Primer Testing And Ranking

overbore

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Please note that is a partial reprint of work found under Primer Testing Reference
and only represents testing numbers of 50 to 100 primers of each type as to their power, (brisance) range of power and Standard Deviation. It is my opinion that any accurate long range load for any purpose starts at this end of the cartridge then works it way up through all the factors Shawn described but also includes melpleat length and total loaded runout as the last steps to developing an accurate round. Use only as a guide as lot numbers can and will vary. A good chrony is a must but "on target" group is the truth.

Brand Power Average Range Std. Deviation My Accuracy
Ranking
Fed Match 6.12 5.23-6.8 .351 6

Fed.215 LRM 5.69 5.2-6.5 .4437 9
CCI 250LRM 5.66 4.5-7.4 .4832 10
Win WLRM 5.45 5.1-6.0 .2046 1
REM 9 1/2 LRM 5.09 3.5-6.75 .6641 12
WIN WLR 4.8 4.1-6.0 .4300 8
REM 9 1/2 LR 4.75 3.7-6.25 .5679 11
FED Match GM210M 4.64 4.0-5.6 .3296 4
FED 210LR 4.62 3.7-5.5 .3997 7
CCI BR2 4.37 4.0-5.0 .2460 3
CCI 200LR 4.28 3.8-4.8 .2213 2
OLD Rem 9 1/2 4.16 3.8-4.8 .3427 5
Mil Spec 7.62
( mine are not in as of today )
 
Please note that is a partial reprint of work found under Primer Testing Reference
and only represents testing numbers of 50 to 100 primers of each type as to their power, (brisance) range of power and Standard Deviation. It is my opinion that any accurate long range load for any purpose starts at this end of the cartridge then works it way up through all the factors Shawn described but also includes melpleat length and total loaded runout as the last steps to developing an accurate round. Use only as a guide as lot numbers can and will vary. A good chrony is a must but "on target" group is the truth.

Brand Power Average Range Std. Deviation My Accuracy
Ranking
Fed Match 6.12 5.23-6.8 .351 6

Fed.215 LRM 5.69 5.2-6.5 .4437 9
CCI 250LRM 5.66 4.5-7.4 .4832 10
Win WLRM 5.45 5.1-6.0 .2046 1
REM 9 1/2 LRM 5.09 3.5-6.75 .6641 12
WIN WLR 4.8 4.1-6.0 .4300 8
REM 9 1/2 LR 4.75 3.7-6.25 .5679 11
FED Match GM210M 4.64 4.0-5.6 .3296 4
FED 210LR 4.62 3.7-5.5 .3997 7
CCI BR2 4.37 4.0-5.0 .2460 3
CCI 200LR 4.28 3.8-4.8 .2213 2
OLD Rem 9 1/2 4.16 3.8-4.8 .3427 5
Mil Spec 7.62
( mine are not in as of today )



If you ever get a chance, find a copy of the Benchrest Shooting Primer by P.S. magazine and flip to the chapter about primers. There are some fantastic high speed camera shots of all the different primers being ignited in open space in front of a grid. Very enlightening! They surely are not all the same.
 
Primer thoughts

If reliability is your "game" be aware that the mild primers, such as CCI BR, are prone to hang fire in low / hunting temperatures and if you are reloading up to the max velocity and pressure, the Hot primers WILL cause over pressures; therefore, for accurate all temp uses in larger cartridges, I would go with the 210GM;s since they are reliable and accurate in 1,000yd bench rest guns.

Speaking of hang fires, if you have spare eyes and fingers, open the bolt before it goes "boom". Otherwise, keep the loud end pointed down range, have a cup of coffee, keep all personal, valuable parts on the non ejector side of the action, then lift the bolt handle. Overbore
 
Interesting,

I did a very limited test with 50 Federal 215 primers earlier this year. I was going to post and then found nothing interesting. I segregated 2000 primers by weight, chose 10 that weighted 5.6gr and 10 that weighted 5.7gr. I then alternated for 20 shots over a chronograph using a cool barrel each time. The average velocity and SD although not identical, where definitely within margin of error for such a small sample. During my segragation (2000 primers), I found 2 that where very heavy (up to 5.9gr) and 4 that were very light (down to 4.7gr).
The heavy ones showed no velocity difference from the 5.6 and 5.7gr loads. The 4 lighter primers showed a lower velocity, but again with such a limited test, I was hesitant to post my findings. They where low enough, that I think they could be responsible for a flier at long range (40-50fps low).

The test was done using REL22, 7mm Rem Mag, 24" barrel, 50 degrees, 162gr Amax bullets. Segregated/preped once fired Norma brass. The load was fairly stiff at around 3000fps.

AJ

BTW: After segregating into groups, I re-weighed them all to verify the segregation. I used an RCBS digital and it repeated exactly for the primers in the above test.
 
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