do you shoot .308 FACTORY ammo out of your 7.62x51 chamber semi-auto?
- Thread starter elfster1234
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Yes, loads of it and have never had an issue. In contrast to the issue with 5.56 NATO ammo in .223 Rem chambers, all I have read is that there is no realistic issue with using .308 Win commercial ammo in a 7.62x51mm NATO chambered rifle.
i guess the reason why i'm asking this open ended question, and yes i know this topic has been beaten like a dead horse on here before but i really would like to discuss this here and now, BUT....... i've been measuring some factory .308 ammo headspace and I've seen about an average of 1.625 headspace on brand spanking new factory ammo.... I even have a brand new box of hornady .308 factory ammo that was damn near all 1.624ish headspace.... Even my "nato" 7.62x51 american eagle designed for MIA all measures factory new at 1.626 headspace (which fires great out of my LMT by the way)...... now, if most of this factory .308 ammo is measuring around 1.625ish, some down to 1.624 as in the case of this brand new box of hornday ammo......... and my brass fired out of my LMT is around 1.631 to 1.632ish which is about normal IMO (which leads me to believe my 7.62x51 LMT's headspace is around 1.635ish after the brass springs back a little bit once ejected), then wouldn't that friggen make my headspace difference on this factory .308 ammo of 1.624 headspace damn near .011 difference!!!!? You would think I'd run into atleast some type of blown primers or case head seperation or something. That is the reason why I'm asking.
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Well within spec for both .308 Winchester and 7.62x51 Nato. It is a very forgiving round and designed to be that way for it's military uses. Consider the headspace tolerance variations in machine guns and the variety of rifles chambered in this caliber. I have assembled 14 .308 AR's and never had a headspace issue. Some variances as much as you describe but all fired great with no issues. I would imagine if your headspace was on the outside edge of range your brass would stretch more and eventually fail sooner but that may mean the differnece between a normal 5-6 loadings or just 3-4. Any new factory ammo or milsurp NATO will be fine. Just be careful when reloading.
I use FACTORY Black Hills 175 Match in my AR10 (T)..... and reloads of the same spec... I have NO issues.. I shot the same out of a CMMG MK3 as well.
Matt (LEO SOUTH GA.)
Matt (LEO SOUTH GA.)
Just as a semi-related side note, go check the length of your ammo after it is chambered once or twice. A lot of semi-auto rifles will knock the shoulder back a few thou each time the round is chambered, just from the inertia of the bolt & carrier. Once you observe this, there isn't a whole lot of reason to sweat the details of cartridge vs. chamber headspace.
And on that note, be extremely wary of reloading cases that have been fired in a military-style semi-auto rifle - they've lived a hard life, and should be treated to an early retirement.
And on that note, be extremely wary of reloading cases that have been fired in a military-style semi-auto rifle - they've lived a hard life, and should be treated to an early retirement.
I shoot the M1A American Eagle 7.62X51, Federal 150 gr .308 and FGMM 168, 175 .308 out of my M21 and SOCOM 16 without issue.
Never had a problem with my HK SR9(TC) either except the ejected cases from that baby would travel almost as far as the bullets.
Never had a problem with my HK SR9(TC) either except the ejected cases from that baby would travel almost as far as the bullets.
Have probably 700 rounds of .308 GMM through my OBR with no issues. Can't say the same for shooting the 7.62 out of my .308 bolt gun though. Live and learn.
Headspace is just one form of checking chamber tightness. It's more than bumping back the shoulders. NATO chambers are also larger in diameter, and they may have longer throats. My AR10 SASS with both the SASS barrel and Novekse Barrel are super consistent when I use Savage Fireform Brass.
However, most like who cares about super accurate AR's, when we are talking AR's, all rifles will be 3 MOA or more once you put a full 10 round mag through her no matter how quality your ammo is.
Magtech makes my ECC choke, which is strange because I've shot all kinds of surplus out of it without any failures (accuracy not withstanding).
I have kind of the opposite problem, my LMT throws the MagTech brass out really hard and far. I was wondering if it will be a problem to shoot suppressed with this setup.
I can't disagree with you more. If a precision AR opens up to 3 MOA after 10 rounds of rapid fire, it has SERIOUS issues.
What is Savage Fireform Brass?
I've been in the business for 20 years and never heard of it.
Ya that statment puzzled me. If any of my rifles opened up like that it would go back in the bag and taken directly to the workbench for a checkout.. It happened once to me and I found out the newly installed Smith Vortex with front sight on my M1A had worked loose a little.
Maybe he was kidding??? Or is he just a bolt gun fan.
We've heard of Savage rifles. We didn't know anything about "Savage fireform brass".
OP:
You're over-thinking it. Just shoot it. My 7.62-chambered AR I've fired Federal .308 match ammo. I don't remember if I compared their .308 and 7.62x51 GMM, but I believe they headspace the same anyway.
OP:
You're over-thinking it. Just shoot it. My 7.62-chambered AR I've fired Federal .308 match ammo. I don't remember if I compared their .308 and 7.62x51 GMM, but I believe they headspace the same anyway.
You do not know what Fireform Brass is? Or do you do not know about Savage Rifles? Savage barrels and chambers in particular.
It depends on how over gassed you are. The more over gassed you are, the faster the groups will spread. It might take 10 rounds of rapid fire, it might take 20 rounds of rapid. I always said for gas guns, all groups will be 6" if you do 2 mag dumps (40 rounds) in less than a minute. Does not matter what ammo or how accurate your semi-auto rifle is, given enough rounds, the groups will spread.
Over gas can be a good thing in that it insures more reliability. I read stories where the Aussies ran their L1A1's (FALs) always ran their rifles on the highest setting. Bad about over gassing is the gun heats up faster.
Oh and BTW, I get into 7.62x51 NATO vs. .308 discussion at least 3 times a year for about 10 years now. These 2 rounds can be treated as the same rounds, do not let anyone tell you different.
No, please explain to the idiots what Fireform Brass is.
We know what fire-formed brass is...and there's nothing unique about doing so in a Savage. Once its resized, its resized.
Yeah I've heard of Savage rifles but not your Savage Fireform Brass. Is Savage selling pre-fireformed brass for your barrel?
Explain it for those of us that know nothing.
Are you really saying you fireform brass in a Savage bolt gun and then shoot it in your AR10 or Noveske without resizing?
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That must be it. Savage is fire-forming brass in their rifles and selling it. Cartman is buying it up and not resizing it. You figured out the mystery, bustin!!!!
You know the 7.62x51 came around when used in the M1A. The pressure of the 7.62x51 was dropped from that of the 308 so it could be reliably used in the M1A without breaking parts.
Same size, not the same pressure.
You do not think there is nothing unique about doing it in a Savage? Are you sure resize is resize? you do not think full size is different than neck sizing? in my neck of the woods, resize usually means "full size", and we have to explicitly say "neck size" when we are talking about neck only sizing.
Fireform in my neck of the woods means you are neck sizing only, that you keep the over all shape of the brass after firing, and only sizing the neck, and not doing a full re-size. Savage Fireform is shorthand meaning I shoot the case from a Savage Barrel (known for tight chamber dimensions), then neck size only.
Please Discuss...
Has nothing to do with 7.62x51 NATO Ammo
You are talking about Old School M118LR in particular. It was way too hot for the M14, and beat up the rifle pretty bad. M118LR was initially made for bolt guns, but as usual, the Military uses what they have in inventory. New School M118LR is mellowed down quite a bit so it does not beat up M14s.
Fire-forming is what you do when you fire a cartridge in a given chamber. It is then "fire-formed" to that chamber.
Neck-sizing is neck resizing.
Full-length sizing is full-length resizing.
There are different degrees of resizing depending on desired goal. I may choose to neck-size my brass by resizing a given amount to end up with a desired neck tension.
Meanwhile, I may want to full-length resize to end up with a desired dimension. I may have one rifle, be it bolt or semi-auto, that is closer to the minimum spec and want all the brass to function in that rifle. Meanwhile, I may have one rifle on the high end of specifications and only desire to shoot that brass in that rifle, thus I would want to adjust my die accordingly.
Be specific if you want to speak with the adults.
There is no discussion about it.
Neck-sizing is neck resizing.
Full-length sizing is full-length resizing.
There are different degrees of resizing depending on desired goal. I may choose to neck-size my brass by resizing a given amount to end up with a desired neck tension.
Meanwhile, I may want to full-length resize to end up with a desired dimension. I may have one rifle, be it bolt or semi-auto, that is closer to the minimum spec and want all the brass to function in that rifle. Meanwhile, I may have one rifle on the high end of specifications and only desire to shoot that brass in that rifle, thus I would want to adjust my die accordingly.
Be specific if you want to speak with the adults.
There is no discussion about it.
That is what I was waiting for, just wanted to be sure what you were saying. I didn't know if you were saying you were using Savage 300 brass in your AR10 or buying Savage 308 brass or what. Capitalization and punctuation is the difference between you helping your uncle Jack, off a horse and you helping your uncle jack off a horse.
Neck sizing for use in a semi auto. Craziest thing I've ever heard, well maybe not but not advisable to fireform in one rifle of any kind and then only neck size for use in another especially a semi auto.
Fireforming in my neck of the woods is what we do to form brass for wildcats. There's about 500 pieces of Lapua 6BRX brass 15ft from me.
So "Savage Fireform" was not clear enough for you?
I never heard of anyone consider full size cases "fire form brass". In my neck of the woods, fireform and necksizing go hand in hand, and you can say one or the other (without mentioning both) and people will know what you are talking about.
Please Discuss....
Ah gotcha! You thought I was talking about fireforming for wildcats. Well you can fireform for the same caliber too. I was forming brass in .308 Savage Chambers to fire in my .308 AR10. Cases from the Savage fit much tighter in my AR10s, and still cycles reliable. Not just that, but ammo is much more consistent. .50 MOA or less for 4 rounds on a cold bore.
I discovered this by accident, brought 2 rifles to the range and 2 different boxes, I was getting the most consistent groups I have ever gotten out of this particular rifle, it was not till I was done and about to shoot my Savage that I discovered I shot the wrong reloads ;-)
Based on his stated location, I'm guessing he's been working at home for about 6 months now. See below.
Why working at home is both awesome and horrible - The Oatmeal
English is my 3rd Language so forgive me.
I guess "Savage Fireform Brass" was not clear enough for you? You have been in the game 20 years, you are the expert here. Do you need hand holding and have me explain what Savage Fireform brass is? If you do, just let me know, I have no problem holding hands and helping you cross the street.
After all, you have been in the game 20 years!
Please discuss...
At this point in my life, I am actually bored of guns. But can never get bored of gun forums!!! hahahaha
Oh poor Cartman, he's not having fun with his wittle Savage and people just don't let him troll as much as he likes these days.
Trapped!
Lucky I have you in my life, a guy who has "been in the business for 20 years".
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