Primer weighing test

hounddawg · January 19, 2021, 11:45 PM

It was completely unremarkable, that is about the best that can be said. I loaded 50 rounds of .260 Remington with 40.0 grains of H4350 and Barnes match burner 140's. twenty five rounds were loaded with CCI 200's picked randomly from the tray. Twenty five were loaded with primers weighed on my A&D 120 to the milligram minus the error rate of plus or minus 1 milligram.

shot five groups of five rounds each @100 yards over a chrono with five mph crosswinds blowing from 9 to 3

average group size for the non weighed groups was .62 inches, smallest group at .51 inches, largest at .76 inches. Group height for all 25 shots was .68

average group size for the weighed primer groups was .6 inches, smallest at .49 inches and the largest was .8 inches. group height for all 25 was .66 inches

random weight velocity SD for all 25 rounds was 20 FPS
sorted weight SD was 23 FPS

To me this rabbit hole is not worth exploring any farther

Shadow9mm · January 19, 2021, 11:46 PM

good to know. Had been thinking about this since the other post. Your time and primer expenditure is much appreciated.

hounddawg · January 19, 2021, 11:51 PM

Thanks, it was a fun way to spend a afternoon. This barrel is not the best barrel that has ever been on this rifle but I figure I may as well get some use out of it. I have plenty of powder and LRP's to use it to play with.

I will not be wasting my small rifle primers and Varget repeating this test with SRP's

Bart B. · January 20, 2021, 12:20 AM

What percent of the primer total weight does each ones detonating pellet have?

hounddawg · January 20, 2021, 08:48 AM

no idea Bart and that is the core of the problem. there is no way to determine that without firing the primer. I could have numbered and weighed each primer before and after each firing to determine how much was pellet but why bother. My purpose in doing this little experiment was to see if weight sorting before firing made a difference on paper or on the chrono. It did not so my question was answered. I see no need to spend any more time on the subject

dahermit · January 20, 2021, 09:00 AM

Quote:

To me this rabbit hole is not worth exploring any farther

Have you weighed each bullet? Back when I was intent upon max accuracy, to my dismay I found that my match bullets had significant variation in weight from the same box.

hounddawg · January 20, 2021, 11:09 AM

yep went the bullet weighing and case volume route also. Could not tell any difference on paper with either. I think a lot of us of chase our tails down rabbit holes when our scores plateau. Rabbit holes and theory are ok for cold winter days but for improving scores there is no substitute for practice. Of course natural talent trumps everything

jetinteriorguy · January 20, 2021, 12:05 PM

Quote:

Originally Posted by hounddawg

yep went the bullet weighing and case volume route also. Could not tell any difference on paper with either. I think a lot of us of chase our tails down rabbit holes when our scores plateau. Rabbit holes and theory are ok for cold winter days but for improving scores there is no substitute for practice. Of course natural talent trumps everything

This has been my experience. I’ve done everything I can to make my equipment and ammunition as consistent and accurate as possible and have come to one conclusion. In my case I’m a consistent sub MOA shooter, usually 3/4 MOA and am more than happy with that. Every once in a while I’ll shoot that ragged one hole target, but cannot consistently repeat that.

scatterbrain · January 20, 2021, 02:28 PM

I know shooters who shoot very good that do weight the primers, I don't. They also measure their bullets on the ogive, but don't weight them. I try measuring both to the ogive and overall length. I have tried everything I have heard about except lubing the bullets, and that may be next. I can't get my head around lubing and bullet "hold", how does that work?

Bart B. · January 21, 2021, 12:50 PM

Quote:

Originally Posted by scatterbrain

I can't get my head around "lubing" and bullet "hold", how does that work?

"Lubing" usually means coating bullets with molybdenum disulfide (moly coat) so they're more slippery. Theory is they're more accurate.

"Bullet hold" typically means how tight the case neck grips the bullet. SAAMI calls it release or pull force needed to push bullets out of the case neck, typically in pounds. Arsenal specs for 7.62 NATO service ammo is 60 pounds minimum, match ammo is at least 20 pounds. Some handloads for match ammo have about 1 pound bullet release force. For 30 caliber bullets, each pound of pull/push/release force needed requires about 13 pounds psi pressure to move it. Its cross section area is about 1/13th square inch.

RC20 · January 21, 2021, 02:34 PM

It would be a false assumption to start with the premise that primer weight has affect.

If powder varies by 10%, then primers?

Starting place would be how much energy does a primer release. Then see what weight does to that measured energy level.

Primer makes may have methods but have not ever heard of it.

Metal god · January 21, 2021, 02:45 PM

Thank you , I'm glad I'll never need to go down that rabbit hole because you did for me .

Just the expense of a scale capable of weighing those differences would be something I'd hate to spend just to find out primer weight has no effect .

hounddawg · January 21, 2021, 03:03 PM

the real problem is that when you weigh the primer you are not sure how much is the pellet and how much is the anvil/cup etc. To weigh it before and after will give you tat answer but what good does it do? It's not like you can use it a second time

Also I figure it is like case volume and bullet weight. An extra CC of volume or an extra .1 gn of weight is pretty insignificant compared to the energy the powder is generating. Add in shooter error and you have some back of the gunshop theorizing BS to argue over but nothing that will make a damn when you are looking through the mirage at a target several hundred yards out with a five mph intermittent crosswind

The longer I play at this game the more I realize the only road to improvement is through hard work and lots of rounds fired. You cannot buy pixie dust through Midway no matter how anal you get and how much money you spend

Bart B. · January 21, 2021, 05:53 PM

It may have been Col. Hatcher who knew that bullets need to be at least a few ten-thousandths inch larger than the barrel's groove diameter for best accuracy..

Why else would arsenal 173 grain FMJBT .3086" match bullets mic larger than M1 and M14 barrel groove diameters?

When the British commonwealth started shooting 7.62 NATO M80 ball ammo's. 3070" bullets in their fullbore rifles, best accuracy was with 1:13 or 1:14 twist 30 inch barrels having. 3065" groove diameters

And all the best match winning record setting barrel's groove diameter smaller than the best match bullet's diameter.

hounddawg · January 21, 2021, 06:27 PM

Quote:

It may have been Col. Hatcher who knew that bullets need to be at least a few ten-thousandths inch larger than the barrel's groove diameter for best accuracy..

Why else would arsenal 173 grain FMJBT .3086" match bullets mic larger than M1 and M14 barrel groove diameters?

When the British commonwealth started shooting 7.62 NATO M80 ball ammo's. 3070" bullets in their fullbore rifles, best accuracy was with 1:13 or 1:14 twist 30 inch barrels having. 3065" groove diameters

And all the best match winning record setting barrel's groove diameter smaller than the best match bullet's diameter.

Thanks for that info but what does that have to do with sorting primers by weight

Bart B. · January 21, 2021, 06:32 PM

Quote:

Originally Posted by hounddawg

Thanks for that info but what does that have to do with sorting primers by weight

It's related to accuracy.

hounddawg · January 21, 2021, 06:37 PM

My bad, I should have put 2 and 2 together

**Unclenick** · January 21, 2021, 06:43 PM

Thanks for the quick run-through. I'll probably still do my test in 308 when it warms up a little, as I've got another co-experiment to conduct using the same materials, but you've confirmed other variables are normally going to be dominant. I will include pre and post-firing cups and anvils weights to learn how much variation they have. PITA, since all the residue has to be cleaned out first, but doable.

hounddawg · January 21, 2021, 07:03 PM

That would be interesting Nick, good luck in cleaning the residue and keeping the cases in the right order. I have not depinned those that I shot, if I had a ultrasonic I would clean them to see what the variation in the metal parts would be. I could not match them to order fired and velocity however. I toss my all of my shot brass into a container of soapy water for the trip home from the range.

It might be worth repeating in a more accurate rifle also. That barrel has never been what I would call impressive no matter what I run down it. Good news it is .5 - .75 out to 850 yards, bad news is it shoots .5 to .75 MOA out to 850. If nothing else it consistently mediocre. Kind of like a lot of my shooting in a way

Bart B. · January 21, 2021, 07:22 PM

Keep in mind the most accurate stuff at 1000 yards keeps all shots inside about 7 inches.

Jim Watson · January 21, 2021, 07:29 PM

Sticks in my head that there is about 50 milligrams of mix in a large primer. 0.77 grain.
No, I do not have a documentary reference any more.
NRA says 36 mg in a shotshell primer, 20 in a small rifle primer.

**44 AMP** · January 21, 2021, 08:52 PM

Let me be sure, you shoot at 100yds, with a 5mph wind and you get a 0.02" difference between group aggregates and you attribute this to the PRIMERS??

wow...

hounddawg · January 21, 2021, 09:19 PM

Reread the tirst sentence of the first post 44 Amp

It ( with it being the test ) was completely unremarkable, that is about the best that can be said.

to be more clear the primer's weight did not affect the accuracy in any way

hounddawg · January 21, 2021, 10:04 PM

For the data geeks

I weighed 114 CCI 200's to get 25 of a single weight which turned out to be 339 milligrams. Low weight was 334 milligrams, high was 345 milligrams for a extreme spread of 11 milligrams and a average of 339 milligrams.

I slapped together a quick spreadsheet. Column A is weight, Column B is the number of that primers of that weight, Column C was used to get the average

I have decided to soak the fired primers in Simple Green and some Lemishine then weigh each in the same manner. I will do another spreadsheet and chart of the spent primers. That should be able to show what the average pellet weighed and the weight range of the 25 pellets since all weighed 339 mg before firing. That's assuming the anvil mechanism stays in the cup and I get all the crud out of course. I don't own a ultrasonic which would be the preferred method of cleaning

Bart B. · January 22, 2021, 12:40 AM

https://www.federalpremium.com/safet...ation/sds.html

Download the safety data sheet for primers to see the component weights.

January 19, 2021, 11:45 PM	#1
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	Primer weighing test It was completely unremarkable, that is about the best that can be said. I loaded 50 rounds of .260 Remington with 40.0 grains of H4350 and Barnes match burner 140's. twenty five rounds were loaded with CCI 200's picked randomly from the tray. Twenty five were loaded with primers weighed on my A&D 120 to the milligram minus the error rate of plus or minus 1 milligram. shot five groups of five rounds each @100 yards over a chrono with five mph crosswinds blowing from 9 to 3 average group size for the non weighed groups was .62 inches, smallest group at .51 inches, largest at .76 inches. Group height for all 25 shots was .68 average group size for the weighed primer groups was .6 inches, smallest at .49 inches and the largest was .8 inches. group height for all 25 was .66 inches random weight velocity SD for all 25 rounds was 20 FPS sorted weight SD was 23 FPS To me this rabbit hole is not worth exploring any farther __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek Last edited by hounddawg; January 19, 2021 at 11:54 PM.

January 19, 2021, 11:46 PM	#2
Shadow9mm Senior Member Join Date: March 21, 2012 Location: Indianapolis, IN Posts: 4,603	good to know. Had been thinking about this since the other post. Your time and primer expenditure is much appreciated. __________________ I don't believe in "range fodder" that is why I reload.

January 19, 2021, 11:51 PM	#3
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	Thanks, it was a fun way to spend a afternoon. This barrel is not the best barrel that has ever been on this rifle but I figure I may as well get some use out of it. I have plenty of powder and LRP's to use it to play with. I will not be wasting my small rifle primers and Varget repeating this test with SRP's __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek Last edited by hounddawg; January 19, 2021 at 11:56 PM.

January 20, 2021, 08:48 AM	#5
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	no idea Bart and that is the core of the problem. there is no way to determine that without firing the primer. I could have numbered and weighed each primer before and after each firing to determine how much was pellet but why bother. My purpose in doing this little experiment was to see if weight sorting before firing made a difference on paper or on the chrono. It did not so my question was answered. I see no need to spend any more time on the subject __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

January 20, 2021, 11:09 AM	#7
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	yep went the bullet weighing and case volume route also. Could not tell any difference on paper with either. I think a lot of us of chase our tails down rabbit holes when our scores plateau. Rabbit holes and theory are ok for cold winter days but for improving scores there is no substitute for practice. Of course natural talent trumps everything __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

January 20, 2021, 12:20 AM	#4
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	What percent of the primer total weight does each ones detonating pellet have?

January 20, 2021, 02:28 PM	#9
scatterbrain Senior Member Join Date: February 7, 2015 Posts: 178	I know shooters who shoot very good that do weight the primers, I don't. They also measure their bullets on the ogive, but don't weight them. I try measuring both to the ogive and overall length. I have tried everything I have heard about except lubing the bullets, and that may be next. I can't get my head around lubing and bullet "hold", how does that work?

January 21, 2021, 02:34 PM	#11
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,334	It would be a false assumption to start with the premise that primer weight has affect. If powder varies by 10%, then primers? Starting place would be how much energy does a primer release. Then see what weight does to that measured energy level. Primer makes may have methods but have not ever heard of it. __________________ Science and Facts are True whether you believe it or not

January 21, 2021, 02:45 PM	#12
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 7,135	Thank you , I'm glad I'll never need to go down that rabbit hole because you did for me . Just the expense of a scale capable of weighing those differences would be something I'd hate to spend just to find out primer weight has no effect . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

January 21, 2021, 03:03 PM	#13
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	the real problem is that when you weigh the primer you are not sure how much is the pellet and how much is the anvil/cup etc. To weigh it before and after will give you tat answer but what good does it do? It's not like you can use it a second time Also I figure it is like case volume and bullet weight. An extra CC of volume or an extra .1 gn of weight is pretty insignificant compared to the energy the powder is generating. Add in shooter error and you have some back of the gunshop theorizing BS to argue over but nothing that will make a damn when you are looking through the mirage at a target several hundred yards out with a five mph intermittent crosswind The longer I play at this game the more I realize the only road to improvement is through hard work and lots of rounds fired. You cannot buy pixie dust through Midway no matter how anal you get and how much money you spend __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

January 21, 2021, 05:53 PM	#14
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	It may have been Col. Hatcher who knew that bullets need to be at least a few ten-thousandths inch larger than the barrel's groove diameter for best accuracy.. Why else would arsenal 173 grain FMJBT .3086" match bullets mic larger than M1 and M14 barrel groove diameters? When the British commonwealth started shooting 7.62 NATO M80 ball ammo's. 3070" bullets in their fullbore rifles, best accuracy was with 1:13 or 1:14 twist 30 inch barrels having. 3065" groove diameters And all the best match winning record setting barrel's groove diameter smaller than the best match bullet's diameter. Last edited by Bart B.; January 21, 2021 at 06:03 PM.

January 21, 2021, 06:37 PM	#17
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	My bad, I should have put 2 and 2 together __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek Last edited by hounddawg; January 21, 2021 at 06:42 PM.

January 21, 2021, 06:43 PM	#18
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,743	Thanks for the quick run-through. I'll probably still do my test in 308 when it warms up a little, as I've got another co-experiment to conduct using the same materials, but you've confirmed other variables are normally going to be dominant. I will include pre and post-firing cups and anvils weights to learn how much variation they have. PITA, since all the residue has to be cleaned out first, but doable. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

January 21, 2021, 07:03 PM	#19
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	That would be interesting Nick, good luck in cleaning the residue and keeping the cases in the right order. I have not depinned those that I shot, if I had a ultrasonic I would clean them to see what the variation in the metal parts would be. I could not match them to order fired and velocity however. I toss my all of my shot brass into a container of soapy water for the trip home from the range. It might be worth repeating in a more accurate rifle also. That barrel has never been what I would call impressive no matter what I run down it. Good news it is .5 - .75 out to 850 yards, bad news is it shoots .5 to .75 MOA out to 850. If nothing else it consistently mediocre. Kind of like a lot of my shooting in a way __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek Last edited by hounddawg; January 21, 2021 at 07:11 PM.

January 21, 2021, 07:22 PM	#20
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Keep in mind the most accurate stuff at 1000 yards keeps all shots inside about 7 inches.

January 21, 2021, 07:29 PM	#21
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 19,189	Sticks in my head that there is about 50 milligrams of mix in a large primer. 0.77 grain. No, I do not have a documentary reference any more. NRA says 36 mg in a shotshell primer, 20 in a small rifle primer.

January 21, 2021, 08:52 PM	#22
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 30,496	Let me be sure, you shoot at 100yds, with a 5mph wind and you get a 0.02" difference between group aggregates and you attribute this to the PRIMERS?? wow... __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

January 21, 2021, 09:19 PM	#23
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	Reread the tirst sentence of the first post 44 Amp It ( with it being the test ) was completely unremarkable, that is about the best that can be said. to be more clear the primer's weight did not affect the accuracy in any way __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

January 22, 2021, 12:40 AM	#25
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	https://www.federalpremium.com/safet...ation/sds.html Download the safety data sheet for primers to see the component weights.