RMR’s position on using Lee Factory Crimp

[Asking4afriend]

I recently ran across several reviews from pre-Covid days where it was stated Speer says not to use the LFC on bullets without a cannelure as it ruins the bullet and degrades the accuracy and other bullet companies say the same thing. Reportedly this info was posted in Speer’s FAQ but I looked and did not find it. Lee supposedly responded by stating not to use the LFC on Speer bullets lacking cannelures.

I’m guessing it’s not just me shooting the 69 and 75 gr 3GH through an MSR and not strictly bolt guns (I don’t have a bolt gun with a fast enough twist anyway). It’s been my practice to apply a “light” LFC crimp to these rounds (you can still see separation between the collet fingers).

What is RMR’s position on using the LFC die with their 3GH bullets?

[SC]

I don’t know what Jake would say, but I have tried the Lee FCD on the 69 3GH and it did not seem to make a difference.

[Sadie Woolman-Morgan]

I personally out a Lee factory crimp on every single load I develop and every single bullet I shoot for consistency. Seems that it depends on whether you develop your loads using it or not.

Since I do, tests using the same exact loads without the crimp yielded poor results. Conversely, one could assume that a test of the crimp used on loads developed without a crimp might yield poor results.

[SC]

@Sadie Woolman-Morgan
What kind of differences in accuracy have you observed in rifle loads? Is the difference in 100 yard groups or further out?

[mdi255]

I believe you are using the Lee Collet Crimp die, not the “post crimp sizing die”. The collet crimp die squeezes the case neck and the “carbide” FCD (for handgun calibers) uses a regular taper or roll crimp and the as the case is extracted, the carbide ring removes any bulges and insures the cartridge is in factory specs. Never heard of any problems or complaints about the collet crimp dies. I use 3 of Lee’s collet crimp, 2 handgun and 1 rifle and the only “carbide crimp die” I owned now resides in a landfill somewhere in southern Oregon…

• This reply was modified 8 months, 1 week ago by mdi255.

[Asking4afriend]

My takeaway from RMR is the company has no problems with the LFC dies being used with their 3GH bullets.

mdi255,
For clarity I am using Lee Part #90817, 223 Lee Factory Crimp Die for my .223/5.56. I also use them with other rifle cartridges.
It does use a collet to apply the crimp, but collet is not part of the die family nomenclature.

Probably trying to avoid confusion with the Lee Collet Neck Sizing Die (e.g Part #90954) which uses a collet to squeeze the neck of a resized piece of brass against a mandrel to improve neck uniformity and improve neck tension consistency. I find the collet neck sizer works best when used in conjunction with a small base body die (e.g. Redding #74111) to bump the shoulder back to SAAMI spec. and not touch the neck.

I do use a collet neck sizer on 300 AAC Blackout brass formed from 5.56 LC brass. The brass is formed by removing the decapping assembly from an RCBS Small Base AR resizer die (die set #11107) and running lubed 5.56 cases through the die. The cases are then delubed and cut using a HF min-chop saw and a jig that’s no longer available. I then anneal, trim to length, debur and final neck size them using the collet neck sizer (no lube necessary). The TTL and deburring can be done after the neck tensioning. I haven’ noticed any difference.

I also use Lee Carbide Factory Crimp Dies (available for handguns cartridges only), which apply a taper crimp or roll crimp depending on the cartridge (e.g. 9mm is taper, .357/.38 is roll) and final resizes the cartridge with a carbide ring at the opening (it resizes as you raise the ram). It replaces the Lee Bulge Buster that you’d buy separately and insert into a Lee Carbide Seating Die.

I use both kinds of LFC dies because they are not dependent on cartridge trim length like the Redding taper/roll crimp dies I used for years.

Although I may split a lot of brass and use the LFC on half and the taper crimp die on the other (all other components being the same) and see if there is any apparent advantage of one over the other.

[mn]

Since the question is about LEE Crimp Dies….My comments are general to this subject and not only RMR Projectiles. I have been reloading for about 30 years now.

Sorry to be long winded below….There are many factors that go into producing accurate ammunition, that discussion goes way beyond Crimp Dies.

Never had a problem with the Lee Crimp dies, goes for 300WSM, 30.06, 7.62X51, 243, 25.06, 22.250, .223 Bolt Rifles, 5.56 platforms and Pistol calibers.

Projectiles used, Barnes, Berger, Hornady, Nosler, Sierra, Speer, Winchester and some others. NOW RMR PISTOL. RIFLE UPCOMING.

I use Redding and Dillon Die Sets (Dillon in all Pistol, and appropriate Rifle calibers) (Redding for hunting calibers and accuracy loads), again depending on the purpose, but most often add the Lee Crimp dies as the final stage.

Never had accuracy issues with the final loads using LEE CRIMP DIES. All are typically MOA, sub MOA and many are sub .5 MOA (Bolt Platforms).

I load long in Rifle, and most are over SAAMI COAL, but still magazine compatible when applicable. Been doing this since Walt Berger and Erik Streker, taught me what I did not know about reloading, Ogives, COAL, about 2 decades ago, and more recently at SHOT, from other named manufacturers in the last decade).

I am not a 3 Gun, competition guy, but what I do know is that today projectile manufacturers build far better projectiles than 2 decades ago.

In 5.56, I am using Heavy Barrels 1:7, 1:8, 1:9 twist, 16″ to 26″. Depending on the purpose of the load, most are MOA if I do my part in the 5.56 and in longer Barrels many are Sub MOA, if I do my part.

5.56, 1:8 Barrels produce the best accuracy for me personally, great for P.Dogs at distance, and other things.

Projectile weights in 5.56 range from 53g to 77g.

Can’t see that there would be a problem with RMR, based on my experience with other manufacturers, but just starting with the 5.56 RMR product next month.

RMR projectiles are now my go to product based on my Pistol results in the appropriate calibers. Use LEE Crimp here too.

BTW – All loading is done on a Dillion 550, has been since the early 90’s. I use a Rock Chucker for resizing and case trimming with the Dillon Case Trimmer.

RMR – If we do our part, RMR, will preform accordingly.

• This reply was modified 8 months ago by mn.

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