Primer Reloading - NC V4.2 for EPH-2x

[P Flados]

NC V4.2i:

NC: 45 gr W296, Acetone: 20 ml, IPA: 9 ml (0 before NC, 9 ml after).

For this batch, I tried to see what no heat would do. It did not progress well and I stopped mixing too soon. I harvested a small amount of NC powder, but this was not a “good” batch.

[P Flados]

I started work on evaluating different smokeless powders as NC V4.2 source material. However I put all result testing on hold. After my V4.2h results, I had loaded a good sized batch of 9mm. A few of the fired rounds seemed off normal. I went back and did some re-testing of primers only. A handful were marginal for power level.

I decided to run a series of primer only tests with the objective of optimizing the EPH-20 mix ratios.

These were all assembled as double pack. Double pack starts by loading cups in the plate. Excess powder is spread around and scraped off. This fills each hole flush to the plate surface where the cups are actually sitting down ~0.015”. Do one tamp and refill flush to the plate. Tamp again and agitate to get all powder down inside the cup. Tamp again and add water for activation. Place anvil and press flush with plate. With this low density NC, the amount of mix per cup in grains drops a good bit as NC percentage goes up.

I decided to go down on GG first. The original EPH-20 had 15.6%. Adrian had gone as low a 7.5%. After thinking about it I decided that going “as low as possible” does not buy much. The volume ratios are really more important than the weight ratios. Bulk volume determines how much we can pack into a primer. So I ended up with taking GG down to 9.5%. For my small test batches this is 1.0 gr of GG for a mix that runs 10.5 gr.

While doing this test series it occurred to me that my previous inconsistent results could well have been from inadequate mixing of the dry powders. The NC V4.2 is very low density making it both “fluffy” and somewhat “clumpy”. With mixing as less assured with NC V 4.2 as compared to other NC sources, the optimum ratio for ingredients is probably the mid point of the range that gives acceptable results.

A batch at 12.4% NC and a batch at 14.3% NC both were about the same and were just a little less powerful than I wanted. A batch at 16.2% NC was very good. At 23.8% NC things were still good, but less than at 21.9% NC.

I will not claim this was a perfect test series. It was all based on one batch of NC V4.2 made from W296. The methods involved less precision for batch preparation than I would have liked and the evaluation of the results were somewhat subjective. For now, 20% NC seems to be the mid point for good performance even though a little less may actually be a more powerful. As I evaluate other source powders, I will probably test the NC powder at two mix ratios. If test results are good at both 16.2% NC and 23.8% NC, a mix with 20% NC should very reliable and consistent for actual use.

[P Flados]

For visual reference, here is the LH, LN, GG and NC for a small test batch with 16.2% of NC made from W760

[P Flados]

And here is the same with 23.8% NC

[mvintx]

I'll be curious as to your EPH20 sensitivity with 9.5%GG.

[P Flados]

I'll be curious as to your EPH20 sensitivity with 9.5%GG.

I have had zero primers fail to go off on first strike during the recent primer testing. If I was "too close" to the minimum, I would expect an occasional primer not go off on first strike. I should probably run a test down at 7.5% GG and confirm I have some "comfort margin" for this parameter.

[P Flados]

I just concluded a GG reduction test series. With my NC 4.2, I went as low as 5% GG and got good reliability (10 for 10) with my weakest firing pin strike guns (revolvers). I do not see any reason to run lower than 8% or so for regular production work.

I am also done with all but one of my tests of NC made from different smokeless powders. NC V4.2 worked with HS-6, Win 296, Win 760, 4198 and 4895. Double base ball powders dissolved easiest and required the least acetone. I am “drying” a batch of Promo that I am sure will work fine. As I was testing the last 4 powders, I tested each one at two different NC percentages.

Based on all of the testing, my recommended EPH-20 mix ratios using NC V4.2 has shifted a little. For 100 primers, I recommend 8.5-8.5-1.9-5.1 (LH-LN-GG-NC) as a low GG mix and 8.5-8.5-2.2-5.1 as a medium GG mix. Note that the NC to LH ratio is the same. This seems about optimum. If you plan to load a lot with a low GG percentage, I would first try a batch with less GG (say only 1.5 gr) to confirm good function with your guns.

[P Flados]

The promo batch worked fine.

I also ran a batch of "mixed ???" powder pulled from 45 ACP and 9mm range pick up in a 100 ml beaker. Most of it was a very small flake powder, some of it was ball powder. I just kept adding powder to my 40 ml acetone & 4 ml IPA until it got thick enough that the magnetic stirring bar was iffy to keep spinning. As I was adding the additional 16 ml of IPA, it got so thick that manual stirring was required. At about 19 ml of total IPA the viscosity dropped off and I was able to get the mix spinning with a good vortex using the magnetic stirring bar. The resultant < 100 mesh NC was 89 gr.

I am calling it quits on the testing phase of NC V4.2. It works with everything I tried, but double base ball powder or a fast flake seems to give better yields per ml of acetone. It is a good way to make use of pulled ??? powder. Double pack is required for EPH-20 using NC V4.2 as previously discussed.

I will be glad to post method details I used, but only if there is enough interest.