Revolver Crimp…..How much? How to repeat?

[Nathan]

When crimping for revolvers, how do you decide how much crimp you need? I know I need it enough to stop bullet movement, but how much is that? I tend to look at factory ammo and try to make visually similar.

Then from session to session, how do you make it the same?

Right now I’m doing this visually, but would like a more precise method.

[Recycled bullet]

Use your crimping die as a locator for the case mouth. After seating the bullet back out the seating stem and back out the crimping portion. With the ram all the way up start spinning down (using your fingers) the crimp die until you can sense the pressure that occurs from contact between the case now and the die...that is your zero point.

I like to tighten it by hand as hard as I can, then back the ram down adjust the die one quarter turn further, then lock it into this position then verify by running ammunition through and confirming correct setup.

[ghbucky]

Originally Posted by Nathan

Then from session to session, how do you make it the same?

Right now I’m doing this visually, but would like a more precise method.

Use an uncharged case without a primer to work out seating and crimping. Once you are happy with it, keep that dummy round. That way if you ever have a reason to set your dies up again, you can use that round to set your dies up again.

Hopefully, you have a press where you can leave the dies alone once they are set up to your liking. (maybe a removable turret, for example in the case of a Lee turret press)

[Sevens]

You have a couple questions here. First is how do you know how much and the second is how do you repeat it?

I'll start by saying that I believe it's extremely important to note that roll crimp in revolver rounds and taper crimp in semiautomatic rounds are much different animals and require different approaches.

In revolver ammo, the crimp is key for holding that bullet in place both to avoid bullet jump and for high pressure stuff, to help ensure a full combustion of the powder.

I choose how much crimp based mostly on the particular bullet I'm using and sometimes on the load I'm building. When I load for .460 Magnum, I'm basically putting a gorilla crimp on my rounds because this stuff absolutely demands it. On the far other end of the spectrum, if I'm making light/medium .38 Special using plated bullets, I use very little crimp because the plating on these bullets is extremely thin and a heavy crimp can/will/does slice completely through the plating.

HOW do I know how much crimp I'm rolling in? For me it's almost entirely by feel and feedback in my press lever. If I take the handle to full end-stop and there's no extra resistance at the end of this stroke then I know I am imparting no crimp or a very slight crimp. And lots of resistance at the end of the throw and I can definitely feel the crimp I am rolling in to this round.

THE ABOVE will vary if your case lengths vary. It will also vary if you are the kind of reloader who uses mixed brass and mixed headstamps. (I am not)

HOW DO I repeat a crimp that I did in a previous session? Well, the gross adjustment is easy to find because I use an index line on my press and an index line on the body of my dies to always put the die exactly back where it was. The fine tuning adjustment is done simply with the feedback of my press handle.

All of the above is my take on revolver rounds.

When it comes to .380,9mm,.40,10mm,.45 then we're talking taper crimp. Crimp here is not meant to hold the bullet in place (proper sizing and limited use of the flare die does 100% of that work) a taper crimp here is the proper method for removing the prior case mouth flare.

It's extremely important to get on board with that. And if you try to OVER-crimp a semiautomatic round with a taper crimp die, your net result will be less case mouth tension and a suspect, potentially dangerous round.

[gwpercle]

Experience is going to be your best teacher ... a zillion words can be written on how to ...
be it bullet crimping or how to kiss a girl ... you are just going to have to do it .
You may need to do it a few times but that's called "experience" and you will soon get a handle on it .

The way I would re-set my dies is with a "dummy" ... no primer , no powder but bullet seated to proper depth with the right amount of crimp . Screw die down onto the "dummy" to get the same seating depth / crimp .
I make a dummy for every bullet design and keep the dummies in the box with the reloading dies and shell holder .
This is the simple , easy way to do it ... Some folks like to make this so complicated you need to have a degree from MIT to understand what they talking about ...
Us Louisiana Cajuns roll with simple and enjoy easy !
Gary

[Shadow9mm]

if your using bullets with cannelures and a taper crimp, frim crimp. if your using lead bullets, or bullets with grooves, you want it rolled into the groove to the point where you can slide your finger down the bullet and not catch on the case mouth.

[44 AMP]

When crimping for revolvers, how do you decide how much crimp you need? I know I need it enough to stop bullet movement, but how much is that? I tend to look at factory ammo and try to make visually similar.

Get a factory round, and use it for setting you "baseline". By feel, not by eye...
I'm talking here about using the built in crimp shoulder of the seating die. Not talking about any other separate die.

With the seater die body backed out, and the seater stem backed well out of the die body, put the factory round in the shell holder and run the ram all the way up.

Then screw the seater die body down, until you can feel the die contact the case. Firm contact, hand tight, don't gorilla it. This is the crimp shoulder in the die firm up against the crimp of the factory round. Then snug down the die lock ring to keep the die set in place.

This is you base starting point for a full crimp.

Then from session to session, how do you make it the same?

You make it the same by using cases of uniform length. Yes, this means measuring, sorting and possibly trimming.

You set your die on a factory round, compare the brass you have to it's length, and you'll probably find cases shorter and possibly longer than the factory round is.

Cases longer than whay you set your die for will be crimped more (possibly too much) and cases shorter will be crimped less (and if too short, not crimped at all). You can either adjust the seater die as needed for each individual case as you load it (time consuming and not at all efficient),
OR you can sort and trim your brass to one uniform length, so they are all the same and will all be crimped the same amount. That's the best way.

Revolvers don't care about case length, provided its below max listed specs. Recommended "trim to length" is usually about 0.005" less than listed max length for most revolver rounds. Some auto pistol rounds are less.

Measure your fired brass and sort it by length. Anything shorter than the trim to length for your caliber should be separated and processed separately.

All the cases longer than the trim to length get trimmed to the trim to length, and you have a uniform case length, to adjust your crimp to.

Now load 10-12 rounds using the crimp setting you did on the factory round. Shoot 5, check the unfired round for bullet movement. If it has moved, you need to adjust for a bit more crimp. IF it hasn't, shoot 5 more with that same round in the cylinder (so it gets the recoil effect of all ten shots) and check it again. If it goes 10 rounds with no bullet movement, call it good an start loading ammo.

This method has worked for me for over 50 years, in guns from .38Spl through .45 Colt.

Bullet creep (crimp jump) is not a constant force. It varies with the recoil of the gun (and the load being shot). Heavy slugs have more inertia, light guns have more recoil. What works in an N frame might not in a J frame size guns.

Your gun, and your loads determine how much is "enough" and that is always a trial and error testing process, requiring shooting. Be prepared to adjust your crimp setting as needed, based on your actual shooting results.

There's a bit more to it, but that's the basics.

Good Luck!

I did not cover bullet seating and crimping in one single step. It can be done (no matter what some people say), its not difficult, just another series of adjustments, and I generally do it that way. IF you do it that way, be aware you probably will have to change your settings if you change the bullet you're using.

The key is uniformity.

[ballardw]

Originally Posted by 44 AMP

IF you do it that way, be aware you probably will have to change your settings if you change the bullet you're using.

Which is why I spend time at gun shows looking in the used dies for seating dies. That way I have separate .38 Special and .357 seat/crimp dies for the three most common bullets I use in each caliber (not the same for both cartridges). Plus another for experimenting...

And similar for several other rifle and pistol cartridges. Not critical but nice to have. Just make sure you have a system for identifying which bullet/cartridge combo these spares are intended with.

[jetinteriorguy]

1. Uniform brass length for uniformity.
2. Seat and crimp using separate dies.
3. Depending on what caliber and the amount of the load/recoil you’re expecting, I load up a dummy and put it in my inertial bullet puller and see how many’s whacks it takes to move the bullet. If it’s a heavy load I’ve figured out as long as the bullet doesn’t move with five really good whacks it’s good to go. I check this by measuring OAL before and after with a good calipers. For lighter loads I use fewer whacks.
I know this isn’t the most scientific method, but like most things in this business you learn by feel with experience.
One last recommendation, for magnum ammo I prefer the Lee Collet Crimp Die. It’s more tolerant of variations in case length and is easier on the case mouth than a roll crimp, extending brass life.
These are merely my opinions based on 30+ years of experience, and not the only way to skin this cat.

[totaldla]

This might help a bit.
https://sites.google.com/site/hobbyh...ping-44-magnum

[Unclenick]

Originally Posted by Nathan

When crimping for revolvers, how do you decide how much crimp you need?

This can vary considerably by firearm. What causes a revolver bullet back out is the gun's recoil, which pushes the gun rearward, and with that, the cylinder is pushed sharply back against the rims of the remaining unfired cartridges. Inertia tries to keep the bullet where it is as that sharp force on the case rim tries to move the whole cartridge rearward. If the crimp and case friction fit against the bullet combined are not enough to overcome that inertia, the case moves further to the rear than the bullet does, leaving the bullet sticking out. I call it a case of the gun "pantsing" the bullet.

So, how much crimp do you need to prevent that? How hard does your gun recoil? A simple taper crimp worked fine when I occasionally shot my Dan Wesson v.15 in matches with wadcutter loads. The gun was heavy enough and the charge light enough that the cartridge cases weren't being slapped rearward hard enough to "pants" them. At the other extreme, a friend of mine got a titanium snubby in 45 Colt and found no amount of crimp, even that on commercial loads, could make a 250-grain bullet stay in place in the cylinder through firing. Only by moving to 200-grain bullets was he able to make that stop happening, and this guy is 6'2" and 280 lbs and with big hands. The light gun was so easy for recoil to push back really fast and hard that he couldn't grip it hard enough to make that stop pulling bullets. I have since suggested he try with a Lee Collet-Style Crimp Die or with the Redding Profile Crimp Die, both of which can be made to do extra firm crimps, but he's never done it, AFAIK.

Originally Posted by Nathan

Then, from session to session, how do you make it the same?

Same crimp setup and cases, all trimmed to the same standard length.

Originally Posted by Nathan

Right now I’m doing this visually, but would like a more precise method.

As suggested, for all but that Lee Collet-Style Crimp Die, you set the case in your press, run the ram up, and turn the die with the crimp shoulder in until it just kisses the mouth of a resized case you have trimmed to your standard length. I would recommend this case not yet be flared when you do this to avoid unevenness. When you have found the contact depth for your die body thread or, with the Lee CFCD, the right amount of adjustment plug turn-in, you turn in deeper by graduated amounts. You can use a Sharpie to put a registration mark on the die body threads and press or, for the Lee CFCD, on the plug threads and die body. Then it is just how far past the registration mark you must turn to get the round to behave in your gun. If you can, take a Lee Hand Press or similar tool to the range, bring your charged and plugged cases and your bullets with you, and experiment to find exactly what you need. You can also see how far you can go before getting rounds swelling to a broader diameter below the case mouth. These rounds may rub the chamber walls on their way in. Figure halfway between those extremes is a good target value for general purposes. Unless you have a light, hard-recoiling gun, that should work. If you have one of the latter, go for maximum crimp short of swelling the body of the case out below the crimp.

[akinswi]

Nathan,

I ran into this issue the other day shooting 158 grain LSWC. I noticed that my cases had some unburnt powder and the cases were very sooty even using bullseye powder (which is dirty but your hands will thankyou)

So I crimped them more , and the 2nd time no unburnt powder and cases were cleaner.

If your using a popular load like me 3.5 grains of bullseye for 38 special with 158 grain LSWC I knew I didn’t have enough crimp

In other words my brass told me I needed more crimp. I tried to read thru all the posts if someone already mentioned this sorry for the repeat

As far as consistency, like others said make sure your cases are uniformed. Some like me have dies setup paticularly for one caliber and 1 load. So if your revolver loves the load set your dies with the amount of crimp. bullet seating depth etc etc. Same for 357 dies setup just for that caliber. This Why I switched to a coax for single stage reloading no more shell holders or bushings.

[jetinteriorguy]

Originally Posted by akinswi

Nathan,

I ran into this issue the other day shooting 158 grain LSWC. I noticed that my cases had some unburnt powder and the cases were very sooty even using bullseye powder (which is dirty but your hands will thankyou)

So I crimped them more , and the 2nd time no unburnt powder and cases were cleaner.

If your using a popular load like me 3.5 grains of bullseye for 38 special with 158 grain LSWC I knew I didn’t have enough crimp

In other words my brass told me I needed more crimp. I tried to read thru all the posts if someone already mentioned this sorry for the repeat

As far as consistency, like others said make sure your cases are uniformed. Some like me have dies setup paticularly for one caliber and 1 load. So if your revolver loves the load set your dies with the amount of crimp. bullet seating depth etc etc. Same for 357 dies setup just for that caliber. This Why I switched to a coax for single stage reloading no more shell holders or bushings.

Interesting note on using the crimp to clean up the usual soot from shooting BE. I may have to give it a try so I can start using up the twelve pounds I have on the shelf.

[Nathan]

Thanks for the info. I probably should be clear more. I know how to setup crimp. I have a pretty good eye for it, but I’m looking for a reliable way to adjust the die going between single stage and progressive to keep the same amount of crimp exactly.

As I reread the op, I see that is not very clear.

[tangolima]

Originally Posted by Nathan

Thanks for the info. I probably should be clear more. I know how to setup crimp. I have a pretty good eye for it, but I’m looking for a reliable way to adjust the die going between single stage and progressive to keep the same amount of crimp exactly.



As I reread the op, I see that is not very clear.

Try having registration marks on the lock ring and the die body. The die is set up for each load, and for different press in your case. You then record the corresponding registration mark settings.

I used to do that with sharpie. It didn't last. I ended up engraving the marks into the metal with electric pencil.

-TL

Sent from my SM-N960U using Tapatalk

[jetinteriorguy]

That’s easy, just get two dies and once they’re set you’re good.

[tangolima]

One die for each load?

-TL

Sent from my SM-N960U using Tapatalk

[Recycled bullet]

The minimum amount of crimp required is that which will allow the completed hand load to freely fit AKA chambering fit in the revolver cylinder. Any adjustments from this baseline will be specific combination of brass used, assembly tools used, to the bullet and propellant used in that particular gun.

I use Lee dies for the most part, I am playing with an RCBS 38 Special die set today I think I like it .
At this exact moment I am crimping 38 Special Federal brass with a powder coated 124 grain hollow point bullet sized 358. The amount of crimp is one third turn after the baseline has been located. I am crimping into the ogive of the bullet. The powder charge is 6.5 g of Winchester Auto comp and the gun they will be fired from is a Ruger Blackhawk 4 5/8 357. The Ruger Blackhawk is heavy and counteracts the equal and opposite recoil and jet effect that occurs upon discharge of ammunitions. I have not noticed any significant bullet pull with any reasonable loading in this handgun.

This baseline crimping guideline is also useful for magazine fed auto loading handguns.

When I am shooting heavy loads from the J frame some things I have to do differently to reduce or prevent bullet pull. The J frame weighs 1/3 or 1/2 what the Blackhawk does so it is to be expected. I tend to degrease the brass with stainless steel pins and soap and lemi shine and perhaps adjust the sizing die slightly further down to increase the depth of neck tension at the case mouth. I will use the dial mechanical measuring calipers as a no-go/go gauge and sort brass of a certain tolerance so that I can have reasonably consistent crimps while avoiding the truly enjoyable task of trimming brass. I will use bullets that have a deep crimp groove and this also helps to take up some of the slight differences in case length for example the MP 358429 has an excellent deep crimp groove that work perfectly with Remington or federal 38 Special brass.
Regardless of what I'm loading I bell the casings however much is needed to ensure a non problematic seating of the bullets without scraping powdercoat. I have found that disregarding admonitions of reduced case life from over working the brass has significantly increased the quality and repeatability of my handloads. The majority of case failures is cracks around the case mouth during the belling operation. I prime the brass after I bell the brass so I do not end up wasting primer on broken brass.

The first picture is showing 38 Special crimping. The blue bullet is with three and a half grains of Tight group. The silver casings are five and a half grains of unique. The last four on the end is the 124 grain powder coated hollow points with autocomp. I am unable to show a picture to show how I crimp the 38/44 I have shot them all . Maybe next time!

The second picture is my match load for my CZ p09. It's just to show an example of the crimp I use to ensure adequate and free chambering fit. It is the same 124 grain bullet loaded over 4.3 g of Winchester Auto comp.

The final picture shows the Lee hand press with the RCBS seating crimping die with the seater backed all the way out and the crimper adjusted where I want it. I'm using the two bucket method and listening to the birds today is brightening my spirit I hope you all have a good Sunday!

[44 AMP]

The minimum amount of crimp required is that which will allow the completed hand load to freely fit AKA chambering fit in the revolver cylinder.

I would point out that straitening the case (removing the case mouth flare) is not "crimping". I have yet to find a revolver (or any other firearm) that requires any amount of crimp to allow a round to be chambered.

You are entirely correct that crimp jump (bullet creep) is entirely situational and what works in one gun might not be enough in another.

I have tested this in my own guns and its quite true. With some guns and loads, case neck tension is entirely sufficient. In others, some crimp is needed, and in a few guns a heavier crimp than that is required.

I have single shots, lever guns, revolvers of different sizes, and even some semi auto pistols in several "revolver" cartridges, and the amount of crimp needed to prevent bullet movement is entirely dependent on the gun being used and the recoil level of the round.

[jetinteriorguy]

Originally Posted by tangolima

One die for each load?

-TL

Sent from my SM-N960U using Tapatalk

See post #14, he stated adjustments between a single or progressive press. That’s what I meant my reply to.

[Metal god]

The simple answer is get a second crimp die . One for each press . Id also recommend a Lee collet crimp die for all revolver crimps . The collet crimp die is less reliant on case length for consistency.

[RoyceP]

Agree - I use the bullet seating / crimp die to set the bullet / OAL cartridge length. In the next hole I use a Lee Factory Crimp Die (FCD). You need a minimum of four holes to do this.

[Recycled bullet]

I am crimping these 359 hammers right now.

[akinswi]

Water Jug madness right there!

[jetinteriorguy]

Originally Posted by Recycled bullet

I am crimping these 359 hammers right now.

Yowza.