Large rifle primers vs. magnum primers?

[TNSleeper99]

AM PRS shooter and reloader here. So far I have developed loads I am happy with but have only used FGGM primers (small and large). I have seen large rifle magnum primers in stock a few places local to me. Can I use large rifle magnum primers as a substitute? What can I expect? I would expect to drop down on powder charge and work back up to my current velocity?

 

[Winny94]

They say drop down and redevelop. I've never noticed a difference in velocity, but I don't run near max either. I will say group size was 2x as large when I shot magnums in my regular load, so be prepared to essentially start from scratch.

Below photos were shot running a pressure test . Big group is fed 215m, small gryis fed 210m

 

[vinniedelpino]

If for long range stuff I'd hold out. When I played with this, velocity was all over the place.

Let us know how it goes.

 

[rockchalk06]

I tried the same using 210M v's 215M. I couldn't get a stable group over different days using the 215M's. Not like I could with 210M's. I just used the 215M's for my plinking 308 stuff out of the M1A and looked harder for 210M's.

That is just a small sample size though. I have no idea of CCI or others will act the same.

 

[TNSleeper99]

So far, it seems like a waste of powder and time......

 

[XLR308]

Like many others all I use is small rifle magnum primers for everything from 223 to 308win.
For large primer applications I have BR2, 200, 210M and 215M and wouldn't hesitate to work up a new load with any of them.
As was allready said you are pretty much starting over if jumping to a LRM primer to find the node unless you just luck out.

 

[PinesAndProjectiles]

I find it rather interesting how so many guys run Magnum SRPs in their rifles, but it's almost unheard of to run Magnum LRPs.

Edit:. I'm talking about precision rifle shooting/prs events and have no experience in ELR type shooting or benchrest.

I'm curious to see how this plays out if you do choose to run them.

 

[junkyard.brody]

I actually did a test with my 140 ELD Match load over H4350 out of my 6.5 creedmoor with fed 210’s, cci 200, cci 250 and BR2’s. All produced a little different results. Group sizes were a little smaller with some. BR4’s ended up working the best for me. I can upload a picture of the target later. If you do end up switching I wouldn’t worry about it, just rework your load up and you should be good to go. Before the test I used CCI 250’s only with good results.

 

[TNSleeper99]

Right now I’m getting .2-.25 MOA results out of my 6mm CM, but like I said I’m on a limited supply of 210M primers and I seem to be able to find magnum primers more often. I’m trying to prepare for a few years of shortages. Just in case.

 

[AMG04]

You can never have too many components. Buy whats available, it will be consumed eventually.

I'd rather have and not need, than need and not have.

 

[Mr Tibbs]

The LRM primers are designed to have hotter and longer burning flames, to ignite large amounts of slow burning powers like IMR-7977, or IMR-8133 just to name a couple, in cases like 7MM Rem Mag or 300 Win Mag, just to name a couple .They are also used When hunting in very cold conditions, when slow burning powders are even harder to ignite.

 

[MLS2GO]

I am a Noob to reloading for precision rifle and getting started at this time is not a good time. I will be reloading in 6.5 CM and I lucked into a good supply of CCI Magnum Small Rifle Primers. That is what I will be working up my loads with. I have 2 powders, 4350 and 6.5 Stabal. I plan on working up to loads with both. In your guys experience will the 4350 be better than the Stabal with the magnum primers? The Stabal being a ball powder seems like it may be suboptimal with magnum primers which appear to be favored for stick powder. Anyone tried this combo?

 

[supercorndogs]

CCI450s

Virgin brass and once fired, same load. 6 Creed Starline brass 105 Hornady HPBT h4350, 21" barrel. The slower one was the virgin and also a new barrel.

 

[308pirate]

CCI450s

Virgin brass and once fired, same load. 6 Creed Starline brass 105 Hornady HPBT h4350, 21" barrel. The slower one was the virgin and also a new barrel.

What was accuracy like? That's what really matters

 

[264Proto]

The assumption that a lot of people seem to make is that they can simply swap in/out one primer for another into an existing/tested combination and then judge that magum/non magnum primers are good/suck based on that one action alone.

Folks need to work up a load all over again.

You may find that specific primers dont work well with a specific powder....but that doesnt mean that the primer sucks or results in less accurate ammunition because of the primer.....its a combination of different variables that typically stacks up to produce a poor/sub optimal combination

Personally, I find that 4831sc with a magnum primer in 6.5 creed is a very accurate combination IN MY RIFLE

In my experience #34's and CCI LRM's are interchangeable wrt accuracy (both are magnums)

4831 is a slower burning powder than 4350 (and most others for that matter) that are commonly used in 6.5 loads.

Its extremely insensitive to temperature being one of hodgdons "extreme" powders and I see almost no variation whether its below freezing temps are a warm sunny day.

YMMV

 

[DeathBeforeDismount]

Well considering the BR primers are just higher QC/QA magnum primers, there is zero reason to use anything but mag primers.

The thicker cups will resit piereced primers and help contain pressure better.