Crimping

MarkT

Well-Known Member
Hi All,
After reading all I can find on the subject , including an excellent explanation of the advantages of crimping and the effects on SD and ES by Muir .l've decided to purchase a Lee crimping die.
I can find basic set up imfo but nothing more than that .
I'm sure there are those on the forum with a wealth of experience using one of these , is it as simple as ? I'm using non cannelured bullets .
All advice welcome and apologies if it's already been covered.
Regards and TA in advance.
Mark
 
The instructions are clear and easy to follow. There is also a very good demonstration video on Utube.
You can easily adjust the amount of crimp applied, the most being when the jaws have fully closed.
Best results are when all your cases are trimmed to the same length.
Muir 'converted' me to using the Lee Factory Crimp Die and I have been very pleased with the difference it makes.
Crimping bullets without a 'crimping groove' is not an issue.
 
An excellent addition & likely to improve consistency of neck tension aiding more consistent MV's & closer ES.
Best starting off with a gentle crimp to see how it works for your cartridges/rifle & progress as necessary.
 
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I have been watching these vids for weeks,,,set it and forget it,,,,preferably with allen key locking rings,;) thats why i said on another thread about quick change (conversion bushes ),so once they are set i have no need to change them,next on my list!
 
If you don't want to use locking rings (the kind with the set screw) you can get very good repeat set-ups by using a small set of feeler gauges ti measure the gap left between the crimp collet fingers. Alternatively, you can use a small tapered pin set into the gap and marked at the location where it stops. If you have some cash to spend and want to really get technical, you can order one of the tools people are making that attach to your press handle and measure the amount of pressure required to crimp. (Google it) ~Muir
 
I've managed to start this post twice. Funny the other post is receiving opposite opinions to this one.Bizarre :scared:
 
Are you sure that you're not from Yorkshire ?
I've already got the collars , all fairly easy stuff. Thankyou all .
Are there any caveats to be aware of?

Cravats aside...

Dont crimp too tight- it's not necessary and if there is no cannelure/crimp groove then, in the words of the Lee instructions, "one will be formed".

I only crimp where necessary (tube-mag heavy recoil etc.), having found I get better consistency without. If your neck tension is consistent and adequate, adding a crimp is an unnecessary step which is subject to variability of its own.

If you have inconsistent neck tension, you might see an improvement in accuracy if you crimp, though I suspect you'd get better results from solving the neck tension issue.

Do successful benchrest and F-class shooters crimp? I suspect most do not. I approached it with an open mind, tested my loads and found a deterioration in accuracy in bottle-neck cases. Your experience may be different.
 
I'm very methodical, so can't see that neck tensions would be inconsistent. I'm not experiencing problems at the moment, I may well be making unnecessary work for myself .
I may try a small batch if I run into any problems with consistency.
Cheers:)
 
F-Class shooters don't crimp? I'm not seeing that as a reason to avoid it.
As to inconsistent neck tension: It's not what YOU do, it's the brass that has inconsistencies. I chroned my 6.5CM Tikka the other day. I has a Standard Deviation of 9 fps using crimped ammunition loaded in Hornady brass. My 308 RPR using surplus Lake City military brass has SD's of 12 fps. Crimping will not fix a poor load combination, but it never hurts. This is why most ammunition manufacturers crimp their loads -even their Match ammunition. Hmmm. I wonder why....:rolleyes:~Muir
 
F-Class shooters don't crimp? I'm not seeing that as a reason to avoid it.
As to inconsistent neck tension: It's not what YOU do, it's the brass that has inconsistencies. I chroned my 6.5CM Tikka the other day. I has a Standard Deviation of 9 fps using crimped ammunition loaded in Hornady brass. My 308 RPR using surplus Lake City military brass has SD's of 12 fps. Crimping will not fix a poor load combination, but it never hurts. This is why most ammunition manufacturers crimp their loads -even their Match ammunition. Hmmm. I wonder why....:rolleyes:~Muir


Just got a bit of tweaking to do on my load development to eak the last bit of accuracy. Then I'll try a side by side comparison.
Final question, 1 or 2 have said they were getting a lot of case damage, is this a result of excessive crimping?
Thanks to all from a newby reloader.:D
 
Dont quote me on this but to my eyes anyway it seems with the lee fcd the only way you could damage cases is if you dont set the die correctly, ie too low so it bumps the case,or not enough lube,,,,,,in simple terms,and it has to be simple for me!,you would be squeezing the case between the collet and the press/shellholder,because there is nowhere else for it to go,but i,m also a noob,
 
Final question, 1 or 2 have said they were getting a lot of case damage, is this a result of excessive crimping?
Thanks to all from a newby reloader.:D
I have been crimping pretty much everything for about 12 years now after the chrongraph data kept showing smaller velocity and SD spreads. "Case damage" is nonsense. The small mark on the case mouth is usually trimmed off on the next loading.

Which reminds me. If you are going to FCD crimp (or any crimp) you should trim your cases at every loading. I trim to the length of the shortest case in the LOT.~Muir
 
I've tested identical loads before and the cripmed load always has slightly lower SD & ES. Accuracy at 100 was the same. But obviously lower figures I've the chrono make for tighter groups down range..... It's dead easy to do and I now always crimp
 
I have been crimping pretty much everything for about 12 years now after the chrongraph data kept showing smaller velocity and SD spreads. "Case damage" is nonsense. The small mark on the case mouth is usually trimmed off on the next loading.

Which reminds me. If you are going to FCD crimp (or any crimp) you should trim your cases at every loading. I trim to the length of the shortest case in the LOT.~Muir

I crimp each reload and only trim when the cases exceed their SAAMI dimensions, I can't see any obvious problem.
 
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