Thread: Accuracy expectations

Listening to all the feedback here, I’m starting to ‘get it’. Pragmatically it’s good to go as is, and has already put a heap of meat in the freezer. I was enquiring because one virtue of the cartridge is it’s excellent accuracy, something that I have failed to find so far. But in itself the term ‘excellent’ is very subjective.

For those that were asking, here is the rundown on the rig.

BSA Hunter action, was originally a .222 reamed to .223 until it’s barrel wore out. It was rebarrelled with a take-off Sako .243 1-10 twist barrel. That barrel had shot ‘only a handful of groups’ before it was removed. Reason for removal unknown.
Due to it being ex .243, it has been fitted to the action with a bush. In other words, by the time the chamber was cut off, there was not enough meat for a barrel tenon, so an adapter was made over the barrel to then thread into the action. This was work a friend and mentor of mine (original owner) had done. It ended up at 18” bolt face to muzzle. I don’t think he did a lot of work with it before selling to me to buy himself a thermal. He’s a mate of mine of 20 plus years, and shoots accurate rifles so I didn’t think this would be any different. The firing spring was a bit tired, so I replaced it with the one from my .222, and although it makes a better striker indent on the primer, no noticeable difference on target. Lug engagement is good on both lugs. Magazine and bolt throw lengthened out to 2.435” so plenty of room.

The stock is a glass one that I built in a previous thread. Bedded by my, and the bedding checks out with a dial gauge. No stress there. It’s fitted with a custom gun works supppressor, thread is 9/16x24.

Scoped with a Leupold VX1 3-9x40. Holds POI and adjusts fine so don’t suspect that being an issue. Sits in Parker hale scope mounts. RALS3.

Loads:
Best group was with 85gr Sierra SPT at 9mm. This bullet is the most accurate overall averaging 22mm, but also the slowest at an average of about 2650fps.
Next best is the 85gr Sierra HPBT. Best group of 16mm, and another at 18mm. General average of about 28mm. Got better velocity at around 2700-2720fps.
100gr core-lokt shot ok at about 28mm but as expected slow at 2450fps. Possibly a nice bush load though. Starting load for this was very accurate, but at 2200fps.
Worst bullet is the 87gr Hornady BTHP. Best group at about 20mm, all the way up to 60mm. Average of about 38mm. Struggled to get 2700fps with that one too.

I started with PSD mil brass, then progressed to new Winchester brass via Lapua match. Gave up the Lapua because it formed donuts when necking up, and was jacking up pressure as they were crimping the bullets when chambering.
I started with 2206H, then Win 748 and finally BM8208. I tried the others as I couldn’t get to book max with the 2206H due to powder compression, just not enough space in the case. The 748 didn’t help speeds or a accuracy, and BM8208 gave the same velocity with higher pressure. All loads individually weighed.
Initial testing of all loads was done at -0.010” (using a comparator). I also did a Berger bullet seating test with the Hornady because of its more secant style ogive. Made no difference to group accuracy. My load methodology is the OCW method as outlined by Dan Newbury pretty much to the letter. I thought I was seeing trends and nodes, but probably just confirmation bias to be honest. Some good loads were found right up at max pressure and 2700fps but primary extraction was getting stiff so wasn’t keen to keep it operating up there. Primers were very flat, but I noted the primer pockets were not that tight from new with the Fed 205M primers.

Only thing I haven’t done is try 70gr bullets. I thought about that but I personally feel a bit happier chasing deer with a bit more sectional density. And to be fair, there’s no point necking up a .223 case to shoot bullets that are lighter than what the .223 runs these days anyway.