Swapping to magnum primers

[TradLife406]

Current loads for the 22 creed is a max load of n565. Using federal large rifles.
Just wondering since I'm using magnum powder and a lot of it if I should try testing some cci magnums?

If so do I need to back off my charge weight say a half a grain?

Groups are ok and the SDs aren't horrible for 10 shots.

Just thinking it might be worth a try.

 

[mlevimadden]

Depends where you're at for load data. If you're running a load at book max, definitely back off a couple grains and work back up when swapping components.

I don't see any need for a large rifle magnum primer to ignite 40 grains of powder in a creedmoor case though. I think most the experts recommend switching to LR magnum primers around 60-70ish grains of powder column.

I'm running standard Federal 210 primers in my 6.5 PRC with 57 grains of N565 and haven't had any ignition issues.

 

[Harvey_NW]

I think I've heard that a rule of thumb is around 60gr of powder to start considering switching to a magnum. I'm loading 56.5gr N565 in my 6.5 PRC and am using a Rem 9 1/2 LR primer, and it shoots lights out at expected velocity, so I've never tested anything different.

Cross referencing a few different sources of load data for the 6.5 PRC, all used a standard LR primer. If I were to test a magnum I would probably drop a couple grains and work back up, just to be safe.

@mlevimadden beat me to it. We've discussed our very similar results before.

 

[mtnbound]

Current loads for the 22 creed is a max load of n565. Using federal large rifles.
Just wondering since I'm using magnum powder and a lot of it if I should try testing some cci magnums?

If so do I need to back off my charge weight say a half a grain?

Groups are ok and the SDs aren't horrible for 10 shots.

Just thinking it might be worth a try.

I recently experienced some hangfires with Mag SRPs in one powder, so I switched to Mag LRP because I had them on hand. I did not reduce my load and did not notice any speed or psi jumps. I think I can get by using LRP's, but again, I already had the Mags LRPs.

What was your load with N565?

 

[SupressYourself]

SRP, but I've tested CCI BR4 (standard benchrest) and CCI 450 (magnum) in 22 Creedmoor with Staball 6.5, and found velocity to darn near the same.
Note: The 450s actually had a bit better ES.

 

[TradLife406]

45 grains of n565 88 grain eldms
46 grains of n565 with 77 tmks

All alpha lrp brass.

 

[SDHNTR]

Zero need

 

[Wrench]

Sometimes you can get worse sd by going to magnum in small volume cases. You won't over pressure, but perhaps upset the seat before full ignition during the dwell time.

 

[TradLife406]

What about swapping primer brands? Staying with a large rifle but going from federal to cci or Winchester?

 

[Wrench]

Federal are softer and smaller cups, cci harder and hotter. Winchester is all over the place. They used to be awesome....but anymore I don't go there unless the options are gone.

 

[SupressYourself]

In that case I'd back off a bit. But don't go to Winchester, those are not going to be better.

 

[Lawnboi]

Don’t waste the time or barrel life.

 

[longrangelead]

I've only had one rifle where it made a dramatic difference, a 22-250.
going from Fed 210 to 215 cut the group in half so it was apparent it worked.

load 10-20 and try it. no harm either way.

 

[mtnbound]

What about swapping primer brands? Staying with a large rifle but going from federal to cci or Winchester?

I use a Hornady L&L progressive to load, so a relatively significant amount of pressure is applied when seating primers. As a result, the Federal primers are often damaged, whereas the CCI's are never compromised. I have not seen any consistent numbers that make me believe one is hotter than the other.

 

[cbuck516]

I tested CCI 200 vs CCI 250 in my 25CM earlier this year and the groups were worse with the LRP mag primer, but velocity was 5fps faster and slight improvement in ES/SD.

In previous load development work for 270Win and 25-06AI, I have seen the LRP magnum improve group size pretty significantly with certain load combos. My default is to start with LRP magnum for those larger cases now, and the smaller cases like 308Win I start with regular LRP and just see if I can get the accuracy I’m after without any primer change.

I tend to live on the edge of pressure in many cases so the heavier cup and tighter fit of the CCI seems to work best for my abusive reloading style

I started doing some frozen round testing earlier this year and was pretty pleased to see how well a non-magnum LRP ignites when the powders is below 0F. I also tested some CCI 450 with zero hang fires. There is more that goes into ignition issues that just primer selection. It certainly plays a part though.