crimps

[Paul Harm]

From the Accurate reloaders Guide - Crimping: This is certainly one of the most important aspects of the shotshell reloading process. The influence of crimp on the ballistics is often ignored, and assumed to be of lesser importance than primers and wad make/design. The fact is that the effect of Crimp-strength can totally overshadow the influence of the other components and parameters. This is controlled by the following: Crimp depth, condition of case, wad length and condition.
Some reloaders want to extend case life and they tend to crimp as shallow as possible. However this pratice can be problematic if a "soft" combination is used it can lead to underperformance or in extreme cases "bloopers".
They go on to say the difference between a shotshell and a rifle is the rifle cartridge gets its resistance and Maximun Peak Pressure from the bullet being engraved from the rifleing where as the shotshell gets its from the crimp. There for, the shotshell Maximun Peak Pressure is reached long before the base of the shot/wad assembly has left the case. From what I've read in other articles, reloading data is with a .060 deep crimp. A .020 depth would have about 2000psi less pressure.
Just thought I'd give you guys something to think about. Maybe that's why I had trouble with nitro powders in Brass hulls and glueing in the over shot wad - too much volume for the powder and no resistance for load. Paul

[charlie cleveland]

paul i totally agreewith what uve just said...ihave been loading a lot of the plastic and paper hulls using no crimps at all...i noticed that when you seat the wads with pressure that they will rise slightly back up...thus with no crimp to put a little pressure back on the wads you will have a few bloopers....i use the no crimp method to lenthen case life....but on my hunting shells i crimp all of them.....boy you sure hit the nail on the head..... thanks charlie

[Mark Landskov]

I wondered about crimps. I had originally considered Magtech drawn brass with RCBS 12 gauge dies. The RCBS dies apply a nice little crimp to hold the over-shot wad in place, much like brass factory loads in the early 20th century. Unfortunately, the RCBS dies come in 12 gauge only. 4D makes a large array of brass case shotshell dies, though.

[charlie cleveland]

precision reloaders also have several differant crimpers for the roll crimp....they work very well i have one in the 8 ga that does a good job....need a reverse type drill or drill press to make it work right...... charlie

[Paul Harm]

Mark, I never crimped a brass shotshell. I would think it wouldn't last very long - that's why everyone glues in the overshot wad - the brass shell would last forever. I had at one time 14 boxes of Magtechs and loaded black powder. It just got to be too much of a pain in the a** to clean them. Sold every thing to a cowboy shooter. I run the shotgun venue at our club and we shoot three times a week. My wife and I go through about 24 to 30 boxes of shells a week. The Remington hulls in 12ga will reload 10 to 20 times before I throw them out. And the cheap " Gun Club" ones are laying everywhere. For that reason I like a nice deep crimp. I believe when useing the roll crimp you'll have less pressure than a star crimp. That could be helpfull if you're trying to keep pressure down. Just about all my guns are damascus barreled so I'm always watchfull of reload pressures. Paul

[Mark Landskov]

Paul, I bought a very nice BGI roll crimper and a worn out 10 gauge crimper was thrown in the deal. I tried the 10 gauge unit on a few old hulls and it really does a swell job. I plan on using it when my 10 gauge gets put together. I agree with crimping brass hulls. I would imagine that their lifespan is greatly reduced. If I go with brass, I plan on RMC and a suitable adhesive for over the shot wads. Cheers!

[Harry Collins]

The quickest overshot card adhesive that has immediate set up is the hot glue gun. Waterglass is expensive, takes a day or so to set up, has a short life and is difficult to remove from the brass.

To deep of a crimp on plastic hulls will cause excessive pressure.

Harry

[charlie cleveland]

harry ive also noticed thedifferances in preassure when you crimp to deep and some times i get a shell thats bent a little bit from me pulling on the handle to hard...have learned not to pull on the handle so hard....some hull do not need as much preasure on the handle....have you noticed this before or is it just me......charlie

[Harry Collins]

I have the most problems with 10 gauge shells bending or denting in a little. 3" 410's have been a source of agrivation as well.

Harry

[Robert Rambler]

Food for thought ?

http://www.clayshootingusa.com/html/archive/aug_sep10/Cases%20and%20Crimps.pdf

[Paul Harm]

Robert, looks like I was off a little on my numbers - I was going from memory. I'm going to copy that article so I have it for correct future reference. Now, I wonder what the pressures are for glued overshot wads? Or rolled crimps? The glued would be way less, but how about the rolled? In old reloading manuals going from paper wads to plastic they used to recomend useing 10% less powder. Ah, the fun of reloading. To all those guys who say "why reload- I can buy almost as cheap" - ya but you can't get low pressure or any of our custom loads as cheap. Paul

[charlie cleveland]

interesting thinking paul ...roll crimping should have morepressure than the glued over shot cards...it will be nice to know what the differance is....probly want be much differance....what do you think....charlie

[Paul Harm]

I think the roll is only a small bit less than a star crimp - the glue a lot less - JMHO - Paul

[charlie cleveland]

i had about gave up on the shooting of smokless powder in a brass shell....but today i said i would try it once more....first i loaded up alliant bluedot no bang just a fizzle...tried a hotter powder....it was clays still a blooper....i was using plastic wads i wrapped the bottom of wad with sometape to have a tighter gas seal with still another blooper.....but i have solved the mystery of usingsmokless in brass hulls now....i was about to give up on smokless in brass but i decided i would try onse more....i loaded blue dot powder then used the plastic wad with no tape used....then my 1 1/4 ounce of shot....then i used 3 top cards over shot instead of one..... ifired this load over 15 times with not a blooper one....the pattern was very good could not tell the differance with 2 or 3 top wads in patterns....this was a 10 ga alcan brass hull i was using with the remington no 57 primer....the secret to using smokless powder in brass is in thetop wad.....i do not know what the load will do in cold weather yet but at 60 degrees plus here today it was a very good and pleasant load to shoot and as a plus not much cleanup....buy the way all these loads were fired throgh a parker p grade 10 ga with 32 inch barrels and the barrels are twist steel..... hope the extra top wad helps somebody out with there use in smokless in brass....remember these over shot wads are over the shot.... charlie

[David Lien]

Charlie,
I have loaded Alcan brass cases for 50 years. The problem is I only loaded heavy loads for my fluid steel 10s. I have no knowledge of light loads for damascus guns. I do know some things about reloading Alcan brass cases though.

1. Inside diameter of Alcan brass are tapered. Alcan allbrass wads are also tapered. The blue side goes to the shot and fits up like a morris taper. You can also use Alcan PGS wads under the nitro cards.

2. Ball powders have always worked best in brass cases. I shoot HS6 and 540Winchester.

3. The Alcan maxfire 220 primers are a must for loading alcan brass cases. They are hot!

4. The Remington 57 primers are not the best choice. If you will PM your mailing address to me then I will try to UPS you some 220 maxfire primers.

Good luck

David Lien

[Mike Stahle]

I wonder what the pressure increase is with the melted together crimp.

http://i99.photobucket.com/albums/l308/mountaincreekphotos/PetersShotshellLR.jpg

[Paul Harm]

Mike, good question. When I tried heavier overshot wads I got blown patterns. But then I was useing black powder [ 92grs ] and only 1oz of shot. I've been told after, the more power when useing BP, the more shot so there's a resistance for a good burn. Glad to hear someone has figgered it out. Paul

[scott kittredge]

Mike, good question. When I tried heavier overshot wads I got blown patterns. But then I was useing black powder [ 92grs ] and only 1oz of shot. I've been told after, the more power when useing BP, the more shot so there's a resistance for a good burn. Glad to hear someone has figgered it out. Paul

i too had blown patterns in my 10 ga. with thicker over shot wads .most test cut patterns from 85 % to 30 % and not a good 30 % , clumps of shot and big holes :cuss:

[Paul Harm]

Charlie, have you tried paper wads? A good tight over powder card would do the trick like David uses. Circle Fly sells any size wads you could want. Besides, who would use plastic wads in a brass shell? :rotf: David, where did you get reloading data for your powders? How much are you useing? Paul

[charlie cleveland]

paul i have some of the right paper wads for the brass shells now....the y have blue and red markings on one side of them...have loaded brass hulls and used the paper wads and glued my top wad good all over and i have had good results...i guess im the only fells that uses the plastic wad in a brass shell...i had a lot of bloopers at first with the plastic wads.but since i increased the top wads2 or three on top ignightion has been no problem...but i believe why i having no trouble now with the plastic wads is because of yalls info to glue the top wad solid creating alittle more time for the powder to ignite good...but the right paper wads for a brass shell are better than plastic wads but in a pich you can use the plastic wad but you need to seal the top wad good with glue wich is possibely best sealing agent for a brass shell... charlie