I don't reduce powder when I use my CCI 450's. My loads are usually .5 grain or so above published max loads. I may be wrong, others chin in, but I think the magnum primer is used to ignite certain powders better, not necessarily to give more velocity. I use the 450's in all my loads whether called for or not. I got a good deal on them a few years ago so I have several bricks.

As with any load, start somewhere in the middle and increase powder by 0.2-0.3gr until you see signs of over pressure. You'll find the sweet spot your gun likes that gives the best accuracy and won't be to hard on the brass.

Work up slowly and be safe.

 

but I think the magnum primer is used to ignite certain powders better, not necessarily to give more velocity.

That's what I'm wondering about the 450's and the CCI41's. Do they have more power or a bigger flame when ignited, I'm not exactly sure how they work to begin with. I've been told numerous times that the 41's are the same as the 450's except they have a harder cup.

 

I would reduce your known good load by 10% and work your way back up. Generally this is the safest way to rework your loads.

 

IIRC use 400's for stick powders and the magnum 450's for ball powders. I don't know about the 450's and 41's being the same with exception of harder cup on the 41's. Someone else please chim in on that.

 

CCI 34 & 41 are magnum primers. See here at CCI's web site.

http://www.cci-ammunition.com/products/primers/primers.aspx?id=30

 

As suggested in the replies, it is always safer to reduce and work up loads.

If I had a SPCII chamber and was using SAAMI load data, I would probably substitute the magnum primers with my current SAAMI recipe and fire a few and evaluate for any pressure signs. But that is me.

 

I've not seen a noticeable difference but if you are loading max with standard primers, you would want to reduce the charge with magnum primers and work back up as already stated above.

 

daddy: My advice is to always use mag primers in the 6.8 SPC, e.g., CCI 450s, CCI 41s and Rem 7-1/2s. Due to the cartridge's high expansion ratio, the powder charge needs to be ignited quickly so it can mostly burn before the bullet gets too far down the tube. Use the load data in the stickies at the top of this subforum, but start about 2 grains lower and gradually work your way up a half grain at a time until you begin to see faint swipes (semi-circular shiny spots) on the case heads. Either stop there, or back off a half a grain, searching for the "best accuracy" node. good luck - CW

 

I bought a brick of Wolf magnum, and noticed they are harder to seat than the CCI 400's I've been using. is this normal?

 

Thanks for all the responses guys, you've answered my question completely, which is greatly appreciated.

 

You don't 'reduce' a load the way you're thinking. If you switch primers, you should work the load back up just like you would for a brand new load. I don't use anything but mag primers in my 6.8 loads, but every load was worked up from mid-level charges. That's the safe and correct way to do it.

I've also found that the mag primers, at least in my rifle, give a more consistent and smaller extreme spread, and a smaller standard deviation. I like things consistent, especially when working with ball powders like AA2200.

 

You don't 'reduce' a load the way you're thinking. If you switch primers, you should work the load back up just like you would for a brand new load. I don't use anything but mag primers in my 6.8 loads, but every load was worked up from mid-level charges. That's the safe and correct way to do it.

When you're loading for SPC2 Chambers, do you normally start in the middle SAAMI spec. loads as a good starting place then work up? Or do most of you start at SAAMI minimum charges? Obviously I want to be safe, but I also don't want to waste time at a super low charge, when the gun is capable of more.

 

What barrel do you have? If it's a ARP, you can start at max and work out the most accurate load up or down.

 

I don't care who makes the barrel (and for the record, I think Harrison's stuff is the best there is), that is totally unsafe in terms of proper procedure, and has no place in this forum.

 

Really? How many times have you seen the listed data from a powder manuf be actual max, especially with specII chambers? Be real

 

And how did you determine that their data wasn't actual max. You have all the specialty equipment they use to test it? Just curious how you could possibly know that.

 

You are 0.2gr below max per Ramshot load data 5 listing. Use common sense and watch your primers for craters and flattening and caseheads for swipes and you'll be OK. Just don't increase powder charges once you see pressure signs begin.