lg. magnum rifle primer or lg. rifle primer


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hvychev77
September 18, 2011, 06:30 PM
so, i shot my first reloads out of my 300 win mag today with very satisfactory results. I've never shot groups that tight with factory ammo. My recipe is, 69g of IMR7828 under a Nosler Partition 180g, with a Winchester Lg. magnum rifle primer. My rifle is a Remington 700 SPS Buckmasters edition chambered in 300 win mag. My question is, my loading manual ( Modern Reloading by Richard Lee ) doesn't state whether the recipe calls for a magnum primer or regular primer. My Lyman manual states they used a non-magnum rifle primer. What's the difference? is it risky what i've loaded and shot? I saw no signs of high pressures, however, this was the lowest powder charge in the Lyman manual. So, i didn't go any higher yet. Advice? suggestions? Thanks in advance, hvychev77

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rcmodel
September 18, 2011, 07:04 PM
Hodgdon, who sells IMR-7828, used Win Std LR primers in all it's loads.
They show 73.0 as a Starting load.
And 78.5 Compressed as MAX.

But that is with a 180 grain Speer Mag-Tip soft point.

I might up your load to at least the recommended Hodgdon starting load.
Reducing below that is bad juju in Magnum calibers.

Your 69.0 grain load is probably giving you about low end 30-06 velociyu, if that.

In the end, it doesn't matter which primer you use, as long as you don't change in mid-stream during load development.

rc

hvychev77
September 18, 2011, 07:20 PM
my Lyman book states that for a jacketed HPBT, 180 grain, the starting load for IMR7828 is 69.0 grains. Is there a big difference between what type of bullet you're using as long as it's in the same weight? thanks again...

ojibweindian
September 18, 2011, 07:26 PM
Yes, there is a difference.

hvychev77
September 18, 2011, 07:31 PM
would someone please explain it to me?

rcmodel
September 18, 2011, 08:52 PM
Your Nosler Partition has a solid copper partition in the middle of it, with soft lead & thin jacket on both ends of the bullet.
Link from Nosler website:
http://www.nosler.com/Images/BulletPics/partitionsplit.jpg

The Speer bullet, or any other conventional jacketed bullet doesn't.

That makes them softer and easier to push through the rifling at the moment of the "engrave the bullet to fit the rifling" as the bullet leaves the case.

They also probably have a different ogive shape them other some bullets, which changes how much full-diameter bearing surface is rubbing on the rifling.
In other words, bore friction changes with bullet shape.

rc

hvychev77
September 18, 2011, 09:55 PM
thanks for explaining that to me. i guess i'll have to go ahead and load some more up and head back to the range this week. i do have some already loaded up that are 74.5 grains of IMR7828 that I did not shoot today. It shot such good groups with the other recipe i didn't even touch 'em!! thanks for sharing the info rcmodel................hvychev77

Grumulkin
September 18, 2011, 10:11 PM
I'm always more concerned with how accurately a load shoots as opposed to how fast the bullets are going. If your load is giving you satisfactory accuracy, don't worry, be happy.

I've always used magnum primers in my 300 Win. Mag. but if large rifle primers are working for you, there is no harm in using them. On the other hand, in my 7mm Rem. Mag. I use standard primers.

For solid copper and for copper jacketed bullets, I've never had a problem in mixing and matching starting loads with bullets of the same weight. The maximum load may be different with different bullets though I haven't found that to be the case very often. What you can expect, is for different bullets of the same weight to hit in different places with the same load unless you get lucky.

JTJones
September 18, 2011, 10:12 PM
I have the Nosler reloading guide 6. The starting load is 73.0 grains of IMR 7828 @ 2878 fps and the max is 77.0 grains. That with the 180 gr partition .

hvychev77
September 18, 2011, 10:36 PM
thanks for the help mr. jones. I need to get the manual for each bullet i'm using. the last thing i wanna do is damage myself or my weapon. i'll just have to work 'em up slowly. sounds like i'm good to shoot the rounds that are charged with 74.5 grains though......

ArchAngelCD
September 19, 2011, 12:44 AM
is it risky what i've loaded and shot?
A lot of people worry about magnum primers blowing up their guns, well they won't. Magnum primers will burn slightly longer and slightly hotter than standard primers. They are normally needed to insure proper ignition in very cold weather and for cases that are loaded with 70gr of powder or more. I think you would be best served with a Magnum primer for your 300 Win Mag ammo. The increase in pressure is minimal and not a worry unless you are right up against the pressure limits already and then switch to a magnum primer. (just as a safety measure since you should not change components without working up the load again)

critter
September 19, 2011, 07:11 AM
Let the accuracy of the load be your guide as to load development and whether or not you use mag primers.

I have a Win M70 in .300 mag and use IMR 4350. In MY GUN, standard primers worked just fine. Then, I tried my same loads using mag primers. Waalah! The groups tightened up considerably from 'pretty good' to 'really good'! Guess they burned the slow powder more consistently or some such. SO-guess which I now use!

Galil5.56
September 19, 2011, 08:43 AM
A thicker primer cup can be a benefit of certain mag primers in certain situations. I also find my .243 Win is always significantly more accurate using CCI 250s and Fed 215s and ball propellant. I also use them in other non magnum caliber applications, especially when ball propellant is used/ball propellant and cold weather hunting.

GooseGestapo
September 19, 2011, 09:03 AM
To take the discussion a little further;
The type powder you're using, the climate you're using the rifle in, and specfic bullet weight, powder, climate combination can dictate primer needs.

The CCI #250 primer (magnum) is, in my experience, about the same as the Federal #210 (non-magnum primer). The Federal magnum primer and Winchester Magnum primer are very close in performance, as are the Winchester LRP and Federal #210.

My personal guide lines are this:
Small cases (.308wcf and smaller); Extruded and spherical powders- Standard
Larger cases (.30/06, ect) extruded powders, standard
spherical powders- BLC2 and faster, standard, H414 and slower-magnum
Magnum cases; .257wby and smaller-extruded powders IMR4350 and faster-standard LR,
All others (ie:larger) magnums; Magnum primers......
Any of the above combinations used with slow powders/light weight bullets may benifit from a hotter primer.

If used where weather conditions dictate temp's below 30degF, use of a Magnum primer may be advisable. IE: I'm loading a .338Marlin Exp. with LVR powder. I tried some rd's with Win LR and Fed #215 primers. At 90+deg temps, there was no observable difference in velocities, or accuracy.

I placed the rifle in a case, and ammo in my freezer over night. Shot them through my Chron'o on the back yard range. The velocities of the #215's were 30-55fps faster than the Win LR primer. The #215's were only 20-30fps below 90deg temp velocities.
This is only "anecdotal" data, but it tells me which direction to go on MY ammo.
btw -Freezer temp was about 10degF.

hancjamk
September 19, 2011, 09:09 AM
For me and my 300 Win mag , I have found two extremely accelerate loads. My first load I use H4831SC with 215M primers 168 SMK. The second and a little bit milder is a IMR 4895 with standard CCI BR-2 155SMK. My rule of thumb is it’s a slow burning powder use mag primers.

gamestalker
September 19, 2011, 05:46 PM
I had a rather bad experience with standard primers in my 7mm RM loads. I use RL22 and a lot of it. Some time back there was that shortage of components so I thought I would try a standard primer with my RL22. What I got was low velocity, low pressures, and unburned and still burning particles blowing back in my face.
A second experience with this was with 296 in my .357 magnum loads and a standard small pistol primer with simular results.
In both of the above experiences I was using CCI primers. I later learned that a Winchester small pistol primer was sufficient to completely light the 296, but never ventured beyond that point with my magnum rifle application by experimenting with Win. LRP.

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