I have a Sinclare primer pocket uniformer with a fixed cutting depth. My question is, do I need to remove metal until the bottom of the pocket is completely cleaned up, i.e. until 100% shinny metal is observed ? I have done this and the primers seat pretty deep, around .008-.010" deep. Or should I just square the bottom radius ? I have read the the primer should be bottomed out at around .004" below flush of the cartrige head. Need help from you experts.
Thanks,
Jim

We just had some discussion about this very topic at a range where I shoot---we've done some experimentation along these lines due to a lot of difference of opinion; some was quite recently concluded. I'd like to report that the experiments convinced us all that uniform pockets - or even a difference in primers caused a variation in downrange performance--but---

This could be a bore for those not shooting for best accuracy--be warned



You will never ever ever get ALL primers to seat at the same depth time and again because all primers are not created equal. There is an allowed tolerance which will vary within and between brands,lots, sizes and even boxes. Your primer uniformer is designed to cut a pocket to such a depth that all primers will seat below flush--hopefully. If you are using the tool to clean dirty primer pockets--as it sounds from your post--stop it. Use a brush for that. Some "experts" suggest that the initial uniforming of the virgin brass is the only time this tool should be employed. Dire consequences are hinted at though never explained. Other "experts" say that the primer pocket grows and thickens with reforming just as necks do, so periodic uniforming is required for best results downrange.

I have not seen any evidence to support either theory, so I split the difference and re-uniform after every annealing--the requirement for this varies according to the cartridge and application. For example, a 30BR case that is fired from a close fitting custom chamber then sized in a die custom built to reflect the chamber in which it has been fired needs less frequent annealing than a .223 rem fired through an AR-15 factory chamber and FL resized with a factory die.


To get back to the primer pocket--there are certain applications in which you might see some improvement in accuracy ( as defined by the repeated ability of you, your rifle, and your ammo to predictably hit a specified target) and in which a uniform primer pocket might be not only be desirable, but of actual practical, cost effective use. Outside of the various BR games, and long range sniping or varmint hunting--they might be few or none, even.

Assuming you are loading for one of the applications that actually do see a benefit from uniforming, you might keep in mind that conventional wisdom at this point in time is that primer ignition is enhanced by a uniform "crush" as opposed to depth below head flush of the cup. There is even a tool used by a lot of target and other precision shooters which allows you to actually measure accurately the primer pocket depth as indexed on the cartridge head, the height of the primer, and the amount of crush you have applied after the primer has bottomed out in the pocket. There will be people who insist that they can "feel" the proper crush (.002" to .003" of a small rifle primer seated in a 6ppc case)......Evi\dently Elvis, ancient aliens, psychics and Jesus are all guiding these folks along with dowsing branches............

I got to participate in a realistically run test of this alleged ability to seat primers to such exactness by "feel" and that educated me to the point of buying the K&M seater with the dial indicator--there may be another brand that does the same thing these days but I have not seen it. On the other hand, there are some very successful match shooters who seat by "feel" and win. Some are at least realistic enough to admit that it is their superior skill, talent and decades of practice that makes the difference, not the depth of seating their primers...........I think that the vast majority of these folks will agree that any of the handloading techniques are incremental in effect and secondary to the development of shooting skills and the aquisition of good firearms.

So--if not loading for a moose howitzer which will negate any advantage in handloading through the wild recoil and also the likelyhood of not being built to tight tolereances-besides, who needs pinpoint accuracy when shooting at a kill zone the size of a platter?-Will the shape and depth of a primer pocket mean the difference between a hall of fame shooter and an also ran? Well, we also rans like to think this way--but the truth is probably that the hall of famer is more careful and adept at remembering all the details in loading and shooting and would beat you with factory ammo and your own gun in a high wind..........

That is one of the most intelligent answers that I could ever hope for ! Thank you very much for taking the time to post. I really appreciate it. I shoot benchrest and totally appreciate your opinion.
Jim

quote:

Originally posted by amamnn:
... If you are using the tool to clean dirty primer pockets--as it sounds from your post--stop it. Use a brush for that. Some "experts" suggest that the initial uniforming of the virgin brass is the only time this tool should be employed. Dire consequences are hinted at though never explained. Other "experts" say that the primer pocket grows and thickens with reforming just as necks do, so periodic uniforming is required for best results downrange. ...

I disagree with the "stop using it" portion. The Uniformers make Pocket Cleaning easy and indicate to you if the Pocket is not being Compressed, lightly Compressed, Compressed, or overly Compressed. It is relatively easy to judge after you have done it for awhile.

I use a brush, but also check them out with a light twirl of the uniformer, also.

I have some .45 Auto Rim brass that had shallow primer pockets, and the primers would not seat flush. I used the Sinclair uniformer on them and removed about .003" from the bottom of the pockets to equal the depth on my ACP brass. Beyond that I don't routinely clean primer pockets.

quote:

Primer Pocket Uniforming

For a hunting scenerio.....IMO...just another reason to add "thingys" to the loading bench....

I've done it.....and no longer waste my time doing it.

quote:

Originally posted by vapodog:

quote:

Primer Pocket Uniforming

For a hunting scenerio.....IMO...just another reason to add "thingys" to the loading bench....

I've done it.....and no longer waste my time doing it.

+1
Everyone, when they start out reloading, should do some of everything. Then they (most anyway) can quickly learn that a whole lot of the mysterious, esoteric BS is to sell thingies, not to increase accuracy. Spend you money on powder and shot and practice, practice, practice and when (and if) you reach some vaulted plateau of significant ability, the makers of thingies will happily GIVE you one in exchange for an endorsement. In fact, they may even slip you a few bucks to SAY you use it.
As you practice more, it will surprise you how much better your ammo is.

quote:

Originally posted by Jim Hundley:
I have a Sinclare primer pocket uniformer with a fixed cutting depth. My question is, do I need to remove metal until the bottom of the pocket is completely cleaned up, i.e. until 100% shinny metal is observed ? I have done this and the primers seat pretty deep, around .008-.010" deep. Or should I just square the bottom radius ? I have read the the primer should be bottomed out at around .004" below flush of the cartrige head. Need help from you experts.
Thanks,
Jim

Yes I have the same gear and called Sinclare and that is what they told me and that is what I do.

"remove metal until the bottom of the pocket is completely cleaned up, i.e. until 100% shinny metal is observed"

quote:

Originally posted by amamnn:


If you are using the tool to clean dirty primer pockets--as it sounds from your post--stop it.

........

Do you mind if I politely and seriously ask why one should not use their Sinclair primer pocket uniformer to clean case primer pockets after each firing?

I did exactly that for years of benchrest competition in the '90s and 2000s, and won many, many matches while doing it.

And, it isn't as if my cases are not fired a lot. In my best rifle, I often used only ONE CASE during a several week period of matches, reloading that same case between each and every shot.

The rifle is set up so that the case neck is an interference (friction, or zero clearance) fit with the chamber neck when reloaded and the tip of the bullet is a slight interference fit of a few thou length with the origin of the rifling.

As a result, I do not have to resize the case between shots, and do not have to use a bullet seater either. Basically, after a shot, I deprime with a nut-cracker type hand decapper, twirl the Sinclair cleaner in the case primer pocket one turn with my fingers (it is not in the Sinclair handle, just in my fingers), reprime the case with a K&M tool, throw the charge of 29.5 grs VV N-135 from a Jones powder measure, seat the bullet with my fingers, and fire the next shot for record.

I find I have no trouble at all putting three or four sighters and five shots for record down-range during the 10 minutes allowed for each match...and in the 10-shot group matches I have no trouble firing 10 for record and 5-7 sighters in the 15 minute allowed time. And I still have plenty of time to read, or even wait for, the wind.

Anyway, I can't say that cleaning the primer pocket each time makes for smaller test groups, but it makes me feel better, which probably IS good for groups fired under match conditions.

And I'll throw in the standard warning...zero tolerance loading is something boys and girls should NOT try at home. Except for very, very precisely dimensioned brass, used by people very experienced with the process and the practical practice of doing so, it is damned dangerous.

But my question is about the primer pocket uniforming tool being used for primer pocket cleaning...why not? Never, ever, been a problem for me.

Just curious, not being critical.

I'll second that as I'm doing exactly the same for all my rifle calibers. Truth is you'd be surprised to see the primer pocket being re-cut a little after several firings. Brass not only lengthens but it elongates in all directions, including backwards.

quote:

You will never ever ever get ALL primers to seat at the same depth time and again because all primers are not created equal. There is an allowed tolerance which will vary within and between brands,lots, sizes and even boxes. Your primer uniformer is designed to cut a pocket to such a depth that all primers will seat below flush--hopefully. a brush for that. Some "experts" suggest that

Totally true which is why I trim to depth each and every time. My 308, 30-06 and .223 ammunition is fired in service rifles with free floating firing pins. Even though seating depth is a varible, I do it to ensure each and every primer will be below the case head. Hopefully.

I also ream each time the brass is fired. I found that primer pockets collaspe with time. It is my belief that as pockets enlarge, due to pressure, the center also caves in. It is unusual not to have some brass come out each reaming.

quote:

Originally posted by wasbeeman:

As you practice more, it will surprise you how much better your ammo is.

Regardless which aspect of reloading we are discussing on ANY thread, I agree 100% with this advice from wasbeeman.

I hit every pocket on every reload with a Sinclair uniforming tool. I've found it much easier than using a brush and I don't have to think about high primers if I feel a normal seating force. Sometimes it just cleans out the ash and sometimes it removes the metal if it is softer brass and a high pressure load. I get excellent results doing that.

I have the exact same tool. Although I usually only load 20 rounds at a time, it doesn't take very long to do it. Chucking it in an electric drill only takes about 10 min. or so. Not a lot of "wasted time" IMHO. Whether it makes a difference in accuracy, I dunno - probably not but it's something I do to insure that I have the best ammo I can load.
Just what I do.
Bear in Fairbanks

B in F :
Ditto

As usual and continuous...everyone has opinions.

Whether or not to do ANY kind of "Accuracy improving techniques" depends on the level of accuracy you EXPECT...the level of accuracy YOU are capable of shooting...and the level of accuracy your RIFLE and AMMO system is capable of.

As far as "needing" to do it, for a factory rifle and normal hunting that's a resounding NO. What little possible added accuracy is far outweighted by all the negative accuracy things.

As far as uniformity is concerned I uniform the primer pockets, do the flash holes, trim, turn necks, weigh, etc, for EVERY case and EVERY rifle caliber in my rack...EVERY time a case gets reloaded...I LIKE uniform ammo.

I have done MANY tests on several calibers using uniformed brass AND bullets, compared to "picked at random" from a 100 case batch...and I can pretty much guarantee the uniformed brass/bullet groups will be much smaller...no matter if the rifle is an off the shelf factory or one I have worked hard on to attain the highest accuracy possible.

I can see a small difference in groups sizes by doing primer pocket uniforming and flash hole deburring really only in my BR quality, varminting and LR rifles...those that are capable of 3's and below and MAYBE my other 1/2" shooters, but that might be wishfull thinking...it doesn't matter...I STILL do the uniforming just in case it does help.

Amamnn points out doing all the little busy work to make and keep your ammo uniform may or maynot be of any direct value...but you WON'T know for certain unless YOU do the testing on YOUR rifle.

AND...if you're into competition and winning is everything...ANYTHING that might give you an edge needs to be done...or just buy Lapua, Norma or RWS brass so you won't need to mess around.

If you look at a primer pocket in a Rem or Win case, you will see the edge corners rounded off which means the top edge of the primer has to be "crimped" in to fit and bottom out. This can give you a false sense of "seated" and also break up the priming layer...all of which "could" cause a FTF in extreme cases.

I'be used two different Sinclair carbide primer uniforming tools chucked in a drill motor to do the job and when done right that round corner is squared off, the bottom flattened and squared and the primers will seat fully to the bottom and you can "feel" it if you use a Lee or Sinclair hand priming tool.

For the most part it is a tempest in a tea cup, just something else to talk about and EVERY forum I've ever visited has an ongoing hoohaw over "What is and what isn't" required to produce reloaded ammo.

If all you want to do is whack some fat hog in the brush, throwing together a few rounds as fast as possible might be all you need...until your shooter goes click because you were too .... to take your time.

There are enough Murphy things out there just waiting for your tender body to NOT take every possible care with reloading your ammo and taking care of your rifle.

Anyway...most of the brass uniforming can be done without hardly a thought while you sit and watch Sunday and Monday night football...or sitting in front of a nice warm wood fire when the snow is azz deep to a tall mule in winter...as I usually do.

It's all a matter of choice...YOUR choice.

Luck

I do all these nit-picky little things because I'm anal and can't stand to not do it.

How much brass do you remove and what I have found is that if I clean up the pocket to fresh, bare metal, my primers are below flush by around .008". Isn't it recommended to seat primers .004" below flush ? If I run the uniformer to the stop the primers seat to deeply.

quote:

Originally posted by Jim Hundley:
How much brass do you remove and what I have found is that if I clean up the pocket to fresh, bare metal, my primers are below flush by around .008". Isn't it recommended to seat primers .004" below flush ? If I run the uniformer to the stop the primers seat to deeply.

If you are holding the tool in your fingers, you can feel it hit the bottom of the primer pocket (or top of the fired primer crud). So, don't turn it in to the stop. Just give it one quick turn with your fingers to break/remove the crud, and then go on to the next case. You needn't remove ANY brass unless you want to.

A light touch is often better in a lot of things...using a pool cue, making love, even cleaning primer pockets.

quote:

Originally posted by Alberta Canuck:
[QUOTE]Originally posted by Jim Hundley:


A light touch is often better in a lot of things...using a pool cue, making love, even cleaning primer pockets.

OK! Where's the still gal? roger

Thanks, everybody !

quote:

Originally posted by Clem:
I do all these nit-picky little things because I'm anal and can't stand to not do it.

Same here....Anal and the damn thingy from Sinclairs is cheap and lasts forever....

quote:

Originally posted by BISCUT:

quote:

Originally posted by Clem:
I do all these nit-picky little things because I'm anal and can't stand to not do it.

Same here....Anal and the damn thingy from Sinclairs is cheap and lasts forever....

You must be young and I'm sure you'll eventually get over it!

quote:

Originally posted by bartsche:

quote:

Originally posted by Alberta Canuck:
[QUOTE]Originally posted by Jim Hundley:


A light touch is often better in a lot of things...using a pool cue, making love, even cleaning primer pockets.

OK! Where's the still gal? roger

Roger - She's (still) taking a short vacation. In the meantime my other signature is filling in.

The new "Temp" has been around since the quill pen, and was even used by the temperance folks in getting prohibiition passed thru yet another "do anything for a vote" Congress.

As usual, those stupid buggers got it arse-backwards from the way it should be. Mine is the original, correct, version!!

I used to use my uniformer to clean pockets after every use. I even bought a uniformer from Russ Haydon that was specifically formed for the Lapua 6PPC and BR cartridge pocket. Someone told me that I should stop using it because I was nibbling out the flash hole--on Lapua and Norma cases of these calibers the flash hole is somewhat smaller than the majority of other cases of other caliber--the why of that is another subject.

The idea was that as the neck of your case grows--so too does the primer pocket--but--where the neck grows in length and thickness and is easily trimmed without affecting the neck diameter--the pocket grows in thickeness--and the length at the flashole begins to "erupt" toward the rear. Using a cutter--or uniformer then trims out the flash hole at some point resulting in a larger flash hole and negating one of the advantages of spending the extra $$$$$ to buy your expensive premium brass in the first place.


If you anneal, this can really become a problem after 15-20 firings, I was told--for match shooters who use a couple hundred cases all season long--it is not worth the risk as the primer indexes on the rim and not the center (flash hole) and loss of uniformity in the flashole is thought to be an even greater variable than some variation in lock time due to the primer being slightly higher in one case than another. Folks who do not anneal or shoot BR matches are not usually looking for this degree of accuracy and therefore see no improvement in uniforming constantly and the risk of weakening the pocket for the larger or magnum rounds works against you.

After fooling with my cases for a few decades, I have come on a method that works for me. I NEVER uniform the case (just brush) after the initial fireforming until I have shot at least 20 rounds, annealing after every five. Before the 21st loading I use the uniformer and if I see bright metal all the way down to the flash hole I discard that case. If I do not need to discard it I will re-uniform that case after ever 5 firings until I see that the flash hole is being nibbled.

This is not something I used to do when I was shooting in competition as you just do not have time for it between relays....you might do it at home after the match, but other things take up your time.

After having done this method for about 20 years now, I think I can say it has done a bit of good for me--again all this stuff is cumulative and no one thing (probably the least in the handloading) makes THE difference in accuracy. All in all I see more of a down side to nibbling away at your primer pocket all the time than any hope of improvement--especially as a brush will clean the pocket quite well. Remember, the real advantage to cleaning the pocket in the first place is to try to ensure good primer seating on the rim of the pocket where the cup touches. A brush is all you need to clean the carbon out of that spot............

That's an interesting explanation, and shows how experiences can vary.

Believe it or not, and I know many folk won't, I have actually worn out a BR barrel or several with less than 5 pieces of brass each. I'm talking worn out for winning competition purposes...over 3,200 rounds in one specific barrel where I kept track of every round shot through it.

Anyway, I never found any measurable (gaugeable) enlargement of the flash holes of those few cases (Lapua in my first BR gun). And I used a primer pocket reamer (a Sinclair) to clean them every time I fired any of them. I tried various brushes early on but the little bristles kept getting bent and the cleaning wasn't consistent as a result. As much as possible, I avoid ANY inconsistencies during match shooting.


Interestingly enough, in other guns I also used a lot of plain old Winchester .300 Savage cases, reformed to .30-BR with a tool similar to Butch Lambert's "bushing" tool, as well as Lapua cases.

I first tried the Winchesters because they were handy and cheap (compared to the Lapua). Figured they might be "good enough" for practice purposes. It turned out that the accuracy of those large primer pocket cases, when carefully and properly formed, was absolutely as good as any of my cases made from the much more expensive Lapua stuff with the little flash-holes.

Of course, the Winchester cases made from .300 Savage brass had pockets and flash-holes for standard large rifle primers, while the Lapua brass had both pockets for small rifle primers, AND the smaller European flash-holes. Didn't make any measurable difference in either group size or scores over many thousand shots through those rifles.

What DID make a difference was proper bench technique (sometimes varies greatly from rifle to rifle)., uniformity of one's match bench layout and match procedure, and his ability and concentration in reading the winds.

(Folks may feel they are shooting on a day calm enough that wind is unimportant. If you have really good flags and really know your rifle, you ill soon learn there are very, very, very seldom any such days for BR score shooters. For BR group shooters there are absolutely none. And wind will affect ANYTHING that flies, no matter how big, how long, how fast. Heck, it affects a Boeing 747, so you know it's gonna influence a light little thing like a .30 calibre bullet....)

Anyway, every shooter, especially a competition shooter, needs to stick pretty close to whatever he believes in. Confidence is another of the really important things in competition. Anything which improves a competitior's confidence will help him finish higher in the results.

Best wishes....

As have I---but wearing out barrels and scoring in the top 5 are two different things----I guess the short answer is that nibbling out the pocket every time you load has no upside and also has a possible--and some folks feel a demonstrable downside--this is what makes a horse race--or a super shoot--or whatever

quote:

Originally posted by amamnn:
As have I---but wearing out barrels and scoring in the top 5 are two different things----I guess the short answer is that nibbling out the pocket every time you load has no upside and also has a possible--and some folks feel a demonstrable downside--this is what makes a horse race--or a super shoot--or whatever

I agree with you, and I have finished in the top 5 in many, many matches...won a bunch of them outright.

And as I pointed out earlier, if you have any feeling at all in your hands, there is no need to "nibble out" the pocket. Nibbling out the fired primer crud likely IS of some minor importantance for top level benchrest.