Dasher Primer Choice?

[DJ111]

Blank = Peirce

 

[xswanted]

Well I played around again tonight.

I had really good results with the Rem 7 1/2 and 31 grains of r-15.

No pressure signs on that primer and it shot one hole at 100 yards.

On to 300 yards!

 

[Hal]

Jim

When you blank a primmer there is a small disc of primmer cup blown out the primmer.
The disc pieces usualy ends up in your bolt body.

Hal

 

[4xforfun]

I've used nothing but 205 match primers.

Look what dominates close range.......

6PPC

 

[Bradley Walker]

Remingtons are very similar to 450s...

[br]
In toughness, yes. But, the Remington 7½ is regarded as a bit hotter, only exceeded by the Fed 205. The attached chart shows relative brisance of both large and small rifle primers. The BR4 and 450 are usually considered similar. [br]
I'm about to conduct some tests using Lapua Palma .308 brass with a load developed using Wolf KVB-5.56M, substituting Remington 7½, Federal 205M and CCI 450 primers in the same final series. If the results are significant, I'll post them. Primer performance has been a problem when trying to ignite ~45 grains of N550 in Palma cases.

There were some flame tests and I thought the Fed 205 had a very small flame. 400 next bigger, 450 next bigger and Rem had the biggest flame.

 

[Steve Blair]

There were some flame tests and I thought the Fed 205 had a very small flame. 400 next bigger, 450 next bigger and Rem had the biggest flame.

[br]
It is somewhat more complex than that. Primer compounds differ, producing varying flame temperatures. The amount of explosive force varies. Some are said to incorporate aluminum particles (used in solid rocket fuel) to increase powder ignition. The time exposure photos that I have seen support the chart but certainly could vary with lot. Also, there is nothing to say that manufacturers cannot change the formulation. [br]
As a general statement, the mildest, consistent primer that provides reliable ignition gives the best result. Some of the mildest primers, like Russian Tula, seem to have problems igniting ball powders. Winchester, which once offered exclusively ball powders from the St. Marks, Florida plant, produces some of the hottest primers. But, I have also found extruded powder loads that worked best with hot primers. [br]
The testing method also affects how primers are ranked. Some tests used a pendulum or ball, physically moved by the primer. This only measures the explosive force. Some tests used time exposure photography to capture the flame. Since I never saw one that used infrared imagery, this is also a little suspicious. The photos sometimes showed spark showers well beyond the flame extent, supporting aluminum powder inclusion. My approach is to use the chart as a rough reference and test at the range. [br]
While working with Picatinny Arsenal on the Ultra Lightweight Howitzer program, I learned that Army Ballistic Research Lab (BRL) did not run computer models of internal ballistics as it was too complex and chaotic a system for reliable results. They just characterized the impulse from empirical testing.

 

[Bradley Walker]

There were some flame tests and I thought the Fed 205 had a very small flame. 400 next bigger, 450 next bigger and Rem had the biggest flame.

[br]
It is somewhat more complex than that. Primer compounds differ, producing varying flame temperatures. The amount of explosive force varies. Some are said to incorporate aluminum particles (used in solid rocket fuel) to increase powder ignition. The time exposure photos that I have seen support the chart but certainly could vary with lot. Also, there is nothing to say that manufacturers cannot change the formulation. [br]
As a general statement, the mildest, consistent primer that provides reliable ignition gives the best result. Some of the mildest primers, like Russian Tula, seem to have problems igniting ball powders. Winchester, which once offered exclusively ball powders from the St. Marks, Florida plant, produces some of the hottest primers. But, I have also found extruded powder loads that worked best with hot primers. [br]
The testing method also affects how primers are ranked. Some tests used a pendulum or ball, physically moved by the primer. This only measures the explosive force. Some tests used time exposure photography to capture the flame. Since I never saw one that used infrared imagery, this is also a little suspicious. The photos sometimes showed spark showers well beyond the flame extent, supporting aluminum powder inclusion. My approach is to use the chart as a rough reference and test at the range. [br]
While working with Picatinny Arsenal on the Ultra Lightweight Howitzer program, I learned that Army Ballistic Research Lab (BRL) did not run computer models of internal ballistics as it was too complex and chaotic a system for reliable results. They just characterized the impulse from empirical testing.

Wow, that's cool...

My only complaint with Fed 205 was that they are soft in my AR-15 on hot days and sometimes will pierce during rapids... If they would go to that thicker cup like the others, that would be nice...

I really thought the size of the flame was all that mattered, but what you are saying makes great sense!!!

 

[johara1]

Maybe thats why point blank break triggers .....Feds?.......jim