To crimp or not to crimp

[steveNChunter]

Just looking for opinions and personal experiences about when a crimp is or isn't needed with rifle loads. In the last year since I've taken up reloading, I haven't crimped a single round. It hasn't caused me any problems, my ammo is accurate once I figure out what the rifle likes, and I've never had a bullet come out of the case if I chambered it and then cycled it out without shooting it.

So what (if anything) am I missing out on by not crimping? When should I be crimping and how much?

[GP100man]

If it ain`t broke ,don`t fix it !!

Alot of variables since we don`t have particulars .

But there is a time when crimpin is needed such as big heavy bullets ,inertia phisics will move em a bit , almost all magazine/tube fed firearms.

I crimp almost all my revolver stuff.

Even some loads/powders work better crimped or not .

But I do like some styles of bullets so I can find the rifles sweet AOL without the cannelure showing , purely cosmetic, but sure makes a more attractive/presentable round !!

[steve4102]

I crimp all of my semi-auto ammo with the Lee Factory Crimp die. I crimp all types of bullets cannelure of not. This not only helps secure the bullet, it improves accuracy. YMMV.

Is it "Needed" no. Does it help, yes.

Of all my bolt action rifles I only use the LFCD on one. It is defiantly not required, but improves accuracy, plus it makes me feel better.

There are those that crimp for some of the Big Boomers so the bullet stays put while in the mag. I do not.

Note that Sierra is now manufacturing some of their Highly accurate MatchKing and GameKing bullets with cannelure to give the Accurate shooter the option of crimping.

[Brian Pfleuger]

Well, this thread is going to turn into the battle of the ages, or at least the week, with pictures of crushed bullets, claims of improper use of dies, quotes of the claims from the manufacturer, etc, etc.

Almost no one crimps rounds for bolt guns. The top accuracy shooters certainly don't. That means that in a properly built gun its not a net positive. If it was, they'd be doing it because they find out what works and they do it.

In factory guns, well, see paragraph one. If you're curious, get a crimp die, set up a test and find out for yourself.

For this thread, get out the popcorn and watch. It's going to get ugly.

[howlnmad]

Only thing that I crimp are revolver rounds and 30-30. That's it.

[oldpapps]

"haven't crimped a single round. It hasn't caused me any problems, my ammo is accurate once I figure out what the rifle likes" steveNChunter

As GP100man said, "If it ain`t broke ,don`t fix it !!"

I crimp some, not all, of my .375 H&H loads (Ruger Number 1 so no set back) and all of my heavy/stout loads in .44 mag.

I don't crimp any others. Neck tension holds well. None of the powders I use require a hard crimp to burn properly. And I have never had any problems.

My standard answer is to test (what ever) both ways and see what works best for you.

Always error on the side of safety,

OSOK

[frankgh22]

Like Steve4102 said, I crimp all my magazine feed stuff especially my .300 Blackout since it seats the bullet deeper going up the feed ramps. Open tips seem to be more prone to do this, for me at least. Maybe I will polish my feed ramps and see what happens.

[dahermit]

...I crimp some, not all, of my .375 H&H loads (Ruger Number 1 so no set back...

"set back"? Or, did you mean, "jump forward"?

[Bart B.]

Normally, rifle bullets weighing less than 300 grains don't need to be crimped in for sporting use.

That said, a 5-pound .300 Weatherby Magnum may need its 250-grain solid behemoth buster bullets crimped in.

However, if your preferred tools and techniques of using them to reload fired rifle cases produce better results for you by crimping in the bullets, by all means do so.

Steve, what Sierra Matchking bullets have a cannelure for crimping? That's news to me if it's a fact. Sierra Bullets proved crimping their Matchking bullets made them shoot less accurate resulting in Lee adding a comment in their documentation saying something about don't crimp Matchking bullets in place.

[oldpapps]

""set back"? Or, did you mean, "jump forward"?"

Good question. I think of 'set back' when the round is jammed into the feed ramp and as I shoot more self feeders, there is my mind set.

I think of 'jump forward' in a heavy revolver loading trying to 'pull the bullets' the the remainder of the cylinder.

So, it could be either, depending. Good neck tension covers most.

Enjoy,

OSOK

[steve4102]

Originally Posted by Bart B.

Steve, what Sierra Matchking bullets have a cannelure for crimping? That's news to me if it's a fact.

.22 CALIBER (.224) 77 GR. HPBT MATCH CANNELURED
The .22 caliber 77 grain HPBT MatchKing is a cannelured version for the civilian market. Due to the fact that the 77 grain bullet is the heaviest magazine length tolerant .22 caliber bullet Sierra makes, it is a big favorite with the AR crowd. For years many customers requested that we sell a cannelured version for civilian use. Sierra is happy to have made that a reality for them.

https://www.sierrabullets.com/store/...red-box-of-500

Originally Posted by Bart B.

Sierra Bullets proved crimping their Matchking bullets made them shoot less accurate resulting in Lee adding a comment in their documentation saying something about don't crimp Matchking bullets in place.

Got some documentation and test results if this is indeed a fact?

[Bart B.]

Steve, thanks for the info on Sierra's crimped HPMK. That reminded me of their first Ballistics Manager telling me back in the '60's that all their bullets shot more accurate without crimping of any kind. Even knurling in a callelure unblanced them and they weren't as accurate as the unknurled ones.

Regarding anything I might have documenting the "Sierra vs. Lee" war of words on the Lee FCD versus HPMK accuracy, I've nothing physical. But it happened and I remember seeing magazine ads with all the bantering between them. Here's one link to Unclenick mentioning it; read post 7 in this thread:

http://thefiringline.com/forums/show...+crimp+die+fcd

Ballistic tech's at Sierra have also mentioned this to me. Call Sierra Bullets and ask them, then you'll get it straight from the horses mouth.

I will admit that the Lee FCD may well fix poorly assembled ammo and make it shoot more accurate. But if you can shoot your stuff into no worse than about 1/4 MOA at 100 yards all day long, with uncrimped case mouths on Sierra HPMK's, use the Lee FCD on some and watch the accuracy to to hell in a hand basket.

Decades ago, the arsenals making 30 caliber match ammo quit crimping those 172-gr. bullets in place and the improved accuracy was easily seen. While the smallest test groups didn't get any smaller, the largest ones did; mean radius of all shots from group center got smalller.

I also suppose it doesn't matter that crimped case mouths on centerfire rifle match bullets haven't shot winning and record setting results in the US for decades. Ask the benchresters about crimping bullets and they may well just walk away shaking their heads.

Name one top ranked (upper 20% of their classification system) competitive centerfire rifle shooter in any discipline who crimps his reloaded cases on bullets and I will reconsider my position.

[steve4102]

From Sierra.

To counteract this tendency, the semi-auto shooter is left with basically two options: applying a crimp or increasing neck tension. The first option, crimping, brings up some other issues that can be troublesome. In general, crimping degrades accuracy. Most match bullets are not cannelured (which also seriously damages accuracy potential), a requirement for correct application of most crimps. Still, there are taper crimp dies available from most of the major manufacturers. Lee offers their “Factory Crimp” die as an alternative, which seems to be one of the better options for those bullets without a cannelure. That having been said, crimping is still, at best, an occasionally necessary evil. Avoid it if at all possible.

Are you sure you are not confusing Sierra with Speer? Speer ran this Speer/Smear campaign several years ago.

Note how badly Speer deformed the bullets in their so called accuracy test.

[Toney]

I only crimp auto rds after flaring for lead, and my revolver rds.

[sea2weed]

For my rifles I only crimp the 45-70 but that's pretty much a no-brainer with a tube mag and 300-500 gr bullets. Everything else not, never needed to even on the magnums loaded hot. Revolvers, yes of course for the 357 and 44 mag.

[steve4102]

Originally Posted by Bart B.

Name one top ranked (upper 20% of their classification system) competitive centerfire rifle shooter in any discipline who crimps his reloaded cases on bullets and I will reconsider my position.

Apples to Oranges at best.
Name one competitive centerfire rifle shooter in any discipline that uses an off the shelf sporting rifle or 16" carbine $800 AR-15. Or one that uses inexpensive bulk Varmint Nightmare or Bulk Dogtown bullets.

I would be willing to bet that if you dig deep enough you would be able to find the same comment and analogy you just made in regard to FL sizing vs Neck sizing.

Name one top ranked (upper 20% of their classification system) competitive centerfire rifle shooter in any discipline who Full Length Sizes his reloaded cases and I will reconsider my position.


As you know the Neck sizing is better, cuz the Benchresters do it has been proven to be false.

Oh, and while we are naming names, Name one competitive centerfire rifle shooter in any discipline that has actually tested the LFCD is his/her $$high$$ competition rifle.
"Don't knock it till ya try it" .

[steveNChunter]

Well since all of my reloading so far has been in bolt action rifles with the heaviest bullet being 195 gr in a 8mm Mauser, I'd say I haven't missed out on anything by not crimping. I recently bought a set of .357 mag dies and I do plan on crimping those for use in my revolver. I need to get a couple more die sets in the near future so I can reload for everything I own, but I think I'll just buy the sets that don't have the FCD for my bolt actions. I have a .35 rem lever action that I will probably crimp since its tube fed, whenever I get around to loading for it

[Brian Pfleuger]

The best competitors in any discipline will try every available tool.

Not only they, lesser competitors who are looking for any advantage to push them to the next level.

They've tried it. You don't need to name names. That's what competitors do.

They don't all have to do it and they don't have to advertise that they tried it and it didn't work. Most things DON'T work. You don't get a bunch of folks talking about all the stuff they tried that DIDN'T work. They talk about that DOES work.

Think about it. If you had 10 minutes in a room filled with world class competitive shooters, would you ask them what DIDN'T work or what did?

On the matter of Sierra's crushing of their bullets, there's no question that Lee's instructions specifically state that their die will FORM a cannelure. That may not be how you use the die but it IS one of Lee's marketing claims, right along side the accuracy claims.

You can't blame Sierra for forming cannelures in their bullets, per Lee's claims.

[Bart B.]

Steve asks:

Name one top ranked (upper 20% of their classification system) competitive centerfire rifle shooter in any discipline who Full Length Sizes his reloaded cases and I will reconsider my position.

Me. From being in the top 2% when I got my High Power Rifle Long Range High Master card from the NRA.

David Tubb. Mid Tompkins, his wife Nancy and their two daughters Sherri and Michelle. These five High Master classified people have probably won more matches and set more records than any other five folks in competitive shooting.

Martin Hull, whom also was Sierra Bullets' first Ballistics Tech, who convinced them in the 1950's by his centerfire high power rifle competition success and all sorts of proper tests that full length sized fired cases produced the best accuracy. Sierra's been doing that ever since.

And most benchresters are now full length sizing their fired cases, but not very much: http://www.6mmbr.com/gunweek041.html

[steve4102]

You missed my point Bart.
I said, that if you dig deep enough into history you will find those that claimed Neck sizing is "more" accurate than FL sizing, so if you want the best accuracy possible you must neck size, cuz that is what the benchresters do.

I also said,

As you know the Neck sizing is better , cuz the Benchresters do it, has been proven to be false.

Read brother Bart, Read.

[steve4102]

Originally Posted by Bart B.

I will admit that the Lee FCD may well fix poorly assembled ammo and make it shoot more accurate.

Please explain.
First explain what is meant by poorly assembled ammo.

Then explain what the LFCD does to this poorly assembled ammo to make it more accurate.

Then explain how the above cannot also improve accuracy in not-so-poorly assembled ammo.

Then show your targets and test results verifying the above.

Thanks

[fshfindr]

I am not a competitive shooter. I load only 38's, 357's & 380's. No rifles. I have had pre-mature bullet-shell sepration. I crimp all because it is so easy to do. Actually, I think it takes more effort not to crimp.

[sc928porsche]

I always crimp. Lightly of course unless it is for rounds like the .357 and .44 mag.

[William T. Watts]

William's rule, for rifle I crimp for lever guns only, otherwise it's neck tension only! Taper crimp for 1911, I keep it simple! William

[Bart B.]

Finally got Sierra Bullets' replys to my queries on their new, cannelured .224 caliber 77 gr. HPMK bullet. Their man says Sierra finally figured out how to do that.



Those HPMK's are roll cannelured with tiny, oblong dimples, not in the bottom of a groove that's commonly done, so bullets are not significantly deformed. These shoot just as accurate as their non-cannelured ones. But only when they're not crimped in the case neck by any means. Crimping them, even the slightest amount, degrades accuracy as tested at 200 yards in their rail guns. They've known this for decades.

I see no objectives in testing crimp issues when folks with better equipment eliminating all the human variables thay I have have proved by any doubt that when best accuracy is the objective for centerfire rifles, no crimped in bullets will be used.