How bad can "unmatched" ammo make your rifle?

[BigFatGuy]

Let's say you're hunting.

Let's say you don't have your "favorite" ammo with you.

Let's say you grab a random box of ammo at a gas station on the way, in the right caliber and bullet weight.

How much precision can you reasonably lose from using ammo that isn't "matched" to your rifle?

[Dano3467]

I see it this way

Your scope is zeroed to you favorite load, so you change that, you will IMO have a different POI. will it be terrible Idk but will make a difference IMHO..

[Varg Vikernes]

You could end up shooting Tula or something. Something that isn't exactly precision minded.

[maxx03]

Depends on YOUR rifle.

[Citadelgrad87]

It will definitely change your POI, it remains to be seen what it will do to groups. In your hypothetical, find a range or safe spot and shoot a group.

[BigFatGuy]

Depends on YOUR rifle.

True, but it's not going to suddenly go from 1/4 minute groups to 20moa groups, I'd imagine.. There's got to be some kind of bound on a reasonable-ness...

To be clear, I'm not talking about a POI shift, I'm talking about a loss of precision, a greater "cone" of group size.

[2shotjoe]

Where's this gas station I can buy ammo from?

Sent from my SM-N950U using Tapatalk

[Divernhunter]

I do not use factory ammo but I can tell you with my hand loads I have found that just using different brands of brass will effect where the group prints. Enough that it will make a rifle that shoots groups that are 5 rounds touching into something like a shotgun with 4"+ groups. Changing bullets has also effected where the group prints.

Many years ago I had factory rounds do the same.

If you change bullet weights there will usually be a big difference.
Some rifles will show more differences than others so there is no exact set rule----just as in life.

My suggestion is to sight it in with one brand/bullet and buy extra of the same(even the same lot) then do not forget it when you go hunting. Carry extra with you(like in the truck/car) so you do not use up your supply. One way I never forget my ammo is that I have those elastic sleeves on my rifles that hold 10 rounds. Should I forget my ammo I still have 10 rounds to hunt with and I have not run out big game hunting yet.
Squirrel shooting I just have to remember to bring my plastic ammo boxes and the GI ammo cans of ammo.
One way I always remember to bring the ammo is I but it by the front door/in my backpack or some place I will not forget it for sure.

[5.56Geo]

Let's say you're hunting.

Let's say you don't have your "favorite" ammo with you.

Let's say you grab a random box of ammo at a gas station on the way, in the right caliber and bullet weight.

How much precision can you reasonably lose from using ammo that isn't "matched" to your rifle?

It will still group within a pie tin! Most modern factory ammo will group at 1" +/- being shot out of a modern rifle. Your POA and POI will change but I don't think it'll be more than 8" drift from your favorite ammo.

My thoughts...

[BigFatGuy]

Where's this gas station I can buy ammo from?

:-) I have no idea... but I keep hearing that the best reason to use "standard" calibers is the ability to raid gas stations and cop cars for ammo after SHTF.

The gas stations near me only sell pot and lotto tickets.

Enough that it will make a rifle that shoots groups that are 5 rounds touching into something like a shotgun with 4"+ groups.

You've seen a group size increase of 4moa from BRASS?

It will still group within a pie tin! Most modern factory ammo will group at 1" +/- being shot out of a modern rifle.

That's basically what I'm hoping for... my specific issue is I may or may not know someone who owns a decent cache of rifle ammo, but it's not all the same brand, and I'm practicing with ammo that isn't my much more expensive hunting ammo.

I haven't noticed anything horrific so far, but it's good to see how things may change in the future...

[PatC415]

One of the 10 things NOT TO DO before hunting:
Hunting without properly sighting in your rifle.

Can you guarantee an ethical shot? NO

[JackEllis]

This is one reason why I use common calibers (.22lr, .223, .243 and .30-06).

You're typically not going to use more than maybe 7-10 rounds on a deer or elk hunt, including rounds to check zero. Your ammunition should be in your backpack or your pocket when you leave home if driving, or in your rifle case (but not the rifle) if you're flying. If your rifle likes ammo that can be purchased at a local Walmart, chances are you'll be able to get that same ammo just about any place. Until the lead ban takes effect, Remington 150 grain Core-Lokts in 30-06 work in my rifle and I can find them all over the place.

If you have to use rounds your rifle has not been zeroed for, I suggest you recheck zero with the new ammunition before shooting anything. Same if you happen to bump your scope hard. You don't want to miss a nice buck or bull, but more importantly you don't want to wound it!!!

[Cuda440]

Where's this gas station I can buy ammo from?

Sent from my SM-N950U using Tapatalk

Wyoming

https://www.yelp.com/biz/west-laramie-fly-store-laramie-2

[Bull Elk]

While there is some ammo that it might make a difference, you likely would notice little difference under the scenario you described at 100 yards. But I do believe that depending upon the rifle, bullet type and bullet weight, there could be a noticeable change of impact. Several weeks ago I was shooting lead free 140 grain ammo out of my Tikka 7mm-08. On average, my groups were about 1.1 inches. Just for fun, I shot some different ammo 139 grain and a different manufacture. My groups were slightly larger 1.3 inches. Since I pretty much limit my range to 300 yards, the difference between the two for hunting purposes is for all practical purposes irrelevant. I don't consider myself to be a great shot (I was better when I was younger), so most of my rifles definitely shoot better than I can on my best day.

[Jimmy's]

It can be dramatically off so if ever needed re zero rifle before hunting.