Loading .223 with magnum primers
- Thread starter Matteralus
- Start date
- Location
- Western Manitoba
Is typical to read to reduce powder when going from standard to magnum primers - but is really up to you to do pressure test series to know what your loads and your gear want. I do not think it is very good idea to simply swap magnum primers with standard primers - in a load that you have been satisfied with. Is too many postings that perfectly acceptable loads can be "worked up" using magnum primers for most cartridges.
Other's experience will likely be different, but I found is not unusual to go through 20 to 50 rounds to do pressure series, to find "best loading" and to verify scope sighting in. Or, as I started - using a Lee Loader - scoop of powder as per the chart - go shoot a deer with that.
Other's experience will likely be different, but I found is not unusual to go through 20 to 50 rounds to do pressure series, to find "best loading" and to verify scope sighting in. Or, as I started - using a Lee Loader - scoop of powder as per the chart - go shoot a deer with that.
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in my 20" Tikka 223, I tried CCI400 small rifle vs CCI450 magnum with D8208BR powder and 55gr Speer SP
CCI 400 21.90grs - 2960 fps, SD26
CCI 450 21.90grs - 2958 fps SD22
In my 16.1" Ruger 223, same test with Hornady 55gr SP
CCI 400 21.90grs - 2765 fps SD27
CCI 450 21.90grs - 2712 fps SD8
Don't expect much difference in pressure. I always get better standard deviation with the magnum primer, it's my go-to primer for 223
CCI 400 21.90grs - 2960 fps, SD26
CCI 450 21.90grs - 2958 fps SD22
In my 16.1" Ruger 223, same test with Hornady 55gr SP
CCI 400 21.90grs - 2765 fps SD27
CCI 450 21.90grs - 2712 fps SD8
Don't expect much difference in pressure. I always get better standard deviation with the magnum primer, it's my go-to primer for 223
I load almost everything with magnum primers. I get lower SD and typically better accuracy. You may or may not need to adjust your load. That is for you to find out. I would suggest dropping your load a bit and redeveloping.
I TOO use CCI450 with ALL powders and bullet weight in my 223 Rem Tikka rifle . RJ
Outside of a ballistics lab, how does someone do a "pressure test series" in the field?
Ganderite's post makes much more sense to me. If I change any components, I just use my chronograph and adjust the powder charge down or up (if necessary) to achieve approximately the same velocity from my past proven loads. If I'm happy with the accuracy, I stop right there. I don't burn through 20 to 50 rounds doing that.
Just work up your load using the CCI450 primes just LIKE if your were to use CCI400 primers ! Its NOT rocket science or NOR difficult to do ! RJ
- Location
- Western Manitoba
"pressure test series" - maybe I chose the phrase poorly - of course only a pressure lab is going to produce psi numbers - I was thinking more like the ladder test and "working up". An acquaintance had extremely tight to open bolt in 7mm STW, and a second acquaintance broke the handle off his Rem 788 in 22-250 Rem, trying to tap open that bolt - both instances on their first hand loaded round. I believe all issues that were eventually discovered would have been found with reducing their loads initially - both guys had reasons not to bother.
I will normally do up a series starting at published "Start" level and go up to 0.5 grain past a published Max loading - feeling for bolt getting tight on opening - looking at primer "flattening" - both have been demonstrated not to be conclusive about pressure levels, but sometimes they work, but your check for velocity is considered a near proxy for breech pressure. Although that may not always be a perfect representation of "peak pressure", but is usually the best that we have available, short of an actual pressure test lab.
And for sure, when I get lucky (make better guesses), is many less rounds to find a "good combination" - but is the ones that do not initially work out - maybe eventually swap to different powder, play with seating depth a bit. I went through many rounds with IMR 4350 for 225 grain in my 338 Win Mag - got much better results with RL-19 powder. I went through a lot of test rounds with IMR 4831SC and 250 grain in same rifle - best group was at Start load (5 shots 1 1/4") and got worse as I increased powder charge (5 shots 3 1/2" +) - gave up on those - I use 225 Accubonds now. At the time was too stubborn (too cheap ?) to change brass or primers - was R-P brass and Fed 215 primers throughout. On the other hand, first choice of same IMR 4350 with 154 grain Hornady in 7x61 were just fine, near maximum was best groups - once I had "worked up" to that, without incident, in the rifle.
Likely 20 years ago, I was taken with the writings by John Barsness - his recommended combinations of powder, primer, case, bullet weight for 7x57, 9.3x62 and 338 Win Mag, turned out to work well in my rifles. I still did "work up" to his loadings though, even though he claims several of his published loads were truly pressure tested at Western Powders lab in Myles City, Montana. I have several times ended up with different cases and primers than he used - sometimes that might matter - sometimes it does not appear to. I am old - I no longer "enjoy" surprises - so I do take the time to back off a couple grains, at least, from a "hot" load, whenever I change out a component in that load - bullet, primer, or case.
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Potashminer: "pressure test series" - maybe I chose the phrase poorly - of course only a pressure lab is going to produce psi numbers - I was thinking more like the ladder test and "working up". An acquaintance had extremely tight to open bolt in 7mm STW, and a second acquaintance broke the handle off his Rem 788 in 22-250 Rem, trying to tap open that bolt - both instances on their first hand loaded round. I believe all issues that were eventually discovered would have been found with reducing their loads initially - both guys had reasons not to bother.
Maybe they should LEARN to reload properly before they BLOWN themselves up ! Starting AT MAX ?? is Not a Good procedure !
RJ
Maybe they should LEARN to reload properly before they BLOWN themselves up ! Starting AT MAX ?? is Not a Good procedure !
RJ- Location
- Western Manitoba
Maybe they should LEARN to reload properly before they BLOWN themselves up ! Starting AT MAX ?? is Not a Good procedure !
In the case of the guy with the 7mm STW - was almost unique - he went to Nosler website and started with the Start Load that they list for H1000 powder and 175 grain bullets in his rifle that he inherited. Amazingly, Nosler lists identical Start and Max weights for that powder for both 160 grain and 175 grain bullets for 7mm STW - and the error continues in my copy of the Nosler #9 Manual. I am sure that was a clerical typo that someone pasted something where it should not have gone - I did notify Nosler but received no reply. Too boot, I do not own #8, but have #7 back to #1 - and in every case that listed H1000 powder for 7mmSTW, their previous Max loading, for 175 grain, was LOWER than the current Start loading. So, mostly because he relied on one on-line source for data, he did essentially start with MORE THAN a Max load. It did not help that the GrandPa had had a custom barrel installed - with significantly less than SAAMI dimension case neck diameter - we confirmed by cerrosafe casting and then measuring - obvious that GrandPa was thinning case necks - grandson did not know that - never heard of that - the main clue was that his 175 grain bullets could not be put back into the case mouth of the fired cartridge - after firing, were still "too tight" to accept a bullet.
The guy with the 22-250 - was my next door neighbour - he and I each got Lee Loaders about the same time - mine was 308 Win and his was 22-250 - he did not actually "fess up" what he did, but I think instead of using powder listed in the Lee chart, he acquired some "better to use" powder on advice of another acquaintance - but used the same scoop. In small town Saskatchewan - I am quite certain it ended up taking months and more than the rifle had first cost him - to get a gunsmith to unlock his locked up bolt, and then to re-attach that bolt handle. I do not recall him having a positive thing to say about hand loading, ever.
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Anthony Nardelli
Regular
- Location
- Newmarket, Ontario
I read an article that outlined the pressure differences between standard and magnum primers in a rifle cartridge load. The findings indicated the different primers types exhibited only a minor difference of pressure when compared with other variables, such as ambient temperatures, with the pressure impulse curves remaining approximately the same.
Magnum primers are not hotter than standard primers, they just burn longer. They are designed to be used with slower burning powders for a complete burn. However, magnum primers often have thicker cups and light primer strikes may become an issue if they are used in certain rifle configurations.
Magnum primers are not hotter than standard primers, they just burn longer. They are designed to be used with slower burning powders for a complete burn. However, magnum primers often have thicker cups and light primer strikes may become an issue if they are used in certain rifle configurations.
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Interesting, I'd not heard that before. Do you happen to remember where it was you read that? I'd be interested in reading the article.
I'm in a similar situation with starting to use magnum small rifle primers in .223
They're available, which is a factor in today's world of shortages.
If using magnum primers has hidden benefits in velocity consistency and more complete powder burn, that's a bonus.
The longer burn time of magnum primers really shows up in very cold weather.
Usually a load developed at 20-25C will not show a noticeable difference in POI when the ambient temps plunge below 0
Of course what happens at either of the extreme high/low temps is another story.
Usually a load developed at 20-25C will not show a noticeable difference in POI when the ambient temps plunge below 0
Of course what happens at either of the extreme high/low temps is another story.
