In the reloading section on African Hunting Info, the following statement is made:

"Crimping is generally not recommended for doubles because it can prevent the rifle closing if incorrectly done."

For those reloading for big bore doubles, is crimping necessary? Recommended?

[Spare me the answer, "Like the quote says, just do the crimping correctly and there is no problem." ]

I would say crimp for definite, without you run the risk of the bullets moving forward under heavy recoil and jamming into the lead.

The bigger the calibre and hence the greater the recoil comparatively speaking, then the greaster the need for a crimp.

It is probably not the crimp per se that causes a double to fail to close, but rather an incorrectly adjusted seater die that causes the case to buckle beneath the neck and leaves a series of ripples around the case which prevent proper chambering.

As a precaution I would be inclined to crimp all calibres larger than the .375 bore

quote:

Originally posted by Jonathan Tomlinson:
I would say crimp for definite, without you run the risk of the bullets moving forward under heavy recoil and jamming into the lead.

The bigger the calibre and hence the greater the recoil comparatively speaking, then the greaster the need for a crimp.

It is probably not the crimp per se that causes a double to fail to close, but rather an incorrectly adjusted seater die that causes the case to buckle beneath the neck and leaves a series of ripples around the case which prevent proper chambering.

As a precaution I would be inclined to crimp all calibres larger than the .375 bore

I agree. Well said.

Some do... some do not...

I crimp everything 375 on up...unfortunately Lee will not make a their crimp die in 470NE...at least when I asked them..

If you set you seating die up and use a washer under the die when seating...and remove it to crimp...it can be done without much of a problem.

I definitely think crimping is necessary when you are using the bullets in the field. One thing that I've found when crimping is that it does increase the pressure and velocity if you use the same load that you were using without crimping. For example, I was shooting an uncrimped load that was generating bullets speeds of 2121-2137 fps. Using the same load with a crimp, my speeds picked up to 2169-2171.
I have normally crimpled during the seating process, but had Lee make me one for a .470. I haven't used it yet, but if it works as well for a .470 as it does for my .375, I think I will be pleased.

JJS,

So that I am sure that I understand, when you set up the seating die, set it up so that the bullet is being seated to the desired depth with the end of the die hitting a washer on top of the shellholder. Then after the bullet is seated, turn the seating die in the press down ever so slightly to contact the shellholder directly to make the crimp. In other words, you are adjusting the seating die down by the width of the washer to make the crimp after the bullet is seated. Did I get that right?

Mike

Kind of difficult to follow...without seeing.

Place the washer at the top of your press...where the die screws into the press.

Check your press at that point ...to check size of washer you need...then go to a hardware store and purchase a few different thickness of washers...a little initial trail and error is part of this...but once you have it...save the trouble of adjusting the seating die for crimping/seating everytime you reload...and you have the same crimp/seating if done properly..

If you do not follow, PM me your phone number, and I will be glad to discuss with you..

Is the washer used to raise/lower the die relative to the press?

Used to raise the die when seating...take washer out when crimping...I think I got that right ...but not near my press so can check right now...but you follow????

jjs is correct. That is the way I do it.
After seating all of the bullets I remove the washer and then do not forget to turn the bullet seating stem UP so it does not touch the bullet when crimping.
By seating and crimping in two seperate steps it is easier to get the correct crimp without bulging the case neck or body.
You have to reset the seater each time but you do not have to readjust the crimp adjustment.

I presume that we are talking about a pretty thin washer, something that would be 1/32 or 1/16 inch thick. Does that sound about right? Thicker? Thinner?

quote:

Originally posted by N E 450 No2:
jjs is correct. That is the way I do it.
After seating all of the bullets I remove the washer and then do not forget to turn the bullet seating stem UP so it does not touch the bullet when crimping.
By seating and crimping in two seperate steps it is easier to get the correct crimp without bulging the case neck or body.
You have to reset the seater each time but you do not have to readjust the crimp adjustment.

Now I'm with you... So IN ADDITION TO adding/removing the washer, one also has to raise the bullet seater.

That makes sense. Just adding/removing the washer without changing the seater obviously did not.

So the first step is the adjust the crimp w/out the the washer.

Second, add the washer and adjust the seater.

Third, remove the washer (returning the die to the desired crimp setting) and back off the seater (as not to seat the bullet any deeper).

Makes me wonder how much an extra seating die costs...

quote:

Originally posted by MJines:
I presume that we are talking about a pretty thin washer, something that would be 1/32 or 1/16 inch thick. Does that sound about right? Thicker? Thinner?

Within reason, I don't think it matters. All you need is enough of the cartridge (and bullet) in the seating die to properly align the two for the seating operation.

actually I do not use a washer, I just put the allen wrench that adjusts the dies under the lock ring when seating, then remove it, up the seating stem, lower the die and cromp. That was I do not have to screw the die completly out of the press.

Why not just have Lee make you a factory crimp die. Then you just have to seat with your seating die, then crimp with the crimp die. Send Lee a dummy round (no primer or powder please) along with $50.00 and a cover letter, and they will make a die for you. I have dies in .416 Rigby, .458 Lott, .470 NE, and .500 NE and they work great. One caveat is that the nitro-express dies are large body(1 1/4") so they require a press that has an insert like Rockchucker or similar.

Geronimo

I never crimp double rifle ammunition and have never had a problem with recoil moving a bullet in the case. Adequate neck tension is all that is needed.
------------------------------------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

Geronomo:

I called and ask Lee about making one in 470NE..Like you I had a 416 & 458 Lott made..but they told me they could not make a 470NE...well I just learned something very useful...I will be ordering one!

Thanks, jjs

I am starting to really appreciate the approach outlined by 400 Nitro Express.

I guess my question would be, as a practical matter, how likely is it that the recoil is going to move the bullet in a double. The right barrel is not a problem since that bullet is gone when you pull the trigger. That just leaves the left barrel. I can see that theorically there could be an issue, particularly with a magazine rifle where you may have one in the chamber and three down so that the last round in the magazine has been subjected to the full recoil of three prior rounds, but in a double just seems to me to be very unlikely that the recoil from the one round in the right barrel is going to unseat the bullet in the left barrel.

Here is one way to tell if you need to crimp.
load both bbls. Shoot the right bbl 4 times. Take out the still loaded round from the left and see if the bullet has moved foward.
Oh I do this with my crimped ammo to, to see if my crimp is good enough.

Also when hunting If I have occasion to fire more that one shot from one bbl, when things calm down I will check out the round that has been in the gun.
I do not crimp in my 9,3x74R, but if the bullet has a crimping grouve I use it in my 400 and 450 No2.
When you are 6 yards from several elephant I consider it a little extra insurance.

Mike:

In the big nitro expresses, it's pretty simple. The above gyrations necessary to crimp are pretty amusing and, yes, improperly done, it can cause chambering problems. The very best crimp is not to need one in the first place.

To do this with normal dies:

1. Remove expander ball/decap assembly from sizing die.

2. Throw expander ball/decap assembly into deep lake.

3. Decap by hand.

4. Load normally.

Or, if you insist on decapping with the press, just remove the expander ball and replace it with a much smaller one that is certain not to touch the inside of the neck after sizing.

This is the way I've always done it with DRs. Done this way, the bullets won't move under recoil.
-----------------------------------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

Let me see if I can accurately walk through this entire process as described above:

1. Put a shell in the shellholder and pull the handle on the press down.
2. Screw the seating die onto the press and screw it down until you can feel the shell make contact with the die (without a bullet in the shell and the bullet seater backed offed).
3. Adjust the locking ring on the die.
4. Either back the die off enough to insert the allen wrench used to lock the die between the press and the die or remove the die and put a washer between the die and the press.
5. Screw the die down against the washer or allen wrench.
6. Adjust the bullet seater, insert a bullet into the shell and seat the bullet to the desired depth.
7. Then back off the seater die, remove the allen wrench or washer, back off the bullet seater and screw the die down on the press to the locking ring.
8. Run the ram into the die to crimp.

I am slow and want to be sure that I have the process down since it is a little hard to visualize. Thanks.

So does Lee make factory crimp dies for the bigger rounds now? The largest they would make was my 458 lott a couple of years ago due to the the size of die body they used. Have they gone to a 1.25" die body now?

lb404: Geronomo noted above he has one...

I was told the same as you were, about a year ago....I plan on giving Lee a call soon, hopefully have will make it...that would definately be the way to go..

MJ: It is a little difficult to describe such things as reloading processes in brief internet conversation...I will offer again, if you want to discuss this, PM me your phone number and I would be glad to give you a call..

400Nitro: It is actually a very simple process to crimp the bigger NE rounds...I see no problem in crimping them...your preference is not to crimp, understand that, but I crimp everything over 375H&H my preference...

I will call Lee on Monday myself.

quote:

Originally posted by lb404:
I will call Lee on Monday myself.

I’m anxious to hear what they say. I too was told nothing above .458†for their crimping dies.

I would say, that unless Lee has changed their policies since last April they should be able to make a nitro-express die for you. As I mentioned, they charged $50.00 for the larger body dies which is twice what they charged for the standard body custom dies. Speak directly with the manager, IIRC Bob is his name? Tell him what you want and that you have a press which will accomodate the large body die and see what he says.

Geronimo

I hope they haven't but here's what their FAQ states:

"Custom Factory crimp dies for rifle cartridges can be made for any cartridge with a bullet diameter up to .458 inch and a maximum outer diameter at the base of .580. Send payment of $25 plus $4.00 s/h with a dummy cartridge (a bullet seated in an empty case)

Custom Carbide Factory Crimp dies can be made for most handgun cartridges that are not in regular stock. Send $30 (No case needed)

Factory crimp dies are cartridge specific and there are a few that cannot be made. Please allow 6-8 weeks for delivery."

Having said that, I now see that - in contradiction to the quote above - they do offer a 50BMG crimp die in the same 1&1/4 die as Geronomo indicates his are.

There could be hope

Anyone have a view whether the eight step process I outlined above for crimping is correct?

quote:

Originally posted by lb404:
I will call Lee on Monday myself.

Any word from Lee?

I'm sure we could put together enough guys to meet a 10x or 20x unit "minimum order"...

Update Here