Mulligan
Silver $$ Contributor
Seating primers with Sinclair hand primer
- Thread starter TommyD11730
- Start date
danny
Silver $$ Contributor
Agree with that, bottomed out in the pocket is what you want, and I also agree with forgetting about numbers. The OP is uniforming his primer pockets and that is excellent. Sometimes it isn't simple, though. One could, in some circumstances find that when bottoming the primers, primers could end up too deep, or not deep enough, with primers standing proud of the case. These things rarely happen, but they do, and one of those happened to me. If you religiously seat till the primers bottom out and they end up too deep or not deep enough, something is going on with your primer pocket depth, and some of the reasons could be: not uniforming primer pockets or having a primer pocket uniformer that is not dimensioned properly (I had that happen). Once you get an issue with the seated primer depth, you need to start systematically figuring out why your primer pockets are too deep, or not deep enough.
Danny
Alex Wheeler
Site $$ Sponsor
After going full circle, Id recommend not touching the pocket and seating them by feel. Never did beat that for accuracy. Tom thinks we need a seater that seats by force not depth. I dont disagree. Theres a bunch of primers that crush easy and you need to feel those. Even with that tool you wouldnt pick up on those. Some things just need human touch.
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It never ends.
Soooooooo no thread on weight sorting primers next??
I USE THE "KISS" PRINCIPAL!!! There is a point of overkill!!! You have to set tolerance standards or you will waste a lot of money with very little gain!! And there are other ways to make the ignition of the powder more consistent!!! That being said, seating and crush is not as critical as the flash holes being uniform and having a slight chamfer on both end of the hole is way better than having burrs and sharp 90° edges!! It creates better laminar flow of the flash flame!!! The slightly less primer pocket residue and less scorching is a testament to this exercise!!! And the paper punching proves its worth of using this process!!!
Designing and installing million dollar air handling systems in reducing environmental breathing exposures for floor workers in a leads acid battery plant requires a major understanding of air and fluid dynamics!!! 1. Knowledge of particulate velocity (lead requires around 700ft/sec or the speed of a 22 rf). 2. Understanding of duct diameter and pressure and effects of static drop from branching, sweeping, and long runs!!! 3 Summation of all branching and calculating main duct sizing!! 4 Determine total flow and how many time the air exchange occurs in a given work area in a given time frame!! 5 Understanding of fan design, fan curves, and belt horsepower!! One project required a 150 hp motor, driving a backwards incline fan, moving 750000 cubic feet a minute, at 12in H20 negative pressure, at 700 feet per second turning the air in a very large work area 4 times an hour!!! With the 2000 6" x 6' tyvec sock bag house, fan, motor, 54" main duct, duct work installed above roof airhook, support structures, under roof ducting, and utilities, THE PRICE TAG: 1.5MM!!! I also supplied the final drawing for bidding, and the contract vendor had to provide approval from their engineers!!!
Do I have to go any further to explain that laminar flow of the flash is more critical than totally perfect seated primers!!! Turbulent flow kills consistent ignition!!! K I S S!!!
The Sinclair seater is a dream tool!! Personally, feel is more important than primers setting at an exact depth!!
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Mulligan
Silver $$ Contributor
Do you cut the pockets to a uniform depth?
What do you chamfer the flash hole with on the pocket side? From your line of work, education , and background, what is your experience on optimum chamfer for efficient flame flow? I’m super curious
Thanks
CW
To get really uniform pocket depth, I lightly file the base until it is flat around the primer pockets on virgin brass!! In the primer pocket extrusion process at the factory, the punch can cause a slight depression or pulls the brass back upwards causing a slight mound!! The code stamping also shifts brass around!! Use light, but firm, short strokes into the cutting edges of the file while firmly holding the base flat on the file, and rotating slightly while stroking!! Draw back keeping the base flat on the file will clear filings and burnish the brass!! Indexing the base before the next stroke will greatly reduce tapering or ramping of the base!! Holding the brass as close to the file will reduce "Dancing" which defeats the purpose of flat filing casing rounding of the base!! Strokes are around half to an inch!!! Observation is critical, and you can see the irregularity of concave and convexing regions around the pocket while trying to achieve a full milled finish around the pocket region!!
I use a Sinclair pocket uniform tool!! No tool handle or power tools!! Use light, but firm, twisting motion back and forth, feeling in uniforming cuttng of the pocket!! This eliminated irregularities of concentrisity!!! Then, I can't remember if it is a No1 or No2 center drill with a stop collar is used to chamfer (touch more than break edge) the sharp edges around the flash hole left by the pocket cutter!! Once again, by hand, feeling and eliminating unwanted excessive brass removal!! FIRE FORM THE BRASS COMPLETELY WITH HIGH PRESSURE LOADS!! ONCE AND DONE FIRE FORMING!! With the base being totally flat, the brass stretched region will be more uniform and concentric!!!
The fire formed brass get trimmed, then the flash hole is reamed slight and chamfered (touch more than a break) on the inside with a Sinclair Inside flash hole chamfer tool with adjustable stop!!! All brass has broken edges, burring, and flashing from flash hole punching at the factory which tends to hang the powder further away from the flash hole!! Once again hand operate for feel!!! The tool will sometimes catch on the irregularities!! Pulling the tool up a bit, and light rotate while dropping the tool will help in these situations!!! If it doesn't, twisting back and forth will cut down the flashing!! Then use smooth and light B and F twisting motion to finish!! Then I give it a couple light fast spin for a nice clean finish!!
Seat primers till they bottom out with even hand pressure and feel of the Sinclair primer seater!!! Primers are generally within a couple to 3 of thou difference in depth!! NOT A BIG DEAL OR SHOW STOPPER!!! IMO, not bottoming out the primer increases the area between primer pocket base and primer causing the wafer flares to bounce around, expending energy, in the pocket region causing irregular and cooler ignition!! Bottom seating force the flares through the flash hole!! Once again, even flow of those flares is essential to consistent ignition!! REDUCING THE AREA, FORCES MORE FLARES THROUGH THE FLASH HOLE!!!
WARNING NOTE:
DO NOT CHANGE THE FLASH HOLE DIAMETER TOO MUCH!! The force that shoves the primer back into the bolt face will increase as the diameter increases!! Fundamental Laws of Physics apply!!
Force = pressure x area!!!
Increase the diameter of the flash hole increases the area (directly proportional) and force on the primer (directly proportional) while holding pressure at a constant!!
This formula is one of several fundamental used for the ductwork design, particulate velocity, etc!!!!
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memilanuk
Gold $$ Contributor
You could always pair one of these with a good Mitutoyo indicator... 
I always assumed that if the anvil legs protrude some amount past the edge of the cup, No matter how hard you push the anvil leg can only be pushed in till it is even with the cup edge. This means if you seat by feel they are all the same within some unknown tolerance of the stack up of cup and anvil dimensions. Pushing hard beyond this could only flatten the cup dome if that's possible. I still use my Lee hand seater I bought for about $7 in 1970. Both my rifles shoot great considering they are for varmint hunting (under.400" groups).
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I know that feeling!! I've went through 3 Lee hand seaters before the soft cams created a dam on the cams!! I now have a Sinclair with around 600 seatings!! Much nicer feel than the Lee with much less effort!! I have hand seated around 20000 or more primers!! You feel that little hangup or resistance, apply a touch more squeeze, then you can feel that primer sliding in with ease as the handle drops smoothly while maintain that consistant squeeze, and then it stops!!! A touch more squeeze force and release the handle!! SO, SO simple once you have that feel!!! And those BR2 and BR4 primers had outstanding results on the paper and in the field!!!
Shooting long ago was cheap!! I still have an old receipt where I picked up 1000 BR4 and 500 Win 209 shotgun primers!!! With taxes, A little over $16!!!! I probably have shot well over 40K center fire rifle and shotgun loads!!! Went through 3 MINI-14s and 1 shotgun along with various other target and hunting rifles!!!
What really affected the shooting sports in that era was the SOB anti 2A Bill Clinton who came down hard on the sport, using Bureaucratic control and installing very costly regulations effecting both the manufactures and the consumers!!! Do you see the results of the similarity with the antics of 46 as a shooter/reloader during his term and today???????
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danny
Silver $$ Contributor
You shouldn't ought to be making sense when you are "talking". It might get you run up before the equipment committee.
Danny
The debate to full seat or seat by depth is interesting!!
My take, with studies in thermodynamics, chemistry, physical chemistry leads me to conclude full seat with light crush!!! WHY??????? Look at your primers, some the region of the wafer is blocked for a straight shot at the flash hole by the anvil and some the remaining region that does have a straight shot, will not take that path!!! This is designed in the primer for the duration of flaming through the flash hole using Brownian motion and Entropy!!!!
Seating high increases the volume in the primer pocket/primer region! More volume, less pressure and heat!! Less pressure means less wafer flares and speed passing through the flash hole! Plus the randomness motion (Brownian Motion) of the flares bouncing around in the larger volume mean even less flares will find and pass through the flash hole!! And, some of those flares could be caught or trapped between the primer wall and pocket corners or under the anvil feet or pads greatly reducing the flaming of duration!! This is a prime example of Entropy (heat lose from a random system and/or surrounds, also called environment), the 2nd law of thermodynamics!!!
Knowing about Entropy, the best solution is to minimize the volume and the distance those flare bounce around in!! Much like a ping pong ball dropped on the table and lowering the paddles towards the table!! As the pp ball bounces between table and the paddle, it increase in frequency and speed as the distance between the paddle and table decrease!! Yes, use Brownian motion to your advantage!! The chances of more flares passing through the flash hole increases by reducing the distances of ricochet and increasing its speed!!
Firm seating will increase the likelihood of even more flares passing through the flash hole!! This is good too a certain point!! Too much force (crush) can result in actually cracking, fracturing, and/or fragmenting the wafer!!! This would cause random larger chucks to fly around giving up flares directed at other chunks basically equalizing the heat energy and causing a cool ignition of the powder!!! Delayed ignition of broken wafer chucks also contribute to cool powder ignition!!!
Now, the ideal seating is much better and reduces the burn rate while increasing the heat!! That wafer does not instantly ignite from the physical/chemical reaction (P CHEM)!! Much like a match, you swap it across the friction surface, it does not instantly light!!! Why, the term Latent heat is involved!!! Latent heat is the result of the delayed reaction of phase change and the addition heat required for a phase change to occur!! Pulling a hot cup of water out of the microwave at the right temperature, drop a spoon it or stir it, will cause a violent, short term boil!! Water at the freezing point but still a liquid, will turn to ice by stirring. The compounds (wafer, match head) have to absorb a certain amount of heat (indothermic reaction) before the reaction (phase change given off heat or exothermic reaction) can occur!!! Yes, the pressure you use to strike the match is also the similar to the high impulse pressure the firing pin has on the wafer!! Pressure and heat go hand in hand in millions of events in our lives and are some of the basic fundamental elements for study in the 1st law of thermodynamics (conservation of heat, heat is energy) especially in deriving and using gas laws!! With this information, if the wafer is slightly compressed, it is more dense and already loaded with some pressure and stored heat (stresses and strains)!! This reduces the latent heat time making the wafer hotter and faster than wafer not being loaded!!!
Another mechanical system that we studied using the 1st Law of Thermo was the combustion engines!! A Prime example of the latent heat is the firing of the spark plug before top dead center (BTC) in an engine!! If the electric spark/fuel air mixture was instantaneous, the engine would knock really bad or the engine would reverse rotation!!! Look at some of the slow motion videos of the spark (BTC) and the delayed fireball creating thrust as the piston breaks past top dead center!! A FIREARM IS A COMBUSTION ENGINE (ONE CYCLE POWER STROKE) IN THE STEADY STATE OF THE FULL COMPRESSION POSITION (TOP DEAD CENTER) WITH A DIFFERENT IGNITION SYSTEM, SUPER HIGH OCTANE FUEL/OXYGEN MIXTURE, AND A ROD LESS PISTON!!!
WITH THIS BEING STATED, THE FEW GRAINS OF POWDER BEING STRUCK BY THE FLARES ALSO EXPERIENCES A LATENT HEAT DELAY!!! But, the latent heat delays are in fractions of a millisecond for the wafer and powder!! But in the short duration of the pressure time build up, it is noticeable at the start of the pressure curve (the left side bell lip being almost flat, non linear, and then the chain reaction of the powder burn exponentially diverging away from the x-axis with respect to time)!!
Added note:
Look at the primer pocket base of those reformed/decapped cases!! Look for the clean regions where the anvil feet or pads were!! If you can see them, you have fully seated the primers!! But, you have to ask yourselves, did I damage the wafer with too much crush?????? Experiment with crush and look at what the carbon residue in the primer pocket is showing you along with the target!!!
My take, with studies in thermodynamics, chemistry, physical chemistry leads me to conclude full seat with light crush!!! WHY??????? Look at your primers, some the region of the wafer is blocked for a straight shot at the flash hole by the anvil and some the remaining region that does have a straight shot, will not take that path!!! This is designed in the primer for the duration of flaming through the flash hole using Brownian motion and Entropy!!!!
Seating high increases the volume in the primer pocket/primer region! More volume, less pressure and heat!! Less pressure means less wafer flares and speed passing through the flash hole! Plus the randomness motion (Brownian Motion) of the flares bouncing around in the larger volume mean even less flares will find and pass through the flash hole!! And, some of those flares could be caught or trapped between the primer wall and pocket corners or under the anvil feet or pads greatly reducing the flaming of duration!! This is a prime example of Entropy (heat lose from a random system and/or surrounds, also called environment), the 2nd law of thermodynamics!!!
Knowing about Entropy, the best solution is to minimize the volume and the distance those flare bounce around in!! Much like a ping pong ball dropped on the table and lowering the paddles towards the table!! As the pp ball bounces between table and the paddle, it increase in frequency and speed as the distance between the paddle and table decrease!! Yes, use Brownian motion to your advantage!! The chances of more flares passing through the flash hole increases by reducing the distances of ricochet and increasing its speed!!
Firm seating will increase the likelihood of even more flares passing through the flash hole!! This is good too a certain point!! Too much force (crush) can result in actually cracking, fracturing, and/or fragmenting the wafer!!! This would cause random larger chucks to fly around giving up flares directed at other chunks basically equalizing the heat energy and causing a cool ignition of the powder!!! Delayed ignition of broken wafer chucks also contribute to cool powder ignition!!!
Now, the ideal seating is much better and reduces the burn rate while increasing the heat!! That wafer does not instantly ignite from the physical/chemical reaction (P CHEM)!! Much like a match, you swap it across the friction surface, it does not instantly light!!! Why, the term Latent heat is involved!!! Latent heat is the result of the delayed reaction of phase change and the addition heat required for a phase change to occur!! Pulling a hot cup of water out of the microwave at the right temperature, drop a spoon it or stir it, will cause a violent, short term boil!! Water at the freezing point but still a liquid, will turn to ice by stirring. The compounds (wafer, match head) have to absorb a certain amount of heat (indothermic reaction) before the reaction (phase change given off heat or exothermic reaction) can occur!!! Yes, the pressure you use to strike the match is also the similar to the high impulse pressure the firing pin has on the wafer!! Pressure and heat go hand in hand in millions of events in our lives and are some of the basic fundamental elements for study in the 1st law of thermodynamics (conservation of heat, heat is energy) especially in deriving and using gas laws!! With this information, if the wafer is slightly compressed, it is more dense and already loaded with some pressure and stored heat (stresses and strains)!! This reduces the latent heat time making the wafer hotter and faster than wafer not being loaded!!!
Another mechanical system that we studied using the 1st Law of Thermo was the combustion engines!! A Prime example of the latent heat is the firing of the spark plug before top dead center (BTC) in an engine!! If the electric spark/fuel air mixture was instantaneous, the engine would knock really bad or the engine would reverse rotation!!! Look at some of the slow motion videos of the spark (BTC) and the delayed fireball creating thrust as the piston breaks past top dead center!! A FIREARM IS A COMBUSTION ENGINE (ONE CYCLE POWER STROKE) IN THE STEADY STATE OF THE FULL COMPRESSION POSITION (TOP DEAD CENTER) WITH A DIFFERENT IGNITION SYSTEM, SUPER HIGH OCTANE FUEL/OXYGEN MIXTURE, AND A ROD LESS PISTON!!!
WITH THIS BEING STATED, THE FEW GRAINS OF POWDER BEING STRUCK BY THE FLARES ALSO EXPERIENCES A LATENT HEAT DELAY!!! But, the latent heat delays are in fractions of a millisecond for the wafer and powder!! But in the short duration of the pressure time build up, it is noticeable at the start of the pressure curve (the left side bell lip being almost flat, non linear, and then the chain reaction of the powder burn exponentially diverging away from the x-axis with respect to time)!!
Added note:
Look at the primer pocket base of those reformed/decapped cases!! Look for the clean regions where the anvil feet or pads were!! If you can see them, you have fully seated the primers!! But, you have to ask yourselves, did I damage the wafer with too much crush?????? Experiment with crush and look at what the carbon residue in the primer pocket is showing you along with the target!!!
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Question: Do you chamfer the flash hole with your center drill every time you clean the pockets, or do you find that it's only needed as a one time operation?
BTW: I find the No1center drill works for the for the SPR's and the No2 for the LRP's!!!
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I concentrate on clean pockets and checking case overall length!!Question: Do you chamfer the flash hole with your center drill every time you clean the pockets, or do you find that it's only needed as a one time operation?
BTW: I find the No1center drill works for the for the SPR's and the No2 for the LRP's!!!
Good job on the center drill info!!! I only used this case prep for large rifle primers!! I don't mess with the 223 (SRP) pockets, flash holes, used in the MINI-14!!! It is just a plinker and self defense weapon!!!
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I believe the primer charge explodes, it doesn't burn???
Thank you Webster for the reply!!! I was wait to dive deeper!!
Hi Explosives like PETN and M112 BURNS at around 8000m/s and these are the low end Hi Explosives. Moving down to Explosive class such as TNT and Nitroglycerin have a much slower burn rate!! Yes, we have Nitroglycerin added to make double based powders, but those few drops of Nitro added to the single based powders (Nitro cellulose) only increases the burn a little!! The Nitro is severely diluted in the cellulose fibers and makes the liquid Nitro stable!! Almost all oxidizing compounds containing N (nitrogen) and/or C (Carbon) that have multiple O (Oxygen) bonds BURNS in a high thermal and/or high shock system or environment! The reloading world does not come near the extreme burn rates that are classified as Explosive or High Explosive!! Reloaders and shooters would all have to have ATF EXPLOSIVE licences if they were explosive products!!
Smokeless powders are chain or branch molecules composed of OXIDIZED non metal elements such as nitrogen and/or carbon!!
Get a time perspective for this!! Say 5 seconds of viewing a high speed camera equals 1 millisecond (1/1000 of a second) of real time action!!
Primer compounds are mainly Oxidized Metals!! Those higher mass particles burn longer and send out flares, or comets much like the sparks from grinding steel which bounce around!!! The higher the Carbon content, the longer and hotter sparking effect!! Primer Compounds tend to fizz like sparklers on the Four of July!! The pressure activated wafer (high impact from the firing pin and the dead hammer anvil point) turns into a very short lived molten mass ring (starting at the center of the wafer, where the anvil point is, with a chain reaction moving outward away from the center of the wafer/anvil point) popping out fast moving, hot molten metal sparks out in random directions during the burn!! It is an outward moving, burning up, flare throwning, molten ring of fire on a flat disc!! But the cup base, sides, and primer pocket base makes those flares acts like pool balls bouncing around in a one end, center located, one large pocket (the Flash Hole) closed cylindrical shaped billiards table!!! 3D POOL ANYONE??? The affects of the pressure differential between the now higher pressure primer region and the high volume case interior at ambient pressure and temperature forces a majority of those flares through the flash hole!!! Near DYNAMIC FLOW with PURE CHAOTIC Brownian Motion with the PRIMER ANVIL SHAPED BUMPER ADDED TO THE EQUATION (breaking the 3D rake of pool balls effect)!!! Thank goodness for the Higher Temperature and Pressure Differentials Occuring in the Primer Space (the SYSTEM) Compared to the Ambient Conditions in the Case Space (the SURROUNDINGS)!! ENTROPY!!!! The 2nd Law of Thermodynamics!!!
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