reloading the .303 Epps

[Treeman]

So yea!, finally got that modern actioned .303 I spoke of all those years ago. Yesterday I fireformed the cases, almost 100 cases I guess all in all - just hope I did it slow enough, as not to burn the barrel.

So I now have the weapon and the cases, some 170 Gr Ballistix bullets and my likely bullet of choice, a 180 gr APM bullet. The APM is a cup and core bullet has an rather thick pure copper jacket, 0.3 mm and a huge exposed lead point. I am hoping, believing that this will give me that slow deep, expanding bullet I am searching for.

I do not have S341, but do have 321, 335 and 365. Using the Remington 180gr .312 bullet as a parent bullet (APM is not on my quick load) I have tried very superficially to find a starting load and propellent.

Barrel 700 mm - case capacity after forming is 58.8 ml

I am wanting to achieve 2650 fps - what I consider a bit of a magic velocity for the heavier bullets, and the magic speed in Cody's 7mm08, the rifle that introduced me to slower shooting.
A very basic sweep through quick load gives me the following.
S365 at 55 gr gives me 2650 fps at 41000 psi and 98 % case fill
S335 at 45 gr gives me 2600 fps at 50600 psi and a 88 % case fill
S321 at 46 gr gives me 2640 fps at 47555 psi and a 82 % case fill

I will after shooting over the chrony do the QL in detail and adjust burn rate etc

I will have to pull all my Ballistix 170 gr bullets from their cases as to fireform the cases before developing a high pressure top velocity load for the mono bullet. I will request input again then, but now, I just want a relatively slow and heavy inside 250 m meat hunting load.

Any input will be appreciated.

[janfred]

I once tried S365 loading .303. Was not a success. Too much unburnt powder was blown out the barrel. I managed to get to a speed of 2200ish with 174gr Sierra MatchKing bullets. No matter how much more powder I forced into the case, the MV would not go above that. I finally concluded that I would need a heavier bullet for good results.

What did give me great results was S355.

Maybe the larger case capacity of the Epps might make a difference.

Maybe you can try closer to 200gr bullets with the S365.

[Treeman]

No, I want the 180 gr bullet from this local manufacturer.
I forgot to add that the bullet length is 30 mm

[Treeman]

I found 2 tins of S365, wonder how well it will be suited for the Epps ?
the .303 is pretty much a .308 twin and the Epps a twin of what, 30 06 -300 Win - 300 HH I guess

What you guys thinking ? I was going to try Varget, but perhaps 365 is better, what ya all thinkin ?

[Ds J]

Case capacities according to Wikipedia:

303: 3.64cm³.

303 Epps: 3.9cm³ (guesstimated)

8x57 Mauser: 4.09cm³

30-06: 4.4cm³

Somchem shows a max speed for 180gr bullets for the 30-06 at 2684fps with S365.

You would need to put more pressure behind the bullet to get 2650fs from a smaller case.

The 8x57 launches a 200gr bullet @ 2574fps with S335, but operates at higher pressure than the 30-06.

Given that the 243 also uses S365 (overbore cartridge), you should be able to make the S365 work in the Epps.

Somchem shows +-2450fps with a 180gr bullets for the 303 Brit. Add 10% to compensate for higher pressure and a bigger case, it should be doable.

[Treeman]

Ja, Oom Drie has been helping me with this and he has pretty much answered all the questions. I just got some 365 - 2 tins and I am hoping its a bit hotter than the eno's I had. 110% case fill just to reach predicted Somchem wimp load speeds.
If this is a hotter propellant, then perhaps I can get some velocity out of the case capacity at hand.

[Ds J]

Is there another powder which would give better results? Maybe enable you to swop the two tins of S365?

I get the impression that the S365 is a case of  "maybe, if all works out, under certain circumstances "?

[Tripodmvr]

S341 or S355 or an equivalent like VV N150, N540
IMR432/4350
H4350

[Treeman]

Is there another powder which would give better results? Maybe enable you to swop the two tins of S365?

I get the impression that the S365 is a case of  "maybe, if all works out, under certain circumstances "?

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Yes it is, but we battle with powders, so ?

[oafpatroll]

I find it easier to get the IMI powders I need than heir somchem alternatives. My .270 has never tasted a somchem powder because supply is so erratic it wasn't worth the bother to develop loads with it. Unless I run across 'second hand' tins of their powder for which I already have loads developed (shotty and pistol) I don't even bother to look. Pricing and availability have pretty much eliminated them for me.   

[Treeman]

S341 or S355 or an equivalent like VV N150, N540
IMR432/4350
H4350

****************************
dankie Oom -weer.

[Treeman]

S341 or S355 or an equivalent like VV N150, N540
IMR432/4350
H4350

****************************
dankie Oom -weer.

*****************************
 Varget = S355

[janfred]

Varget is about halfway between S335 and S355 in performance in my .308 target rifle shooting 155gr bullets. Very close to VV N140.

Can also look at Vihta Vuori N150.

[Treeman]

Varget is about halfway between S335 and S355 in performance in my .308 target rifle shooting 155gr bullets. Very close to VV N140.
Can also look at Vihta Vuori N150.

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I have met a few guys using Varget for .303 Epps
We get Varget here in PE
The 7mm 08 uses Varget.
The 303 Epps the 7mm o8, the 7x57, and the 223 all seem good recipients of Varget.

[Tripodmvr]

Looking good !!!!!