Jump to content
308AR.com Community
  • Visit Aero Precision
  • Visit Brownells
  • Visit EuroOptic
  • Visit Site
  • Visit Beachin Tactical
  • Visit Rainier Arms
  • Visit Ballistic Advantage
  • Visit Palmetto State Armory
  • Visit Cabelas
  • Visit Sportsmans Guide

Headspace...GO !


Rabbit79
 Share

Recommended Posts

Fellas ! top of the start of the weekend! 

New topic for open discussion---->

Headspace gauges and I got a tri-set with a field gauge!

Upon inserting and checking I am good for GO on My headspace , on my new build..

Interesting how these gauges,  will indeed save your face!

Feed on, im all ears Guys! You `good ol' boys have amazing knowledge..

I will read up on, soon from you all.

FWD assist has awesome info, keep it coming...

Jay

 

Link to comment
Share on other sites

  • 5 months later...

I believe this is as good a place as any to throw this out there.  this is going to touch on a couple of issues.  1st- 7.62 x 51 versus .308. and 2nd headspace as it relates to the 1st.

Here's what happened.  DPMS AR-10.  the barrel is stamped 7.62 x 51 NATO.  I knew enough of the differences to be dangerous in the NATO and .308.  I Loaded cheap steel cased .308 to test run the rifle.  Bad idea.  problems feeding, misfires during maybe 30-40 rds.  the worst thing (why I stopped shooting for the day) was a case head separation lodged the case firmly in the barrel.  I finally got that out and over a good scotch, watched some videos and read a LOT both on DPMS and AR-10 in general.  I learned that Lubrication and brass casings are your friend.  SO, after getting the casing out, I cleaned, lubed VERY well (probably excessive) and fired 10 rds with PMC.  worked flawlessly.  repeated that cycle for 50+ rds, no issues.  all this is still with PMC .308 147 grain.

I continue to do research this week, and wondered if my headspace might have been an issue with the cheap ammo, and some of the tell tale signs of excessive headspace is failure to fire and case head separation.  I'm open to input (Today is Sunday so can't call DPMS till tomorrow) about how I might have excessive headspace using .308 in the DPMS hunter with the barrel marked 7.62 x 51.  thanks 

Link to comment
Share on other sites

5 hours ago, strikeu said:

I continue to do research this week, and wondered if my headspace might have been an issue with the cheap ammo,

Did you ever check the headspace in that gun, before you fired it?...

Link to comment
Share on other sites

14 hours ago, shooterrex said:

Steel case ammo doesn't shrink back as fast as brass in the chamber. Your BCG was pulling on stuck cases. The case needs to shrink back after expanding before it's yanked out of the chamber.

Checking your head space is a good idea.

spoke with DPMS today, the guy said stop shooting steel cased ammo, and that all of their AR-10s whether marked 7.62 x 51 or not, are spec'd for 308.  he said shoot away...no need to do anything except clean regularly and stop using steel cased ammo

Link to comment
Share on other sites

19 minutes ago, edgecrusher said:

Yup. Also, fwiw, the difference in NATO vs .308 is much less than it’s smaller brother, 5.56 vs .223. And reversed. The NATO round has less pressure. 

I just had some bad cheap ammo that I used and thought worst case that the rifle might not be spec'd for 308.  just me being OCD and Paranoid.  it's shooting fine with a good cleaning and lube with some decent brass.   

Link to comment
Share on other sites

34 minutes ago, Radioactive said:

What does that mean?

it means that in some circles and blogs (including somewhere on this one) there is some bad info that says shooting (especially winchester high grain) 308 in a 7.62x51 is bad.  the guy at DPMS must know exactly where I have been reading because he specifically said that was total BS.  however the differences there are in the 2 rounds, my particular rifle is good with either.  straight from the factory. 

Link to comment
Share on other sites

14 minutes ago, strikeu said:

it means that in some circles and blogs (including somewhere on this one) there is some bad info that says shooting (especially winchester high grain) 308 in a 7.62x51 is bad.  the guy at DPMS must know exactly where I have been reading because he specifically said that was total BS.  however the differences there are in the 2 rounds, my particular rifle is good with either.  straight from the factory. 

So chambered in 7.62 but capable of withstanding 308 pressure.
I think shooterex nailed it with the probs of steel cases which would be amplified if over gassed and the bolt was trying to unlock and extract early. I agree with the bad info out there. I would also tend to believe if someone here put out bum dope they’d get called on fairly quickly. Glad she’s running now.

Link to comment
Share on other sites

1 minute ago, Radioactive said:

So chambered in 7.62 but capable of withstanding 308 pressure.
I think shooterex nailed it with the probs of steel cases which would be amplified if over gassed and the bolt was trying to unlock and extract early. I agree with the bad info out there. I would also tend to believe if someone here put out bum dope they’d get called on fairly quickly. Glad she’s running now.

Yeah, it's the DPMS Gen 2 Hunter.  First AR of any sort for me to have issues with steel casings.  but I think I've just been really lucky because apparently steel casings cause a lot more problems.  I use steel in a few handguns for plinking, but for these AR's I'll stop being cheap and get decent ammo. I hate having to stop shooting to correct some crap that I could have avoided.  

Link to comment
Share on other sites

7 hours ago, strikeu said:

spoke with DPMS today,

How did you do that?  Remington shut DPMS down a few months ago.

4 hours ago, strikeu said:

it means that in some circles and blogs (including somewhere on this one) there is some bad info that says shooting (especially winchester high grain) 308 in a 7.62x51 is bad.  the guy at DPMS must know exactly where I have been reading because he specifically said that was total BS.  however the differences there are in the 2 rounds, my particular rifle is good with either.  straight from the factory. 

That's total bullshiit, right there - that doesn't fly on this board, and never has.  As soon as I see that bullshiit spread, I shut it down.

Go find it, since you saw it here on this board.

Here's an example of that exact discussion, handled last week, through a PM...   Go tell Mister DPMS to read this, and refute it. 

5.56 vs. .223 Rem - right on the money, for ammo.  5.56 is loaded to a higher pressure.  PLUS...  5.56 NATO Chambers have a longer leade than .223 Rem-cut chambers.  5.56 NATO ammo WILL blow up a .223 bolt gun, or other .223 Rem chamber - over time.  It won't necessarily happen on the first shot, of #100, or #25,000 - but it will happen.  That 5.56 NATO ammo in that .223 Rem chamber is NOT a good combination.

.308 Win is the opposite...  7.62 NATO is loaded to a lower pressure than .308 Win Commercial ammo.  Because civilians don't shoot machineguns.  That's the reason.  7.62 NATO ammo has to be able to keep up with sustained full-auto fire from machineguns.

Now, .308 Win is a little hotter - chambers are identical between the two.  The only fear of shooting that "SHIIT HOT .308 WIN CIVI AMMO!" through a 7.62x51 NATO chamber is AGE...   Those old war-surplus 7.62 rifles had barrels that were made of different metal compositions, than these days.  DO NOT shoot .308 Win through an old 7.62-chambered war relic.  Just don't do it. Eventually - like that .223 Rem story - it's gonna fail on you.

If it's not one of those old war relics -and you're shooting modern .308s/7.62s, then it doesn't matter so much.  It's nothing to worry about.  Modern barrel materials make it a non-issue.  Shoot whatever you can get your hands on, no matter what your modern barrel is marked. 

 

Link to comment
Share on other sites

10 hours ago, 98Z5V said:

How did you do that?  Remington shut DPMS down a few months ago.

That's total bullshiit, right there - that doesn't fly on this board, and never has.  As soon as I see that bullshiit spread, I shut it down.

Go find it, since you saw it here on this board.

Here's an example of that exact discussion, handled last week, through a PM...   Go tell Mister DPMS to read this, and refute it. 

 

 

easy big guy, calm down.  I wasn't trying to ruffle your feathers.  if it wasn't on this blog then you have my sincere apologies.  I found that information on several pages, with a very basic search.  so it is out there.  They make a good decaf, maybe you should try it.

Link to comment
Share on other sites

12 hours ago, strikeu said:

easy big guy, calm down.  I wasn't trying to ruffle your feathers.  if it wasn't on this blog then you have my sincere apologies.  I found that information on several pages, with a very basic search.  so it is out there.  They make a good decaf, maybe you should try it.

Oh, however, you directly stated that it was right here on this board - and it's not a "blog."  read your own words below...  vvv - I'll highlight them for you in the same red color, as above.  Makes it easy to see, and pick out in the crowd. 

On 7/20/2020 at 4:17 PM, strikeu said:

it means that in some circles and blogs (including somewhere on this one) there is some bad info that says shooting (especially winchester high grain) 308 in a 7.62x51 is bad.  the guy at DPMS must know exactly where I have been reading because he specifically said that was total BS.  however the differences there are in the 2 rounds, my particular rifle is good with either.  straight from the factory. 

I make that easy enough to see, and understand?

There's nothing for me to "calm down about" here.  You're talking bullshiit, and I'm calling it - it's pretty easy.  Oh, by the way, I was calm, the whole time I was doing it, too.  Just so you know...  :thumbup:

Decaf is for pussies, too.  Don't recommend it to me.  You're an idiot, or a sheep, if you think that decaf helps anything. 

You kinda started with the personal insults, there.  If you'd like to continue that path, I'll shut your Cock-Holster for you real fast. 

 

Edited by 98Z5V
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...