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brent
PostPosted: Sun Jan 21, 2018 7:27 pm  Reply with quote



Joined: 02 Oct 2014
Posts: 45
Location: Iowa

I am roll crimping new Cheddite hulls that I trimmed to 2.5". I use a roll crimping die that I believe I got from BPI (90& sure of that) on my drill press with a crude wooden clamp that I built to hold the shell. I turn the die at 530 rpm, although using 800+ rpm didn't seem to make and difference. I'm not applying much pressure, though the hull seems full, it does not seem over full at all. (1 oz of 7.5s, sg16 wad).

Any suggestions about making more consistent (and prettier) crimps? I can't believe these are going to be very reusable.


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robp
PostPosted: Sun Jan 21, 2018 8:39 pm  Reply with quote
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Try a slower rpm
Lube mouth of hull with Q-tip and some kind of oil/lube
heat up your roll crimper
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putz463
PostPosted: Mon Jan 22, 2018 2:57 am  Reply with quote
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Location: West MI

Actually you're really close, the couple in the top left are looking pretty good but you can see the ribs in the plastic are really distorted from friction. Not pretty but they'll shoot. Looks mostly like a heat/friction/speed issue. Ive never needed to add any oil but some find it helpful.

The press turning as slow as possible is good advice, mines turning in the 250 range. Agree, preheating the die (hair dryer, prop torch) to coffee cup hot helps initially and then keeping a good pace going to maintain the heat in the tool is sound advice. Pausing as the tool comes in contact with the hull for a moment allows the heat to transfer to the hull plastic. Preheating the batch of hulls in the block with a hair dryer can help a little.

If possible, try reversing rotation, think I remember BPI suggesting it when I was struggling using their tools. Sorry to add, IMO, you're fighting an uphill battle using the BPI tool. The Precision Reloading RC tools are hands down superior, I own 1ea in 28ga (used for 24ga), 20, 16, 12 & 10 and all work very very well.

Hope this helps, best of luck with it,

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Eric Johanen
PostPosted: Mon Jan 22, 2018 4:45 am  Reply with quote



Joined: 27 Sep 2010
Posts: 22
Location: West Bend,WI.

I use the Precision roll crimp tool in my drill press with the BPI hull vise. I set the drill press stop for travel and when changing lengths just raise or lower the table. I do not heat the hull mouths and rpms set at 800rmp. Just a nice easy stroke and I get perfect crimps every time. Paper or plastic good crimps. I do 10's, 12's and 16's/
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brent
PostPosted: Mon Jan 22, 2018 10:48 am  Reply with quote



Joined: 02 Oct 2014
Posts: 45
Location: Iowa

Eric, et al.,
Thanks for these comments. I once made really nice crimps with an old handtool which subsequently broke. This morning, however, I was able to cobble to an 8mm bolt that I can chuck in the drill press tonight and see how that works. I think the BPI crimper just isn't working.

I have tried various amounts of pressure and doing it slowly to allow more heat to transfer, holding it longer for more heat, etc. I've been successful in melting the plastic, but I'm not that happy with how it is shaped. I'll try the new (old) tool tonight and see what happens.

I'm running my press as slow as it goes but 520 rpm is the bottom end. If that doesn't work I may try a hand drill at much slower speeds, but I would like the press to work. I think it will. Maybe.

Brent
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goathoof
PostPosted: Mon Jan 22, 2018 2:24 pm  Reply with quote
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Location: eastern oregon

I gave up on the BPI roll crimper a while ago. I tried every way to get it to perform, but with no satisfaction. I purchased two antique manual roll crimpers and have excellent results with plastic and paper hulls. I found very little difference in time spent roll crimping with the crank vs a BPI/drill combo.
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UncleDanFan
PostPosted: Mon Jan 22, 2018 4:52 pm  Reply with quote
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goathoof wrote:
I gave up on the BPI roll crimper a while ago. I tried every way to get it to perform, but with no satisfaction. I purchased two antique manual roll crimpers and have excellent results with plastic and paper hulls. I found very little difference in time spent roll crimping with the crank vs a BPI/drill combo.


+1

Same experience. My 16ga antique crimper takes four or five turns of the handle, and voila. Perfect roll crimp. Takes about five seconds. Bought a 12ga bpi crimper and had the same results as above. If anything, I'd say my antique crimper is faster.

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brent
PostPosted: Mon Jan 22, 2018 7:29 pm  Reply with quote



Joined: 02 Oct 2014
Posts: 45
Location: Iowa

It is going better. I've found that plunging faster, not holding the crimp down at for any length of time and less plastic at the end of the case all seem to improve the product.

in this picture the columns on the left are the first ones I did tonight going slow. As I went along, I went faster and faster, and they got better and better. Still not perfect.

The anomaly is the very bottom right cartridge. I loaded that one first while setting up, so it doesn't fit the chronology.

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MaximumSmoke
PostPosted: Tue Jan 23, 2018 9:56 am  Reply with quote
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I've done a lot of roll crimping in about every gauge I can encounter except 14, 32 and .410 bore. For starters, if you have the BPI crimper with just one pin to form the bump that rolls over the hull mouth, you have a decidedly inferior tool. Nonetheless, I have been able to make decent looking and serviceable crimps with the single-pin BPI units. They produce a rather square-edged result, which I do not like, as it is really destructive of the hull for future reloading. I have not tried BPI's two-pin roll-crimpers. They should be lots better, but they seem to be made the same way as the one-pin jobs. Using a drill press is a good idea with the one-pinners, as there is a tendancy to cock those crimpers. BPI's two-pinners reduce this problem. I like crimpers with 3 or more bumps to perform the roll-over -- e.g. Lyman, GAEP, Precision, etc. You've received usefull advice from those who suggest pre-warming the crimper. I actually pre-warm by crimping -- use of the crimper warms it and keeps it warm. I'm not too high on lubrication, though it probably can't hurt.

One thing I notice in your photos (good ones, thanks!) is a lot of sweeping distortion to the hull mouth. Putz463 pointed out the same thing. See how the lines in the ribbed hull get pulled over? The angle is remarkable and unusual. I think you must have an unusually high friction situation, as I don't get any "sweeping" of the hull material even with my single-pin BPI's unless I really reef down hard and fast with the crimper. Even then it is nothing like what you are experiencing. From your descriptions, it doesn't at all sound like your technique is bad.

The pins on single-pin BPI's are installed at an angle (which is a defective concept in my mind), and I think that makes them one-direction tools. Go with the direction of rotaton the tends not to pinch the hull material in the acute angle the pin makes with the outside wall of the crimp recess. Failing that, look for roughness in the pin, or maybe a burr from where they drilled the hole to install the pin. Is there any rust inside the crimper? If it was there it should have worn off by now, but if there is pitting it could be the friction culprit. Also, return your crimper to BPI and exchange it for another. BPI crimpers can't all perform as badly as yours does. Roll crimping is not at all tricky. I think there is something wrong with your particular tool, not your technique.

Best Regards,
Tony
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MaximumSmoke
PostPosted: Tue Jan 23, 2018 10:06 am  Reply with quote
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By the way, Brent, your crimp depth doesn't look too bad, but I'd use a tad more. It's hard to say exactly from the photos of the crimped hulls because they look so distorted and "mashed". Your first picture shows un-crimped shells in your loading block. Some of those look like they could use a bit more "free hull" at the top to make a good crimp. Finished crimp should have a depth about 1/8 inch. You can even go a bit more, but probably not less. I see a lot of folks doing about a sixteenth, and that is pretty fragile. Picture the rolled over hull and you'll see what I mean -- you need a depth of 3 or 4 hull wall thicknesses. Look at some factory roll crimps for guidance.

By the way again, this means you need at least 1/4 inch of free hull atop the B-wad (that's the over-shot wad).

Cheers!
Tony
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zoli 16ga.
PostPosted: Tue Jan 23, 2018 4:18 pm  Reply with quote



Joined: 23 Aug 2009
Posts: 287
Location: Southern Ontario

my two cents....get the precision reloading tool. no offence but your crimps still look very rough. pm me when you get the new tool, I'll be more than happy to help you out : )

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