Why I Crimp

Blackhawk

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Ok guys, need a little Lee FCD input/feedback. It’s my first venture into using one in 40+ years of reloading (both for competition and hunting, all the thousands of rounds I’ve fired are in prep or practice for one of these or the other). But I digress...

I’m working up a hunting load for a 338 Lapua using new unfired Lapua brass, H-1000, and the Barnes 265 gr. LRX-BT. all brass has been trimmed with the WFT, flash wholes tooled, and primer pockets uniformed. i know none of this is usually required for Lapua brass, but I guess I’m just sort of anal LOL. All brass was sized using a Redding body die and the neck sized using the Redding neck die with a 0.002 neck tension bushing. Then run over a Sinclair 0.002” mandrel. Surprisingly enough, the mandrel did feel like it was opening the necks up. Didn’t expect that, but moving on....

Started out with Fed 215GM primers but was getting one round out of every 4 or 5 that would fly out ofthe group and the chrono would show a big drop in velocity for that round. So my suspicion is that I’m not getting consistent ignition. Hence i decided to give the FCD a try, thinking maybe a little light crimp may enhance the burning process. I also shifted over to using CCI primers. I know shouldn’t be changing two things at once but I’m working on a tight time frame. I leave on a hunt in 8 days and would like to take the 338 if possible.

So, anyway, set up the die initially one half turn down from when it contacted a loaded round. Got what looks to be a pretty good crimp. I was surprised to see that you can actually see the crimp. There’s a pronounced line visible on the brass just barely down from the case mouth:
View attachment 222221
Thinking this might be too much, I Backed the die out approx. one eighth of a turn or slightly more and still get a crimp, but not nearly as pronounced a mark on the case:
View attachment 222222
Since my intention was to try a light crimp to see if it mattered or not, I’m leaning towards using the lighter setting. So, here’s my questions:

1. Do you normally see a line like this on your brass with the FCD? i was expecting more of a taper crimp that wasn’t visible like this.

2. Do you think the lighter crimp is enough to make any difference? I’m an hour away from the range and can’t reload once there so i need to take a best guess approach.

3. Is the heavier crimp too much? The current load is right near the top listing in the Barnes manual. Concerned about pressure increases as well.

ANY serious suggestion, impressions, etc. are welcomed. I’ve currently got 5 rounds ready to go with the heaviest crimp, 10 with the lighter crimp, and 38 with no crimp at all. Range trip planned for tomorrow. Any ideas or help from those experienced with these dies?
Using a bullet puller kinetic or otherwise(collet type) remove a bullet from its brass hull.
Examine your bullet for any deformities (ie ring around your bullets copper jacket). Any grooves or marks on your copper jacket can cause all kinds of problems downrange.
In that light, if nothing is found leave your die alone, however, if a ring is found on the bullet jacket you are over tensioning your collet in the Lee FCD die. In that case, you should back off 1/8 -1/4 turn and crimp another round.
Now repeat the procedure by removing and examing your bullet for deformities.
Keep this up by pulling your bullets and examining them until there are no rings present on your copper jacket.
Now you are set correctly. ( A small ring around the case neck is normal and nothing to get excited over )
A little time spent now will result in a more enjoyable day at the range while sending rounds downrange.
This may seem a little much but with practice, you will find as Butterbean refers to as" the sweet spot," on the FCD die, and no further adjustment is needed.

O.B.T.W. Your Lee FCD die was a smart investment on your part.
Hope this will help you!
 
Last edited:

vernw

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Thanks for the replies, suggestions, and info! Based on these posts, I just pulled a couple of bullets. In the photo below, the left bullet is from the “heavier” crimped round. The totally seated round in the middle is there so you can tell where to look on the pulled bullet for a crimping mark. If you look very very closely I think there might be the tiniest hint of a mark from my heavier crimp. The right bullet is partially pulled from one of the “lighter” crimped rounds, and I’ll be dayumed if I can see any marks on the one at all.
1DD6E135-B195-4EC4-935B-BFA014E86B7C.jpeg

Since all the rounds have been tested for cycling through the action without any issues, I think I’m good to go for a range test tomorrow. I’ll report back on the findings. Again, thanks for all the replies!
 

Tac-O

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Apr 28, 2019
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Sandy, UT
I like this thread alot!!! I've only been handloading for about a year and a half and I've just been using the Lee fcd on everything since I started just because it made sense! I'm glad to see Lee's marketing speak on the this die actually has some substance. I'd always been a believer.

I need to get to fine-tuning my crimps and see how much impact it has
 

ButterBean

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Thanks for the replies, suggestions, and info! Based on these posts, I just pulled a couple of bullets. In the photo below, the left bullet is from the “heavier” crimped round. The totally seated round in the middle is there so you can tell where to look on the pulled bullet for a crimping mark. If you look very very closely I think there might be the tiniest hint of a mark from my heavier crimp. The right bullet is partially pulled from one of the “lighter” crimped rounds, and I’ll be dayumed if I can see any marks on the one at all.
View attachment 222304
Since all the rounds have been tested for cycling through the action without any issues, I think I’m good to go for a range test tomorrow. I’ll report back on the findings. Again, thanks for all the replies!
You can go the slightest bit after contact and you will never see the line but I will promise you it's crimping
 

West Calamus

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May 23, 2019
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texas
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I started using the roll-crimp in my .30-06 Hornady seating die to get more complete burn of RL16. I trim my cases the same and set seating depth then adjust the crimp down ~ 11 degrees rotation. If I rotate down too much, I start seeing compression dimpling in the neck or shoulder. Once it is set, I seat and crimp in one stroke. I’m crimping 150 Nosler BT and AB. BT is load development for AB application since their the same geometry, BC, etc and BT is much cheaper.

I saw RL16 burn improvement and my groups tightened up. Did it for H4350 too, though it wasnt needed for burn, and saw groups tighten up and velocity increase. Admittedly with 4350 that could be due to ambient temp increase of 20 F. Not planning to test to comfirm that possibility though.
I have noticed a significant velocity increase on a 7-08 by adding a crimp using H4350. Don't see the same velocity increase when crimping on other powders and cartridges. So the question is why the H4350 likes the crimp more then other powders? Does the powder H4350 need a little more resistance to build up more pressure?
 

ButterBean

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I have noticed a significant velocity increase on a 7-08 by adding a crimp using H4350. Don't see the same velocity increase when crimping on other powders and cartridges. So the question is why the H4350 likes the crimp more then other powders? Does the powder H4350 need a little more resistance to build up more pressure?
I have no idea on that one but I will say I have seen a lot of varying results over the years but I have never seen it hurt anything, it has always helped my loads
 

J E Custom

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Jul 29, 2004
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Texas
I know this is going to start the age old battle of crimp or not to crimp and that's not what I'm trying to do so I'm stating "This is why I crimp", This is my opinion so take it for that, I'm just sharing my personal experience and what works for me I am not a competition shooter nor do I claim to be Just a LRH . This is the second time this has happened to me in the past thirty years, the first was an Elk hunt in Oregon where I mailed my rifle and ammo out and then spent a week Horseback and the second time was yesterday, I will tell you that I do not abuse my guns, with that being said I use them for what they are intended for and I do not own anything that hasn't been "Well Used" No safe queens here, Now why I crimp, My Coyote Rig is a Rem 700 in 270 with 90 gr Sierra's, I loaded some rounds last month and got sidetracked and didn't crimp ( I use the Lee FCD on everything I load ) 10 rounds, I just let it go cause I wanted to get in the woods,these were loaded into a 5 rd Magazine two weeks ago, i hunt every evening an twice a day on the weekends 2 to 3 sets a trip and last Saturday my gun slipped off of my shoulder and landed on the Butt stock in a field and didn't hurt anything, fast forward to last night, I shot a ground hog ejected and chambered a new round and while unloading the weapon i saw the bullet in the second round in the mag was gone, upon examination I found the bullet had fell back in to the case, as i said this is the second time this has happened to me and why " I crimp" As for a side note this was 3X fired brass annealed, trimmed and FL resized every loading with a measured .0023 neck tension


For many years and many reasons, people have been crimping. I still crimp some cartridges and don't crimp others. Most if not all dangerous game rifle cartridges are crimped for consistent dependability. Other cartridges are crimped for accuracy and SD improvement. I personally have had bullets that had plenty of neck tension move forward and jab in the magazine.

I am a big fan of crimping for many reasons and believe it adds to the quality of some cartridges and uses. The bigger/heavier a bullet is, the more chances are that I will crimp them. Many people don't believe in crimping at all, and they may have a rifle/pistol that could benefit from crimping but wont try crimping and find out if it helps.

I am near the end of a test for the effects of crimping a 22 WMR. The results have been an eye opener The last test that will be performed will be to see how much crimping is best. So far crimping has improved the SD's from 48 ft/sec to 16 ft/sec with the same crimp diameter, and the velocity of the 30 grain load from 2133 ft/sec to 2294 ft/sec (161 ft/sec faster). the final test should prove what crimp pressure is best for all round performance. the worst SD ammo produced a sd of 181 ft/sec and after crimping it went to 59 ft/sec. the best ammo for my rifle a produced a SD of 48 ft/sec un crimped and a SD of 9 with a heavy crimp. so crimping went from 181 ft/sec to 9 ft/sec SD's. I would have to say it can change many cartridges.

It is not exactly the results I thought I would get because it is such a low pressure load and light bullet, but it did prove that crimping can be a benefit in some cartridges even if only to maintain COAL.

I will read all of the post to get the consensus of all, But like everything else in this sport, There is no one way only to do things. 👍 👍 👍

J E CUSTOM
 

Laguna Freak

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Jan 5, 2015
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I have noticed a significant velocity increase on a 7-08 by adding a crimp using H4350. Don't see the same velocity increase when crimping on other powders and cartridges. So the question is why the H4350 likes the crimp more then other powders? Does the powder H4350 need a little more resistance to build up more pressure?
I havent seen that with 4350. I got much better results with RL16 when I went to mag primer and improvement again when I went to crimp. I think 16 is a bit slower than the 4350’s.
 

vernw

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An update — ran into other issues (scope gave out) so only got to fire 3 rds light crimp, none with heavy crimp, and 3 uncrimped with .002” neck tension. Loads are in Lapua brass, CCI MR, H-1000, Barnes 265 gr LRX-BT. Results from LabRadar:
Lightly crimped: 2752 fps, ES 17, SD 8.7
No crimp, .002” neck tension: 2757 fps, ES 7, SD 3.7
Barnes’s max load yields 2772 fps, so still below that and no pressure signs.
Doesn’t look like much diff, between the two loads, but the CCI’s are working MUCH better than the GM215Ms for this load. I think either one will work fine on Indiana whitetails under 500 yards (the max range on the bean field I’ll be watching opening day)
 

ButterBean

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An update — ran into other issues (scope gave out) so only got to fire 3 rds light crimp, none with heavy crimp, and 3 uncrimped with .002” neck tension. Loads are in Lapua brass, CCI MR, H-1000, Barnes 265 gr LRX-BT. Results from LabRadar:
Lightly crimped: 2752 fps, ES 17, SD 8.7
No crimp, .002” neck tension: 2757 fps, ES 7, SD 3.7
Barnes’s max load yields 2772 fps, so still below that and no pressure signs.
Doesn’t look like much diff, between the two loads, but the CCI’s are working MUCH better than the GM215Ms for this load. I think either one will work fine on Indiana whitetails under 500 yards (the max range on the bean field I’ll be watching opening day)
Where are you at in Indiana ?
 

vernw

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I’m actually in Dallas, TX. Was born and raised around Indy, went to school in your area (RPI), and come back every year to see the folks in Brown County and do some deer hunting up near Logansport with Pop, my brother-in-law, my son, and his boy. We’ll hit Brown County next Wednesday and then head on up to Royal Center on Friday, then head back to TX on Tuesday
 

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