First Attempt

[Andy H]

As you are seating the wad just by hand pressure you may need to use the press to seat it a little bit more firmly to create a small (1-2mm) bit of space in the cartridge to allow the crimp to form without buckling the case, Have a read of this thread on shotgun world about wad pressure.http://www.shotgunworld.com/bbs/viewtopic.php?f=13&t=107600

[sitsinhedges]

In my opinion, apart from tidying up star crimps, the rolled turnover objective is purely to fit more shot into a case because the closure requires maybe 6mm instead of 12 and in my experience the patterns produced are exactly the same. We get them where the capacity of a case needs maximising such as in .410 shells and heavy 12 gauge loads such as Alphamax in a 70mm case but effectively containing a 3" magnum load, 10 bore, goose loads etc. None of these would benefit from having an open pattern at close range.

 

I use them in 65mm 20 gauge loads with a 70mm star crimp recipe using 23grams of shot. You can't tell one from the other besides the confetti often produced as the overshot card is obliterated. The claim I have read that an overshot card produces a do-nut pattern appears to be bogus too.

[Continental Shooter]

Well, if you still use plastic cups when loading with a rolled crimp, chances are that the disc will only disrupt the pattern of those pellets which are outside the cup and would be going astray anyway. Different matter if you're using fibre or bior as the disc (especially paper ones, cork are a lot better) will sit in front of the column and definitely spread the pattern.

 

Try putting a cigarette but in front of a pool table hole and shoot the ball through it.... 9 out of 10 the ball will divert from the pattern and not go in.

 

In fact, I use the rolled crimp only with Gualandi bior or dispersor to enhance the dispersion of pellets for short distance shots, so, in that respect, it helps a lot compared to a star crimp which tend to centre the pattern.

 

Using a 70 mm load with a 65 mm case in my book isn't advisable as the 65mm case will enhance the pressure beyond the safe limits for the shell, as the powder will ignite quicker ( i just wish to point out that this is not my belief, it's actually physics).

 

The rule of thumb is to reduce the powder of 0.05 gr when scaling down from 70 to 67 and the same from 67 to 65, moving from 70 to 65 i would reduce the powder of 0.05 and also reduce the prime's powder.

 

That is possibly why you don't notice any difference in pattern: as the load is overpressured, it will inevitably pattern open, however, adding more pellets will lessen the 'visible' effects of it.

 

It is to be noted that when patterning, the outer pellets reach the target later than the central ones especially if you pattern at the correct distance (30 & 35 mt)

 

Thanks,

[Floating Chamber]

Don't you mean 0.5 grain?

[sitsinhedges]

It's my understanding that if you use a 65mm case for a 70mm recipe but use a RTO in place of a star crimp the volume in the case will re.main largely the same and the pressures wont rise. The only difference is the amount of case taken up to form the crimp folds. The crimp will open more easily too in response to the building pressure

If you use a 70mm recipe in a 65mm case then close with a standard star crimp there will be less volume in the case for the expanding gases to move into and the pressures will rise, even if a smaller wad is used to account for this difference. Some of my proof loads have demonstrated this with a significant change for that few mil.

[Guest cookoff013]

Think doughnuts are produced when huge volumes of gas blow out the pattern.

[Andy H]

There is an RTO tool on the bay it's at £10-50 at the moment.

161436828970

[Cyrus1988]

As you are seating the wad just by hand pressure you may need to use the press to seat it a little bit more firmly to create a small (1-2mm) bit of space in the cartridge to allow the crimp to form without buckling the case, Have a read of this thread on shotgun world about wad pressure.http://www.shotgunworld.com/bbs/viewtopic.php?f=13&t=107600

 

Cheers Andy just had a read there. So, from what I understand from that thread is I don't want to go crazy trying to force the wad down on the powder.

[Andy H]

Yes do not put a lot of pressure on the wad , Only enough pressure to alter the height of the wad to give you the correct space for the shot and crimp , the case buckling is caused by the crimp pressing on the shot which then not only presses down but outwards as well causing the wad to grip the case and not slide down further into the case to allow the crimp to form.

[Continental Shooter]

Don't you mean 0.5 grain?

 

Nah, i am not familiar with imperial measurement (they're not conventional), only metric for me .... I meant grams

 

It's my understanding that if you use a 65mm case for a 70mm recipe but use a RTO in place of a star crimp the volume in the case will re.main largely the same and the pressures wont rise. The only difference is the amount of case taken up to form the crimp folds.

 

Sorry, for some reason i thought the load was RTO'd in 70mm as well... i'd still drop the prime a bit especially if using CX2000 or 616, that way you might obtain a tighter pattern.

 

Thanks,

[Cyrus1988]

Yes do not put a lot of pressure on the wad , Only enough pressure to alter the height of the wad to give you the correct space for the shot and crimp , the case buckling is caused by the crimp pressing on the shot which then not only presses down but outwards as well causing the wad to grip the case and not slide down further into the case to allow the crimp to form.

 

Ah right, when you explain it like that it makes total sense. Thanks again.

[Floating Chamber]

A commercial loader puts little or no pressure upon a plastic wad. We, as home loaders, have primitive loaders that lack the space for the specialist tools that 'shoulder' the case (hull) after crimp start. This operation weakens the case just below the initial crimp start and forms a shoulder and 'rim' on the case. The final spin is effected while the case is 'semi closed' and the pressure is taken up by this shoulder. The legs of the wad remain straight, unlike those on our presses.

[pestcontrol1]

 

Ah right, when you explain it like that it makes total sense. Thanks again.

so Cyrus hows your crimps coming on

[Cyrus1988]

so Cyrus hows your crimps coming on

 

Sorry guys, been kicked out the living room so been moving everything up to the spare room. Been out again on the crows, cartridges definitely do the job.

 

Won't prob be able to load any till tomorrow night, got plenty to think about till then though.

 

Thanks again to everyone for their input.

[dipper]

Think doughnuts are produced when huge volumes of gas blow out the pattern.

The proven theory is the cheap heavy waxed filler wad drives in the pattern been proven on camera . Allen Myers uses RTO on most of his high performance loads Go over to bear tooth bullets go on Tech notes by James Gates and read that guys a past master. dipper .

[Cyrus1988]

Yes do not put a lot of pressure on the wad , Only enough pressure to alter the height of the wad to give you the correct space for the shot and crimp , the case buckling is caused by the crimp pressing on the shot which then not only presses down but outwards as well causing the wad to grip the case and not slide down further into the case to allow the crimp to form.

 

So I tried putting the wad down into the case by hand and then placed it in the Lee to give the wad a bit of pressure. Went on to drop the shot, pre-crimp and then final crimp and this was the end result:

 

 

The top of the crimp looks quite uneven and over 3mm deep in the middle, which is, from what I gather, too deep.

 

On another note, I want to say a massive thanks to cookoff013 and John from Folkestone Engineering for sorting me out with a spinner to try out. Just need to get myself a bench drill now.

 

Cheers everyone.

[Andy H]

I have just looked back found that you managed a good crimp on a used case ,Do you know if the new cases you are using have the case mouth skived. ie: thinned out.

[Cyrus1988]

I have just looked back found that you managed a good crimp on a used case ,Do you know if the new cases you are using have the case mouth skived. ie: thinned out.

I've just loaded one with a used case using all the advice from everyone off here and it looks pretty good, too late to get a picture up tonight but will put it on tomorrow morning.

 

As for the new cases being skived, I'm not sure. Is there a way you can tell or is it something you need to ask the supplier?

 

Thanks again Andy.

[Floating Chamber]

The skived mouth of a shell is chamfered or feather edged. An unskived shell mouth is thicker.

Your crimp in your last photo is as good as mine.........then I spin them to look the dog's.

Edited October 7, 2014 by Floating Chamber

[Andy H]

have a look on the inside of a new case and you will see an area of the mouth of the case that looks matt finish and not smooth, That is caused by using a taper roughing to to thin the case mouth.

[Cyrus1988]

This is a cartridge I loaded last night using an old case:

 

 

The crimp looks pretty good, I think anyway. Then I added a card into the cup of the wad and loaded another using and used case.

 

 

The one on the left is with the card and the one on the right is without.

 

 

With or without the card these are probably the best crimps I managed so far. I need to check if the new cases I'm using are skived or not. Will do that tonight.

 

Cheers.

[turbo33]

Good Cyrus If you look at a used shell before you reload it, you will see the how the open end gets stretched.....look at it side on. It means that the petals will not be equal in length, so you are getting that swirling look to them. I found a piece of old gazebo pipe, that was an exact fit for the case. I then cut it so that its about half a millimetre shorter than the used case. Then you can just whip round with a modelling knife to get the stretched bit off and make it even all the way round. They will come out like new!! Those are great and will work fine, but if you want to persevere in your quest, try the above

[Cyrus1988]

Good Cyrus If you look at a used shell before you reload it, you will see the how the open end gets stretched.....look at it side on. It means that the petals will not be equal in length, so you are getting that swirling look to them. I found a piece of old gazebo pipe, that was an exact fit for the case. I then cut it so that its about half a millimetre shorter than the used case. Then you can just whip round with a modelling knife to get the stretched bit off and make it even all the way round. They will come out like new!! Those are great and will work fine, but if you want to persevere in your quest, try the above

I'll definitely keep an eye out for some tubing I can use to try this out.

 

In regards to loading used cases to get a better crimp due to the folds already being present in the plastic, if I use new cases, shoot them, and then go onto to load them again; would I just be getting the usual dodgy crimp I get with new cases or would they behave like the black used cases I've been loading?

 

Thanks again.

[turbo33]

They tend to be a bit better as the memory is already there. But you will find they stretch, so expect them to look much like the black ones, until you trim the excess off. If they are good quality and not skived, they might just stay a bit more uniform in length and shape.

[Paladin]

Hi why is there an indentation on one of the crimp folds ? Have you got some shot or other debris up inside the tooling stopping the full travel ?