Undersized Primer Pockets

[justindad]

I have some Fiocchi brass for .357 Sig that has undersized primer pockets. I also have this Lyman tool with a bit to clean the primer pocket and another to ream the pocket. The tool cannot open the primer pocket enough to accept primers… it seems to just chamfer the mouth of the primer pocket without opening up the diameter. I used CCI 550 and Remington 5-1/2 primers, and neither fit. The primer gets mashed and the case rim gets bent. I am able to seat primers into my Sig brand brass.
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Is there a good tool to open up the diameter of these primer pockets?

[Der Gebirgsjager]

There is the RCBS primer pocket swaging tool that is used to size the pockets when reloading military brass that has had crimped primers. It is essentially just a hardened steel button that is forced into the pocket and expands it to civilian size. It is best used on a single stage press, one case at a time. Both sizes L & S usually come in the same kit.

There is also the hand reamer which you may already be using? It was made by Lyman, but I'm not sure if they make them any more. They require you to hold the reamer in one hand and the case in the other and twist the tool until you get the desired size. You'll experience sore fingers after a couple of hundred rounds! They came in 2 sizes, large and small primer pockets, and they also made primer pocket cleaning tools that appear almost identical except for the tip. Below is one that is a reamer. The pocket cleaner tool will not enlarge the pocket, so
you've got to have the correct tool.

DG

[rancher1913]

imortobot sells a pocket reamer for use on presses like dillons, it actually grinds out the pocket to sami spec, its not cheep but if you have a lot to do its worth it. mine is set up on an automated 1050 and can keep up at full speed whereas the dillon swager had troubles and only did the mouth like you are finding. if you only have a few to do, i would be willing to do them but i would need to find a dillon shell holder plate that fits that caliber https://immortobot.com/index.php?mai...roducts_id=470

[justindad]

I have the Lyman hand tool. I used both the cleaner and the reamer. I chuck them in a drill instead of operating by hand (note: the drill can rip the brass out of your hand if the cutter bites on the brass, which could cut you bad.)
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The reamer doesn’t seem to actually ream the pocket. It’s really just a chamfering tool. It’s not easy to get a good reading on the reamer size, but my mics are giving me 0.1746”. The CCI 550 diameter is 0.1761”. The reamer should be smaller than the primer, but by how much?
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I’ll look at that swage tool. I have a case of 1,000 rounds that I plan to reload after I shoot the factory loads. I have stuck primers in about 200 of these cases, so if this is just an odd box it might just go in the trash.
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Here’s the Lyman hand tool I have, with large primer bits shown.

[FLINTNFIRE]

Get a primer pocket uniformer , your tool is for removing military crimps , wrong tool for what you need .

Crimp remover removes crimp on crimped military brass , uniformer are for cutting depth and diameter of primer pockets , I use mine all the time as some brass is just not quite to right size .

[justindad]

Thank you!

[Loudenboomer]

Dillon Swager

[gwpercle]

Look for Primer Pocket " Uniformer " ... it cuts all pockets to a uniform diameter and depth ... Be sure to remove any Primer Pocket " Crimp " before you use the Uniformer ... I just use the little hand tools .
Gary

[Delkal]

Are the primers crimped in? Take a standard case mouth deburring tool and give the primer pocket some turns to remove the edge. If they prime OK after you need the RCBS primer pocket swager. This swages the crimp out of the way without removing any metal and it works great for military cases. Midway has a video on it that is worth watching and they also mention the RCBS pocket trimmer can remove it too. I have no idea if your Lyman cutter works the same way.

https://www.midwayusa.com/product/1012920663?pid=235832

[Three44s]

I have the Lyman hand tool. I used both the cleaner and the reamer. I chuck them in a drill instead of operating by hand (note: the drill can rip the brass out of your hand if the cutter bites on the brass, which could cut you bad.)
*
The reamer doesn’t seem to actually ream the pocket. It’s really just a chamfering tool. It’s not easy to get a good reading on the reamer size, but my mics are giving me 0.1746”. The CCI 550 diameter is 0.1761”. The reamer should be smaller than the primer, but by how much?
*
I’ll look at that swage tool. I have a case of 1,000 rounds that I plan to reload after I shoot the factory loads. I have stuck primers in about 200 of these cases, so if this is just an odd box it might just go in the trash.
*
Here’s the Lyman hand tool I have, with large primer bits shown.

I wear a leather glove (mine happens to be made from goat skin for dexterity) on the hand I hold the cases with while I cut primer pockets.

This is with the cutter being powered.

Three44s

[Budzilla 19]

If you use the RCBS primer pocket swager,set it to a starting depth, then keep going down until it bottoms out,if necessary! It will open them up. Try a few, see if it primes normally, if not, then keep going till it primes normally. I had some 7.62x51brass that would not prime normally, used the RCBS primer pocket swager, ended up bottomed out before it would re-prime normally. Good to go after that. Good luck.

[country gent]

I use the dillon super swage for primer pockets it will quickly and accuratly open tight pockets and if there is a primer crimp push it back into the case.

A chamfer type tool isnt the right tool for this job neither is a crimp remover, a true reamer with the 45* end will leave a ridge in the bottom of the pocket. this will usually be okay as the primer is straight and centered with it. The swaging tools do the job well and quickly.

[ioon44]

I use the RCBS primer pocket swager.

[ddeck22]

I use the Lee APP primer pocket swager for swaging. I had some old 45 ACP brass that was not crimped but the primer pockets were just too tight. I swaged them and they work fine now.

I find 357 sig brass also has extremely small flash holes, so depriming them can be a challenge unless you have the right diameter decapping pin.

[rbuck351]

Sinclair makes 3 different size primer pocked unifiers. Small that fits both small rifle and pistol. Lg pistol and lg rifle . All are carbide and ream the pocket to the proper size and depth. If the pockets are crimped you may have to give the pocket a twist with an inside neck champher tool to remove the sharp edge of the pocket. The tool works well in a hand drill but I have a mini lathe that make quick work of the job.

[Travlin]

I had trouble with some 45-70 cases with tight primer pockets. Being ignorant of all the fancy tools, I found a drill bit and hand held it does the job.

[Gobeyond]

Use Fiochi primers.

[gifbohane]

Wow for $ 600 bucks I would toss the stuff...unless they were very rare cases.

I do not think that Fiocchi primers will overcome the military crimps.

[turtlezx]

drill press right size drill you only need to open the mouth not inside

[K43]

As posted by others, there are inexpensive tools made to do this. Bubba has a drill and saw because he is too cheap to spend $15 to prep $2 cases for his $1700 rifle. Kind of like buying a $60k pickemup truck and taping plastic wrap over the broken tail light to save $50.
Yes, I have opinions of Billybob trailer park fixes.