.308, N140, loose primers

[Shootist]

I'm using a Savage F/TR .308 rifle with a 32" Pacnor barrel. On this site I have seen several references to a 'standard accuracy load' of 46 grains Viht N140 behind 155 grain bullets. This weight of powder is in excess of published maximum loads but I've had minimal pressure signs so far and accuracy has been acceptable.

 

Last night I sized and primed some Hornady brass that had been shot with this load once, reloaded as above by me without problem. This brass had been shot once before I got it, as factory rounds. It was noticeable that about two thirds of the cases the primers went in very easily indeed. I tried one in a de-capping die and could push the primer out just by holding the die and case. The brass otherwise looks in fine condition.

 

Question is, are the cases safe to use? If not, why not?

[JSC]

'Safe' is a relative term... It's unlikely to be dangerous, but you may start getting primers popping out and blow-past if they're really loose, which is not ideal and could push debris into your bolt/action or even damage it.

 

46 gn of N140/155gn is pretty stiff. I would advise switching to Lapua Palma brass with small primers.

 

It may be the Hornady 'factory' load is quite stiff, or someone had reloaded them before. Or maybe the Hornady brass is a bit generous in the primer pockets.

 

Either way, I would say invest in Lapua brass of either type and you should find the problem will go away.

Also, be aware that some primers will go in tighter than others, so you could try a different primer first.

[AckImp]

That's a very warm load. We experimented when we first got the Kreiger fitted to our Remington 700 and found it to be fast, and accurate, but backed off to 45 grains to save the brass as we were seeing the same problem that you are. I don't think loose primer pockets are dangerous in general but from a practical point of view it's obviously an issue. I've never tried the small primer .308 brass, that might help?

[JSC]

Agreed, just looked at my FTR load with a 32" brl and I was loading 43.1gn N140 with a 155 to give me 2830fps.

 

I don't think I could get to the next node safely, so that's where I stayed with N140.

The most N140 I've loaded in a .308 is 45.7gn.

 

You might also want to think about trying a different powder to bring the pressures down a tad.

[Chanonry]

Well, that's a pressure sign. Been there - overly adventurous loads.

 

Brass is a consumable and I tend to the view that I have been a bit harsh, bin them, grumble a bit, turn the load down and move on.

 

No point risking damage to the gun for the price of a few bits of brass ?

[baldie]

Your brass is scrap. using it with loose pockets will result in gas cutting on the bolt face.

 

Try vhit 150. You have a long barrel and the pressure curve of a slower powder should work to your advantage.

[Shootist]

Thanks for the replies chaps.

 

Baldie, according to Quickload, N150 will lose some MV and appears to fill the case quicker thus restricting the maximum. However, I will take your advice and scrap the brass, or at least those cases where the primer pushes out easily.

[JSC]

This is the compromise you find with the .308 cartridge. Not enough capacity in the case...

 

Run the powder comparison in Quickload and it will give you an idea of which powders might work.

You may need to compress the load with some, but that and increased pressures is not necessarily going to be a problem, especially if you switch to small primer brass.

[baldie]

Thanks for the replies chaps.

 

Baldie, according to Quickload, N150 will lose some MV and appears to fill the case quicker thus restricting the maximum. However, I will take your advice and scrap the brass, or at least those cases where the primer pushes out easily.

 

 

Did you put your barrel length into quick load ?

[Shootist]

Yes, 32".

 

45 grains N150 gives 2758 fps but is a compressed load, 102.7%. Pressure is somewhat lower, 2975 bar.

 

45 grains N140 gives 2897fps at 98.9 full load. Pressure 3662 bar.

 

To match the N140 muzzle velocity with N150 requires 47.5 grains which is 108.4 compressed load reaching 3546 bar.

 

I think I'll be staying with N140. Economy as much as anything else as I use it for .223 also.

 

Another oddity with the rifle is that I can't get it to shoot much better than 1" at 110 yards but it'll shoot almost any load to that. I did fairly well at Bisley on the Phoenix F/TR 4/5/600 though.

[22lrman]

Ref quickload...I assume you have measured and entered in your case volume and all the other little bits correctly... just checking :-0

 

slightly off topic...

Whats your bullet head, COAL, distance off lands, crimp or not crimped etc as a matter of interest.? From what I have read on here, with that barrel length/ velocity you shouldnt have to load to that pressure.. Could be recalling incorrectly though, as ive never had a setup at that level. I only have 26 inches lol.

[baldie]

Hmmm.

 

Personally, I would scrounge a bit of 150 from a mate, and try it.

 

Quickload is a computer programme. It takes no account of real world barrel, conditions, or other factors. Its just a guide.

 

540 might be a better choice than both.

[dannywayoflife]

Have you tried Lapua brass? It seems to handle warmer loads better than some other brands. Also why not try RS52? It seems to deliver more speed at lower pressure

[firedoc]

We use Palma brass and Vhit 150 although a bit slower, never had any loose primers.

[Swarovski1]

I use 44.8grs of n150 behind a 168gr amax. I get 2750fps.was with a 26 inch barrel.for the 2156 155gr smks or 155gr amaxs I use 41.5grs of rs40.both loads are doing nion 2900fps.the smks are good out to 1000yds.ive not shot 155gr amax at 1000yds but they are exceptionally accurate at 100yds.havent used any for ages so I bought some recently ready to use at mcqueens.

[Shootist]

Many thanks to all for the replies. I think I'm going to use a lower load. The good news is that 'loose' may be a variable. I used a 45/70 die as a decapper. and pushed it in the cases one by one. About 15 out of the 50 pushed straight out and the brass is now in the bin. The remainder were pretty firm and wouldn't move so I will keep them for load development, now a necessity again.

[duey]

I have used 46gr N140 behind Scenar 155 in the past with no pressure signs in a Parker hale M84/M85 ( can never remember which one is the single shot action) with a factory barrel

This was worked up slowly from 44 gr and the COAL was a fair bit over Sammi spec if I remember and suited that rifle

If your chamber has a shorter free bore you may not get the case capacity to use 46gr safely, and I always use Lapua brass

 

I am currently using a Vhit 150 behind 165gr SGK in My 308 stalking rifle, as when I used 140 I was getting heavy bolt lift from pressure,

I no longer get pressure problems and have virtually the same MV from 150 that I got from 140

 

As Baldie says try 150, as quick load is just a very good guide, but you cant beat real world data for individual rifles and good luck

[eldon]

I've used 46gr of N140 behind 2125 sierras and Nosler 150gr BT and especially the later shot really well with no pressure signs from a Remington 24" barrel.

 

I now use Sierra 2140 with 44.5grs of N140 for 2725 fps.

 

All Lapua brass.

[clivej]

I

 

Yes, 32".

 

45 grains N150 gives 2758 fps but is a compressed load, 102.7%. Pressure is somewhat lower, 2975 bar.

 

45 grains N140 gives 2897fps at 98.9 full load. Pressure 3662 bar.

 

To match the N140 muzzle velocity with N150 requires 47.5 grains which is 108.4 compressed load reaching 3546 bar.

 

I think I'll be staying with N140. Economy as much as anything else as I use it for .223 also.

 

Another oddity with the rifle is that I can't get it to shoot much better than 1" at 110 yards but it'll shoot almost any load to that. I did fairly well at Bisley on the Phoenix F/TR 4/5/600 though.

 

I'm using your load with 155gr AMax heads in my 24" barrelled Sako 75, pushing out at 2800fps, 1/2" MOA groups. No signs of pressure. Using Federal factory cases and reloded them 6 times now.
Like you I shot the 4/5/600y Phoenix last year, came 9th

[Morse]

I use 46r Vit N140 with SMK 155r Palma heads and CCI BR primers in my AI AE MK2. I am still on my first set of brass (200 lapua) and the total round count on the barrel is approx 1200 rounds. I neck re size 2 of 3 reloadings. The brass is now starting to show some signs of wear (primer pockets are a bit soggy but only on some cases maybe 5%) The load works well for me in my situation and I am happy with it. I know its on the upper edge of cartridge spec but its not given me any pressure signs in this gun. There are a few others on here that use the exact same load, maybe they will shout up with their thoughts. Perhaps using the Palma brass is a good call. I think the key is here is buy good brass and look after it by not working it too much in the press and keeping the loads within sane limits!

[Andrew]

 

Quickload is a computer programme. It takes no account of real world barrel, conditions, or other factors. Its just a guide.

 

 

That about says it.~Andrew

[Shootist]

Thanks to all for the input

[Shootist]

Just for info, I was zeroing at the range yesterday using the 46 grain load (46 gn N140, SMK 155, COL 2.8). The chrono gave an average MV of 2959 and for reasons I couldn't figure out was giving some pretty damned good groups, much better than previous efforts.

 

Given that the rifle will have limited use, not being a plinker exactly, and that I have a couple of hundred rounds loaded up I think I will continue to use it and live with the shortened brass life. The above results were using PPU brass which shows no signs of loose primer pockets (yet). When the brass starts to fail on the primer pockets I have a box of Lapua Palma brass awaiting it's first load.

 

Assuming I now have a useable load all I have to do now is understand this bloody wind business.

[VarmLR]

46gr seems a very stiff load with 155s and N140!!! I believe that 44.2 is the published max recommended safe load by Viht for 155s. Load mine to 44g (also using PPU brass) with excellent results using 155SMKs. At that I'm just starting to get pressure signs (flattening of primers) so wont venture above it. As others have said, it's not worth risking your neck for a hot load.

 

I will be switching to RS52. In 308, it seems you get better MV with lower chamber pressure for that weight of round.

[Swarovski1]

Yes, 32".

 

45 grains N150 gives 2758 fps but is a compressed load, 102.7%. Pressure is somewhat lower, 2975 bar.

 

45 grains N140 gives 2897fps at 98.9 full load. Pressure 3662 bar.

 

To match the N140 muzzle velocity with N150 requires 47.5 grains which is 108.4 compressed load reaching 3546 bar.

 

I think I'll be staying with N140. Economy as much as anything else as I use it for .223 also.

 

Another oddity with the rifle is that I can't get it to shoot much better than 1" at 110 yards but it'll shoot almost any load to that. I did fairly well at Bisley on the Phoenix F/TR 4/5/600 though.

I use to use n140 with 155gr smks,2850fps in a 26 inch tube with 44.5grs, I currently use rs40, using ,41,5grs gets me 2880 ish fps, I use n150 behind 168gr amaxs,44.8grs gives me 2750fps summer temps.n150 is really good.