308 primer testing

[TAZMAN]

Had some time this weekend to test my 18.5-inch custom 308 that I got from a great guy on this forum. I was testing the 185 Berger VLD hunter and found some interesting information.

Using PP2000 I was able to get 2650fps pretty easy, but the ES was all over the place. I reduced the load by a full grain, and it did the same thing. I talked with an older buddy of mine who use to shoot F class and told him what the issue was, and he said use a 215 primer and it would cure the issue. I was skeptical but loaded up 5 rounds with the 215 primer and wouldn't you know, the ES dropped to 6FPS over those 5 rounds and the group tightened up. I loaded up the next 5 at the higher velocity and I saw the ES drop to 11FPS over 10 rounds. I didn't really see a velocity difference with the 215 primers, but the group and ES became very acceptable. I could probably squeeze more out of it, but I am happy with 2650FPS and the groups. I will take it out to 800-1000 yards at some point just to see how it does but overall, pretty happy with the results.

I honestly would have not thought to try a 215 primer, but it worked for this specific application.

 

[BRADMOTO]

I only shoot magnum primers and WLR, since WLR are magnum primer hot.

 

[VinceMule]

I reload at the rifle range, have since 1985. I can tell you that primers are a wild card. As long as I have been reloading, I can rarely, if ever, predict which primer will produce the best accuracy or Extreme Spreads; it is trial and error to find the best.

Yesterday, I was shooting a 12T Krieger 308, R#15 with Sierra 169s. I was shocked when the Winchester large rifle primer produced a bug hole group vs a Federal 210. The groups were so small, they were hard to measure. Some primers will prefer a particular primer with their characteristics, and they are profoundly different.

 

[FEENIX]

Had some time this weekend to test my 18.5-inch custom 308 that I got from a great guy on this forum. I was testing the 185 Berger VLD hunter and found some interesting information.

Using PP2000 I was able to get 2650fps pretty easy, but the ES was all over the place. I reduced the load by a full grain, and it did the same thing. I talked with an older buddy of mine who use to shoot F class and told him what the issue was, and he said use a 215 primer and it would cure the issue. I was skeptical but loaded up 5 rounds with the 215 primer and wouldn't you know, the ES dropped to 6FPS over those 5 rounds and the group tightened up. I loaded up the next 5 at the higher velocity and I saw the ES drop to 11FPS over 10 rounds. I didn't really see a velocity difference with the 215 primers, but the group and ES became very acceptable. I could probably squeeze more out of it, but I am happy with 2650FPS and the groups. I will take it out to 800-1000 yards at some point just to see how it does but overall, pretty happy with the results.

I honestly would have not thought to try a 215 primer, but it worked for this specific application.

As with anything else, YMMV. My preferred primers in order of precedence are CCI, Federal, Winchester, and Remington. However, I've had pretty good success with Rem lately across multiple cartridges, with single-digit SDs or a tad over. Good luck!

 

[TAZMAN]

I have some other primers I may try but I have plenty of the 215's. I was using 210m's but may try CCi or Remington.

 

[VinceMule]

There is a big difference between a CCI 200 and a CCI 250, same for Remington, again, different ignition characteristics.

The accuracy level you are pursuing will determine just how your load testing should go with various primers. If you are happy with 1" groups, then primer choice is of minor consequence.

 

[TAZMAN]

Right now, the 5 shot groups are measuring .4 so some seating depth changes may make it a little better. 185 at 2650FPS isn't bad for an all-around rifle. I have other rifles but the 308 needed some love!!lol

 

[Senecahammer554]

You've found your node. 2650 fps with single-digit ES from an 18.5" .308 with a 185gr bullet is exceptional performance. Don't chase more speed; you'll likely just increase pressure and undo your consistency.

 

[TAZMAN]

The accuracy level you are pursuing will determine just how your load testing should go with various primers. If you are happy with 1" groups, then primer choice is of minor consequence.

I would never settle on a 1-inch group. It's below a half inch 5 shot group now but I think I can shrink that a little with seating depth or maybe .1 change in powder charge. Like I said, the 308 just needed some shooting time and wanted to try something new to me. The 185 Berger at 2650 appears to be a pretty good round out to the 1000-yard mark. The mag primer information was something new to test. I may try the box of 200.20 Bergers I have also just for fun. This rifle has a Huntertown suppressor also.

 

[Bdubose]

Had some time this weekend to test my 18.5-inch custom 308 that I got from a great guy on this forum. I was testing the 185 Berger VLD hunter and found some interesting information.

Using PP2000 I was able to get 2650fps pretty easy, but the ES was all over the place. I reduced the load by a full grain, and it did the same thing. I talked with an older buddy of mine who use to shoot F class and told him what the issue was, and he said use a 215 primer and it would cure the issue. I was skeptical but loaded up 5 rounds with the 215 primer and wouldn't you know, the ES dropped to 6FPS over those 5 rounds and the group tightened up. I loaded up the next 5 at the higher velocity and I saw the ES drop to 11FPS over 10 rounds. I didn't really see a velocity difference with the 215 primers, but the group and ES became very acceptable. I could probably squeeze more out of it, but I am happy with 2650FPS and the groups. I will take it out to 800-1000 yards at some point just to see how it does but overall, pretty happy with the results.

I honestly would have not thought to try a 215 primer, but it worked for this specific application.

WOW! Thanks for sharing! I have a 308 tight neck gun that shoots bug holes. On the last outing I noticed ES issues, and have been perplexed as to fixing it. Nothing about the load has changed except the primers! Going to magnum primers may well be my next move!

 

[Mikecr]

I believe it's luck
But, everyone should do trial & error primer testing for a given action/striking.

 

[TAZMAN]

Shot it again when I got home today with the weather much colder here in Indiana. It held 11 FPS spread over 12 shots so I will play with seating depth and neck tension but as suggested above, 2650fps is plenty of speed, with a 185 Berger, out of this short barrel with suppressor.