Silly primer question?

[RED]

This is probably a silly question BUT here goes...

Would it be possible to sub small rifle primers for small pistol primers? How about with reduced loads?

Seems I can't buy small pistol primers any place around and I have small rifle primers on hand. I did it by accident but in a N frame S&W with .38 Specials in a .357 and I really couldn't tell any difference. This time it would be in a .38 super automatic.

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[MEHavey]

NO.

Rifle primers are taller than pistol primers and WILL protude from the case head.

At best the action will not close at all.
At worst, it *will* fire without having the action completely locked up.


How in the world did you get the Revolver cylinder to rotate w/ a protruding primer?




.

[Mike_Mills]

Gee, I thought small rifle primers were the norm in 38 Super. In IPSC competition, everyone was hot-rodding the 38 Super so they could "make major" on power factor and because the large volume of high pressure gas makes the compensators very effective.

The thing is, they had to develop and use a chamber that fully supported the cartridge case (no unsupported section by the feed ramp.

Anyway, this is what I remember and I think it bears the answer to your question. Yes, it has been done successfully. It requires tweaking the loads.

ETA - if the primers are taller, you may need to run a small rifle primer pocket uniforming tool in the case to reform the primer pocket to the correct depth.

[MEHavey]

ETA - if the primers are taller, you may need to run a small rifle primer pocket uniforming tool in the case to reform the primer pocket to the correct depth.

I know that I use rifle primers in my 500 S&W (Magnum/Match, in fact), those cases are designed for large rifle primers -- being designated w/ and 'R' on the headstamp.

But I did not know that 38 Super standardized on rifle primers. (Does it? I've read both opinions on line.) I'm gonna go measure both SP/SR primers tonight.

That said Mike M's advice to uniform the primer pockets is sound if you are going to use SR's though, and work the loads up for similar velocities as opposed to just substituting primers. Note also that rifle primer cup thickness is different/thicker, so check for hammer strike reliability as well.

[MEHavey]

Well, `ya learn something new everyday here.

I went down to the basement and measured some CCI SP/SR primers and here is what I got below. Note that the SR is a 0.001 larger, but the StdDev's overlap. So uniforming the pockets would be my suggestion.

I also loaded one each empty/primed SR & SP case into my GP100 and took it into a dark room to fire. While I perceived the SR to be "a little" sharper in report, the flame lengths out of the 6" barrel were all but identical. (How's that for a scientific test?) :-)

[FTIII]

It might work but...the burn on a SR rifle primer is hotter and longer than the burn on a SP primer. The cup may also be thicker and can cause a hang fire light strike situation unless the spring is changed to a stronger one. The factory might have already built that into the newer springs, anyone know? One thng for sure.....the factory "does not" recomend it so if you have at it you would do so at your own risk. Good luck.

BudT

[Mike_Mills]

But I did not know that 38 Super standardized on rifle primers. (Does it? I've read both opinions on line.)

Standardized? I didn't say that, just that they were frequently used. Honestly, my information and experiences were from a long time ago. You'd do well to get other opinions than mine on this topic.

[rond]

I use CCI SR primers in .357 magnum and 38 Super Auto. I too am running out of SP primers. Have had no misfires and performance seems unchanged.

[MEHavey]

In the FWIW column, I note that the Speer#14 Manual has an extensive .357 Mag section, and concludes its two-page cartridge introduction with the warning…

"Do not use magnum primers with the 2400 or VihtaVouri N110 [and by extension H110] loads shown here or high pressures will result."

Whether a rifle primer's output approaches (exceeds?) that of a magnum pistol primer is an exercise left to the student -- but you didn't expect an easy free lunch here, did you?

I'd do some lower-pressure load velocity comparisons between the two before loading for any real performance.

[Matt Anthony]

I bought 10,000 Rem. 6 1/2 primers about 10 years ago for 222/223 loads and could not use them in my loads due to their soft cup. I have had my share of pierced primers and pitted bolts. Switching to Rem 7 1/2 primers solved that problem.
Now what to do with the 6 1/2's! I tried them in my 38 specials, cronographing using both small pistol and the small rifle. No difference on velocity nor did I note any depth difference. I've used them for over 10 years without a problem.