308 factory ammo batch consistency

Fishpond

Well-Known Member
So as a newbie I bought several types of 150 grain ammunition and found a couple that work well in my new rifle once I'd broken in the barrel but looking at one batch of my current prefered brand (Winchester) the seating of the bullet in the case is 1mm deeper in four out of twenty rounds in a box - I'm guessing this won't help my groups/accuracy but I went for the b option today (federal) because they seem more consistent in terms of manufacturing tolerances (only one seated slightly deeper across two boxes) - how much of an issue is this? I really don't want to home load as I have little time as it is. I assumed I'd need to check between different batches of the same round from the same manufacturer on the range but in-batch variation wouldn't be an issue! Presume I might need to step up to more expensive rounds to get better consistency and and hence performance in terms of accuracy?

thanks in advance for your thoughts

Richard
 
Despite doing all the measuring and messing about surrounding the reloading process I could never make a load that would do any better at deer distances, say to a max of 300 yards, than the Federal Powershok 308 ammo. It was about the least expensive ammo I could get and just by looking at the ammo I could see that they were all different lengths.
 
I would worry less about the overall measurement on factory and more on how they group. Buy 20 rounds of various make cartridges of the type wanted, and shoot them. Pick the ones that shoot best, cycle the best, plus are readily available. No point in buying ammo which you may only get hold of once if you have to re-zero for the next batch.

I'm guessing that you're measuring overall length using a vernier gauge. The differences in length could simply be down to the meplat of each bullet being slightly different which is pretty normal. They can get deformed in manufacture, handling, processing and packaging and it's rare to find bullets with identical meplats, hence why to measure seating depth reliably, you use a comparator gauge.

Whilst price of cartridges may indicate quality of components and costs of manufacture, it is not always an indicator of how ammo will perform in your rifle. However, where bullets are concerned, you tend to get what you pay for. (eg PPU I've found to be very inconsistent in my .308 and at best, just about moa at 100 on a good day but more usually twice that, but they may perform better in another barrel). Deer don't care who makes the cartridge. Hit them in the right place, the guns still goes "bang" and the deer still falls over. Accuracy for your rifle will depend on things like charge weight, seating depth and bullet used. You won't know which combination is best until you try a few. Most factory is loaded to work in a wide variety of rifles and most mid weight cartridges will have a reasonable to long-ish "jump" to work in most magazine fed rifles. I wouldn't over-analyze things at this stage, just shoot, compare and then stick to what you can readily get that works.

For home loading, there's no doubt that if you can make the time for just an evening or two a month, or every two months, you'll make all you need for deer shooting. For regular range work, you'll be dedicating a little more time. I've found loads that so far, no factory ammo has matched for precision/accuracy in my rifles (Sierra Gameking bullets being very accurate...0.5moa). That's not necessarily an advantage for deer shooting at reasonable ranges, but when loading for the range it is, plus that level of precision helps confidence when in the field. Don't discount home loading. Reloading kits can be had inexpensively and if you do some range work as well as deer shooting, it'll pay for itself sooner than you might think.
 
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I'd agree with the others - I'd judge it on how they shoot and how they group as opposed to price.

I tried (so far) three different makes of ammo in my .308;

1) Norma with Nosler green tips in 150gr (£45 a box)
2) GECO teilmantle in 170gr (£28 a box)
3) Federal power shok in 150gr (£27 a box)

And if you were to reverse that list from 3 to 1 you have the ranking of accuracy from best to worst in my rifle, running from around a 4" group down to about 1". So the cheapest ammo was the best performing, a fact of which I am very glad about hehe :)

Cost isnt necessarily the driving factor of how well ammo shoots - You just need to try a bunch and see which shoots the most accurately and you can get hold of.

If the Winchester and/or Federal are affordable, shoot accurately in your rifle and you can get a regular supply of them then stick with them.
 
I wouldn't worry too much about it. I find that Federal Power Shock 150gr shoot well in my 20" 1:11 twist 308 too. Better than more expensive cartridges and is my default backup deer cartridge.

If you are a little worried, buy a few boxes and separate the cartridges that appear inconsistent in OAL or weight.

I do home load though and my hunting load has the same POI at 100m and very similar ballistics to my target load which is handy.
 
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Thanks to all for your replies - I should clarify I haven't measured them I can see the difference in length with the naked eye and this appears to be bullet seating as the cannelure is covered by the neck of the case in the short ones but not the long. Having shot a few types (Winchester, federal, Sako) the Winchesters were grouping well but I haven't knowingly fired these "short" ones but clearly at 20% of the current box I might have done - will try and shoot some paper and compare group size of the Winchesters and then maybe a switch to federal, Sako or possibly Norma is on the cards if they vary too much - buying twenty to use 80% doesn't make sense to me

thanks

Richard
 
buying twenty to use 80% doesn't make sense to me

Why would you not use all of them? You've been listening to a lot of balderdash on the internet about reloading and measuring things and so on. Just put them in the rifle and shoot them. You are the single biggest factor in group size and that ammo will all shoot better than you will assuming a reasonably engineered rifle.
 
Hi caorach

don't worry I will shoot them at paper to see if it makes any odds and go from there - it's more a confidence thing at the end as you say if I'm still the biggest variable then that's fine with me!

Best regards

richard
 
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