very close die body which produces a precise two stage crimp. But because of this, you must seat and crimp in separate steps. Some folks see that as extra work but I think Its worth the effort.
ArchAngelCD
Member.
I don't load for the 41 but I usually apply a roll crimp on most revolver ammo. You wouldn't want a bullet to pull and lock up your cylinder. The costing is slick and a taper crimp might not be enough especially with the slower powders like already mentioned above.
Palladan44
Member
- Joined
- Nov 7, 2020
- Messages
- 1,904
What's the deal with Lee factory die crimps. I did notice if you go to near the end of the crimp die, you will get what looks like a roll crimp in 357 and 44 dies. It's very easy to overdo, like 1/2 turn is the difference between the factory taper crimp and a rediculous roll crimp that makes the brass lip flush with the side of the bullet.
Riomouse911
Member
The LFC die uses a collet-type arrangement to squeeze a crimp on the case mouth from the sides as you push on the handle, rather than use a shaped interior shelf inside the die to roll one on from the top.
It leaves a flat crimp on the case mouth rather than a rounded one.
.35 Remington, 180 gr Speer, 38 gr IMR 3031.
Stay safe.
Palladan44
Member
- Joined
- Nov 7, 2020
- Messages
- 1,904
Yup, this is what I noticed. Is this arrangement of LFC only on common calibers that would use a roll crimp such as revolver magnums, and tube fed calibers?
This arrangementof LFC I wouldn't assume is on any semi auto pistol loads that headspace on the case mouth, preventing accidental over crimping of these?
Charlie98
Member
As did I... your results were different than mine, and likely the testing parameters were different as well, so that's not surprising.
Powder burn is a tricky thing to define, sometimes. I would have to say that putting a good roll crimp on a H110/W296 load isn't going to hurt anything, although anything done to excess... like the Charlie98 Death Grip Crimp (patent pending...) might. Nothing exceeds like excess.
I use that for 357 magnum, 308 winchester, 300 wm and 300 blackout works good
Riomouse911
Member
Right, no LFC dies for auto pistols or rifles who headspace on the case mouth ( 30 Carbine, etc.).
I also use the LFC on .270, .30-30, 7mmRem Mag, 6.5x55, .243, among others. I don’t know if it is really necessary for several of those rounds, but I haven’t had anything negative happen when I do so I think I will keep using them. Stay safe.
- Status
Similar threads
- Locked
