Author Topic: Crimping (Read 11531 times)

JJD · « **on:** February 19, 2015, 08:08:37 AM »

How many of you reloaders crimp your center fire cartridges?
Just wondered how it effected performance and pressure?

I am running some pretty hot loads through my 300 win mag. Although I have noted no bullet movement as a result of recoil thus far, I figure it can happen.

haulinbass · « **Reply #1 on:** February 19, 2015, 08:26:35 AM »

I don't crimp nor does my buddy. I shoot a 270wsm and he shoots a 300wsm and we have had no problems and my buddy is a reloading encyclopedia himself.

2labs · « **Reply #2 on:** February 19, 2015, 02:21:18 PM »

I wouldn't crimp. Be worried about excessive pressure. Put one of your rounds in a bullet puller and you'll see they don't move that easy.

iusmc2002 · « **Reply #3 on:** February 19, 2015, 02:48:59 PM »

I crimp all my center fire rounds. Some may only have a light crimp, but all get crimped. I like to know that all the rounds are being driven from the case with consistent pressure because there are fluctuations in brass, and neck tension. I notice the difference between crimped/us crimped accuracy in my 300 WM. It isn't great, but is is noticeable to me

grundy53 · « **Reply #4 on:** February 19, 2015, 02:54:37 PM »

I don't crimp except for my tube fed rifle.

carpsniperg2 · « **Reply #5 on:** February 19, 2015, 03:48:53 PM »

Depends on what I am loading for. If it's a tube fed rifle I think it's best to give them at least a small crimp. On some of my larger semi auto rifles I have run crimps but don't think I really needed to.

BULLBLASTER · « **Reply #6 on:** February 19, 2015, 03:54:09 PM »

The only thing I crimp is my 375 h&h

Jason · « **Reply #7 on:** February 19, 2015, 06:57:25 PM »

I always give my 300wm a tight crimp because of the short neck, and I put a light crimp on all my other large rifle center fire cartridges.

JJD · « **Reply #8 on:** February 20, 2015, 08:10:33 AM »

I get the tube magazine issue, makes perfect sense.

Next time I can get out;
I will load a magazine full of cartridges that have not been crimped, fire 1, pull the rest and measure the bullet seated depth with a comparator.
I will repeat the process till all rounds are fired, Last round will have been subject to 3 previous rounds fired above it.
This should be a positive test for movement.
Will also measure/look for signs of increased case pressure and change in point of bullet impact and group size.

note;
I use a Lee Collet sizing die that I have taken .001 off of the collet in order to maintain a slightly tighter fit.

I understand that just because a bullet does or doesn't move in my reloads does not mean it will be the same for everyone's loads.
Just food for thought.

Blacklab · « **Reply #9 on:** February 23, 2015, 06:34:14 PM »

All my center fires got a hug for years. Now not so much and I really haven't noticed much of a difference

(gas guns)

Spawnstar · « **Reply #10 on:** February 23, 2015, 07:55:35 PM »

The only calibers I crimp is auto loaders lever guns and revolvers.

magnumb · « **Reply #11 on:** April 05, 2015, 11:12:14 AM »

Quote from: Spawnstar on February 23, 2015, 07:55:35 PM

The only calibers I crimp is auto loaders lever guns and revolvers.

.............I don't even consider crimping my 300 RUM and there's a bit of recoil/pressures goin' on with that rather warm load. After 3 rounds, measurements of AOL on the 4th cartridge have shown no appreciable difference in length.

HawkCreek · « **Reply #12 on:** April 05, 2015, 11:33:35 AM »

I've begun crimping tests with a .308 no I don't think it's needed (I haven't found any bullet creep without crimping). But in the rather limited testing so far there HAS been an increase in accuracy. I'll need several more range sessions to confirm this but it's been a fun thing to play around with.

As an interesting aside a light crimp moved my POI about 3/4" (maybe a little less) at 100 yards.

dawei · « **Reply #13 on:** April 05, 2015, 11:42:41 AM »

I crimp cartridges for my lever guns...
7/30 Waters
30/30 Winchester®
444 Marlin®

I do not crimp for my...
7mm Remington® Magnum
30/06 Springfield®

JJD · « **Reply #14 on:** April 05, 2015, 01:01:22 PM »

Above experiment completed and I did not experience any bullet movement at all.

Next going to experiment with consistancy with the Lee Factory crimp die.
Can't imagine it will be any better, but ya never know till ya give it a shot. Yeah, it was intended

Stein · « **Reply #15 on:** April 05, 2015, 01:59:22 PM »

I crimp both handun and rifle cartridges. I have no real evidence it is necessary, but it seems to work and it is only one more pull on the lever.

yorketransport · « **Reply #16 on:** April 05, 2015, 06:50:39 PM »

Lever guns and auto loaders get crimped. So do heavy caliber magazine fed rifles shooting bullets over 250 grains. Bullet weight plays a big part in the need for a crimp.

All revolver and semi auto pistol ammo gets a crimp. I've had plenty of magnum revolver loads jump crimp by the time you get to the last round in the cylinder. It helps give a more consistent burn with slow pistol powders as well.

Andrew

magnumb · « **Reply #17 on:** April 05, 2015, 07:09:07 PM »

Quote from: yorketransport on April 05, 2015, 06:50:39 PM

All revolver and semi auto pistol ammo gets a crimp. I've had plenty of magnum revolver loads jump crimp by the time you get to the last round in the cylinder. It helps give a more consistent burn with slow pistol powders as well.

Andrew

..........................my .44 Mag load is rather warm. I load Beartooth 300gr. WFNHCGC bullets and I use a heavy crimp....nothing out of the ordinary. No creep, at all, but I did pay special attention to setting this crimp perfectly and securely as it is my day packin' woods gun and needs to be as foolproof as possible.

I always check the last round in my revolvers handloads and factory loads, as well, after I shoot the rest of the cylinder to see if there's been any bullet creep. Factory or home grown..........makes no difference, they both get the same quality control once over.

Bill W · « **Reply #18 on:** April 05, 2015, 07:32:19 PM »

I crimp revolver ammo and also shotgun shells.

magnumb · « **Reply #19 on:** April 05, 2015, 11:29:53 PM »

Quote from: Bill W on April 05, 2015, 07:32:19 PM

I crimp revolver ammo and also shotgun shells.

Never a bad idea.........

C-Money · « **Reply #20 on:** April 06, 2015, 07:03:20 AM »

I crimp .357 ammo, and like said above shotgun shells

aorams · « **Reply #21 on:** April 06, 2015, 08:08:35 AM »

Hello all, I am an inexperienced reloader. I have been reloading 300 wnm using 180 gr accubonds, 77gr of H1000 and WRMP, OAL is 3.34", I do crimp them using a Lee Factory Crimp die screwed down 1/2 turn. I have been getting signs of high pressure as shown by the flattened primers in the attached picture. The load I am using came from Nossler so I am confident it is good. I wonder if the crimp is the cause of the high pressure, when I lower the reloader lever I try to excerpt a uniform preassure but sometimes I wonder.... Your thought or comments about the flattened primers would be welcomed.
Thank you in advance

aorams · « **Reply #22 on:** April 06, 2015, 08:23:17 AM »

This might be a better picture.
Thanks angain.

Curly · « **Reply #23 on:** April 06, 2015, 08:26:30 AM »

The primers don't look flattened to me. 77 gr doesn't seem all that hot either.

aorams · « **Reply #24 on:** April 06, 2015, 08:48:25 AM »

Thanks for the response. It is the lightest of three loads suggested by nosler, it is a good load for my rifle I am glad to hear (read) the primers are fine.

JJD · « **Reply #25 on:** April 06, 2015, 08:56:42 AM »

I agree with Curly, your cases look fine.
When they speak of primer flattening, the primer face fills in the beveled edges around the primer pocket as the primer backs out and is pushed up against the bolt face.
Something that will often accompany that condition is the pocket in the fired primer, where the pin struck the primer, will have raised edges where the primer metal tries to back into the firing pin hole in the bolt face.
Sure hope that made sense.
Can someone post a photo of a flattened primer? I'll look around if no one has one handy.

magnumb · « **Reply #26 on:** April 06, 2015, 08:57:35 AM »

Great pictures that were very useful. Secondly, IMHO, they show no cause whatsoever for concern. Flattened primers are much more pronounced than that.

If excessive pressure's were occuring, every bit of space visible around the outside of the primer in the primer pocket itself, would be covered by the flattened primer. Excessive pressure would actually make the base of the primer 'flow' and take up almost, if not all, of the primer pocket area.

That load and your pictures would give me no reason for concern.

Smart to ask the questions and offer the pictures that you did. As a newer handloader, you've taken the most prudent approach possible....good for you..

.

JJD · « **Reply #27 on:** April 06, 2015, 09:19:03 AM »

Hope this comes out so you can see it

C-Money · « **Reply #28 on:** April 06, 2015, 09:59:51 AM »

Those look pretty good Aorams, any cracks in the side of the case? H1000 is a great powder for the 300win. Its what my Father uses in his, with great success.

stevemiller · « **Reply #29 on:** April 06, 2015, 10:50:56 AM »

By looking at your pics (nice pics by the way) I cant see any problems,Another sign of over pressure to me would be the cases fitting tighter or not fitting at all in your shell holder.Rare yes but it has happened to me a couple times and I do believe it was from crimping cases that were just a little longer than the set up case.Giving it a tighter crimp than the others.

stevemiller · « **Reply #30 on:** April 06, 2015, 11:23:53 AM »

heres a real bad one

2labs · « **Reply #31 on:** April 06, 2015, 11:26:18 AM »

Steve, that one looks a little spicey.

stevemiller · « **Reply #32 on:** April 06, 2015, 11:37:10 AM »

yep.

Not one of mine just a jpg. off the net

aorams · « **Reply #33 on:** April 06, 2015, 03:31:43 PM »

Thank you all for the responses, they are very informative. C-MONEY, there are no cracks on the casings. JJD, I can't read the red print but the picture tells the story. Steve, I hope not to get that "spicy".
Again thank you for taking the time, I hope to be able to return the favor.
I hope you can enjoy the attached short video

stevemiller · « **Reply #34 on:** April 06, 2015, 04:07:04 PM »

nice

JJD · « **Reply #35 on:** April 07, 2015, 05:22:18 AM »

Stevemiller,
Nice photo of cratering.

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Author Topic: Crimping (Read 11531 times)

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