Primer for 270 WSM - Magnum or LR?

[David_S]

Is it necessary to use a magnum rifle primer (eg Winchester WLRM) for the 270 WSM or will standard Large Rifle primers such as the Winchester WLR be adequate? What are the advantages, if any of the magnum primers for this calibre which is not much bigger than the standard 270?

I have just loaded 30 test rounds with my usual WLR primers before the thought occurred to me

Thanks

David

[dunerjeff]

Magnum primers are prefered for the 270WSM because of the type of powder used in it and the amount used.I think standards will work, but ignition of the whole powder column might be incosistant and pressures may vary.

[black mamba]

Cold weather is a big factor. If you're only shooting in 50° or higher temps then the standard could be OK, but for colder days afield you'll get more consistent velocities with the magnums.

Also, don't work up to max loads with the standards and then switch to magnum primers without dropping a couple of grains of powder. The hotter primers raise pressures.

[Sevens]

Don't confuse the need for a "magnum" primer because the name of the cartridge has "magnum" in it. The term magnum in a cartridge name is 100% marketing. It could be called the .270 WhipperSnapper if they thought that name would generate sales, but last I checked, CCI still doesn't offer any large rifle whippersnapper primers! (but it's been a week since I looked! )

Magnum primers in any handload are a result of the load data calling for a magnum primer and it's typically called for due to a certain type or kind of powder that greatly benefits from it's use.

What are the advantages, if any of the magnum primers for this calibre which is not much bigger than the standard 270?

Better to ask might be, "what are the disadvantages to using a magnum primer when the data doesn't call for one?"

In my opinion, the first disadvantage is having to stock yet another primer. No big hassle for some... I already keep four sizes, I'd rather not move to keeping 5...6...7... or 8 different kinds of primers. (but never say never... as a Handloader, there aren't many limits to what I won't try to get what I want!)

Another disadvantage to using magnum primers in loads that don't call or don't benefit from them is that in some loads, a magnum primer may be found to be upsetting the bullet before the gas created by powder combustion can properly do that work. If/when this happens, throw what you think you know out the window. Not having a lab, equipment, funding and the brains to figure this out, I have no proof nor evidence of this.

Another disadvantage might be erratic performance and/or wild fluctuations in ES of the loaded rounds.

Another disadvantage might be that you don't find the ultimate sweet spot with your combination of rifle and handloads because you completely looked over non-magnum primers when you thought your load required magnum primers.

Check your published load data and see what primer they used. You don't HAVE to use the same primer, but it's one clue on how you might try to replicate what they did in their testing.

[tom280AI]

I load what the reloading manual uses. No point no point in trying to reinvent the wheel. I use Nolser data for my 270WSM and they use WLRM primers.

[David_S]

Thanks Dunerjeff and Black Mamba ( and other posters who posted whilst I was writing this).

These are my first test loads for the rifle which I have'nt fired yet. Looks as if I might have to bite the bullet, pull them and start afresh with magnum primers. It can get a mite chilly in the mountains around here both in summer and winter.

Getting started with reloading for the WSM has not been plain sailing compared to my normal 7x57 and 6.5x55.

First I discovered that neck sizing is not normal - Lee don't even make a collet die for it, then I found the holes in my bullet holder were too small and I had to go to the shed and drill out another piece of 4"x2", then the case was too wide for my autoprime which had to be ground down a smidgeon, then I found my powder funnel wouldn't fit so I had to go back to the shed to make an insert adapter, and of course none of my cartridge boxes were big enough so I had to buy another one, and now I find LR primers are not recommended. That's reloading I suppose. I sure hope it's all worth it and the rifle shoots well.

David

[dunerjeff]

It is a realy good caliber,worth it once things are running.I liked it because of the short bolt,being used to .243 and 22-250 varminting I'd go deer hunting with the old .280 and have a habit of jamming it because I wouldn't pull the bolt back far enough.Plus an elk I got with the 270WSM using Barnes tripple shocks,shot it mostly head on through one shoulder blade(the thickest part)took out four ribs,a lung ,liver,stomach,+more,found the bullet about 6inches from coming out the other end inbetween the hind quarters.Plenty of power.

[David_S]

Don't confuse the need for a "magnum" primer because the name of the cartridge has "magnum" in it.

Good point

In my opinion, the first disadvantage is having to stock yet another primer

I totally agree

Check your published load data and see what primer they used

I did, but ADI Handloaders Guide (which I use as ADI powders are the most readily available here) does not mention the primers they used when developing loads. But I got cunning. ADI manufacture many of Hodgdon's powders including H4350 which is the same as ADI's AR2209. So I looked up the Hodgdon manual and found the same load there - 130gr bullet, H4350, max load 60.5 gr, 3,226 fps, 24" barrel and the additional info that a Winchester LRM primer was used .

So I think I will bite the bullet and change the primer now before I get too far into working up a load.

Thanks to everyone for their input. I am really keen to try out the Sako 75 Finnlight. Should be an excellent rifle/calibre for the longer shots on the chamois we have in the hills around here. But first I need to load some rounds!

David

[Major Dave (retired)]

but I haven't started reloading for it yet. I hope you continue to post your progress, especially the differences with 7X57 reloading.

I happen to have a 7X57, also, and have made up 4 or 5 different loads for it, as American factory loads are very mild, unlike European loads (which I can't get).

I would be interested in comparing 7X57 successful loads.

So, 270 WSM and/or 7X57, I'm interested in sharing info.

[David_S]

Major, you must be a man of discernment - all you need now is a 6.5x55

I really like the 7x57 - great hunting calibre, modest recoil, relatively flat shooting and can shoot a wide range of projectiles. And it is nice to shoot a round with over a hundred years of history behind it - even if your country was on the receiving end in the Spanish-American War and mine during the Boer War (NZ sent 10 contingents to the 2nd Boer War).

My 7x57 is a 1980's Model 70 Featherweight and everything I point it at out to 300 yards seems to fall over, even though it is not what I consider a super accurate (<0.75 MOA) rifle. Just manages around 1.5MOA which is perfectly adequate for a hunting rifle.

As for reloading

For the 7x57 I use 139gr Hornady SP, BTSP and SST projectiles, ADI AR2209 powder, Winchester WLR primers and a mixture of Federal (for SP), Norma (BTSP) and Winchester (SST) cases. Bullet is seated 0.6mm off lands for SP and BTSP and 1.5mm for SST (SST governed by magazine length). The mixture of cases is a reflection of the availability (or non-availability) of factory ammo which finally convinced me to reload. (I also have PMC, S&B, & PPU cases!!)

I had good success with a load of 44.45gr for the SP:- 2550fps and <1MOA.
For the BTSP 46.75gr gave 2,600fps and 1.2MOA. And for the SST 46.75gr gave 2615fps and a best group of 0.6MOA.

I changed to the SSTs as my son had very good results in the 6.5x55 but I am not sure if the SPs are not better in the 7x57. One factor against the SSTs is that their long profile means I cannot seat them close to the lands as they don't fit the magazine if I do.

I then messed everything up by fitting a Timney trigger, new scope (Zeiss), bedding the action and free floating the barrel, and am back at square one.

For the 270 WSM I am trying 130gr SSTs, Winchester cases, WLRM primers (yes I have pulled the WLRs), AR2209 powder and bullet seating 0.6mm (20 thou) off lands. A slower powder such as AR2213SC (= Hodgdon H4831SC) is probably better but I am trying to standardise my powders as far as possible, and don't need another.

I hope that is of help to you, Major.

David

[Major Dave (retired)]

Because my 243 Win (6X51) handles the dual role of varmint/small deer.

Of course, what the 7X57 won't do on big game, at extended range, the 270 WSM will, as I am sure you know.

My 7X57 is a custom DuBiel left handed bolt action. My best load for it is 44.0 grains of IMR 4320 powder, which gives 2,950 feet/second muzzle velocity, using Hornady 139 gr Interlock Boat Tail bullet. It produces 0.75 inch groups.

My 270 WSM is a left hand action Win Mod 70 Classic Featherweight. I don't handload for it, yet. I have tried 5 or 6 brands of factory ammo, and it does best with Win Supreme 130 gr Ballistic Silvertips. I have never chronographed it, so I don't know how close to book velocities it performs.

[David_S]

That DuBiel sounds like a really nice rifle, though I suspect it is not as battered looking as my 7x57 which spends a fair bit of its life strapped to the side of my pack when climbing the hills and has taken a few tumbles.

2,950 fps is pretty impressive. With the same bullet and 44gr of AR2209 (which is slower than IMR 4320) I only get 2,360 in my 21" barrel.

I will keep you informed of progress with both rifles - I hope to fire some test loads this week.

David