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.