Crimping and loading for accuracy

[NWPilgrim]

Thanks for emphasizing my point. "In general, crimping degrades accuracy".

Although as it also said, in some cases it may be necessary (at the cost of accuracy). And as I stated, the various manuals vary on what they consider necessary.

The debate in previous posts was about whether crimping improved or degraded accuracy, as was my post above. And as I summarized, most manuals, though not all, say that crimping may be needed for securing the bullet and vary somewhat on the conditions they deem it necessary.

[steve4102]

Yes, several manuals and the like claim that crimping degrades accuracy. In their tests they may indeed be right. I personally along with many other handloaders have found their conclusions to be incorrect.

These same manuals will also claim that Neck sizing will improve accuracy as compared to FL sizing. As Bart has pointed out numerous times this is simply Not True.

They also claim that up close and personal to the lands is where the handloader will find their best accuracy, again, test show this is a myth and may or may not be the case in your or my rifle.

So, what does it all mean. It means that as far as accuracy vs crimping vs neck sizing vs FL sizing , the manuals are far from the definitive on all things accurate.

As they all try and make very clear. Manuals, load data and techniques are merely guidelines and are not written in stone.

[Bart B.]

Steve, why don't you tell folks that I've also pointed out that folks winning and setting records in competition don't crimp case mouths onto nor into bullet jackets? Or that I've also mentioned that crimping often corrects some other bad tool setup or use issue and that doing all the right stuff doesn't need crimping to shoot the most accurate?

Or does that not fit your agenda? It sure fits mine, and yes, I have one regarding crimping.

[steve4102]

Because you have said that enough times for both of us.

You have also never tried crimping with the Lee Factory Crimp Die, so IMO your negativity towards crimping is nothing more than theory and "he said/she said".

Those that have Actually tested the LFCD have a different story to tell than those like yourself that have not.

Maybe it's just me, but when I am seeking advice and knowledge on a technique or product, I tend to lean towards those with first hand knowledge on the subject. Taking advice from someone that has never been there, just seems foolish to me.

One reason I mentioned your comment concerning Neck sizing vs FL sizing is that you have "been there done that" and so have many of the BR guys. So in this instance you have first hand knowledge and your experience is just that "experience". As far as crimping goes, you have no experience so your comments are basically without foundation and IMO are not worth repeating.

[skizzums]

its love how heated crimping threads get, they are always a good read

[4runnerman]

Steve4102- Say your last target on bottom right. 26.5 gn uncrimped. It's hard to see it real good, but it looks like yor best target there. When I look at targets I do not look at how tight your groups are. That is a secondary issue. I look for verticle stringing. Horizontal groups show nothing more than not putting cross hairs in same spot on target. What I mean is--

we shoot at say 600 yards,2 targets, One target shows a group 5 inch diameter( Vertical but in 5 inch group, Second target show 3 or less inch vertical but 8 inches side to side. Your second target is your best target even though your group is bigger.

Give us a better look at last target ,bottom on right -please

[NWPilgrim]

Your experience may be special. But while true for your circumstances it does not mean it will hold true for most. I don't see what is so hard about admitting that different people can have different results and you should do your own testing, or go with the majority experience of mot crimping unless necessary. Claiming that crimping is the best way to do it is patently not true for most.

[steve4102]

Steve4102- Say your last target on bottom right. 26.5 gn uncrimped. It's hard to see it real good, but it looks like yor best target there. When I look at targets I do not look at how tight your groups are. That is a secondary issue. I look for verticle stringing. Horizontal groups show nothing more than not putting cross hairs in same spot on target. What I mean is--

we shoot at say 600 yards,2 targets, One target shows a group 5 inch diameter( Vertical but in 5 inch group, Second target show 3 or less inch vertical but 8 inches side to side. Your second target is your best target even though your group is bigger.

Give us a better look at last target ,bottom on right -please

Crimped 25.5gr and 26gr





No Crimp 26.5gr.

[steve4102]

In case you are wondering the two targets on the right are my Browning BAR 300WSM.

180gr Nosler Partition, Ramshot Hunter, crimped with the Lee Factory Crimp die.

Settled on 65gr, Crimped. That's three.

[marine6680]

So I apparently kicked a hornet's nest with this one.


For me, I am all about testing and results... and vetting the results of tests others have done.

Also realizing that individual rifles are all different in their needs and wants.

[steve4102]

Originally Posted by marine6680

For me, I am all about testing and results... and vetting the results of tests others have done.

Also realizing that individual rifles are all different in their needs and wants.

That's a good plan.

Have you looked at the test posted in #15? In case you missed it here it is again.

http://www.accuratereloading.com/crimping.html

[lll Otto lll]

Originally Posted by 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.

Steve I've included the last sentence in the Sierra article that you conveniently omitted. I've highlighted it in red.

[4runnerman]

steve4102- I have no issues with you crimping. As i stated in my post if it works for you,Hey thats all that matters. Back to your pic now- That is by far your best target. 26.5 un crimped. I see horizontal,but your vertical is,,what 1/2 inch?. That is what you want ( good vertical) Horizontal , as i said is you not putting scope back to same spot. That target is much better than your crimped loads.
Your vertical on that target is smaller than all your crimped loads.I am a firm believer in the placebo affect,I mean that, If you think crimped loads are better,then you WILL shoot them better and in the end that is all that matters.
I am just stating the facts- Vertical is much much more important the horizontal. Good vertical shows consistency in loads. I would rather have a 10 shot group 8 inches side to side and 1/2 inch vertical then vise versa.

Side to side shows good consistent loads ( fps,ect ect). Just need to learn to dope wind,steady shots,ect ect. Vertical shows need for better load devlopment.

[steve4102]

Originally Posted by 4runnerman

That is by far your best target. 26.5 un crimped. I see horizontal,but your vertical is,,what 1/2 inch?. That is what you want ( good vertical) Horizontal , as i said is you not putting scope back to same spot. That target is much better than your crimped loads.

Sorry I can't agree with your selection for best target.

The 26.5gr un-crimped target measures .760 x 1.113, while the 26gr Crimped measures .479 x .494.

These are the 26.5gr Un-Crimped

[steve4102]

Page two.

These are the 26gr Crimped

[4runnerman]

Yes Steve. I threw out your top two fliers as they clearly were you on the trigger.
What I see left is very impressive. Almost straight in line with each other.
Please don't get me wrong, Your crimping is not my issue. I am simply trying to get you to see your other target. With those 2 fliers out, see what I see. you have multiple shots almost dead in line vertical. If those crosshairs would have been put in same spot you would have one hole.
Both crimped and non crimped are working for you,that is apparent to me.

[Bart B.]

In both series of 5-shot groups referenced in this thread, I'd rather have seen all the shots fired in one group. a 20- or 25-shot groups about 2 to 3 times more representative of the load's real accuracy than the average of 4 or 5 five-shot ones. There's about a 60% chance that one 5-shot group size will be 1/3rd larger or smaller than another one. And the odds of all their group centers being the same distance and direction from the aiming point are very small, if not zero.

I've no idea how much error was introduced into the group sizes by rifle and shooter irregularities. I'd have more confidence in a system that shoots no worse than 1/4 inch at 100 yards with uncrimped bullets then see what the same load does when crimped. 'Twould be nice if a benchrester did this so groups in the 1/3 MOA maximum range could be compared. Sierra Bulletsdid this decades ago with their rail guns and the crimped rounds shot about 1/3 bigger groups.

Or take a box of good commercial match ammo and shoot it in a match rifle; both as new and crimped.

[steve4102]

In both series of 5-shot groups referenced in this thread, I'd rather have seen all the shots fired in one group. a 20- or 25-shot groups about 2 to 3 times more representative of the load's real accuracy than the average of 4 or 5 five-shot ones.

If you are referring to my test target, crimped on the left and un-crimped on the right. There are 10 holes in each target, not 5.

If you are referring to other targets, can't help ya.

If you want or need 25+ rounds per target can't help ya, yet. You can however go here and view the results of a 150 round test. Three rifles, 50 rounds each, 25 crimped, 25 not crimped. They did not however shoot all 25 at the same target. Best I can do for ya for now.

http://www.accuratereloading.com/crimping.html

[45long]

and load to load
don't know why.

My pet load for 243 @ 2730 --no crimp
upper load for 243 @ 2850--crimp

308 rebarreled mauser---no crimp
308 savage---crimp with same load

it's whatever the gun or load likes

[Bart B.]

45long says it's whatever the gun or load likes. As neither has a nervous system connected to a brain, they cannot like (or dislike) anything, in my opinion. It's also my opinion that most of those guns or loads "like" have enought shooter error to make them significant.

Steve, those other series of 25 round tests of a 150-round set were shot in five 5-shot groups; each one's got a header number 1 through 5 for the group. Not all in a single 25-shot one which would have been a lot better. The average column lists what the average of all five fired groups are; I checked a few to see if they're exactly that. The 25-shot composite will be larger by some amount; more for some and less for others as it depends on where each group's center was relative to the aiming point for all groups.

[HJ857]

it's whatever the gun or load likes

I believe you are exactly correct.

It's funny how anti FCD folks tend to speak in absolutes, while those on the other side simply tend to say that the reloader needs to do their own testing.

[steve4102]

Originally Posted by Bart B.

Steve, those other series of 25 round tests of a 150-round set were shot in five 5-shot groups; each one's got a header number 1 through 5 for the group. Not all in a single 25-shot one which would have been a lot better.

Did you read my post?

I'll helps-ya out.

Originally Posted by steve4102

If you want or need 25+ rounds per target can't help ya, yet. You can however go here and view the results of a 150 round test. Three rifles, 50 rounds each, 25 crimped, 25 not crimped. They did not however shoot all 25 at the same target.

[Brian Pfleuger]

Originally Posted by HJ857

It's funny how anti FCD folks tend to speak in absolutes, while those on the other side simply tend to say that the reloader needs to do their own testing.

The trouble with that is that there's mostly no way of knowing what's really happening.

You crimp and your groups get smaller. Is it because crimping is good in and of itself or is it that crimping is "less bad" than a problem that it is now covering?

Personal experience is heavily, heavily over-rated. Individual people are heavily influenced by any number of logical fallacies and biases, besides the fact that our experiments are almost never large enough to eliminate variables and smooth statistical irregularities. Confirmation bias, experience bias, Texas Sharpshooter fallacies, any or all and more could apply to this situation.

We need only look at two points.

1)The upper echelons of competitive shooters have tried crimping and it does not improve accuracy in their guns. There's no sense in another person who's shooting a similar gun to try the tests again. This isn't one or two or three folks of unknown skill who've tried it. It's champions and experts. There's one thing about such folks in any discipline. They've tried it and if it works they do it. Period. They try EVERYTHING. They're always looking for that leg up on somebody else.

2)"Ordinary" shooters with "ordinary" guns have tried crimping an with mixed results. Few of them are ultra top-notch, expert shooters and they almost never have ultra top-notch, accurate and expensive rifles.

Since (1) is well-established, it follows that (2) is a result of any of the biases (or many more) that I mentioned OR that crimping is covering some "greater sin" and "improving" accuracy. That's not really an improvement though, any more than Tylenol can make a broken leg less broken, it just feels better for awhile. The problem is still there, it's just covered. You wouldn't need the Tylenol if the bone wasn't broken. You wouldn't need the crimping if it wasn't covering up some greater problem. Could be loading technique, could be component choices, could be gun problems, could be the shooter. Too many variables to tell.

It really is indisputable though, that when the best shooters man the best guns and shoot the best ammo, crimping is a detriment.

The question that should be asked, IMO, is "What problem is crimping covering up such that it appears to improve my accuracy?"

[Bart B.]

Steve, I think you've missed the point I was making; again. No need to identify it for you again.

Brian, you summed up the issue nicely, but some folks won't grasp the important stuff in it. In other accuracy issues, it's also the reason there's zillions of favorite loads out there for a given cartridge, bullet, case, primer or powder. But only a few for a suite of components that do well in competition.

[steve4102]

Originally Posted by Brian Pfleuger

OR that crimping is covering some "greater sin" and "improving" accuracy. That's not really an improvement though, any more than Tylenol can make a broken leg less broken, it just feels better for awhile. The problem is still there, it's just covered. You wouldn't need the Tylenol if the bone wasn't broken. You wouldn't need the crimping if it wasn't covering up some greater problem. Could be loading technique, could be component choices, could be gun problems, could be the shooter. Too many variables to tell.

Or, and most likely crimping with the Lee Factory Crimp does what Lee Claims it does.

crimp improves accuracy because pressure must build to a higher level before the bullet begins to move. This higher start pressure insures a more uniform pressure curve and less velocity variation.


You guys carry on and preach the evils of crimping without any first hand knowledge. I would expect nothing less.

Me, I'll keep shooting my defective crimped ammo into SUB .5 MOA groups with ordinary off the shelf sporting rifles.

Like my grandaddy usta say, "You can't argue with success, although many will try".

Edit:
Lee also says this about his Lee Factory Crimp die.

Until now, handloaders seated the bullet to touch the rifling to achieve similar results.

Isn't jamming a well known technique by bench rest shooters?
Then it should be noted that this jamming technique is also just a Band Aid and a Cover-Up for poor loading procedures and a Greater Problem