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Discussion Starter · #1 ·
I know for the 12 gauge it's .806 to .808 or so. Right? What is it for the 410? I tried already to Google it and find it in my Lyman and RCBS shotgun manuals but no luck. If I had a box of new shells I'd measure them to see but I do not. I got the Sizemaster giving me .468 at the top of the metal and .474 near the base. Every once in a while one will not want to go into battery and I have to slam the break barrel gun shut to get it to close. Like one shell per box and I can feel on maybe 6 others that I barely gave enough force to close on them.
 

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A copy of the SAAMI maximum cartridge dimensions for 410 2.5" and 3" shells is found on page 408 of my copy of the Lyman manual 5th edition.

The max diameter is 0.4770". Minimum is 0.4680".

Here's a link to the published SAAMI drawing of the 3-inch shell:
http://www.saami.org/pubresources/cc_drawings/Shotshell/410%20Bore%203.pdf

If your reported measurements are correct, you are well under the diameter to fit the chamber properly. Apparently something else than head diameter causing your problems.

--Bob
 

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You might also be getting a swelling at your crimp. Try taking your barrel off and see if your reloads will drop in the chamber, and if not, where they are getting stuck.
 

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Discussion Starter · #4 ·
Thanks. That's the edition I have too and it is there alright. I see the .4770 listing but not the .4680 but no worries, I'll take your word for Gospel truth. Looks like they are in the ball park already and should not be jamming up like this. It's not the top crimp as they fit through my go-no-go gauge even on the small size hole and readily drop into the chamber almost all the way in on their own except the metal part which is held out by the shell ejector so I wouldn't know on the line until I try to close the chamber. That swelling at the top has occured on my 12 gauge shells but not yet on the 410. It wasn't to bad I could seat them with a gentle thumb pressure. There are also huge fresh bright yellow brass scraping marks on the ones that screw up the worst. I'll find one that I just shot today and measure it, just to see.
Thanks again.
Remember, It don't have to be broke, you can still fix it.
 

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Page 408 of Lymans Fifth has drawings showing the dimensions of a SAAMI spec 410 chamber and shell. The pages immediately before this cover the other popular gauges
 

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Discussion Starter · #6 ·
I may have it figured out. Looks to me like the worst offenders may have been stepped on. In any event they measure within the specs but the shell is not in alignment as in the case got tweeked at the junction of the plastic and metal base so that the plastic comes out crooked enough to missalign the metal base and it jams up there toward the very bottom. After sizing my hulls are .470 along most of the metal base and .475 at the bottom for the last 1/8th inch of the taper there towards the primer end. Do yours size up that way too? I can see how that would be okay. Just wondering now where is the size measurement supposed to be taken? I suppose at the bottom since that's where they measure the largest. That should work, eh? Is my machine supposed to be sizing all the metal length the same size or is it supposed to be tapered like mine is?
Thanks again, Sardine.
 

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Sardine said:
Thanks. That's the edition I have too and it is there alright. I see the .4770 listing but not the .4680 ...
Sardine-
The 0.4680" value is obtained from the diameter value on the drawing. it is shown as ".4770-.0090". This indicates the maximum diameter is 0.4770", and the minimum is 0.0090" less than that, or 0.4680".
--Bob
 

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pitted bore said:
Sardine said:
Thanks. That's the edition I have too and it is there alright. I see the .4770 listing but not the .4680 ...
Sardine-
The 0.4680" value is obtained from the diameter value on the drawing. it is shown as ".4770-.0090". This indicates the maximum diameter is 0.4770", and the minimum is 0.0090" less than that, or 0.4680".
--Bob
Problem is that you DO NOT want to resize to the absolute minimum. This will only overwork and damage the collet, causing premature replacement. Resize should be approx. .004, and no more than .005, under minimum chamber size. Minimum chamber size is .478, so resize on ammo should be .474. Resizing more than that is not needed, and will over stress the collet. Measure at the middle of the brass case head. The area next to the rim will always be a bit larger, but doesn't affect the fit, and should be ignored.

Best thing you can do with that go-no-go gauge is throw it in the trash. Those gauges have caused countless miss-adjustments, thus damaging many, many, collets, and are for all practical reasons worthless.

DLM
 

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Discussion Starter · #9 ·
Okay. It looks like I can open up the collet about .003 to get up to .477. That ain't much but as you say DL, best to keep things a a minumum when it comes to re-sizing. Then the whole thing will be the same size the length of the metal base. For some reason that sounds good to me.
 

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As DL says, the MEC gauge is just a fancy wall hanger, and not too useful. The very best gauge is your shotgun. That is the chamber you should size to fit.
 

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Sardine,

I would keep the resize at about .004., as that will assure your ammo fitting any gun you may want to use it in. You may loan a friend some rounds, and if his gun has a tight chamber, they may not fit. Resizing to .474 isn't going to stress anything, and will pretty much assure your ammo fitting all 410 chambers.

DLM
 

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D L Marcum said:
Sardine,

I would keep the resize at about .004., as that will assure your ammo fitting any gun you may want to use it in. You may loan a friend some rounds, and if his gun has a tight chamber, they may not fit. Resizing to .474 isn't going to stress anything, and will pretty much assure your ammo fitting all 410 chambers.

DLM
I have a good friend that must size his .410 hulls to no larger than .475, or they will not fit in his gun.
Good advice DLM. {hs#
 

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Discussion Starter · #13 ·
Yes, thank you. I think I will leave it where it is then at .474 as I do frequently give some away while out shooting. I'm also planning on buying a new 410 this week or next. Browning 725 o/u.
I find my mec size gauge very useful. It hasn't let me down yet.
 

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Sardine said:
I find my mec size gauge very useful. It hasn't let me down yet.
It will as soon as your collets start passing away, but that is something that needs to be learned. The easy way or the hard one which is somewhat more expensive. But some folks seem to prefer that way. :shock:
 

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Discussion Starter · #15 ·
Curly. What are you talking about? What does my mec go-no-go shell checker have to do with my collet? I am only sizing the base .003 less than the maximum size of .477. I do not understand what you are trying to tell me. I was going to move it up to .477 but I think one or two people said just leave it where it is so the shells would fit other guns than mine.
Regards, Sardine.
 

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Curly-Nohair said:
Sardine said:
I find my mec size gauge very useful. It hasn't let me down yet.
It will as soon as your collets start passing away, but that is something that needs to be learned. The easy way or the hard one which is somewhat more expensive. But some folks seem to prefer that way. :shock:
You said that your Mec Shell checker was useful. See quoted text.
I assumed that you were using their gauge to set the collets, which did not agree with your other comments.
Using the Mec Shell Checker gauge to set your collets will cause them to fail early, a fact that has been proven repeatedly.
Now if you are actually setting your collet as you describe, then I do not understand the relevance of your comment about the shell checker by Mec.
So therefore I am confused by your quoted text.
 

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Discussion Starter · #17 ·
No worries. I am using the digital micrometer to set the collet crimp to proper size and the size gauge to see if I am still in the ballpark days, weeks or even months later. My collets don't seem to move once I set 'em and lock 'em down. Mostly I use it to adjust my taper at the top of the shell on station 5. I still don't see how crimping .003 smaller than maximum tolerance and using the gauge could possibly ruin anything but as you say, I will find out about that soon enough. Thanks for all your help with various questions I have presented in the past too.
Regards, Sardine. {hs#
 
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