Primer Pocket Reaming

[syme71]

I got an adjustable primer pocket reamer from RW Hart. Folks at Hart told me to adjust depth so primer seats .001/.002 deep.

When I adjust the tool to ream the pocket to this depth, it only "cuts" the middle portion of the pocket around the hole, not the entire pocket to the side edges. My understanding is that the primer pocket reamer is also supposed to square up the bottom so that you have a 90 degree angle side-to-bottom. When I adjust the reamer to cut deep enough to do this, my primers are now .007/.009 deep.

What's the right approach. Is it a big deal that the pocket is not "squared up"?

btw, brass is new Lapua 308.

Thanks,

Al

 

[USMCj]

Re: Primer Pocket Reaming

First, STOP!!!!! do not touch any more Lapua brass!!!!! Lapua brass does not need the primer pocket "reamed"

Second, what you bought (I hope) is a primer pocket uniformer, not a reamer. The adjustable ones are not a great idea for noobs (no offence)

Third, If you must, buy a Sinclair uniformer that is set to spec and can not be adjusted.

 

[BOLTRIPPER]

Re: Primer Pocket Reaming

get your money back..............

 

[Queequeg]

Re: Primer Pocket Reaming

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">When I adjust the tool to ream the pocket to this depth, it only "cuts" the middle portion of the pocket around the hole, not the entire pocket to the side edges. </div></div>

Are you sure this isn't a flash hole deburring tool? You don't need that for Lapua either. All you should need for primer pockets is an appropriate sized brush to clean the crud out occasionally. A fairly blunt scraper is also made for each size for the same purpose. Not everyone agrees this is necessary.

I agree with USMCJ; do no more harm to those pristine Lap cases.

 

[syme71]

Re: Primer Pocket Reaming

sorry meant primer pocket uniformer. so what else does a noob need to know in order to properly use an adjustable one? Is there a specific depth that is industry standard? I'm using regular Federal primers and they are measuring .128 so I was adjusting the uniformer depth to .130

 

[syme71]

Re: Primer Pocket Reaming

no, I know what a flash hole deburring tool is. I'm using this as well and noticed that there is a slight rough edge on the inside that a few revolutions of the FHDT cleans up. I've peered inside with a real bright light afterwards and noticed a very, very slight chamfer. Again, this is what I was told to do by the folks at Harts. Should I stop this as well??

 

[Queequeg]

Re: Primer Pocket Reaming

For new lapua cases you simply should not need to do anything to the primer pockets beyond inserting primers into them! I guess the Bench Rest folks may have some need for this degree of navel gazing but not sure if that is your game.

Uniforming is just to decrud the pocket after one or more loads have left enough residue to justify removing it. Even then, factory spec depth should be reestablished.

 

[One-Eyed Jack]

Re: Primer Pocket Reaming

I use a Wilson adjustable-type primer pocket uniformer, one for each primer size. I adjusted them once by setting them to the depth of a new Lapua case. (Directions: Loosen the cutting blade insert set screw and pull the blade out slightly. Push it into a new Lapua case primer pocket. Hold the case and uniformer vertically so the cutting blade falls to the bottom of the primer pocket. Retighten the set screw while holding the uniformer against the case. The cutting blade should now be set to the depth of a new Lapua case.) When I use them with Lapua cases that have been fired, they clean the burned carbon out of the pocket without removing any brass.

 

[Queequeg]

Re: Primer Pocket Reaming

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Should I stop this as well?? </div></div>

No, it is still worthwhile. Lapua flasholes are drilled while others are supposedly punched, hence the more pronounced burr in other brands of cases. Even with drilling though you'll still get some protrusion. So deburring, only necessary once per case, is a quick detail that may help and is certainly harmless.

The beauty of Lapua is that while they cost more, they require less screwage and last longer than other brass, hence they really cost less!

I chuck one of the primer brushes onto an extension and into a cordless drill and quickly clean the primer pockets out during each case prep prior to reloading. I haven't seen the need to do more than that but I do miss stuff sometimes!

 

[USMCj]

Re: Primer Pocket Reaming

If you must, adjust it to .130" and it will work fine.

Edit: I just noticed that thats what you have it adjusted to, same as mine, but mine uniforms Lapua brass just fine.

 

[Winchester 69]

Re: Primer Pocket Reaming

Primer height spec per SAAMI:
large rifle: 0.125 min, 0.132 max
small rifle: 0.117 min, 0.123 max

I went to Zediker to see his advice regarding uniforming.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The Haydon uniformers that I have are just shy of SAAMI maximum depth. That's fine. If you want to stay with minimums, and there might be reasons for that, then get a tool that has an adjustable depth.... Only bad thing about the adjustable tools is the tolerance necessary for the adjustment feature; it's tough not to have a tad amount of pitch potential when it's tightened, and even tougher to know.</div></div>
He advises that the purpose of uniforming is to provide a square base for the primer's anvil. However, he warns against overly deepening the pocket to achieve perfection on the first pass. He advocates uniforming for every loading since the brass reforms itself, stating that primer pockets get shallower on each firing.

You should be fine adjusting the tool to provide the one, two or three thousandths margin below the case head, as the mfr recommends.