Primer differences - Does it really matter?

I've been using Federal Premium Large Rifle primers in my Rem Sendero 7mm Magnum with amazing results working through load development. I'm getting 3042fps velocity and 0.38 MOA off the bipod. The gun I believe can achieve better. It's me that's holding back a better MOA
Then I learn you can get "Magnum" primers.
Then I learn "Match" are even better
I hear that they all come off the same run anyway, just when the machine is running smoothly they put those ones aside and label them Match primers.
Should I be using Magnum? If so why? What's the difference?
If I change to Magnum and/or Match will it affect my load development/POI at all?

Why change a good thing if you say yourself its you holding back a better group?

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Originally Posted by johnino

If I change to Magnum and/or Match will it affect my load development/POI at all?

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of course it will.

The only way to find out is try it out ...

When you test your loads, test them using a rear bag AND bipod .. you're testing the load not the shooter. The more consistency you can put into your test , the better the chance that that awesome load gets its chance to shine and not be discarded ...

It is normal when you switch primers for stuff to change, load a few with Rem 9 1/2 mag primers and see what happens, if you load test on a bipod/rear bag and use a benchrest type techinque shooting, your poi will be different in the field unless you get a benchrest type opportunity, might be a good idea to adjust your finished load to your normal hold, even if the group opens up, your poi will be legit( this of course assumes this is a hunting rifle!). I don't shoot off a bipod even on a bench, sling wrap over a day bag, cause you can do that offhand, kneeling, sitting and lying and with just as much accuracy as the bipod, just harder to learn.

Yeah it's a long range hunting rifle. I'm test shooting in the position I plan to take most of my hunting shots in, and yep I'm using a rear bag. Good point 257 about the sling wrap method being easily adapted to sitting, kneeling etc. I've bought shooting sticks for more upright shots but haven't started on those yet. Most of my shooting will be long range so I hope to have the time to find a good rest.

So what loads are you working on?, my pet loads so far:
-120 TTSX at 3450
-160 Accubond at 3050
-180 Berger VLD at3050

Will likely use the TTSX and the VLD as a working pair as they shoot to the same windage, TTSX out to 350 or so, then the the VLD to take over out to 600 (ish)

I'm working with 162 grain Hornady SST's due to the Amax shortage.
My load is 72 grains ADI2217 @ 3040.
Norma brass.
Federal primers
I'm seating the projectiles 0.2mm off the lands.

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Originally Posted by johnino

I'm seating the projectiles 0.2mm off the lands.

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whats a mm ?? :ORLY::wtfsmilie:

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Originally Posted by johnino

I'm working with 162 grain Hornady SST's due to the Amax shortage.
My load is 72 grains ADI2217 @ 3040.
Norma brass.
Federal primers
I'm seating the projectiles 0.2mm off the lands.

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I have a Sendero 7mm Mag as well - shoots similar load. 162 Amax, 72.5gr 2217, Norma brass, Federal Magnum Match primers. Good for 0.5MOA consistently.

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Originally Posted by Mossie

I have a Sendero 7mm Mag as well - shoots similar load. 162 Amax, 72.5gr 2217, Norma brass, Federal Magnum Match primers. Good for 0.5MOA consistently.

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Aah I just checked my ballistics app and my powder is 72.5 grains also. Interesting. I'm hoping SST and Amax will have identical performance otherwise I'll have to go through the load development process again.

How much effect do primers really have on your load?
I'm using cci 400s in my 223 because that's the ones the shop had, is any particular primer better than others?
What if any difference do bench primers have?

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Originally Posted by johnino

Aah I just checked my ballistics app and my powder is 72.5 grains also. Interesting. I'm hoping SST and Amax will have identical performance otherwise I'll have to go through the load development process again.

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Would be interested to see how you go.
I get just over 3100 for my load, although I have 3050 as my speed on my drop charts. Works well out to 1000 yards.

Even more interesting is I know @Tui4Me had the same setup, running 72gr or 2217 and we could use each others drop charts

I'll put my progress up on this site. I've so far only confirmed my chart out to 500 yards. Looking forward to some longer distance tests

Hamsav has got it right. More powder i.e. you have a bigger calibre and you want more oomph to spark that powder so you have a primer designed for that particular job.

Hamsav has indeed got it right.

Some ball powders perform more consistently with a magnum primer even in a .308 size case, however, as already mentioned, pressures will rise. Match primers are supposedly made to tighter tolerances. I did find them marginally more accurate in the 6mm PPC I once owned, but that was just that rifle. Haven't noticed any difference when used in hunting rifles.