reduced powder charge with mag primers

[Hounddog]

Went to LGS the other day and was suprised to see that they had a bunch of primers in stock. Only problem was that the regular SPP's and LPP's were 10 bucks more per K than the magnum primers. Well being the cheap b@$tard that I am i picked up a brick of SPP magnum primers.

My question is how much to drop my powder charges when using these magnum primers in non magnum loads? I always load between printed ranges and never push over max loads. Is there a standard percentage drop or something else. Just wanting to be safe. I value my eyes and hands more than I do trying to hot rod my loads.

Thanks

Hounddog

[countryroads]

Went to LGS the other day and was suprised to see that they had a bunch of primers in stock. Only problem was that the regular SPP's and LPP's were 10 bucks more per K than the magnum primers. Well being the cheap b@$tard that I am i picked up a brick of SPP magnum primers.

My question is how much to drop my powder charges when using these magnum primers in non magnum loads? I always load between printed ranges and never push over max loads. Is there a standard percentage drop or something else. Just wanting to be safe. I value my eyes and hands more than I do trying to hot rod my loads.

Thanks

Hounddog

I have been reloading for a looooong time, and I have never had a problem with using regular and magnum primers interchangably. You hit the nail on the head when you said that you always stay in the middle ranges. Even if you were to move toward the higher end of the range, you would be okay as long as you keep an eye on any evidence of pressures that might be getting a little too high, e.g., case bulges, primer flattening or perforation, etc.

Stay cheap, my friend!

[Recluse]

Went to LGS the other day and was suprised to see that they had a bunch of primers in stock. Only problem was that the regular SPP's and LPP's were 10 bucks more per K than the magnum primers. Well being the cheap b@$tard that I am i picked up a brick of SPP magnum primers.

My question is how much to drop my powder charges when using these magnum primers in non magnum loads? I always load between printed ranges and never push over max loads. Is there a standard percentage drop or something else. Just wanting to be safe. I value my eyes and hands more than I do trying to hot rod my loads.

Thanks

Hounddog

Or, look at this way:


I just saved myself $10 whole dollars for one-thousand primers in order to shoot my $500 handgun more, but I'm not sure how I need to "adjust" the loads in order to be safe and keep my body parts and eyes all in original issue condition.

When you break down the cost of what that extra ten bucks might have cost you versus the comfort and confidence that comes with having known and proven load data for those standard primers. . . and now have to ask how to "adjust" your loads in order to not blow up a $500 (or more) gun, not to mention possibly injure yourself or someone else. . . . how good is that ten-dollar savings looking right now?

:coffee:

[Hounddog]

Thanks for the replies. @Recluse i appreciate the point you are trying to make and understand that it is somewhat dangerous what I am asking, however I am very meticulous when it comes to reloading. I have 6 or 7 reloading books that I refrence and always research every little detail before trying it. I know I have a low post count, but I spend more time lurking on this board and only contribute from my limited experience. I always check each and every boolit I load and work up every load within published specs. I load for precision not volume. Like I said before, I am not looking to get extra juice out of my loads. I fully realize my limitations as a novice reloader. I have plenty of standard primers on hand, but was more curious as in a SHTF situation. If I feel like using these primers will do me harm then I will just trade them off to someone else.

Don't mean to get all defensive, just didn't want you to think I was hell bent on blowing my self up. I was wanting to get some input as I'm sure many on here have been in a pinch and swapped magnum primers in their loads but just backed down the charge a bit.

Thanks again

Hounddog

[Recluse]

Oh, no worries with me. :) I just point out that one of the most common traps of years worth of reloading is that if left unchecked, we can become penny-wise and pound-foolish.

Been PLENTY guilty of it myself, so it's not exactly like I'm scolding or lecturing from the padre's side of the confessional booth. :)

SO. . . now that you've wrangled a confession out of me, I confess to starting my magnum primer loads for CCI magnum primers with a reduction of between 10 & 15 percent for small magnum primers, and 15 to 20 percent for large magnum primer loads.

With Winchester magnum pistol primers, I rarely even vary to load because I never load to max and I've found the Winchester magnums to not be any hotter than their normal primers. A ballistician with Accurate powders once told me that Winchester's magnum primers had an extended flash time so as to ensure powder ignition, where as CCI had an increased "explosive" flash so as to ensure powder ignition.

I rarely use Federal primers (shame, every time I have I've liked them) and I hate Remington primers. Likewise, I've never used the Russian magnum primers, so I have no load data to go buy.

But, if you'd like to toss out a few calibers along with boolit configuration and powder, I'll be happy to open up the shop and grab my notes and share some data that has worked well for me as well as for which makes and models of firearms.

Regards,

:coffee:

[Hounddog]

Thanks Recluse, I had figured about a 10% reduction would be in order but wanted to check on here first. The box of primers I picked up were winchester SPP magnums. I've used a bunch of winchesters in the past and have always had good luck with them. Like I posted earlier, I have plenty of regular SPP's but with the current ammo and component situation I'm always looking to bolster what I already have on hand when the opportunity arises. I always try to pick up a brick or two whenever I can. Most retailers around here have been out of everything for many months so I guess i got caught in the moment but couldn't bring myself to pay more for the regular ones.

I shoot mostly lee 175-tc's out of my M&P 40 and Lee 125-tc's out of my wife's G26 sub Glock with a lone wolf BBL. I prefer to load up with medium powders like unique, wsf, hs-6, aa7, bluedot, 800x, power pistol, and longshot.

Hounddog

[dale2242]

$10 per 1k=$.01 per shot more.
Adding $.01 per shot to the cost of shooting is not what any of us want, but not the end of the world either.
We told ourselves that we started reloading to save money. Didn`t happen.
Most of us have spend a LOT more as reloaders/casters than we would if we shot factory ammo.
Why. Because it`s a lot of fun and we shoot a LOT more.
I`m not made of money but I would be willing to spend $.01 per shot more to keep my loads consistent....dale

[Larry Gibson]

Back to the question;

There is not set "amount" to reduce the load. How much depends on the load used to begin with. For years before I could pressure test I simply dropped back 10% when using magnum primers and worked back up to the same velocity (judicious use of a chronograph is necessary with 10 shot test strings for validity) the load with standard primers had. Having now pressure tested some such loads I found the psi was within test string variation between the two. I can't recall using more than 50 test shots to develop the loads with magnum primers in pistol cartridges.

As with others I always recommend using the same components in a developed load but if done correctly by proper testing the conversion from standard to magnum primer can be done safely.....it's just the same as working up any other load.

Larry Gibson

[Harter66]

Save em' for the mags and monster cases w/slow powders that call for the mag primers, like Colts w/H110.

Now that I've been a smarty pants. I mistakenly picked up LPPMs last time around I intend to use them up in the low end/reduced rifle loads. Beyond that I would echo Recluse and Larry's advice. They might be handy if you explore real BP in typically cowboy cartridges.

[Case Stuffer]

Does anyone else have a copy of Speer Manual Number 8 if so see page 29 , Magnum primers.

The use of magnum primers is recomended when
(1) in any cartridge in very cold weather ; (2) When using ball or spherical powder............................

if the data does not indicate that the data was developed using magnum primers ,reduce the top load 5% and work up again.( This applies to any change in components , not just magnum primers.)


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Some of us have been reloading long enough to realize that components manufactured 40 years ago and today not not exactly always the same anyway.change from one can,drum.lot of powder to another, can from one lot of primers to another,a different brand, different bullet weight,style, batch of casting alloy, sized diamete, depth of bullet in the case,amount o crimp, change firearms which throws in another group of variables and what was only failrly warm in one firearm becomes way to hot.

One should ask themself if they are loading for a specific firearm and what will this batch of ammo really be used for and in what temperature extrems and just how important is it that every rounds cycles as nea perfectly as possible?

I have ammo I loaded over 30 plus years ago is labeled with all of the load data and chrono data for the indivual firearms it was loaded for and fired in.

I would not be at all surprised that if I purchased a current batch of same powder,primers, used the same lot of brass ,;opaded as identical as possible and fired in same firearms at same temperatures and elevation that results would be different.

[Muddydogs]

All I load is CCI mag primers in everything, just work up your load and you will be fine. I have yet to find a load that didn't work up to book max with mag primers. Back in the day mag primers were said to equal an extra grain in powder charge, not sure if its true today still. In your middle of the road loads you will probably not notice any differance.

[fredj338]

Mag primer affects on pressures depends on the powder & load used. With low to midrange, faster powders, it has little affect. The closer you load at the top end, everything matters. Slower powders seem to be affected more than faster powders. I find a 5% reduction & then work it back up w/ a chronograph works for me. All things being equal, vel=pressures. So back of 5%, add the mag primer & shoot it. When you get back to the same vel as the std primer, you are at the approx pressure level as well.

[prs]

Long ago, I recall an article written about shot shell primers and I thing the information may have been supplied by CCI. THe jist of it was that some Mag primers had a higher explosive character I think they used the term "briescence" and others had the same briescence as standard primers plus an added component similar to finely ground glass that spread the heat onto the powder particles throughout the load. Its been a long time. Not sure it caries over to metallic cartridge primers. My Winchester pistol primers says they are for both mag and standard loads.

prs

[Hounddog]

Thanks for all the replies. I will definitely save these mag primers for later but will make a mental note to back off the charge just a little.

Hounddog

[w0fms]

Wow.. I'd gladly pay $10/box more for SPP's.. especially CCI's. I screwed up and (almost) ran out of SPP's and they were one of the first things to disappear in this rush. I've been using Win SRP's in my pistol loads and have been okay so far.. but I'd agree I'd do it right if I could. I've only been shooting "light" target .38's with them, tho. The comment that the Win SPP's vs SPP-Mags probably is why I've been fine with SRPs.. that and it's light loads... And for Win pistol primers.. that is true with the LARGE pistol primers (for standard and magnum loads) but not so on the SPP's...