Substitute roll crimp for fold crimp

[drumgool]

I have been wanting to reload buckshot for varmit hunting ,been reserching for a couple of weeks. I have a lyman shotshell manual all the loads for buckshot list folding crimp. Can I substitute a over the shot card and a roll crimp without getting in to pressure trouble? I have also seen where people have just glued in an over the shot card. Would that hold up hold up in a pump action shotgun?
I will be using hand tools I have no press.

[Reload3006]

If you are not loading the hottest load you can find I doubt seriously you will be getting into any pressure issues. there are places you can send a few rounds to for testing if your worried about it.

[SuperBlazingSabots]

Greetings Drumgool, if you were to load two shells with the same components and roll crimp one and fold crimp the second one! The pressure will be higher with the one fold crimped as it is much harder to open the fold crimp from the inside, out wards. You do get slightly better combustion
with the fold crimp due to that and the pressure could be higher by 400 to 1000 lbs!
A Very Happy New Year to you and your family!
Ajay
Video Memories
www.PreciousVideoMemories.com

[blaster]

Greetings Drumgool, if you were to load two shells with the same components and roll crimp one and fold crimp the second one! The pressure will be higher with the one fold crimped as it is much harder to open the fold crimp from the inside, out wards. You do get slightly better combustion
with the fold crimp due to that and the pressure could be higher by 400 to 1000 lbs!
A Very Happy New Year to you and your family!
Ajay
Video Memories
www.PreciousVideoMemories.com

I'm not sure that roll crimp equals less pressure. I've seen it proven both ways with specific loads. I am inclined to believe that the pressure differences are component dependent.

[UNIQUEDOT]

I've seen it proven both ways with specific loads.

I have seen the same thing, but if the tests were not done on the same day with the same components by the same ballistician the results wouldn't prove anything anyway. The folks at BPI used to claim years ago that their testing proved roll crimps gave higher pressure. I have no idea whether they still claim that or the opposite of it. I use them interchangeably if it's a low pressure load and with a reduced charge if it's a high pressure load, but i rarely roll crimp anything anymore.

[drumgool]

Thanks for the replies . I guess I will reduce loads a little and work up . Are pressure sighns the same as metalic reloading. Flatten or cratered primmers sticky cases and such ,I have 20 plus years reloading rifle and pistol but 0 in shotshells

[eye shot]

I don't know about pressure, but velocity wise I loaded idenical 525 Lyman slugs except the crimps. I chronyed both loads and the star crimp was about 15fps faster than the roll crimp.

[1n5ane]

Thanks for the replies . I guess I will reduce loads a little and work up . Are pressure sighns the same as metalic reloading. Flatten or cratered primmers sticky cases and such ,I have 20 plus years reloading rifle and pistol but 0 in shotshells

Shotshells do not reliably exhibit the same warning signs as metallic cartridges.

Primer flattening will only tell you how "hot" the load is, it won't tell you if you're getting close to pressure limits. Some hulls will stick in the chamber when pushed to the limit; however, this isn't always reliable.

[Reload3006]

if you are loading shot your pattern will tell you a lot more than almost anything else. Slugs .. get a chronograph. other than that your guessing. OR just stay with a published load. But the bottom line is its your gun your life

[turbo1889]

In my experience (IME) with taking pressure traces of shotgun loads as to whether a roll crimp results in higher or lower peak pressure compared to a fold crimp depends mainly on how deep the roll crimp is. If you roll over just enough to form a roll crimp and it isn't very deep (like less then a 1/4" rolled down inside the hull) then IME the peak pressure will be the same or slightly lower where if you make a deep roll crimp (like a 1/2" or more rolled down inside the hull) then it can indeed raise pressures by as much as 1 to 1.5 thousand PSI compared to a fold crimp (or a shallow roll crimp).

[CaptRob]

In my experience (IME) with taking pressure traces of shotgun loads as to whether a roll crimp results in higher or lower peak pressure compared to a fold crimp depends mainly on how deep the roll crimp is. If you roll over just enough to form a roll crimp and it isn't very deep (like less then a 1/4" rolled down inside the hull) then IME the peak pressure will be the same or slightly lower where if you make a deep roll crimp (like a 1/2" or more rolled down inside the hull) then it can indeed raise pressures by as much as 1 to 1.5 thousand PSI compared to a fold crimp (or a shallow roll crimp).

wow...theres really that big oh a difference?...

[SuperBlazingSabots]

Most roll crimps are 1/8 inch deep as the powder and the wads are taking up a lot of hull space.
I like my roll crimps nice and deep for better combustion!

A lot of shooters complain about the loading data that does not fit in the hull as its suppose too. I would say if you can manage 1/4 inch deep roll crimp you are in good shape.
Here is my chart for each powder and hull space it takes with the powders I have and use for shotgun.

Ajay
Video Memories
www.PreciousVideoMemories.com

[UNIQUEDOT]

I don't know about pressure, but velocity wise I loaded idenical 525 Lyman slugs except the crimps. I chronyed both loads and the star crimp was about 15fps faster than the roll crimp.

Here is another example of "it can go either way" i have an article around here somewhere (in a loading manual) and the author tested roll crimp vs fold crimp velocities and the roll crimped loads were 200fps faster. I think turbo may have the correct answer in it having to do with the depth of the roll since depth can affect pressures in a star crimped load upwards of 1,500 psi.

[sargenv]

According to Ballistic Products, Roll crimping will result in about 1500 PSI LESS pressure than Fold crimping... which allows you to obviously add a bit more powder and get higher velocity.. I believe I read this in their "Slug & Buck" manual, revision II..

[SuperBlazingSabots]

Hello Sargenv, can you please post that part from "Slug & Buck" manual, revision II..
Hoping it will help clarify this issue!
Ajay
Video Memories
www.PreciousVideoMemories.com

[MarkW]

The only shotgun loading I do is for slugs, and I changed to roll crimping early on to get more consistent velocities and groups. I roll crimp with a drill press that has the stop set and I believe that also has an effect on consistency, at least in my gun. I worked up the loads separate but they were similar to each other, I never pushed for maximum velocity but went by group size.

I do not know what ranges you shoot your buckshot at, and honestly I have never done any hunting with it so I am not qualified to comment whether or not it will work better for you but I suspect that going to a roll crimp will not make velocities more variable but less.