I have a Ruger Single Seven in .327 Federal with the 7.5" barrel. I have found that loading the .327 Federal presents some challenges, namely dealing with large extreme velocity spreads, 150-200 fps.

Brian Pearce wrote an article about the .327 Federal in Handloader magazine, issue 294 (Feb-Mar 2015) and answered some questions I asked in issue 312 (Feb-Mar 2018) about reloading issues with the 327.

Based on his comments regarding primer testing I decided to run some comparisons of a variety of small pistol and rifle primers in the .327 Fed.

The load was 11.0 gr 2400, in Starline brass. Bullet was the Hornady 100 gr XTP. Cases were trimmed to the same length, primer pockets and flash holes uniformed, and a firm roll crimp was used.

I compared 10 different primers. Fifteen shots were fired with each primer. Velocity was measured 15 feet from the muzzle.

CCI 500
Velocity: 1451 fps
Extreme Spread: 179 fps
Standard Deviation: 60.1 fps

Federal 100
Velocity: 1379 fps
Extreme Spread: 74 fps
Standard Deviation: 20.3 fps

Federal 200
Velocity: 1352 fps
Extreme Spread: 74 fps
Standard Deviation: 21.2 fps

CCI 550
Velocity: 1443 fps
Extreme Spread: 163 fps
Standard Deviation: 56.0 fps

Federal 205M
Velocity: 1360 fps
Extreme Spread: 50 fps
Standard Deviation: 18.0 fps

Winchester WSP
Velocity: 1357 fps
Extreme Spread: 44 fps
Standard Deviation: 13.7 fps

Winchester WSR
Velocity: 1360 fps
Extreme Spread: 69 fps
Standard Deviation: 21.9 fps

CCI 400
Velocity: 1365 fps
Extreme Spread: 138 fps
Standard Deviation: 33.5 fps

CCI 450
Velocity: 1455 fps
Extreme Spread: 73 fps
Standard Deviation: 19.6 fps

CCI #41
Velocity: 1370 fps
Extreme Spread: 140 fps
Standard Deviation: 37.5 fps

Of all of these, the second to the last one, with the CCI450 gave the best results, giving the highest average velocity, with the lowest pressure signs, as determined by primer appearance and ease of case extraction along with good accuracy. One other thing I had noticed - the muzzle blast and flash often varied a lot among the same load, with some giving a much louder report and large flash, with others being not as loud and little flash. The quieter less flashy loads gave the highest velocities. All 15 of the rounds with the CCI 450 primer were like this, no big blast or flash.

This is one of those times when I don't understand everything I know about something.

Mike

interesting test thanks for the report. I am thinking about getting a ruger lcr in.327 as it would be even more versatile than a 357 in my mind.

This message has been edited. Last edited by: coma,

quote:

The quieter less flashy loads gave the highest velocities. All 15 of the rounds with the CCI 450 primer were like this, no big blast or flash.

To me this indicates a more complete powder burn within the gun. i.e. Less powder burning beyond the muzzle. Good light-off by that particular primer.

Nice work-up. You're a patient and diligent man.

RMD

quote:

Originally posted by rduckwor:

quote:

The quieter less flashy loads gave the highest velocities. All 15 of the rounds with the CCI 450 primer were like this, no big blast or flash.

To me this indicates a more complete powder burn within the gun. i.e. Less powder burning beyond the muzzle. Good light-off by that particular primer.

Nice work-up. You're a patient and diligent man.

RMD

Thanks.

Regarding the powder combustion, I've come to the same conclusion. With many of the other primers, CCI 500 for example, there would usually be a few of that batch that would give velocities above 1450 fps. These rounds had less flash and blast. They would also group about 2" below the slower (1350 fps) rounds.

It's interesting that not all the rifle primers gave lower extreme spreads, ie, the CCI 400 and #41.

I felt that 2400 should be a good match for the .327 Federal. I wonder, though, if a different gun, powder lot and primer lot would give the same results.

Federal's factory 100 gr load clocks in at 1626 fps out of my gun. Not sure I want to try and duplicate that with my handloads!

Mike

quote:

I wonder, though, if a different gun, powder lot and primer lot would give the same results.

I suspect that you would see some variance in the parameters that concern you. I know loading precision rifle, a new lot of powder means a new work up for my pet loads.

Good work you have done there.

RMD

quote:

Originally posted by rduckwor:

quote:

I wonder, though, if a different gun, powder lot and primer lot would give the same results.

I suspect that you would see some variance in the parameters that concern you. I know loading precision rifle, a new lot of powder means a new work up for my pet loads.

Good work you have done there.

RMD

Thanks.

One additional note - I tried Remington 1-1/2 primers very early-on during some load development for the.327 and experienced a number of pierced primers. I initially thought there could have been a problem with my gun. I did not see any primers pierced with any other brand of primers since then. The latest issue of Shooting Sports USA magazine has an article about Remington 1-1/2 primers, stating that they are NOT for high pressure cartridges, like the .357 Mag. Piercing and primer flow are the issues.

So a word of warning - Remington 1-1/2 primers should not be used in the .327 Federal!

Mike

We went thru similar with Winchester LRP. A lot of them burned thru at the transition between the side wall and striking face. Cost them some replaced bolts.?
RMD

Nice work-up