Reloading Fox 80g copper in an old .243 rifle

[Doctorken]

I wanted to keep my trusty old tikka 1:10 and use copper. The factory 80g powerhead blades grouped well and killed deer, but I wanted to see what I could do with reloading as had started with my 223.....

I'm very new to reloading so wanted to share my first effort in 243 as the ladder test was a bit different to what I expected

Ed from Edinburgh rifles gave me a good starting point. They used the same rifle for their factory ammo development and their data has n140 at 40g.

The best 4 shot group at 100m with a 5 o clock 5-10mph wind was 80g fox classic hunter, 39g VHT N140, CCI 400 primer and sako brass, COL 67mm

Rifle was a tikka m595 243 with a 1:10 original barrel the MV was 957 m/s (3139 fps) giving 1750 ft/lb

Interestingly the 39g gave 957 with only 2 m/s difference between the 4 shots

Velocities were similar and but variable throughout the rest with a couple going to 961 and 975 at 39.2 then back down to 950-60 at 39.5 but with flattened primers. There was stiff bolt lift at 39.7 and 40g and a couple of flattened primers there too

Could those MV changes and pattern of pressure be due to the N140 maybe? I always assumed more powder = more velocity but after doing some more reading realise it is more complex than that......

I'm only using n140 as have a tub for my 223 and the 50g fox ammo produces sub 1 inch groups in that rifle too....

Just need some deer to cooperate and let me see the terminal effects!

The bull is 25mm x35mm on the photo 1st shot was a bit out probably due to my shooting more than anything else

The cases are in lots of 4 starting at 39g at the top. Am I correct that those flattened primers are early pressure signs only?

I was happy with the result for deer stalking at sensible ranges.

Would anyone consider changing anything? I'm sitting looking at my rcbs precision mic wondering if I have the patience to work out if I need to back off my FL resizing die to avoid overworking the brass or start messing with seating depths....is this the rabbit hole reloaders speak of?

I reckon more shooting practice would outweigh any further meddling if I'm honest!

Ken

 

[Snacker]

40 grains of N140 seems very high for .243 which has a saami pmax of 60,000 psi. Running your figures, at 40 grains you are at nearly 68,000 psi. So you’re definitely going to start seeing flattened primers! I wouldn’t want to be going over 38.2 grains which gives you a safe load, a 99% powder burn and a MV of 3169fps. These figures are for a copper jacketed bullet. The fox bullet will inevitably be longer than a similar lead core bullet so will use more available case capacity which will also increase the pressures, so back your load off a bit. N140 seems a pretty good choice, especially if you’re also using it elsewhere. If you wanted, you could get a headspace gauge and see where to set your sizing die so that you’re not bumping shoulders too much.

 

[Heym SR20]

O40gn of N140 behind the 80gn Fox bullet is one if the published factory loads for Fox Ammunition. They use PPU cases.

I am using this load, but loaded in RWS case in my 30 plus year old Heym SR20. It works well on Roe and Red deer at any normal shooting range which for me is about 250 yards.

However all rifles are different, so too is brass. If you are getting good results at 39gn, stick with it. You often get a good consistency at touch below where you get pressure signs.

If you have a load that consistently puts bullets into a workable group, then just go hunting. The group the OP posted is perfectly workable. Wind, even a 10mph will add a level of variation. Wind drift at 100 in a 10mph wind can be an inch or two. And close to the ground the wind is swirling which can move the bullet all over the place.

4 shots only gives an indication of accuracy, but statistically it’s pretty much irrelevant- you really need to shoot at least 10 rounds if not more to really test a load. However that gets expensive and not really necessary for every day hunting ammo bIf you have a load that works, go hunting.

If you want to win at F-Class at 100m off thee go down the rabbit hole ………..

 

[Will the chippy]

What's your load with fox bullets and n140 for your 223. Ive got both of them and I'd be keen to try the fox bullets on munty.

 

[Stevie/P]

Can’t help with load data but I don’t like seeing human silhouette targets it’s in poor taste IMO.

 

[Doctorken]

@Heym SR20 Thanks for the info much appreciated!

I will stick with 39g as there were zero pressure signs with that so it probably is as good as I will get and also a decent MV too

I'd be confident shooting deer with it for sure

@Stevie/P

They were there cheapest targets that had a large surface area of splatter so I can see 100m away especially if I get a flyer. I generally don't shoot humans as they don't taste great. muntjac are better

@Will the chippy

I will send you a DM but you'll need to be careful as I use lapua match brass that has a smaller case capacity than most....

 

[Heym SR20]

@Heym SR20 Thanks for the info much appreciated!

I will stick with 39g as there were zero pressure signs with that so it probably is as good as I will get and also a decent MV too

I'd be confident shooting deer with it for sure

@Stevie/P

They were there cheapest targets that had a large surface area of splatter so I can see 100m away especially if I get a flyer. I generally don't shoot humans as they don't taste great. muntjac are better

@Will the chippy

I will send you a DM but you'll need to be careful as I use lapua match brass that has a smaller case capacity than most....

Your welcome. I would guess that Sako brass has thicker walls and thus less volume than the PPU brass that is used in the factory ammo, hence the reason you are getting pressure signs at 40gn.

I do like to crimp all my reloads. This does two things

1) it makes the cartridges much tougher with the bullet firmly held in the case. Inevitably cartridges go in and out of magazines, sit in your pocket and get dropped on the floor. I have found out that without a crimp bullets tend to move in their cases which can be a real pain. Yes with correct dies you can adjust neck tension - but a good crimp just works.

2) I find a crimp definitely improves accuracy. Theory is that the cartridge builds a good level of pressure before starts moving. With low neck tension on the bullet in some cartridges the pressure at which bullet starts moving is much less consistent.

The alternative is to seat the bullet on the lands, so the bullet just moves a couple and its then stopped at the lands and pressure then builds and the bullets then accelerates down the bore. This technique is used by target shooters. Indeed I understand that benchrest shooters load the bullet long so when its chambered its hard up against the lands. This works well until you try and unload and un fired cartridge. The bullet gets stuck in the lands and powder goes everywhere.

Also monolithic bullets prefer to be loaded shorter so they get a good run up before they hot the lands.

I just use a crimp die so I get a nice tight consistent tension.

 

[Bowland blades]

Flat primers is nearly always pressure . Yes it can be the primers! can be ruled out by trying a different primer brand but don't ignore it