Corrosive primers

[Krazykarl]

How do the old corrosive primers, FA no 70 for 30 caliber rifle for example, compare with modern non corrosive alternatives? Energy, brisance, etc???

I have read that the corrosive military primers DO have a longer shelf life.

I am exploring the idea of shooting some recently acquired primers (as stated above) through a 1903a3 for scientific purposes.

Karl

[tomme boy]

Are you sure they are corrosive? Around 52 or so they went NC.

[Krazykarl]

The box is dated 1931.

[markm]

The box is dated 1931.

Damn! I don't know a thing about them, but that's pretty interesting.

[jsbhike]

How do the old corrosive primers, FA no 70 for 30 caliber rifle for example, compare with modern non corrosive alternatives? Energy, brisance, etc???

I have read that the corrosive military primers DO have a longer shelf life.

I am exploring the idea of shooting some recently acquired primers (as stated above) through a 1903a3 for scientific purposes.

Karl

I don't know if this gets to the level of detail you are wanting, but(from my reading of it at least) it seems the non-corrosive was simply tweaked over a long period to match the stability, reliability, and longevity of the chlorate primers.

If you ever see these old NRA guides they are worth picking up.

[Krazykarl]

Double post

[Krazykarl]

Went out yesterday with the Oehler 35p and shot the following out of my 1943 O3/A3:

1. RP case, FA 70 primer, 49 gr IMR 4064, Hornady 150 FMJ to 3.250 OAL.

2. RP case, WLR primer, 49 gr IMR 4064, 150gr Hornady FMJ to 3.250 OAL.

5 shots each ( I ran out of prepped RP cases).

FA 70:

Hi = 2736
Lo = 2680
ES = 57
MEAN = 2716
SD = 22

WLR:

Hi =2714
Lo = 2689
ES = 25
MEAN = 2699
SD = 12

Group size at 100 yards

FA 70:

2.75" vertical stringing

WLR:

2.625" with vertical stringing.

Pressure observations:

Easy bolt lift and extraction with both loads. FA 70 Primer is slightly flatter in appearance compared to WLR.

General observations:
1. This is the second outing with the corrosive primed reloads. I chose the 03/A3 for ease of cleaning over the M1. Hot water, dishsoap on a bronze bore brush, and boiling water through the bore, once dry an oiled patch to finish. No rust found. The fired cases were also rinsed in hot water. Would I shoot more of the FA70? Yes if they were free. The numbers don't lie, the modern chemistry of today's primers produce as good results without the extra rust concern. I really wanted to shoot the FA70 through my M1. But just too much work to clean afterwards.

Edited to add:
Great testimony to well stored reloading components being viable. Don't be afraid to use that "Old" stuff.

[tomme boy]

To speed up cleaning of the corrosive primers, run a couple dry patches through first. Then clean like normal. The dry patches will take out the majority of the salts.

[1168]

As a sidenote, a lot of ordinance dept types in various nations used to have a strong aversion to gas ports. In the time period between the invention of smokeless powder, and the dawn of the AK47, there are some really wonky designs because of that. The Germans seemed especially weird about it, but we did it, too. The 03 vs M1 mention reminded me of that, with its strange gas system.

[vicious_cb]

General observations:
1. This is the second outing with the corrosive primed reloads. I chose the 03/A3 for ease of cleaning over the M1. Hot water, dishsoap on a bronze bore brush, and boiling water through the bore, once dry an oiled patch to finish. No rust found. The fired cases were also rinsed in hot water. Would I shoot more of the FA70? Yes if they were free. The numbers don't lie, the modern chemistry of today's primers produce as good results without the extra rust concern. I really wanted to shoot the FA70 through my M1. But just too much work to clean afterwards.

Edited to add:
Great testimony to well stored reloading components being viable. Don't be afraid to use that "Old" stuff.

Pretty much, as someone who's shot 10's of thousands of rounds of corrosive 7n6 before they banned it through AR-15s Ive never has a problem with rust while just using a pot of hot water, an air compressor to dry followed by an oil patch.