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| < 16ga. Ammunition & Reloading ~ Over pressure on some old data |
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 Posted:
Sun Dec 06, 2020 1:16 am
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Joined: 13 Oct 2015
Posts: 348
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RG,
Send at lleast 2 loads. With 2 loads, it is $25 each, and he will do 10 shots each for that price if you send them. You need 10 for saami methodology and stats, might as well send them. I personally wouldn't ever post a load as "below saami map" or passing saami, without a full 10 shots to back it up. Same cost. |
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| Posted:
Sun Dec 06, 2020 7:49 am
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Joined: 21 Mar 2019
Posts: 523
Location: Texas
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Dave
Thanks I agree 10 shots. |
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| Posted:
Mon Dec 07, 2020 5:02 am
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Joined: 30 Mar 2020
Posts: 13
Location: SWEDEN
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| MSM2019 wrote: |
The subject of crimp depth has been beat to death on SGW. The information was gotten from the Alliant techs. Hodgdon supposedly has it written somewhere. As I stated before I have always used Tom Armbrust's suggestion of thickness of a dime or 0.0625". Every 12 & 16 gauge load I developed at Precision Reloading Inc. was set at 0.060" to 0.065" as it made for a very nice radius on the crimp shoulder, while not affecting the chamber pressure and allowing more room for velocity increases. (Velocity and pressure are not linear) Especially important when dealing with Steel powder and steel shot loads. When you start increasing crimp depths it has the tendency to increase chamber pressure more than velocity. Chamber pressure increase does not equal velocity increase, gas volume increases velocity. You get a much better trade off with chamber pressure vs velocity with increasing powder amounts. Increasing crimp depths helps with consistent ballistics at times, but at the cost of raising chamber pressure which you can't always afford to do. The sweet spot has always been that 0.055" to 0.065' crimp depth for most 12 & 16 gauge loads. That is what I know.
For information on why computers can't be used to produce shotshell loads, you might contact White Labs, Ballistic Research (Tom Armbrust), Precision Reloading LLC or SAAMI. But if you were the guy footing the bill, would you pay someone to load and test each load (if you miss than that means multiple tries at the same load) in a lab that has about $10,000 worth of equipment per test station minimum? Or pay for someone to sit down at a $1500 computer? So you have to ask yourself why would anyone not use a computer if that was the correct way to test shotshells?
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Hi,
i havent figure out how just answer so i made a quote:
I often read in load forum stateside and the discussion about crimp deep, and for me who this days make shells the " italian way " and they talk the total length of hull instead of crimp deep, and sorry for using metric but im from sweden , but 0,10mm +/- from standard length of hull make 40-45bar approx , for example when i make 12g shells where 58mm is standard and if you make them 57,5mm and crimp still look the same you can have a raise of 180-200 bar. The big difference in thhe italian way is they always end upp with a Crimper tool in a drill
and if you set it up properly having a stop mounted on drill all shell will be exact.
Sorry for my english but i cant do better..
/ P |
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| Posted:
Mon Dec 07, 2020 5:40 am
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Joined: 04 Mar 2019
Posts: 1844
Location: Central ND
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I think I understand.
Most hulls that are used in the US are not new hulls and most are fold crimped on the reloading machines that we use. The depth of the fold crimp is adjustable. The hulls we use are not all equal in length. When using a fold crimp the crimp depth must be adjustable. Fold crimped hulls cannot not be measured for overall length to determine crimp depth. Our crimp depth is approximately 1.4 MM
We do know of the Italian GAEP system for crimping shotshells and but very few of us use that system. The method of attaining the correct crimp depth that you mention, would work fine with the GAEP system but only with new, roll crimped hulls. |
_________________
Mark...You are entitled to your own opinion. You aren't entitled to your own facts. |
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| Posted:
Mon Dec 07, 2020 1:49 pm
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Joined: 13 Oct 2015
Posts: 348
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| MSM2019 wrote: |
megasupermagnum,
It doesn't matter what the crimp depth is on factory ammo. Why? Because each load is tested during production to be sure it falls within SAAMI Standards.
The bottom line is if you want to try and duplicate the velocities of a certain load than you must reload to the same set of specs. If you don't, then you may or may not produce the same performance numbers. It is as simple as that. It doesn't matter what you MAY HAVE DONE in the past and gotten reasonable results. You have to approach each load the same way, which is to follow the same guidelines that the entity that produced the load in question followed. Some loads are very sensitive to crimp depths, some are not. Some loads are sensitive to primer changes, some are not. With some loads you can use any straight wall hull and get the same basic results. Sometimes choke constriction affects some loads while others aren't. There are no absolutes, so you have to approach every load from not what you think should be done, but from how it was actually done.
ALL loads are different. If you expect every load that you put together to react exactly in the same manner to the same inputs, you aren't understanding why loads are tested.
IF ALL shotshells reacted the same way to a set of inputs, there would be no reason to test any shotshell for pressure and velocity, in the manner that is in the SAAMI standards. You could sit at a computer and produce data to your heart's content. While there are certainly tendencies there are not absolutes.
So if you want to continue to crimp at 0.080" fine, but don't expect that the velocities are always going to fall in line. Same goes for chokes. Same goes for sample sizes.
You asked the question, now you don't want to hear the truth? Why ask the question in the first place?
You believe that the problem with this load is the difference between a Federal 209 and a Federal 209A. Maybe it is and maybe it isn't, but you aren't loading or testing the velocity of load properly to single out the primer.
You have to crimp at 0.55". You have to use a cylinder choke. You have to sample at least 5 rounds if not 10 rounds. If you don't fix those 3 items you are comparing apples and oranges.
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Dead horse I know. But not much is being posted, so I reread this thread. And this thread has a LOT of good points to make concerning test results and methodology. This post above is 100% exactly right. All the points I wanted to make. Factory crimp depths don't matter, they are loaded to achieve results desired and then tested... if you are following a recipe, you have to replicate the stated recipe and conditions. So .055 crimps or whatever the data source used, cyl bore, correct chrono procedures, correct saami statistical procedures (which are all included in the saami docs, easy to read). You will never replicate results, but you CAN get averages and standard deviations to fall within allowable tolerances, which is the goal. |
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| Posted:
Tue Dec 08, 2020 12:27 am
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Joined: 30 Mar 2020
Posts: 13
Location: SWEDEN
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| MSM2019 wrote: |
I think I understand.
Most hulls that are used in the US are not new hulls and most are fold crimped on the reloading machines that we use. The depth of the fold crimp is adjustable. The hulls we use are not all equal in length. When using a fold crimp the crimp depth must be adjustable. Fold crimped hulls cannot not be measured for overall length to determine crimp depth. Our crimp depth is approximately 1.4 MM
We do know of the Italian GAEP system for crimping shotshells and but very few of us use that system. The method of attaining the correct crimp depth that you mention, would work fine with the GAEP system but only with new, roll crimped hulls.
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We dont always use new hulls, i practise the use of a crimper Not a gaep ( who is a brand not a system ) i use OMV brand of higher quality , i get once fired 16/67mm hulls from taget practise hight prass T3 hulls who i reload on a PW 375C, but i dont set it up for a taper on mounth of hull, actually a bit of " muchroom" i just insure center is tight and next step is run it with a crimper in a machine with adjustable stop, so all my shells will have exact lenght and i get wery uniform speed. I reload mostly once becouse i have thousands of that hull. We use a spool / crimper on all types of crimp styles not only roll crimp and its easy get all hulls exact.
/ P |
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| Posted:
Tue Dec 08, 2020 5:35 am
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Joined: 04 Mar 2019
Posts: 1844
Location: Central ND
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Well we are just a bunch of dumb Americans that don't know much.
We are kind of muddling our way through this reloading stuff. We have a lot of trouble getting uniform velocities and pressures with our fold crimps. |
_________________
Mark...You are entitled to your own opinion. You aren't entitled to your own facts. |
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| Posted:
Tue Dec 08, 2020 6:00 am
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Joined: 21 Mar 2019
Posts: 523
Location: Texas
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Culot,
I知 gonna have to disagree with you that there is a better quality then gaep crimpers. I have a lot of their products and they are excellent quality. They are expensive, but you get what you pay for. |
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| Posted:
Tue Dec 08, 2020 6:04 am
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Member
Joined: 09 Jan 2013
Posts: 2170
Location: Florida
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| MSM2019 wrote: |
Well we are just a bunch of dumb Americans that don't know much.
We are kind of muddling our way through this reloading stuff. We have a lot of trouble getting uniform velocities and pressures with our fold crimps.
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| Posted:
Tue Dec 08, 2020 12:16 pm
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Joined: 13 Oct 2015
Posts: 348
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| RGuill96971 wrote: |
Culot,
I知 gonna have to disagree with you that there is a better quality then gaep crimpers. I have a lot of their products and they are excellent quality. They are expensive, but you get what you pay for.
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Nah, take a look at the OMV stuff for the Italian method of loading, it is better quality than the GAEP brand. And he is talking the systems with a motor on the final crimp station, nothing like what we use in the US. Gaep crimp dies are nice, but he is talking what.looks more like a factory loading machine that spin crimps a fold, not just a die. |
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| Posted:
Tue Dec 08, 2020 12:37 pm
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Joined: 21 Mar 2019
Posts: 523
Location: Texas
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Dave:
yea, but who wants to spend that kind of money on a whole machine. I will put my gaep crimp up against any crimp that can be done with drill press. I could just buy a shotshell factory and be done.
Just watched a video with the pw 375c maybe the guy doing video but my crimps look better. |
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| Posted:
Tue Dec 08, 2020 12:48 pm
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Joined: 21 Mar 2019
Posts: 523
Location: Texas
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Dave& culot:
I would love to see some pictures of your crimps. |
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| Posted:
Tue Dec 08, 2020 4:41 pm
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Joined: 13 Oct 2015
Posts: 348
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| RGuill96971 wrote: |
Dave& culot:
I would love to see some pictures of your crimps.
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Lol... at ease, tiger... no one is challenging your crimps 
You didnt appear to understand the Italian guy was talking about a.completely.different reloading system. Whether you like it or not, that is how they load over there. Yeah, super expensive mostly and wouldnt meet my needs, but there it is.
I tap the tops of my shells with a Gaep bn4 , or a Precision rto die for non 12ga loads, so you're not gonna see anything different. |
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| Posted:
Tue Dec 08, 2020 5:02 pm
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Joined: 21 Mar 2019
Posts: 523
Location: Texas
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Dave:
Ok claws back in. I take my reloading pretty seriously. I知 always looking for ways to improve. I follow the load data, unless working on a new load, and then it gets tested, and if there is a better way or better tool then I知 interested. Maybe things are different across the water, but not into knocking other people痴 equipment. Now if you can show your results as being better, then I知 all ears |
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| Posted:
Tue Dec 08, 2020 5:07 pm
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Joined: 13 Oct 2015
Posts: 348
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All good. I'm sitting out here in the desert dove hunting right now, waiting for the dove to fly. I only saw and bagged one bird so far, so chatting with you on 16-gauge. Com has helped pass an hour while I waited for Sunset  unfortunately I'm not using 16 gauge, it's a 28 gauge. I almost grabbed the Auto 5 16, but I didn't feel like chasing hulls at sunset |
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