WTK: Are magnum primers necessary for 300WM
- Thread starter colt933
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Re: WTK: Are magnum primers necessary for 300WM
The round was developed with a magnum primer. If you shoot a faster burning powder (IMR 4350, etc), you can get away with a standard primer. A standard primer and slower burning powders can cause hang fines.
The round was developed with a magnum primer. If you shoot a faster burning powder (IMR 4350, etc), you can get away with a standard primer. A standard primer and slower burning powders can cause hang fines.
Re: WTK: Are magnum primers necessary for 300WM
Why risk it? Magnum primers have a thicker cup, and are able to handle the higher pressures of magnum cartridges.
Why risk it? Magnum primers have a thicker cup, and are able to handle the higher pressures of magnum cartridges.
Re: WTK: Are magnum primers necessary for 300WM
When I load for my 300 WinMag I ALWAYS use magnum primers. For larger powder collumns the more fire from the magnum primer helps get it off to a quicker start of burning. Some powders in a different geometry may have different burn characteristics. But I'm sticking with what I know.
When I load for my 300 WinMag I ALWAYS use magnum primers. For larger powder collumns the more fire from the magnum primer helps get it off to a quicker start of burning. Some powders in a different geometry may have different burn characteristics. But I'm sticking with what I know.
Re: WTK: Are magnum primers necessary for 300WM
If you read the Lyman reloading manual 48th edition, under the 300 WM data, it says "Our data was developed using the standard Winchester primer and the use of a magnum primer will cause a pressure incerease..." I thought that was interesting. Have I used regular primers? Yes I have with RL22 (Winchester large rifle primers--non magnum). Never had any problem with it. However, I am using exclusively Fed 215M now. It's just because my groupings are awesome with Fed 215M. Hope that helps.
If you read the Lyman reloading manual 48th edition, under the 300 WM data, it says "Our data was developed using the standard Winchester primer and the use of a magnum primer will cause a pressure incerease..." I thought that was interesting. Have I used regular primers? Yes I have with RL22 (Winchester large rifle primers--non magnum). Never had any problem with it. However, I am using exclusively Fed 215M now. It's just because my groupings are awesome with Fed 215M. Hope that helps.
Re: WTK: Are magnum primers necessary for 300WM
I've shot my .300 Win Mag using regular Large Rifle CCI primers before. Yes it works. However, my groups did tighten up with Magnum primers.
I've shot my .300 Win Mag using regular Large Rifle CCI primers before. Yes it works. However, my groups did tighten up with Magnum primers.
Re: WTK: Are magnum primers necessary for 300WM
My rule of thumb has always been:
More than 65 grains of powder: Use Magnum Primer
Less than 65 grains of Powder: Use Standard Primer
This rule has been working for me since 1973. YMMV....
The broader question is: Can you use regular LR primers in Magnum type cases? Sure you can, but what you risk are any combination of: hangfires, incomplete ignition, unburnt powder, large SD's, and reduced accuracy, in large cases.
Bob
My rule of thumb has always been:
More than 65 grains of powder: Use Magnum Primer
Less than 65 grains of Powder: Use Standard Primer
This rule has been working for me since 1973. YMMV....
The broader question is: Can you use regular LR primers in Magnum type cases? Sure you can, but what you risk are any combination of: hangfires, incomplete ignition, unburnt powder, large SD's, and reduced accuracy, in large cases.
Bob
Re: WTK: Are magnum primers necessary for 300WM
Been running mine exclusively with Remington Large Rifle Primers (9 1/2) since day one. Slow burning powder too, 69-72gr H4831, sea level at 90F. NO excessive pressure signs, 26" barrel yadda yadda. ymmv, not all barrels are equal, standard procedure of working loads up applies.
Been running mine exclusively with Remington Large Rifle Primers (9 1/2) since day one. Slow burning powder too, 69-72gr H4831, sea level at 90F. NO excessive pressure signs, 26" barrel yadda yadda. ymmv, not all barrels are equal, standard procedure of working loads up applies.
Re: WTK: Are magnum primers necessary for 300WM
Powder Burns,
Questions:
Since day 1, i.e. since 1963, introduction of the 300 Win Mag, or some other date, or some other cartridge??
Excessive pressures is not a sign of using too cool a primer, and H4831 is relatively easy to ignite @ 90F, not so @ 30F and below. What are your SD's?
If you've never tried any other primer than the Rem 9 1/2, how would you know if a magnum primer: improves accuracy & velocity, worsens accuracy or velocity, or everything stays the same?
I've never said you cannot use a standard primer, I've only said that when I tested that hypothesis, a magnum primer delivers more consistent results. If you never tested it, then a data point of one, is no mean measure.
However, if your happy with your results, then your happy.
Bob
Powder Burns,
Questions:
Since day 1, i.e. since 1963, introduction of the 300 Win Mag, or some other date, or some other cartridge??
Excessive pressures is not a sign of using too cool a primer, and H4831 is relatively easy to ignite @ 90F, not so @ 30F and below. What are your SD's?
If you've never tried any other primer than the Rem 9 1/2, how would you know if a magnum primer: improves accuracy & velocity, worsens accuracy or velocity, or everything stays the same?
I've never said you cannot use a standard primer, I've only said that when I tested that hypothesis, a magnum primer delivers more consistent results. If you never tested it, then a data point of one, is no mean measure.
However, if your happy with your results, then your happy.
Bob
Re: WTK: Are magnum primers necessary for 300WM
If I ever run out of these Rem primers I would like to try the 215M's which always seem to be unobtanium around here. If possible I will run some of my loads through a chrono this weekend and come back with SD numbers. You do raise some valid points, I've got some more testing to do.
If I ever run out of these Rem primers I would like to try the 215M's which always seem to be unobtanium around here. If possible I will run some of my loads through a chrono this weekend and come back with SD numbers. You do raise some valid points, I've got some more testing to do.
Re: WTK: Are magnum primers necessary for 300WM
The reason I ask is that I do not have any magnum large rifle primers on hand but I do have all other components necessary to start loading 300WM. It's about an hour drive each way to the reloading shop.
But it looks like I will be making that drive!
The reason I ask is that I do not have any magnum large rifle primers on hand but I do have all other components necessary to start loading 300WM. It's about an hour drive each way to the reloading shop.
But it looks like I will be making that drive!
