30cal crimp die

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30cal crimp die

Post by flashman » 19 Dec 2021, 8:04 am

Hi all just a quick question iv got a 30/30 crimp die could i use on my other 30 cal rounds 308 win for example or are they cal specific ...thanks
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Re: 30cal crimp die

Post by flashman » 19 Dec 2021, 8:13 am

Ok after some research online found out no i can not use 30/3 it is to short for 308 win .......bummer
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Re: 30cal crimp die

Post by bladeracer » 19 Dec 2021, 11:28 am

flashman wrote:Ok after some research online found out no i can not use 30/30 it is to short for 308 win .......bummer


You could make a collar to increase its length.
But Lee FCD's aren't expensive and work great.
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Re: 30cal crimp die

Post by in2anity » 21 Dec 2021, 5:25 pm

Just curious flashman - what’s your need for a crimp? A semi or pump is it?
At what point does lack of maintenance become patina?
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Re: 30cal crimp die

Post by flashman » 22 Dec 2021, 8:25 am

HI reloading for a friend its a Win 94 lever action , done some reading on neck tension though i might experiment on my 308 Howa ,they say it can improve accuracy from the moment the bullet jumps , so i like to put it too the test ..... :allegedly:
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Re: 30cal crimp die

Post by in2anity » 22 Dec 2021, 6:50 pm

The crimp in a lever can be benifical due to the extra potential stresses placed on the cartridge during cycling - i.e. bullet set-back is in theory more prevelant. When it comes to bolt action spitzer cartridges, a crimp can also be beneficial if the action is being worked quickly and agressively, such as a service rifle "quick-fire" event. Other than that, you'll probably find a crimp will actually be detrimental to accuracy (vs light and conistent neck tension). However this is presuming your jump is arleady optimized, and you've already found that harmonic sweet spot - i.e. the other factors are optimised. Unfortunately these three factors (neck tension, OAL and charge-weight) are all coupled to each other - change one, and it can invalidate the others... It's why large sample sizes of data are necessary, and small incremental changes advised (i.e. change only one variable at a time). Annealing helps wth maintaining consistent neck tension - do it if you plan to recycle brass, yet want to marvel at your tiny groups. Cheers, In2.
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Re: 30cal crimp die

Post by flashman » 23 Dec 2021, 6:21 am

Well thanks In2 had a theory with the crimp giving it time for the pressure to rise and all the powder given a chance to burn , giving me a cleaner burn we are talking nano seconds....
or well I could be wrong ............
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Re: 30cal crimp die

Post by in2anity » 23 Dec 2021, 10:05 am

flashman wrote:Well thanks In2 had a theory with the crimp giving it time for the pressure to rise and all the powder given a chance to burn , giving me a cleaner burn we are talking nano seconds....
or well I could be wrong ............


AKA "shot start" - indeed ignition can be altered through the use of a crimp. This is particularly relevant for lead bullets as they are much "slipperier" than jacketed, and tend to exit the barrel sooner, demanding a faster powder or perhaps accelerated ignition. Also, if gettting close to lands is an impossibility (either due to magazine-length limitations, or perhaps just the design of the action/chamber) increased shot start might yield better accuracy, I stress the word might here, lots of annecdotes fly about. Some of my service buddies seem to think various service rifle design needs crimping for accuracy, for this reason (big jumps to the lands) - I'm still on the fence about this. May or may not be true, but I'd rather inherently tighter-tension over a crimp.

But you can also improve ignition through perhaps the use of a magnum primer, or think about other ways to increase inherent neck tension. One "hack" way I use to increase neck tension is to get myself a Lee Collet die and polish down the mandrel a thou or three as needed (in a drill with fine steel wool and polishing compount). You can even get offically undersized mandrels from flea bay, or just get a spare if you want to retain the original mandrel that shipped with the die. All my Service Rifles go through the Collet using undersized mandrals because as I said, a quick fire event is hard on the cartridges and I want to prevent any bullet set-back.

Then there are all the fancier dies, like the Redding bushing dies - which work great at precisely controlling neck tension. But they are expensive and couple you to a certain brand brass. You can make very accurate ammo without them.

But then my Target Rifle (single feed) is a different story. I don't use an undersized mandrel - I just bog standard mandrel and I'm only Collet Dieing lightly to minimise brass runout - neck tension is light and consistent, which comes from a combination of things a) brass annealing 2) good quality brass 3) FLS to achieve neck tension

Food for thought. In2.
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Re: 30cal crimp die

Post by straightshooter » 24 Dec 2021, 6:52 am

Flashman
I assume you are reloading a 308 and have standard dies to do so and the projectiles you will use have a cannelure.
I also assume you are unaware that just about all standard loading dies have a facility for crimping into a cannelure if one knows how to use it.
The procedure is quite simple.
Starting with the seating die partially screwed into the press and the seating stem screwed into the die seat a projectile into the case.
At this point the OAL will be excessive.
Gradually screw the die into the press until the cannelure is only just visible above the case mouth.
Now back out the seating stem a considerable distance.
Using the press as normal seat the loaded round fully into the die and screw in the die by hand until you feel resistance.
Now a little at a time screw in the die and operate the press and inspect. When you have a correct crimp stop and tighten the die lock nut for that die setting.
Again seat the loaded round into the correctly setup die and now screw in the seating stem to contact the loaded round firmly.
Load a new round as normal and inspect carefully that everything is correct with the crimp. If necessary make minor adjustments.
The only problem that will arise is if there is too much variation in overall case length.
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Re: 30cal crimp die

Post by disco stu » 24 Dec 2021, 7:28 am

I could have sworn that I read instructions in a book covering what you said above straight shooter, but couldn't seem to find it again. I just had a look in the Lee die set I have and sure enough the neck stops before going right into that narrowest part.

From memory the book I read this in said there is a roll or taper crimp and then a full crimp. Is that method what they call roll crimp?
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Re: 30cal crimp die

Post by bladeracer » 24 Dec 2021, 7:58 am

You don't need a crimp groove in the bullet to crimp it, you can crimp perfectly smooth bullets as well, or crimp a grooved bullet somewhere other than the groove.


straightshooter wrote:Flashman
I assume you are reloading a 308 and have standard dies to do so and the projectiles you will use have a cannelure.
I also assume you are unaware that just about all standard loading dies have a facility for crimping into a cannelure if one knows how to use it.
The procedure is quite simple.
Starting with the seating die partially screwed into the press and the seating stem screwed into the die seat a projectile into the case.
At this point the OAL will be excessive.
Gradually screw the die into the press until the cannelure is only just visible above the case mouth.
Now back out the seating stem a considerable distance.
Using the press as normal seat the loaded round fully into the die and screw in the die by hand until you feel resistance.
Now a little at a time screw in the die and operate the press and inspect. When you have a correct crimp stop and tighten the die lock nut for that die setting.
Again seat the loaded round into the correctly setup die and now screw in the seating stem to contact the loaded round firmly.
Load a new round as normal and inspect carefully that everything is correct with the crimp. If necessary make minor adjustments.
The only problem that will arise is if there is too much variation in overall case length.
Practice Strict Gun Control - Precision Counts!
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Re: 30cal crimp die

Post by straightshooter » 26 Dec 2021, 6:07 am

[quote="bladeracer"]You don't need a crimp groove in the bullet to crimp it, you can crimp perfectly smooth bullets as well, or crimp a grooved bullet somewhere other than the groove.

A long time ago I thought so too, but buckled necks and/or collapsed shoulders told me otherwise.
My only resort at that time was to acquire a CH bullet canneluring tool.
I was experimenting with loading for the maximum possible OAL that would still cycle through the action of a 444 Marlin with 300 grain projectiles with the loaded rounds not collapsing under recoil.
I am aware Lee released a special crimping die but I haven't tried one so am unable to comment on whether any of the hype is reflected in reality.
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Re: 30cal crimp die

Post by flashman » 31 Dec 2021, 9:27 am

Wooooow thanks for the info ,going to rely on neck tension . used a bullet puller in my single stage and was surprise at the amount of tension on the bullet ,ok now for the jump........factor ............ :thumbsup:
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Re: 30cal crimp die

Post by disco stu » 31 Dec 2021, 10:25 am

From my reading, the lee collet crimp die doesn't require the groove, but the roll crimp ones that push down on the case do. The collet crimper doesn't push down on the case at all, only squeezes inward on the neck. I've had a little play with one I've recently got, but haven't fully used it in action.

I say this fully aware that you guys have way more experience with this than I do
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Re: 30cal crimp die

Post by flashman » 31 Dec 2021, 2:21 pm

In 30cal why have a cannelure in the first place , can see tube mags and real hard kicking mags need them but i understand 308 win not so.........
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