Is any crimp required for wadcutter bullet reloading?

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DocDerm
Posts: 35
Joined: Fri Jan 29, 2010 7:44 pm
Location: near San Jose, Calif. USA

Is any crimp required for wadcutter bullet reloading?

Post by DocDerm »

Hi, all
I would appreciate Your input on the above question. 32 Smith and Wesson as well as 38 special.

Some folks on the Internet seem to argue that there is sufficient neck tension from just pressing the word cutter into the mouth of the case to hold the wadcutter bullet immobile.

Others caution that crimping a wadcutter bullet can put excess pressure on the cartridge case leading to bulging of the case.

What can go wrong if there is no crimp or if the crimp is insufficient? These rounds are going to be used in a Pardini HP and a Smith & Wesson model 52.

What is best practice?

Thanks
fc60
Posts: 736
Joined: Fri Nov 25, 2005 11:46 am
Location: Western Washington State, USA 98385

Re: Is any crimp required for wadcutter bullet reloading?

Post by fc60 »

Greetings,

The NRA did extensive testing on crimping 38 WadCutter ammo.

Result was no measurable difference in grouping. PROVIDED you fired groups with the same crimp on all rounds.

Often, crimping is needed to ensure positive feeding with auto-loaders.

Roll crimp offers the best for feeding and is used by the big ammo companies. Downside is it fatigues the case mouth and splits occur soon.

Taper crimping does not work the case mouth as much and due to the long taper, cases of varying length are not affected by the crimp. With roll crimping all cases should be near the same length.

Cheers,

Dave
David M
Posts: 1632
Joined: Wed Mar 24, 2004 6:43 pm

Re: Is any crimp required for wadcutter bullet reloading?

Post by David M »

Here is what Lee has to say about crimp....

"Handgun loads need a firm crimp for accuracy, dependable
functioning and uniform velocity. The Lee Carbide Factory Crimper will produce ammunition with factory-like dependability.
A carbide sizer automatically sizes every round after crimping to insure they will fit any standard chamber. Slow burning powders
must have a firm crimp for proper ignition. Full charges of some slow pistol powders, if not properly ignited, can actually leave a
bullet stuck in the barrel. The Lee Factory Crimper can help avoid this dangerous and embarrassing problem.
Extremely light recoil and low noise target loads are practical. Light, low density charges frequently
produce erratic results if the bullet is not firmly crimped.
Often charges must be increased above the desired level to insure uniform ignition. A firm crimp permits lighter charges while maintaining uniform ignition and velocity.
The crimp is correct for the cartridge. Revolver cartridges are crimped with a beautiful, uniform roll crimp found
on factory ammunition. The crimp is fully adjustable, from minimum amount for maximum case life, to heavy crimp that embeds
the case mouth into the bullet. Often needed to generate sufficient start pressure for slow burning magnum powders.
Many cast bullets need not be sized. Modern molds, especially those made by Lee, are held to very tight tolerances.
Most bullets will function very nicely and usually give better accuracy when loaded as cast. An occasional oversize bullet or
case with thick walls will enlarge the case and prevent chambering. The Lee Carbide Factory Crimper sizes the case after it is
loaded. A bulged case will be sized to fit any standard chamber. We certainly don’t recommend knowingly loading excessively
oversize bullets. While the die will size the bullet and case to fit any standard chamber, the quality will suffer. The bullet will
no longer be a press fit because the case will spring back more than the lead."

What I have found is....
Semi auto's with wadcutters need a roll crimp with about 0.005"-0.008" of lead exposed to crimp into, helps with feeding.
Do not load under flush.
Revolvers also need some crimp but not excessive, enough to stop the extra wadcutter rounds from backing out with recoil.
The amount of crimp will also depend on your powder type and charge. Some powders need the pressure to burn fully.
The old Universal crimp die being part taper and part roll (parabolic) was very good for wadcutters in both types of guns.

38 Special..easy to load for both Auto and Revolver. Lots of load data for std. 148g HBWC.

32 SW Long... a pain to load, need to slug your barrel and match the dies to barrel and chamber.
The .32 has the worst spec. of any cartridge. 0.314" +0 -0.006" or from 0.308" to 0.314" diameter.
Most European pistols are .312"-.314" (except FAS down to.306"-.308") whilst American dies are made for both 32 SW long
and .32 Mag at 0.311". Very hard to load 0.314" without distortion. Hence custom dies needed.
It takes a lot of work to get a good load to work.
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rkittine
Posts: 195
Joined: Sat May 30, 2020 6:59 am
Location: Sag Harbor & Manhattan, New York

Re: Is any crimp required for wadcutter bullet reloading?

Post by rkittine »

I have two .32 S&W Long WC Pistols, one of each bore diameter. My Star Reloader was set up with dual crimp stations so I can get the crimp I need on either.

Bob
rkittine@aol.com
Sag Harbor and Manhattan, New York
WA2YDV
JamesHH
Posts: 218
Joined: Sun Mar 04, 2018 8:10 pm

Re: Is any crimp required for wadcutter bullet reloading?

Post by JamesHH »

With wadcutters - soft lead hollow base wadcutters - most of the effect on accuracy is from case-bullet interference.
Case-bullet interference needs to be right, ie not loose and not so tight it changes the bullet dia. I think this can change of time - older loads often seem to have a lower velocity than fresh ones.
A little taper crimp doesn't seem to do any harm and can help with consistency - also feeding in an auto.

Hard cast flat or bevel base button nose wadcutters - I think they benefit from a slightly more aggressive crimp.
RodJ
Posts: 56
Joined: Sat Jun 26, 2021 4:08 pm

Re: Is any crimp required for wadcutter bullet reloading?

Post by RodJ »

Hi Docderm, some of the back and forth on this, in my view, has to do with why you are crimping, which type and amount, and the load characteristics.

In my mind, taper crimps or simply case mouth reforming (straightening and removing the bell) are for cartridges that rely largely on the case mouth for headspace, such as 45acp in autoloaders. But even in an auto loader, some argue that the chamber position of the case is really established by the extractor hook - many cases are too short to contact the front of the chamber. And if they always did, some cases would be too long for auto loaders and could cause malfunctions. Also taper “crimping” can help with feeding, if needed.

Roll crimps, to me, in autoloaders, are for feeding reliability, if it is proved to be needed. That’s one reason, similar to taper crimping for feeding. Also, in 38 spl autoloaders, the cartridge may headspace on the rim or at the front of the chamber, depending on the barrel and gun.

RC is also used to hold bullets in the case under heavy recoil and heavy bullets - preventing the bullet from being pulled out of the case. Especially true for heavy recoiling revolver loads with heavier bullets. I think of 357 mag and 147 gr bullets. Light 38 spl loads, maybe don’t need much crimp at all, maybe none, and the bullets won’t move. 30.06, roll crimp into the cannelure, and they typically need it to hold the bullet.

Finally, roll or taper crimps maybe necessary to add some tension and delay bullet movement to get a good clean burn. While the bullet is still largely stationary, the pressure rise causes the temperature to rise. The comment elsewhere about dieseling is partly true, but I think of cartridges as being spark ignited. Once that happens, pressures and hence temperature rises dramatically. High pressures may help partially combusted gases to “ignite” - aka diesel - but I think that’s true in spark ignition engines as well. Some of the heat that goes to helping atomized gasoline continue to burn, comes from the pressure increase raising temperature in a constant volume. So heat from that T increase is additional to the heat given off by powder combustion. I doubt you could truly get solid powder to ignite without a primer. You’d have to inject superheated air into the case (which by the way is how a Diesel engine works - highly compressed air that is now at a high T is injected into atomized diesel fuel.

That’s a long way around the barn to say that - in my mind - a taper or roll crimp is used if it is needed and the type and amount of crimp is dictated by what you are trying to accomplish. Feeding, preventing bullets from being pulled by inertia, or by a need to delay bullet movement so that higher temps are reached for more complete / faster combustion.

For your 52, try just a little RC or maybe TC or none and see how you like it. But trim all cases to the same length so that you get the same crimp and thus a consistent effect from loaded round to loaded round.

Hope that helps!
mister G
Posts: 147
Joined: Sun Mar 07, 2004 8:09 am

Re: Is any crimp required for wadcutter bullet reloading?

Post by mister G »

I’m with David M . On my Dillon Progressive, I used the 3rd stage to seat only, leaving the 4th position for a Redding CRO HRP. (Taper crimp) as a dedicated station.
mister G
Posts: 147
Joined: Sun Mar 07, 2004 8:09 am

Re: Is any crimp required for wadcutter bullet reloading?

Post by mister G »

Forgot to mention, Third station takes DEWCs and HBWCs with a minor adjustment.
SP22
Posts: 4
Joined: Tue Mar 22, 2022 10:01 pm

Re: Is any crimp required for wadcutter bullet reloading?

Post by SP22 »

Winchester Super Match and the Remington 38 Wadcutter appear to be roll crimped. They feed well in my Mod. 52s. I have found that should I over taper crimp a case, that the magazine fingers may allow a stovepipe on the 52 and P240. So I pay attention to that. Somewhere on the web, the specs for case dimension and magazine finger spacing exist. The 52 can be Ammo sensitive to reloading. Trial and error is necessary. Those old Remington 148 HBWCs that were heavily graphited, fed well. The Delta Precision slugs do too. I’m the only guy on the firing line that puts a drop of oil on the top round of each mag. If the chamber is wetted, the gun seems happier. I always had the notion that with fast burning powders, a good roll crimp would create a better recoil impulse. But I’m not a physicist.
TonyT
Posts: 259
Joined: Fri Aug 20, 2004 6:50 am
Location: Michigan

Re: Is any crimp required for wadcutter bullet reloading?

Post by TonyT »

I have always used a very light roll crimp in the 4th stage of my Dillon to insure reliable feeding in a pistol. No reliability issues with either my Walther GSP, PArdini or S&W 52.
Last edited by TonyT on Fri Jul 15, 2022 9:23 am, edited 1 time in total.
fc60
Posts: 736
Joined: Fri Nov 25, 2005 11:46 am
Location: Western Washington State, USA 98385

Re: Is any crimp required for wadcutter bullet reloading?

Post by fc60 »

Greetings

This is my story....

A friend shoots a Benelli 32 S&W Long and experienced failures to feed about the third round.

I gave him a box of my reloads, with similar ballistics, and after 50 rounds, no malfunctions.

Looking closer at the pistol cycling the loaded round into the chamber, his ammo did hesitate.

Out came the micrometer. His ammo was taper crimped to 0.332". My ammo is taper crimped 0.325".

We discussed the mechanics of these events and determined that my case mouth having a smaller diameter enabled the cartridge to enter the barrel a wee bit more and the magazine spring was able to push the rear of the cartridge up under the extractor, as designed.

So, crimp does help in some situations.

Accuracy improvement? I await with the greatest anticipation for actual test targets fired at 50 yards demonstrating one method being better than the other. In the last 40 years of loading the 32, I have not found any difference.

Thanks for reading, film at 11.

Cheers,

Dave
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