• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

Seating primers with Sinclair hand primer

TommyD11730

Ok guys I just picked up a Sinclair hand primer (used). Coming from a RCBS bench primer I have a lot to learn.

So... if my pockets (small) after uniforming measure .124" deep, and a BR4 is .109" tall I should be looking for .015" below the base of the case?

I'm currently at .010 and it felt real tight seating.

Thanks guys!!
 
Been using this outstanding tool for about 25 years now. I have loaded thousands of rifle and pistol cartridges with it and never had a slam or misfire.

Seat the primers by feel so they bottom out in the primer pocket and are slightly below the case head. It's that simple, no need to get into measurement stuff.

Also, press the handle slowly apply steading and even pressure, do not force it or try to speed seat primers with this tool. As you lock the case down, I found that applying a slight pressure to the case while rotating the shell holder assembly to lock the case in place aids in aligning the case with the primer cup.
 
TommyD11730 said:
Ok guys I just picked up a Sinclair hand primer (used). Coming from a RCBS bench primer I have a lot to learn.

So... if my pockets (small) after uniforming measure .124" deep, and a BR4 is .109" tall I should be looking for .015" below the base of the case?

I'm currently at .010 and it felt real tight seating.

Thanks guys!!
Click to expand...
No reason to measure anything. Seat by feel to the bottom of the pocket. If you seat to some number you will get varying distances from bottoming in the pocket. You want the cup to bottom in the pocket so no FP energy is lost pushing the cup forward. Why do you guys make this complicated and get talked into buying expensive primer seating tools? I understand that uniforming should make them all the same. When the cup edge touches the bottom of the pocket you cannot push it in any farther. If you push extremly hard you may flatten the cup crown. That's the only place the metal can move after the cup edge contacts the pocket bottom.
 
A little information some of you may find useful: First of all I seat by feel not depth, having observed that top shooters in short range groups that I know seat by feel. Secondly, some time back I actually called CCI and spoke to a technician, asking him what they consider to be proper primer seating. He said that primers should be seated to the point where the bottoms of the anvil feet are flush with the cup. I repeated my question to be sure that there was no misunderstanding. After that I seated a primer with as much force as I could muster using a hand tool and very carefully removed and examined it. Two out of the three anvil feet were flush with the bottom of the cup, the third was almost, but not quite. The corners of the cup were not flattened. Bottom line, IMO just because we have the means to measure something does not mean that uniforming it will show up on target. I might add that no one has convinced me that uniforming primer pockets is anything more than a feel good exercise.
 
Last edited:
ShtrRdy said:
Please re-measure the primer height. It should be more like 0.121" tall.
Click to expand...
But, that height includes the anvil that's well above the cup height. . . right?

I've taken some primers and removed the anvil to measure the cup height for various primers (e.g. Federal, CCI and Remington) and found that primer dimension chart to be pretty much right on, with maybe a variation of ~ .001".

Overall primer heights can vary. For example: some of my CCI-400's, the overall height measured from .120 to .122"; Federal 205M's were .118 - .120; Remington 7 1/2's were .123 to .124. And I also found those overall measurements to vary from one lot to another . . . more so than the cup height measurements.

I'm pretty sure that .109" he stated is from the chart for the cup height, not the overall height that includes the anvil protruding.
 
Last edited:
Webster said:
No reason to measure anything. Seat by feel to the bottom of the pocket. If you seat to some number you will get varying distances from bottoming in the pocket. You want the cup to bottom in the pocket so no FP energy is lost pushing the cup forward. Why do you guys make this complicated and get talked into buying expensive primer seating tools? I understand that uniforming should make them all the same. When the cup edge touches the bottom of the pocket you cannot push it in any farther. If you push extremly hard you may flatten the cup crown. That's the only place the metal can move after the cup edge contacts the pocket bottom.
Click to expand...
Maybe ..... maybe not. I guess it depends on what your intentions are with your shooting.

 
I completely agree with what Boyd says, I've been shooting BR for years seating primers with the Sinclair tool. You may have the side edges of the primer hanging up on the sides of the primer pockets. Run a pocket uniformer and see if you get the same results. I don't think you'll see on target difference.
 
ShtrRdy said:
Please re-measure the primer height. It should be more like 0.121" tall.
Click to expand...
Ok, keep in mind I'm measing with a caliper, there will be some margin for error. I'm getting anywhere between .1175 and .1195. So, if anything this is a lesson learned that graphs found on shooting sites are worth what you pay for it.
Guys, I understand this is a touchy subject. If you seat by feel (like I did till today) that's great. However I don't want the thread going down that path.
Hope you all understand and I value everyone's input.
 
TommyD11730 said:
Ok, keep in mind I'm measing with a caliper, there will be some margin for error. I'm getting anywhere between .1175 and .1195. So, if anything this is a lesson learned that graphs found on shooting sites are worth what you pay for it.
Guys, I understand this is a touchy subject. If you seat by feel (like I did till today) that's great. However I don't want the thread going down that path.
Hope you all understand and I value everyone's input.
Click to expand...
IMHO, seating by feel can work just fine. But, from a test done several years ago that was done to determine how consistent the seating depth is when doing so, it was found that seating by feel just doesn't produce consistent seating, even with the most experienced hands. . . AND, the seating was not getting the cup to touch the base of the pocket as thought. I wish I had archived that test for reference, but apparently, I didn't or I'd post it here for sure. It was this test that convinced me to get away from seating by feel (given I like to be more assured about how the primers are actually seated in the pockets). . . though, like in the video TTE posted above, I found it hard to get really consistent seating where the cup was really touching the bottom of the pockets. For sure, seating by feel doesn't do it.

I've asked myself, why is seating by feel working so well for so many??? Like was concluded in the video, it appears getting within the right range of "crush" on the anvil is key and doesn't have to be precise. Ideally, the cups should touch the bottom of the pockets, but it's not necessary. What seems to be more important is getting a decent crush on the anvil and having a consistent seating below the case head to get good and consistent firing pin strike.

With regards to your OP, I wouldn't worry about not seating the cups all the way down to touching the bottom of the pockets. I'd say, a long as you're getting .03 or .004" of "crush" and consistent distance below the base of the case, you'll be good. Like everything else in precision reloading . . . consistency is what we're after, huh??? ;)
 
Last edited:
TommyD11730 said:
I'll be honest with you, I took 4 granted this chart was right. Per your suggestion I'll measure a sampling 4 myself.
Click to expand...
HERE WE GO AGAIN DOWN THE SAME RABBIT HOLE!!!

Do not use that table and crappy generic drawing!!!
Most of us forum members will not go down the mis information RABBIT HOLE AGAIN!! As an engineer with 25 years of CADD experience, that drawing and table are not accurate and have proven the table is wrong!!!
That attachment has been proven wrong in at least 2 other forums that I'm aware of!!
PLEASE, DELETE THAT ATTACHMENT!!!
If you don't believe me, do a destructive analysis on one primer!
Add oil to the wafer between the cup and anvil and saturate it!!!
This will deactivate the wafer and make it safe for disassembly!!
Pull the anvil out and clean the cup!!
Now measure the cup thickness and the wall thickness!
They are not the same as the drawing depicts!!
NOT ALL THE DATA IN THE TABLE IS CORRECT EITHER!!

Back on the subject, the Sinclair seater is awesome!
I've used the Lee seaters, but the Sinclair is a much better, smoother tool!!!
Just use nice even pressure until it seats!! Add just a touch more pressure after it seats!!
 
Last edited:
BoydAllen said:
A little information some of you may find useful: First of all I seat by feel not depth, having observed that top shooters in short range groups that I know seat by feel. Secondly, some time back I actually called CCI and spoke to a technician, asking him what they consider to be proper primer seating. He said that primers should be seated to the point where the bottoms of the anvil feet are flush with the cup. I repeated my question to be sure that there was no misunderstanding. After that I seated a primer with as much force as I could muster using a hand tool and very carefully removed and examined it. Two out of the three anvil feet were flush with the bottom of the cup, the third was almost, but not quite. The corners of the cup were not flattened. Bottom line, IMO just because we have the means to measure something does not mean that uniforming it will show up on target. I might add that no one has convinced me that uniforming primer pockets is anything more than a feel good exercise.
Click to expand...
Guys will keep asking this question a hundred times with new post. What does it take to make guys believe what the top shooters and manufacturers tell you. A lot of dense people. I see where some companies are now selling adjustable primer tools for over $250. I guess if your OCD you need one. After a lot of post it would seem that a lot of OCD reloaders don't even have what sounds like a quality rifle.
 
Webster said:
Guys will keep asking this question a hundred times with new post. What does it take to make guys believe what the top shooters and manufacturers tell you. A lot of dense people. I see where some companies are now selling adjustable primer tools for over $250. I guess if your OCD you need one. After a lot of post it would seem that a lot of OCD reloaders don't even have what sounds like a quality rifle.
Click to expand...
Many, not all, of the folks that are trying to set records at distance and those winning long range BR are putting in the work to do these sort of things. It has been hashed out a bunch, but let me remind everyone, there is a fella selling $700.00 primer seaters that are very nice and another fella selling accoutrements for said primer seater for another few hundred bucks. Additionally there is an outfit that sells a quite accurate gizmo to measure pocket depth and seated primer depth. Now I do not own all of the above mentioned tools, but I do own the Accuracy One primer gauge and consider it and other tools they sell indispensable. The fella that makes these might just know a thing or two about shooting small?????

In my testing, all things ignition MATTER.

Carry on
CW
 
Mulligan said:
Many, not all, of the folks that are trying to set records at distance and those winning long range BR are putting in the work to do these sort of things. It has been hashed out a bunch, but let me remind everyone, there is a fella selling $700.00 primer seaters that are very nice and another fella selling accoutrements for said primer seater for another few hundred bucks. Additionally there is an outfit that sells a quite accurate gizmo to measure pocket depth and seated primer depth. Now I do not own all of the above mentioned tools, but I do own the Accuracy One primer gauge and consider it and other tools they sell indispensable. The fella that makes these might just know a thing or two about shooting small?????

In my testing, all things ignition MATTER.

Carry on
CW
Click to expand...
I seem to remember that in a post, Alex Wheeler said that he seats primers by feel. Just sayin'...
 
You must log in or register to reply here.

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Classified Ads

Forum statistics

Threads
165,781
Messages
2,203,017
Members
79,110
Latest member
miles813

Share This Page

Back
Top