Home Forums Hunting & Shooting Long Range Hunting Lee Factory Crimp Die

This will give the jerks a chance to bash me since I can no longer post photos.

In the beginning this rifle was more or less a one MOA shooter.

At https://hammerbullets.com/hammertime/ there is a guy going by the name of Butter Bean. He suggests one tries using the Lee Factory Crimp Die to adjust a load like one would adjust a load with overall length. I tried it. I ran my 7RUMLN up to pressure with WW2 H4831 I received from John Lachuk before he left the range. I settled on 87.0 grains. After this, I did a primer test and settled on WLRM primers. I then did Bean's crimp test. I started with 1/16 rotation and went to 8/16 rotation by 1/16 increments. Since I couldn't afford custom dies, I used Lee 7RUM dies and ground off .100" from the bottom. Afterward I smoothed the edge with 1000 grit sandpaper. The necks have about .003" - .004" grip. The bullets are Hammer Hunter Tipped 132 grainers crimped in the top "groove".

I fired two three shot groups at 300 yards. The first one measured .710" but was about 1/10 mill to the right. I made an adjustment and fired another three shots. They measured 1 3/8".

The six shots average velocity was 3,665 feet per second with an Sd of 10. The fastest was 3,681 fps while the slowest was 3,649 fps.


If one of our .com friends wishes, I will text him the photograph and he can post it.

I have a few of them but I've not used them enough to have an real opinion of their effect on accuracy.

I have several LFDs and I've shot a fair amount of Hammer bullets. IMO, the benefits/detriments of crimping Hammer bullets cannot be pre-determined, as so many Hammer fans claim. I've had some groups shrink and others open notably. I've seen predicable SDs become erratic.

Shooters are crimping in the groove, on the shank and everywhere in-between. Some use a hint of crimp while others profess the need to really grip the bullets. Nothing is even close to universal.

Overall, I've had the most consistent results by NOT using the FCD with my Hammer bullets.

My suggestion would be to work up a load as you would with any other bullet. Then try the FCD and see how it affects your groups. If things improve then stick with it. If not, save yourself the extra step and move on.

Charlie-NY,

Thanks for this heads up. I tried it only on this 7mm. Based on your observations, I agree. I followed you suggestion about working up a load before I fooled with the LFCD.

Wondering if changing neck tension through the use of a bushing would reap the same +/- of crimping.

beretzs,

Your idea may work. Lee Factory Crimp die is way cheaper. Before I was so broke I used bushing dies, but I can no longer afford much of anything. If I didn't already have the supplies, my shooting would be almost nonexistent.

Totally understand that.

I have a few sets of 7mm Bushing dies so I can swap the bushings amongst the different sets.

Use whatever works. Some of us don't need all that extra schidt.

It certainly can. You may see SD/ES changes .

Shooting in the Marksman class, it may be difficult for you to discern the difference...
Carry on though.

I've experimented a lot with the Lee FCD and I have quite a few of them. I think they're great for hunting rifles that see a bit of recoil as they stop bullet setback in the magazine, anything bigger than a 30-06 I'll use one on for that purpose. For accuracy I've seen them change the dynamics of a load some, I have had loads that tightened up with them. However, I've found that if a load is so sensitive that something like that will change it's accuracy then it's not a well tuned load and the accuracy will likely be "hit or miss" as conditions change. A good rifle/load combo shouldn't need to be crimped to shoot well, if it does then there's something else that needs investigating and fixing. I'm of the opinion that they're best kept in the realm of keeping bullets from moving, not using them to tune for accuracy.

Crow hunter,

Do you feel the same way about overall length tuning?

I do a light crimp on ammo that is going into a high capacity magazine. If for nothing more than a little peace of mind that no bullets will set back. I can't say if it makes the ammo more accurate or not. It's more about peace of mind verses accuracy.

kwg

No. Seating depth is a critical part of tuning a load for me.

Got addicted to the FCD with my lever guns and handguns. I abhor trying to achieve a seating depth and crimp at the same time in a standard die. An extra step with the FCD but well worth it.

Was blown away by what a FCD did with my 300WM load using 190 SMKs when I tried it just for giggles. Wow, just wow.

So, those those of you using the FCD, what neck tension are you shooting for BEFORE you use the FCD?

I only use it on one bottleneck non-levergun cartridge and that's my 300WM, and tried it because the necks are so short, just to see what it would do.

.002" neck tension before crimping.

i have noticed with cheaper grade brass and or used standard grade brass when using the Lee Factory Crimp die i did seem to get a little better accuracy in a bolt action rifle. i have never done the Lee crimp die thing with my Lapua brass the Lapua brass is much more consistent neck thicknesses . myself i feel the Lee Crimp Dies are an excellent to have on hand in your reloading area ,i have about 15- 20 of these different Lee crimp dies. > Mule deer a while back posted this reason why its more about neck thickness consistency not being the same in regular brass is why a Lee Crimp Die can help i believe ? Pete53

Mine is .003"-.004". I discovered 7/16 of a rotation definitely improved the groups.