Lee Factory Crimp Die

[NJC]

I’ve heard a lot of good feedback on the results obtained while using a Lee factory crimp die. Unfortunately, I do not know exactly how they work (index off the shoulder, base, other) to actuate the crimping motion. My question would be this:
Given the differences in case shape between the 375 flanged and the 375 belted could I use the 375 H&H belted crimp die on a 375 Flanged round?

 

[fourfive8]

It won't work as is- because of length. But you can possibly make it work by adding a spacer (thick washer) around the cartridge base once you place it in the shell holder before running up into the FCD. Measure the difference between the HH case length, which is what the Lee FCD is designed for, and the Flanged case length. That difference determines the approx thickness a spacer will have to be so it will work. I'm assuming you have a 375 Flanged Magnum? The book difference shows a standard Flanged Magnum case to be about .1" longer than the Belted Magnum. If that is correct for yours, the spacer (washer) will need to be about .1" thick. Your pic seems to show the difference to be more than .1"... but that could just be a photographic distortion?

I use a 458 Lott FCD for my 450 Watts which is a little longer than the Lott. I simply add the correct thickness spacer (an aluminum washer) over the cartridge and run it up into the FCD to crimp. Pic below shows that set up

The FCD is a collet die with 4 fingers which compress inward on the rim of the case mouth as the shell holder pushes up against the bottom of the sliding collet body that is within the die body. Very simple once you see how it works. The Lee FCD, IMO, makes a superior crimp. And no more expensive than the FCD is, it would be worth it to give it a try with a spacer (washer).

 

[Shootist43]

NJC, I use Lee FCD(s) on all of my magnums. You can contact them for info, send them a fully prepared inert case for the caliber in question and they will make you a FCD for it. Go directly to their website, they offer a lot of custom FCD(s) not listed by the major distributors of reloading equipment and components.

 

[CAustin]

NJC, I use Lee FCD(s) on all of my magnums. You can contact them for info, send them a fully prepared inert case for the caliber in question and they will make you a FCD for it. Go directly to their website, they offer a lot of custom FCD(s) not listed by the major distributors of reloading equipment and components.

And we know the one we ordered for me works!

 

[MMAL]

It won't work as is- because of length. But you can possibly make it work by adding a spacer (thick washer) around the cartridge base once you place it in the shell holder before running up into the FCD. Measure the difference between the HH case length, which is what the Lee FCD is designed for, and the Flanged case length. That difference determines the approx thickness a spacer will have to be so it will work. I'm assuming you have a 375 Flanged Magnum? The book difference shows a standard Flanged Magnum case to be about .1" longer than the Belted Magnum. If that is correct for yours, the spacer (washer) will need to be about .1" thick. Your pic seems to show the difference to be more than .1"... but that could just be a photographic distortion?

I use a 458 Lott FCD for my 450 Watts which is a little longer than the Lott. I simply add the correct thickness spacer (an aluminum washer) over the cartridge and run it up into the FCD to crimp. Pic below shows that set up

The FCD is a collet die with 4 fingers which compress inward on the rim of the case mouth as the shell holder pushes up against the bottom of the sliding collet body that is within the die body. Very simple once you see how it works. The Lee FCD, IMO, makes a superior crimp. And no more expensive than the FCD is, it would be worth it to give it a try with a spacer (washer).

View attachment 369116

Two things:

I use them on all of my reloads .300 win mag and up. I think they are great and give a consistent crimp. In addition as a relatively new reloaded they are very easy to use.

Concerning above why would you just adjust the crimp die from above using the threads and locking nut? What am I missing here?

 

[M McDindi]

I can't answer your specific question about using the same Lee FCD on both 375 cartridges but I use them on 308, 30-06, 375 Ruger, 45-70, 450Marlin and 458 WM. I do like them except for one specific application/loading.

I LOVE latest generation of the .30cal 180gr Speer Grand Slams. When I tried my first loads for just cheap range time in 3 different 30-06 rifles with various powders and charges with the FCD accuracy serious sucked. All three rifles are at or near MOA with TSX but with the Speers, they would all be 2"-3" at best. Called Speer to ask for suggested load data.

Very first question the Tech Support guy asked was if I was using a Lee FCD - yes. He said don't. Just use your regular seating die with a roll crimp. Tried his advice and used my "known" powder combinations and with just a little tweaking of the the charges all three again shot as well as with TSX.

Not sure what impact the FCD had but it apparently puts enough pressure on the crimp that it can change the shape of the bullet enough to maybe cause accuracy issues. I still use the FCD on everything else I load, just not with those particular bullets in 30-06. I also use the Grand Slams in .375 cal and 286gr. I use a VERY light FCD on those without any ill effect on accuracy.

 

[fourfive8]

Don't know about what Speer's tech support's idea was regarding a roll crimp versus a collet crimp?? If anything the roll crimp is, by design, going to be more inconsistent for neck tension. If there is enough recoil to change OAL of cartridges in magazine by ramming bullets deeper into case or "pulling" unfired bullet in second barrel then I would think increasing neck tension and/or adding a crimp would be necessary for reliable function. Also, if there is no crimp groove on the bullet shank, ANY crimping attempt is a crap shoot.

As to why simply adjusting the FCD die in the press for the longer Flanged case won't work? Simple, the length difference between the Flanged and regular Belted case is too great.

 

[M McDindi]

458 - No clue as to Speer Tech's reasons. All I know it that one change worked and was across the same caliber and three different rifles - Ruger 77 RSI, Husqvarna HVA and a Styer Mannlicher (full stock) 56.

 

[fourfive8]

Most target/accuracy only shooters shooting calibers that don't require a crimp don't crimp but are fully aware of and strive for consistent neck tension. However, for heavy recoiling rifles where reliability trumps 1/4 MOA accuracy differences, then a crimp may be absolutely necessary.

I've found it's very easy to foul up a roll crimp and end up with either inconsistent neck tension or actually a reduction in neck tension. The direction of crimping force using a roll crimp shoulder can actually buckle and loosen neck tension on the bullet. And the roll crimp function is extremely sensitive to small variations in case length. Whereas the collet crimp is not significantly affected by small variations in case length. The collet crimp is a separate operation and is not affected by or limited by the bullet seating process or bullet seating adjustments. The roll crimp done by the shoulder in the seating die is directly linked to and affected by the bullet seating process.

A light roll crimp done properly into a crimp groove can yield pretty consistent tension. Whereas an overcooked, incorrectly FCD crimp may not. Who knows? I do know that a properly applied collet crimp using a Lee FCD is consistent and that consistency is far easier to achieve with the collet die than a proper and consistent roll crimp is using the shoulder inside a bullet seating die.

 

[Wyatt Smith]

I do love my Lee factory crimp dies. Very easy to adjust as well.
When I roll crimp, I do it in a separate operation, it just seems easier to me.

 

[NJC]

Thank you all for the great information and advice! I’m going to both try the spacer and contact lee about a cartridge specific die.

 

[MMAL]

Just an fyi, I had Lee make me a custom die for 500/416ne and the diameter of the die is larger than will fit in Hornady or I believe some rcbs presses. Make sure your continue that prior to ordering it.

 

[Luvthunt]

The Lee will fit a RCBS Rockchucker if you remove the adapter bushing on the tool. Not an issue other having a wrench to fit. The Lee die works great. No loss of 416 Rigby cases with this die ie pushing the shoulders back doing the crimping.

 

[fourfive8]

Yep, if your die is 1 1/4" diameter, you'll need to remove the reducer bushing in the press (RCBS). They can be pretty tight from the factory. Use a correct fitting 1 1/2" wrench. A 15" crescent will work with care as the head is fairly thin.

 

[NJC]

Unfortunately, Lee has indicated that while they can do the 375 flanged as a custom die they aren’t taking Custom shop orders right now.
I am going to order the 375 belted mag FCD and try the spacer as described by @fourfive8.

once again, thank you everyone for all of the great information!

 

[fourfive8]

The FCDs aren't expensive at about $12 plus shipping from most outlets. I just checked my supply of flat washers and it appears most thick washers, as found in hardware stores, range between about .08" and .12" thick which is an ideal range for choices if your Flanged is about .1" longer than the Belted. The outside diameter of an average 7/16" flat washer is about 1" but the hole will have to be opened up a little to fit over the base of the case... .535+" should work. To open up washers where center precision isn't critical usually I just chuck the washer in a vice and use a rotary tool. A 9/16" bit will work as will a round file.

Go slowly... for example if trying a .1" thick washer to start with, watch as the shell holder/washer pushes the collet into the collet body and the 4 collet fingers come together around the rim of a dummy round with bullet. Watch the 4 fingers by viewing from the top of the die. Go slow... If overdone, a compound press can easily damage this type die. You can fine tune the amount of crimp by adjusting the die in the press. If the FCD is properly adjusted, a complete crimp is accomplished with very little felt effort in a modern compound press.

Pic is of average .1" thick flat washer opened up large enough to easily fit over base. In this instance a belted case with a .530" diameter.

 

[Bob Nelson 35Whelen]

NJC, I use Lee FCD(s) on all of my magnums. You can contact them for info, send them a fully prepared inert case for the caliber in question and they will make you a FCD for it. Go directly to their website, they offer a lot of custom FCD(s) not listed by the major distributors of reloading equipment and components.

@Shootist43
Art they even made one for my wildcat 25/303 Epps Newton improved, as well as collet die, FLS and seating die at a fraction of the cost of Redding dies. Very good quality as well.
Bob

 

[Bob Nelson 35Whelen]

I can't answer your specific question about using the same Lee FCD on both 375 cartridges but I use them on 308, 30-06, 375 Ruger, 45-70, 450Marlin and 458 WM. I do like them except for one specific application/loading.

I LOVE latest generation of the .30cal 180gr Speer Grand Slams. When I tried my first loads for just cheap range time in 3 different 30-06 rifles with various powders and charges with the FCD accuracy serious sucked. All three rifles are at or near MOA with TSX but with the Speers, they would all be 2"-3" at best. Called Speer to ask for suggested load data.

Very first question the Tech Support guy asked was if I was using a Lee FCD - yes. He said don't. Just use your regular seating die with a roll crimp. Tried his advice and used my "known" powder combinations and with just a little tweaking of the the charges all three again shot as well as with TSX.

Not sure what impact the FCD had but it apparently puts enough pressure on the crimp that it can change the shape of the bullet enough to maybe cause accuracy issues. I still use the FCD on everything else I load, just not with those particular bullets in 30-06. I also use the Grand Slams in .375 cal and 286gr. I use a VERY light FCD on those without any ill effect on accuracy.

@M McDindi
I experienced similar th o you and your ought 6 but mine was a 223.
The problem turned out to be TO MUCH CRIMP in my case. Backed off to just a light crimp and the problems disappeared.
Bob

 

[5shot]

I glued a washer to the top of a spare shell holder and then Dremeled out the opening so that I could move the crimp up. I use it only for crimping.