Sinclair Primer Pocket Uniformer

[Butte Sink]

Hello All,

All you guys that use this tool, let me hear how it's working for you.
I'm concerned that the new one I just got is actually larger then SAAMI max specs.
This is for a large primer pocket, SAAMI spec-- .125 / .132
I'm reaming pockets on some once fired Nosler brass, 300 RUM and seem to be taking out what I think maybe quite a bit a brass. I put the bit on my caliber and I'm coming up with .137, kind of hard to measure and I'm not quite sure just how accurate this measurement truly is.
Now maybe Nosler primer pockets are at the minimum .125? Sinclair states that their bit is about .130 +/-
Any suggestion for peace of mind?
I did seat a primer "WLRM" with my 21st Century and it looks good.
Again my concern is depth.

Any info would be great

Thanks

 

[Butte Sink]

Thanks for the reply but you lost me on that?
Transform Nosler to Lapua?

 

[swadiver]

Mine cut a bunch of depth out of my large primer Lapua brass as well. everything is shooting fine though. it is disturbing to see how much brass gets removed, though

 

[Mikemci]

Measure the depth of the pocket, after cutting it, rather than trying to measure the cutter length. Mine looked like it was going too deep. I measured the pocket depth, after cutting it and the height of a primer and it was .002" below the case head (perfect). It seems that most of the brass shavings were from squaring up the badly radiused perimeter of the pocket.

 

[Butte Sink]

Measure the depth of the pocket, after cutting it, rather than trying to measure the cutter length. Mine looked like it was going too deep. I measured the pocket depth, after cutting it and the height of a primer and it was .002" below the case head (perfect). It seems that most of the brass shavings were from squaring up the badly radiused perimeter of the pocket.

Good call, I did think of doing that.
Any tricks on how to get a good pocket depth measurement?

 

[T-shooter]

Here are the specs for regular primers. .137" seems too much. You should be able to use the end of a caliper to get a depth reading. A depth micrometer is the best way.

 

[gotcha]

Good call, I did think of doing that.
Any tricks on how to get a good pocket depth measurement?

The best way would be to use a depth Mic If you're like me and don't have one use the depth rod on your caliper. The trick is to bridge the case head with the Beam portion of the Caliper and make full contact. This is a bit tricky to do. So I take several measurements and notate. I go with the one that most often repeats itself. Takes a little practice but you'll be a Pro in no time. FWIW

 

[jepp2]

All you guys that use this tool, let me hear how it's working for you.

I use them on everything. The cutters last a long time unless they run into SS pins stuck in the flash hole. There is variation between similar cutters on the length of the carbide cutter from the portion that comes in contact with the case head. I run mine in a cordless drill.

 

[A Marsh]

My Sinclair tool cut a lot first time uniforming Norma SAUM brass. I think that Norma makes Nosler brass.

It worked great - I did not measure anything but the cases came out looking fine and I have fired the cases multiple times. I just assumed that Norma is a little shallower pocket.

If I lost or broke my Sinclair tools I'd buy more. They work as well as I could hope for.

 

[Butte Sink]

The best way would be to use a depth Mic If you're like me and don't have one use the depth rod on your caliper. The trick is to bridge the case head with the Beam portion of the Caliper and make full contact. This is a bit tricky to do. So I take several measurements and notate. I go with the one that most often repeats itself. Takes a little practice but you'll be a Pro in no time. FWIW

HELLO!! Hahahaha
I don't know how I didn't think of that Age is creeping

I'm coming up with .132 consistently each time, that's a max according to SAAMI

Question, what could happen if your pocket depth was say .002 - .003 too deep?

 

[Butte Sink]

Here are the specs for regular primers. .137" seems too much. You should be able to use the end of a caliper to get a depth reading. A depth micrometer is the best way.

View attachment 1015359

Thanks for pulling this up.
Very interesting after reaming these and taking measurements, nothing flies and I'm under the minimum listed-
Dia Min-- 2.085, I'm at 2.070 / 2.075
Primers measurements are dead on to specs listed

 

[gotcha]

I'm coming up with .132 consistently each time, that's a max according to SAAMI

Question, what could happen if your pocket depth was say .002 - .003 too deep?

Good goin'........... You're a Pro already! .......... Some folks here would have a conniption at .002" to .003" too deep. Unless your loads are in the Nuclear range I don't think it will matter. However I'd caution you to take read on depth after firing to insure the web of the case isn't flowing to the rear. ................. If you should have ignition problems but no flow of web rearward you may have to adjust your firing pin protrusion to compensate. I think this would be highly unlikely. FWIW

 

[gotcha]

I'm a bit confused about your placement of the decimal point ......... Just for giggles I measured Dia. of a Fed. lg. Rifle Std primer. It came to .0211" Sometimes charts can be confusing, Google: "rifle primer chart". The measurements there match my primers (FED. & CCI) to within .001" with my Mitutoyo's. If you're measuring thickness it is CUP depth NOT cup plus anvil. Hope this helps

 

[Butte Sink]

Thanks!
Your right, typo on my end
That .2070 / .2075 is my case pocket diameter

 

[gotcha]

Thanks!
Your right, typo on my end
That .2070 / .2075 is my case pocket diameter

My bad !!! Age is creeping in here too Your primer pocket diameter is spot on FWIW, SAAMI says you can have as much as .008" gap from top of primer to case head. Good luck and have fun.

 

[T-shooter]

I just checked my cutter and a primer pocket and for large rifle primers, the both measure .128". And for the ones that cut or clean to the bottom, I see about .002" gap with Federal primers. I use the tool to clean the primer pockets and since it's carbide, it'll last near forever. A few primer pockets are deep enough that the cutter doesn't quite bottom out and I just ignore it and let the primers seat a little deeper. I haven't found any over .005" with several different brands of brass.

 

[PatMiles]

If you are measuring the depth of the primer pocket, measure it before and after using the cutter. I have yet to see a case head that is flat. Most are proud at the outer edges which will give you a false measurement.

 

[pacificman]

Hello All,

All you guys that use this tool, let me hear how it's working for you.
I'm concerned that the new one I just got is actually larger then SAAMI max specs.
This is for a large primer pocket, SAAMI spec-- .125 / .132
I'm reaming pockets on some once fired Nosler brass, 300 RUM and seem to be taking out what I think maybe quite a bit a brass. I put the bit on my caliber and I'm coming up with .137, kind of hard to measure and I'm not quite sure just how accurate this measurement truly is.
Now maybe Nosler primer pockets are at the minimum .125? Sinclair states that their bit is about .130 +/-
Any suggestion for peace of mind?
I did seat a primer "WLRM" with my 21st Century and it looks good.
Again my concern is depth.

Any info would be great

Thanks

I have the sinclair tools and have just not got too technical with them. They work perfectly and I just never
measured how deep they cut...never had a problem seating primers too deep either. They seem to uniform
all my brass to the same depth and being consistent is what I've been after so all seems well for me.
Hope this helps.