Using magnum primers instead of large rifle?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by budlight, Nov 25, 2004.

  1. budlight

    budlight Well-Known Member

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    I sighted my new 4X12 56 mm scope today and I wanted to go varminting. I was low on 100 grain bullets for my standard .270 winchester. So i just grabbed a bag of my previously resized/cleaned/primed brass.

    I loaded up about 100 rounds of 100 grain with IMR 4320 52 grains. Without thinking [​IMG] I realized that they were all CCI 250 mag primers. The load is under max with large rifle primers that i tested before by @3 grains.

    I've heard that mag primers is like adding a couple of grains of powder. What's your opinion before I shoot one?
     
  2. James Jones

    James Jones Well-Known Member

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    I once used some mag primers instead of larger rifle because just wanted to see what would happen , only thing I saw was inconsistant accuracy. I was told that the primer going off might be moving the bullet out of the case a bit before the powder goes off
     

  3. wapiti13

    wapiti13 Well-Known Member

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    Primers are a very critical facctor in your accuracy formula, especially if you are pushing the envelope. Using a fat type case, such as the 300 WSM, 284, etc., I have been doing a primer experiment for my own knowledge based on some recommendations from Ram Shot & CCI. In several instances, just a change of primer has really had some eye opening effects. For instance, using both H414 & Ram Shot Hunter in max loads with a 284, velocity,standard deviation, and pressure have been changed to a verifyable basis. Some primers are hotter than others, not just magnum vs standard primers. For example, using a max load of H414 with a WLR primer as the starting point, everything was left the same with only a change of primer. Going to a Fed 210M, velocity increased 70 fps with a drop in pressure, and much better Sd. This was verified with several additional loads run over my Oehler chrono. In another instance, Ram Shot suggests using a standard primer in most loads under a 60 grain or so load. Approaching larger loads, experimentation is suggested. Their powders are designed to burn slower for consistency. Using too hot a primer can cause the powder to light off too fast and not do its best. Using Hunter powder in a max load in the same rifle with a different bullet, after max pressure was reached and then backed off 1 grain using a CCI magnum primer. A WLR primer,Fed 210, Fed 210M, & Fed 215 were changed with everything remaining the same. Again, pressure sign changed, velocities changed, and Sd changed. In fact, as suggested by Ram Shot, velocities were much higher (over 100 fps)by using std primers vs magnum primers. Same has held true with H4350 and several other powders in similar burning rates. Just a reference for your future load developments. Good luck. [​IMG]
     
  4. Brent

    Brent Well-Known Member

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    Get some more brass and work up the load, or break a few down and reload them progressively lighter. Check for excessive pressure signs as you work up to the ones you have all loaded up at 100 grains. That is probably the most sane suggestion. The second most sane suggestion, okay, maybe the third or fourth, but clean your barrel well so pressure starts a little lower at first, then fire a few over a good reliable chronograph and compare MV and pressure signs to the load with a standard 200 primer.

    I would guess that you'll be fine, but if you notice excessive pressure signs early on... well, stop.

    I've seen pressure go higher using mag primers, but I've seen it lower just as many times too, and very often I've seen it simply remain the same... this while testing with the Oehler M43 and PressureTrace.

    Anytime one changes components he should start low and work up. I know, probably just preachin to the quire...

    I force myself to check, double check, then triple check components etc, and only one can of powder, primer and bullet is ever down on my bench at a time.

    Here's hopin you don't have to pull bullets. Then, will that load even shoot with the primer change?
     
  5. budlight

    budlight Well-Known Member

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    If it's not raining today I'm going out testing. I've pulled bullets before and have one of the nice knockers that makes it easy.

    As I stated above I've shot as high as 55 grains of 4320 in that gun with 100 grain moly coated bullets. Which these are using CCi #200 large rifle primer. That is the upper limit with very flat primers and short case life.

    This is 52 grains of 4320 and CCI 250 primers
     
  6. Brent

    Brent Well-Known Member

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    Oooops! Had 300 Ultra capacity on the brain when I typed 100 grains!

    I would expect you will still fall short of the 55gr loads performance with the 200's, assuming throat and bore condition, OAL, neck tension, brass lot #, powder lot #, barrel and ammo temperature are consistant... just my best guess though.

    [ 11-27-2004: Message edited by: Brent Moffitt ]
     
  7. cowpatties

    cowpatties Member

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    You'll be fine! Did the same thing when I ran out of regular large rifle primers......
     
  8. cinch

    cinch Well-Known Member

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    I use CCI 250 primers in everything large rifle that I load for. 22-250 on up. I have never had any pressure issues or accuracy problems. Ya, it is not needed for everything, but I wanted to buy one primer for everything to keep it simple.
     
  9. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Interesting... I am using Fed GM215M with H4350 in my 300 WSM. I'll have to do some experimenting with the 210's
     
  10. TOM H

    TOM H Well-Known Member

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    In my 270WSM same load I used 9.5,9.5m,WLRM,WLR,215,215m,CCI-200,210 there was 11fps spread on that load 58gr/IMR4350 150gr bullets. In my 300WSM I use either Fed 215,210 and in my 6.5x284 I haven't had a problem switching primers.

    I've done the same thing in my varmit rifles with Fed 205 and Rem 7 1/2.
     
  11. dbhostler

    dbhostler Well-Known Member

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    Primers are just another variable in the formula. Others are powder burn rate, barrel length, case capacity, bullet weight, neck tension, twist and on and on. You just have to find what works best. For example, in a 300 RUM, I use F 210s when ignighting RL 25. Then with my 244 Ak, I use Rem 9 1/2s with I 4350. Should be the other way around, but it's not. Bottom line is, a mag primer is not always needed.
    db
     
  12. Chalky47

    Chalky47 Member

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    After reading this thread I am more confused about which primer to use than when I started. I am just starting out reloading and have bought some LR Magnum primers from Federal. I recently have purchased a .280 A.I. and already had a .300 win mag that I am still waiting on brass for to begin reloading for that. What is the best method to figure out what to use so you don’t end up with a bunch of primers that will not be used. Thanks for the information and look forward to reading the response.
     
  13. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    The 215 is a great primer. I've got thousands loaded. The others are correct that a mag. primer isn't always need but it can usually be used to good effect if you start with it right away or re-work an existing load to accomodate it. Do NOT simply swap and hope. I shoot in cold weather often and usually use more primer than necessary to ensure good fire in below zero temps.
     
  14. Catfur

    Catfur Well-Known Member

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    From the grave, it arises, not once, but TWICE.

    Behold, the undefeatable Zombie thread...