DPMS LR308 ejection marks

[Thor2j]

Hi guys,
just getting into reloading .308, been reloading lots of other stuff mainly handgun. I was shooting factory winchester 150gr bullets and was wondering why the ejection marks on these cases are so bad. Also was wondering why winchester puts these marks at the top of their cases. Any help would be appreciated.

I also loaded about 20 rounds of Lapua new brass with varying amounts of Varget from 42-44 and the ejection marks on the Lapua brass arent nearly as bad. All these cases are factory winchester.

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[turbo54]

Re: DPMS LR308 ejection marks

The dents are par for the course. With an adjustable gas block and/or cutting down your ejector spring, you can tune that out somewhat.

The marks on the caseneck are from Winchester crimping the case onto the bullet.

Some may disagree, but my opinion is Lapua brass is a waste in an AR, unless you've got money to burn - and I'm guessing you don't.

 

[amaxwell5]

Re: DPMS LR308 ejection marks

Mine does the same thing but smaller less noticeable dents. Gunsmith said he could grind and smooth the piece that the bolt assembly fits into. I can't remember the exact name right now but it's the piece that looks like a gear. I'll remember it as soon as I hit submit I'm sure. You might look into that if you can.

 

[turbo54]

Re: DPMS LR308 ejection marks

...you're referred to the barrel extension...

The lugs on my barrel extension were really sharp, so I removed my barrel and used a dremel with a cratex wheel to smooth them out.

Smoothing their leading edges will stop the scratching along tge length of the case, but won't fix the denting.

 

[Platypus]

Re: DPMS LR308 ejection marks

Interesting, the dents I am seeing on my brass out of my DPMS 308 are coming from the hard edge on the forward assist body as the brass is slapped back into it with ejection. Thinking about knocking that hard edge down and see what happens. anyone else seeing the same issue?

 

[turbo54]

Re: DPMS LR308 ejection marks

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: platypus</div><div class="ubbcode-body">Interesting, the dents I am seeing on my brass out of my DPMS 308 are coming from the hard edge on the forward assist body as the brass is slapped back into it with ejection. Thinking about knocking that hard edge down and see what happens. anyone else seeing the same issue?
</div></div>

Getting an adjustable gas block and turning the gas down, and/or trimming the ejector spring down a bit will help that.

 

[Platypus]

Re: DPMS LR308 ejection marks

Thank you for the advice and options to look at. I guess I am now in the hunt for an adjustable gas block to fit under a Troy 13.8 fore end. I will pull the ejection spring out tonight and try that first but with a 308 can in the future I might as well start on my quest for a gas block as well.
Thanks again,

Danel

 

[Subxero]

Re: DPMS LR308 ejection marks

my brother in laws dpms 308 does the same thing but worse. the dents happen right at the case mouth and are pretty severe, its a pain in the ass

 

[Thor2j]

Re: DPMS LR308 ejection marks

Fixed almost all my problem. Brass was ejecting and smacking into the forward assist. Placed some Velcro (soft side) on the forward assist riser. Now only marks are small scratches on the neck from the extractor dragging it across something on the way out. When I put a loaded round in the chamber and cycle it the bullet looks like Freddy Kruger got a hold of it.
For what it's worth, the winchester brass is a whole lot softer then the Lapua brass.