Crimping and neck tension, etc., etc.

[Bixster_inc]

Because acclimate weather has done muddied up my shooting spot I’ve been doing a lot of reflecting on rounds I’ve made while waiting for everything to dry up.

Other than a mishap with some .30-30’s I crushed in the press I really haven’t given much thought to the benefits of crimping. All my dies say they “roll crimp” but no matter how hard I try I can never seem to find that perfect place in set up to where it actually crimps aside from my .45-70 rounds but that was just dumb luck multiplied by the the fact I was using Hornady FTX bullets. With those, you have to trim off about .060 off the top and it was recommended (by a YouTuber) that after seating you removing the seating stem and give the die body another 1/4 turn or so before running the rounds through again. Because this is a pain I ordered the Lee FCD for future loads.

However a few days ago I was able to kind of get to my spot after a few weeks of dryness and before the rain came back through to play around with some .44 mag/special loads I whipped up for my new Henry and ended up with nice shooting bullets but some just nasty looking casings when I was done. So again with the rain coming back I have some lab time to learn a little more and I’m probably overthinking this (again) but with information I’ve been finding being all over the map I’m confused (again).

With my goal being consistency do I crimp everything? Some of the bullets I use (Hornady Match, ELD Match & Sierra MK’s) do not have a cannelure, does that matter? I’ve read that a crimp allows better, consistent pressure build up therefore tighter groups in the end.

Possibly because my brass is mostly virgin with some stuff from off the shelf ammo that has only been fired from my guns once I’ve never really looked at neck tension. However I have noticed when seating bullets the level of resistance at the lever varies from case to case. I don’t feel like I’m ever forcing a bullet in, I’ve never damaged a bullet jacket but some feel like they seat considerably easier than others. Does this mean I need to look into neck turning or is that another die adjustment I’m doing poorly? I would assume a bullet that seats easier than others would suffer from inadequate pressures but I could be mistaken without a chronograph.

Back when I created those sweet, custom 45° .30-30’s I believe it was Walkalong that praised the benefits of the Lee FCD’s so I’ve picked them up for .30-30, .223, .308 & .45-70 with .44 mag/special, .303 Brit, 9mm, 300 blackout & 6.5 Creedmoor in my Midway shopping cart pending what I hear here and figuring out a few other things I need.

I also should say that my guns are a mix of auto-loading, bolt and lever actions.

As always, thanks in advance.

 

[Toprudder]

You probably are already aware, but in revolvers, a good crimp promotes more consistent powder burn, and also prevents bullet jump during recoil. In a tube magazine rifle, like most lever actions including 30-30, the crimp also prevents bullet setback during recoil. While I don't crimp my 223 rifle rounds, I would not consider not crimping my 30-30 loads, as the brass is thin on 30-30 rounds and I don't think neck tension alone will hold the bullets.

Having said all of that, I have factory 357 and 44 mag ammo that have no crimps at all, but they appear to use some sort of glue to hold the bullet.

Unless the bullet has an actual crimp groove (not just a cannelure) I prefer to crimp separately from my seating operation. In this situation, I really like the Lee collet style crimp dies. I believe all their rifle crimp dies are the collet style, but the normal pistol factory crimp dies are not. They make collet crimp dies for some of the magnum pistol calibers, like 357, 44, etc. They will not crush the case during crimping, and are not critical about trim length of the brass, either.

 

[Blue68f100]

^^^^^^

Like said the only rounds that need roll crimping is tubular fed magazines. These are normally your 30-30, 45/70, and revolver rounds. I would not crimp any rifle round that is bolt fed. I do not crimp any for my AR's either. If you do decide to crimp your std rifle ammo that have a cannalure for the crimp, all brass must be the same length if you do it with your seating die. Crimping is also harder on the brass. Crimping is just another step in which you can damage the bullet and/or make the round so it will not chamber.

 

[Charlie98]

I'm not a big LFC die fan, I have one for the .348WCF and it doesn't work worth a foop. I will say, with roll crimps, case OAL is paramount, particularly with thin cases like the .30-30.. or you will have inconsistent crimps... and probably a few crushed cases.

Generally speaking, if you have proper neck tension, you don't need to crimp rifle cartridges unless it's in a heavy recoiling cartridge, or, as was said, a lever-action. I no longer crimp my 7.62mm cartridges for my M1a, or even 5.56mm for my AR's... with good (BTHP) bullets; I still lightly taper crimp my FMJ blasting ammo, just because.

I prefer crimping in a separate step, if possible. I bought my progressive press specifically because it had 5 stations... so I could taper crimp my auto pistol cartridges, and separately crimp my rifle cartridges.

You mentioned sooty looking cases in your .44 Henry... It could be a number of things... wrong powder selection, poor crimp, poor ignition, oversize chamber. My brother has a Winchester Trapper in .45 Colt... with an oversized chamber. Those are the dirtiest cases evarrr, unless I'm loading something like W296 which expands the case enough to seal the chamber. Even big charges of Unique are not enough, and I get dirty cases.

 

[Grumulkin]

I have found that crimping has seemed to benefit in the following scenarios:

1. It did improve accuracy in some 45 Colt loads.
2. It's essential in heavy recoiling bolt guns like 378 Weatherby, 458 Lott, etc.
3. It's essential in heavy recoiling revolver loads.
4. It seems to improve accuracy with Barnes TSX bullets and Banded Solids.
5. If you have excessively flared lower pressure straight walled cases like 40 S&W, 45 Auto, etc., it's needed to remove the flare but other wise it's not needed.

I generally don't crimp cartridges to be shot in single shot firearms and don't flare cartridges like 300 Winchester Magnum, 30/06, etc.

With some cartridges, crimping with the seating die works fine. Most of the time when crimping is needed, I use a Lee Factory Crimp Die even if I have to have one custom made.

I don't stress over neck tension but then I anneal case necks which make neck tension more uniform.

 

[243winxb]

in my Midway shopping cart pending what I hear here

Empty cart now.
Neck tension holds the bullet. A bell/flare on the case mouth needs removed by a standard crimp die.

This guestion will start the debate on 30-30 crimping AGAIN. Your gun, do as you wish. Or test the neck tension. The long neck contact with the bullets bearing surface may produce as much as 100 pounds bullet pull.

 

[Rule3]

Empty cart now.
Neck tension holds the bullet. A bell/flare on the case mouth needs removed by a standard crimp die.

This guestion will start the bebate on 30-30 crimping AGAIN. Your gun, do as you wish. Or test the neck tension. The long neck contact with the bullets bearing surface may produce as much as 100 pounds bullet pull.

Well I wouldn't empty the entire cart. The whole post has a so much infr and rambling on it is hard to tell what the question is. Rifle calibers are different from handguns.
So if this statement by the OP
Back when I created those sweet, custom 45° .30-30’s I believe it was Walkalong that praised the benefits of the Lee FCD’s so I’ve picked them up for .30-30, .223, .308 & .45-70 with .44 mag/special, .303 Brit, 9mm, 300 blackout & 6.5 Creedmoor in my Midway shopping cart pending what I hear here and figuring out a few other things I need.

I would get the crimp dies for the 9mm and the 44 mag/special
Crimping rifle rounds is a whole other issue but then I do put a light collet crimp on my 556 ammo as most bullets I shoot have a cannelure

Every round of those (9mm and 44) I have crimped as the cases are flared. 9mm is taper, 44 is a roll.
Now of course you can seat and crimp with the seating die but a separate crimp die makes life easier. Not even gonna get into the LFCD debate. I use them and like them

 

[Stew0576]

I'm a new reloader, started last spring, I crimp all my reloads, the way I see it is if it didn't need it then it wouldn't be added to every die set, i could be wrong but it makes me feel better so.......

 

[Blue68f100]

Most of the time crimping will hurt your accuracy in rifles. It all depends on how much and how used during development.

 

[FROGO207]

From my testing the crimping is unnecessary on rifle rounds unless the ammo is being used in a tubular MAG. It actually decreased accuracy for me. But you should try both ways for yourself to see which way is better. I also crimp all revolver ammo as well.

 

[MagDog]

Here, this may help to explain crimping pros & cons better than I can. Note: This is from from ‘Sierra Bullets.’

Neck Tension
When we stop to consider the vigorous (read, downright violent) chambering cycle a loaded round endures in a Service Rifle, it becomes pretty clear it suffers abuse that would never happen in a bolt-action. This is simply the nature of the beast. It needs to be dealt with since there is no way around it.

There are two distinctly different forces that need to be considered: (1) those that force the bullet deeper into the case, and (2) those that pull it out of the case. When the round is stripped from the magazine and launched up the feed ramp, any resistance encountered by the bullet risks having it set back deeper (pushed) into the case. Due to the abrupt stop the cartridge makes when the shoulder slams to a halt against the chamber, inertia dictates that the bullet will continue to move forward. This is exactly the same principle a kinetic bullet puller operates on, and it works within a chamber as well. Some years ago, we decided to examine this phenomenon more closely. During tests here at Sierra’s range, we chambered a variety of factory Match ammunition in an AR-15 rifle. This ammunition was from one of the most popular brands in use today, loaded with Sierra’s 69 grain MatchKing bullet. To conduct the test, we chambered individual rounds by inserting them into the magazines and manually releasing the bolt. We then repeated the tests by loading two rounds into the magazine, chambering and firing the first, and then extracting and measuring the second round. This eliminated any potential variation caused by the difference between a bolt that had been released from an open position (first round in the magazine) and those subsequent rounds that were chambered by the normal semi-automatic operation of the rifle. Measuring the rounds before chambering and then re-measuring after they were carefully extracted resulted in an average increase of three thousandths (0.003") of forward bullet movement. Some individual rounds showed up to seven thousandths (0.007") movement. Please bear in mind that these results were with factory ammunition, normally having a higher bullet pull tension than handloaded ammunition.
To counteract this tendency, the semi-auto shooter is left with basically two options: applying a crimp or increasing neck tension.


Summary: Crimping is good, but is it good for accuracy? IMO yes, so long as you apply the right crimp. What's the right crimp? For me, it is the Lee Factory Crimp Die. It works with any bullet cannelure or not, case length is not an issue and if applied properly can increase accuracy. (I suggest you test fire at least 2 cartridge sets - 10 rounds each (20 total) of your hand loaded bullets - one with and one without a crimp. You can also conduct additional accurts Using various crimps... eg: light, medium & heavy.) Oh, and be sure NOT to expand the case neck too much when preparing the case for the bullet seating die step. The tail of the bullet should just begin to fit into the lip of the case. And you can aid this step by deburring the inside neck mouth of your cases before you use the neck expansion die.

 

[Bixster_inc]

First, thanks all for replies.

A lot of nays on the FCD outside of tube fed and 9mm. I’ll buy the crimps for 9mm and .44 mag/special and forget the others.

Still however thinking about the feel of some over others. If a bullet takes a noticeable amount of pull more or less than others to seat a bullet what is that attributed to? Or is it normal and I’m over analyzing?

Maybe it’s time to pull the trigger on the chronograph and see how consistent my rounds are coming out.

 

[Grumulkin]

Yea. It's time to pull the trigger.

 

[243winxb]

If a bullet takes a noticeable amount of pull more or less than others to seat a bullet what is that attributed to?

Brass has a memory. After the expander exits the neck, brass springs back.

Mixed range brass can make the most difference. I tested 5- 45acp cases, each different brands. Took 45 lbs, lightest, to over 100 lbs to move the bullets. In fact i stopped at 100lbs, bullet didnt move.

Brass of all the same brand , lot may have a slight difference in wall thickness. Pressure to seat would be closer then range brass. Outside neck turning rifle brass may help.

When working up a load, starting to maximum pressure, brass will expand differently. Brass memory comes into play again.