Copyright 2023 – Stephen Redgwell
Sellier and Bellot LR primers
I have been reading people’s experiences with primers since the shortages began a few years ago. The biggest complaint was not being able to find any. This problem is still ongoing, but slowly seems to be easing.
When primers appeared during the shortage however, a few people were upset about the poor fit. These primers came from Europe – Ginex and S&B. Most of the observations suggested that they were undersized. I checked some, but did not find anything out of the ordinary. It doesn’t mean that undersized primers aren’t out there. It only means that I never came across any. Did the Internet rumour mill strike again? Probably. There might have been a bad lot of primers, but the trouble was likely blown out of proportion.
I also read complaints about the quality of Prvi Partizan and Winchester brass – and the high cost of all brass, regardless of maker. Like primers, the biggest problem however was lack of product on store shelves.
What I did was a quick check some brass and primers that were in my shop to check for size and fit.
It certainly isn’t definitive, but I was satisfied that the components here were okay.
Primer Diameters
I started by looking at three different primer brands in my cabinet. Was it possible that I might have some undersized European primers? I have a few thousand Sellier and Bellot primers that I bought two years ago. How would they measure up against some US made Federal match primers and Winchester’s standard LR?
I dug into one of my reference books for primer sizes. LR primer diameter – min and max – 0.2105 to 0.2130 inches —Reference – SAAMI Z299.4 – 2015, Pg 36, PRIMERS AND PRIMER POCKETS
That was simple. All the primers should mic between these two values. Here is the standard disclaimer.
Disclaimer
The micrometer I used has not been calibrated recently. Any errors would be small however.
The variance in diameter between the brands will be valid however, as the error was constant throughout.
The number of primers measured would be insufficient for the scientific types. There were 1000 of each brand, and I sampled 10% of each of the three – 300 of 3000. 10 per sleeve. I included examples for you to see.
I only tested one lot of each of the primer brands because that’s all I had. None was recalled.
Primers
I measured 10% of the primer diameters from three boxes of 1000. That being ten (10) from each of the ten (10) flats for a total of one hundred (100) for each brand. I recorded each measurement and averaged them. The results were rounded off to the closest thousandth of an inch.
Box Sampling – one flat
| S&B .2095, .2095, .2096, .2095, .2096, .2099, .2095, .2094, .2099, .2096. Avg .2096 – round up .210 in. | Federal GM210M .2103, .2104, .2104, .2106, .2104, ,2108, .2104, .2103, .2104, .2104. Avg .2104 – round down .210 in. | Winchester .2098, .2099, .2100, .2099, .2099, .2099, .2099, .2099, .2100, .2100. Avg .2099 – round up .210 in. |
Observations
I started with the S&B primers. The first thing I noted was that the diameter was clearly marked on the box. In this case 5.3 mm or 0.2086 inches. I rounded this up to 0.209 inches. Note that the S&B primers were the smallest of the three. These primers mic smaller than the SAAMI standard. It is important to remember that these are European, not US made.
It is also important to note that SAAMI specifications are a voluntary, industrial recommendation, not law!
The S&B primers were the smallest diameter of the three brands tested (barely) – by 3/10,000 of an inch compared to Winchester – if you trust my mic. Honestly, I don’t think it can measure accurately down to 10000ths of an inch though.
The Winchester primers had the smallest variance in diameter of the three brands tested, but that could change, lot to lot.
All primers miced on the low side of the SAAMI standard. I didn’t consider this a problem. My micrometer was the likely culprit. The variance was consistent between the three brands.
I do not know the allowable manufacturing tolerances for these primers from the respective companies.
Of the three lots of primers used, none has been loose or failed to fire.
It is possible that users who miced the European primers might have noticed that they are slightly smaller than ones made in the US. Undersized cases are likely the result of expanded primer pockets that result from use. I encountered no fitting problems with new cases.
Cases
LR primer pocket diameter – min and max – 0.2085 to 0.2100 inches — Reference – SAAMI Z299.4 – 2015, Pg 36, PRIMERS AND PRIMER POCKETS
Although I did not have thousands of cases to sample, I decided to check the diameter of the primer pockets from my unfired inventory to see if the primers would fit properly.
I chose 100 cases for three different cartridges – 303 British, 7.62×54r and 30-30 Winchester. All were new and unfired. I recorded each measurement and averaged them. The results were rounded off to the closest thousandth of an inch.
This micrometer measures in millimeters. I converted to inches using a computer conversion program.
Box Sampling of 30 cases (10×3)
| 303 British (Remington brass) mm 5.28, 5.29, 5.28, 5.28, 5.27, 5.28, 5.29, 5.27, 5.27, 5.29. Avg. 5.28mm – .208 inches | 7.62x54r (PPU brass) mm 5.29, 5.28, 5.31, 5.30, 5.29, 5.28, 5.30, 5.28, 5.29, 5.29. Avg. 5.29mm – .208 inches | 30-30 (PPU brass) mm 5.28, 5.29, 5.28, 5.28, 5.27, 5.28, 5.29, 5.27, 5.27, 5.29. Avg. 5.28mm – 2.08 inches |
Observations
All primer pockets miced on the low side of the SAAMI standard. I didn’t consider this a problem. As in the primer results above, my micrometer was the likely culprit. The measurement was low by approximately 5/10,000ths of an inch. The error was consistent between the three case types.
Conclusion
For a small test did verify one thing: The primers are approximately two thou (0.002) larger than the primer pockets. No problem. Load away!
One Sad Note
While going through my primers, I found this box. Check the Price for 1,000 – $27.99.
