Cannelure/Accuracy Test 38 spec

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cove posted this 27 March 2021

My experience with shooting/loading/component testing on u-tube, is that most of the videos are not very informative, with some of them being worthless.  This all changed the other day when I came across a site titled: "Pounder Labs 38 special 148 gr HBWC cannelures"  This is the most in depth test I have seen and if you shoot WCs you should give it a look.  What I gleaned from this video is that bullet pull does matter, and (as Steve Hurst points out in TFS#255), it is hard to duplicate factory match ammo when using previously fired cases and not applying a cannelure.  Also, Pounder Labs has other videos on tests that might be of interest.

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Eutectic posted this 31 March 2021

Ric, Cove,

The bullet cannot be held firmly by the cannelure any more than lead bullets will be held firmly by sizing the bullet by compression in the loaded cartridge by running it into a die after bullet seating. The elasticity of brass is large compared to lead, the brass case springs away from the bullet. 

Bullet pull is often measured by pulling on the bullet. This is equated to resistance on firing which is incorrect. Pressure over a few hundred pounds (before the bullet starts to move) expands the case against the cylinder wall. At this point resistance vanishes.

Yes, excessive crimp can damage the bullet. Using fired cases, which all of us do, introduces the possibility of a case mouth split. A split will throw the shot several inches out of the group. Minimum crimp, just enough to remove the bell works best in my experience.

 Steve

 

 

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358156hp posted this 30 March 2021

Or remove the guts from a LEE 38 Spl Factory Crimp Dies and use it as a sizing die to "uniform" your fired case diameter. You'll need to decap in a separate step. Doing this with matched cases has helped me a lot in the past. Try various combinations, such as unsized bullets, and various sizing diameters to see if you can find a sweet spot.

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RicinYakima posted this 31 March 2021

All of the factory WC ammo I have shot has a cannelure below the bullet and one in the top lube groove. Crimp for efficient burn with WC ammo is mostly a myth. Plus it scraps the sides of the bullet on exit, so that doesn't help. Of course my experience is from the 1980's when I shot International Pistol, so that may no longer be revenant.

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cove posted this 03 April 2021

Larry:  I looked in my Lee catalogue and it states that the collet die is so powerful it will form a crimp groove in the bullet, even if one is not present and they show a jacketed bullet.  I think the idea with soft cast/swaged bullets is that if the bullet is deformed, accuracy suffers.  There are several mentions of this in the comments above.  During my testing, when I ran a loaded round into a sizing die to to tightly secure the bullet, velocity went up, the ES was better, but accuracy suffered.  I suspect the accuracy suffered because WC was deformed.

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cove posted this 31 March 2021

Steve: I find it interesting that the bullet was not held more firmly by the cannelure. If it could be moved, there must not be much of a crimp.  There seems to be a conundrum.  You need a firm grip on the bullet to achieve efficient burn and keep the bullet from moving due to recoil, but you do not want to deform the bullet.  I have been sizing cases using a Lee carbide sizer that has been lapped so that it reduces cases just enough so the bullet is a snug slip fit (bullet can be seated with thumb).  The case is then run into a crimp die just enough to remove any flare.  Problem is, the WC is not firmly held so they may be at different depths upon firing.  A while back I posted what I thought might be a solution. That was to place a cannelure in the case that would limit the seating depth and that depth would be such that the WC nose would be in contact with the start of the cylinder throat.  This system would ensure the  WC was held firmly while not being deformed.  Problem is, this would require the purchase of a cannelure tool at a cost of over $100.  My Scot's background makes that a tough decision.  Well, anyway it is going to be another interesting summer of experimentation.  Thanks guys for your comments, there are a lot of shooters/reloaders here in the Cove, but no casters, so it is great to be able to exchange ideas on this forum. Bill

 

 

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cove posted this 04 April 2021

CatWhisperer: There are a lot of unknowns in the cast bullet business, but a fact I and others have learned, is that too much lube affects accuracy.  I don't know about stickness, I only use Lee Liquid Alox.  As Ed recommends, it should be thinned and used sparingly.  I use 50/50 LLA/mineral spirits and around 6 drops per 15 HBWCs. No leading, good accuracy.  Last summer during extensive testing HBWCs at 100 yds,  I was using almost 1 drop per bullet.  Accuracy was good for a while, but later in session shots went up to the right.  When I went to less lube groups had same POI throughout test of 50 shots.  As far as  grooves, that is another mystery that alludes me.  

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Eutectic posted this 30 March 2021

Thanks Cove,

I really liked the Pounder Lab video. Nice work, well executed and an excellent presentation.

One thing I noticed when deconstructing factory HBWC loads was the bullets were sometimes loose in the case.The bullets were held by the cannelure. Seating force was probably zero and the ammo was excellent.

It is nice to know cannelures work,  but I am not about to but a cannelure tool. To much trouble and cannelures shorten case life.

Steve

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cove posted this 30 March 2021

Steve-First let me say that I have read your WC article (and Ed's) many times an appreciate the information found within.  I agree that application of cannelures to handloads puts handloading on a different level and going to that level is beyond my interest, and expertise.  One thing I am a little confused about is your comment "---the bullets were sometimes loose in the case. The bullets were held by the cannelure."  Could you please expand on that?  Bill

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Eutectic posted this 30 March 2021

The bullets could sometimes be moved slightly with finger pressure. The bullets were not tightly held by the case. The cannelure was retaining the bullet. The case was sized and expanded to bullet diameter, probably to avoid damaging the very soft bullet.   

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45 2.1 posted this 30 March 2021

Use a carbide 38 Super or 38 S&W (same thing) for sizing wadcutter brass for soft bullets. No damage or size reduction (somewhat dependent on case wall taper) and accuracy increases.

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LarryW posted this 02 April 2021

How about a Collet Crimp Die ?  The hype says "will make its own cannelure" Seems to do just that on .357

& 45 Colt. ??  

A day late & a dollar short, story of my life ???

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RicinYakima posted this 03 April 2021

ES is not any indication of accuracy.

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TRKakaCatWhisperer posted this 03 April 2021

I'm curious as to the effect of the sticky-ness of the lube used AND the form (mini-grooves vs standard-grooves) of the contact sides of the bullet - on both bullet pull and accuracy.

 

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cove posted this 04 April 2021

RicinYakima: You are correct that ES does not determine accuracy, but it doesn't hurt. I have submitted an article to TFS about my findings last summer shooting HBWCs at 100 yards.  When the ES was low, groups were great.  So I am using ES as a guide in an effort to produce consistent loads. I'm assuming the chronograph is more accurate than my shooting ability. That being said, I do wonder how accurate my old chronograph is.

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TRKakaCatWhisperer posted this 04 April 2021

Years ago I drew in 3d CAD two bullets - one with conventional grooves and the other was a Lee with the tumble lube grooves.  Calculating the VOLUME of the lube it turned out to be the same.  I should have also calculated the surface area that would be in contact with the bore....

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