Using D4064 in 308 and possible pressure signs

powdergun

powdergun

CGN Ultra frequent flyer
Rating - 100%
245   0   0
So I loaded a box of 308 with 150 gr Speer and 43 g of D4064 ( min load listed for IMR4064). It shoots well but three of,the rounds I fired were a wee bit tight ejecting the spent brass. Primers looked good no flattening or cratering. I developed the load following the instruction given for the Dominion powder.

Just wondering as I was using some used Federal brass. ( neck sized) When priming the brass some of the primers went in very easy while the others went in with normal pressure. Is it a brass issue or is the Dominion powder hotter than its IMR counterpart. I will be tossing the federal brass and switch to new starline.
 
First thought is neck sized used brass. Try running them through an fl die and I bet they'll work great after. Should be nowhere near sticky bolt pressures with that load and the primers certainly agree with that theory.
 
Federal brass is a little thicker, and softer than most. Without using a chronograph, it's hard to say if you have excess pressure, but I'd bet your load is at nominally safe pressure with Federal or any brass. "A wee bit tight ejecting" is a fairly ambiguous pressure sign. Tight extraction is one thing, tight ejection is another. If your brass was used an unknown number of times or in a different rifle, full length sizing may help. Loose primer pockets makes me suspicious that the brass was stressed during a previous firing. So new Starline is a good idea for the next batch.
 
Extraction vs ejection ? The bolt was a little tight lifting but the brass popped out without issue so which is which ?
 
powdergun said:
Extraction vs ejection ? The bolt was a little tight lifting but the brass popped out without issue so which is which ?
Click to expand...

I've had the same issues with factory ammo.

IMHO, a bit of bolt lift drag during extraction is fairly common and nothing to be worried about.

Now, if you have ejector drag marks on the base or cratered/flattened primers, which you state aren't present, IMHO you're good to go with your present load.

You could bump the shoulder of your case back a few thou, which would partially resize the sidewall as well. Sometimes this clears up the issue.

If you're satisfied with the velocities and there is nothing else that's obvious, go with what you have and don't worry about it.
 
Federal brass is useless for detecting pressure except for how much pressure soft federal brass can handle.
42.5gr of the D4064 with 168's match my varget load for velocity with 43gr, it is a very mild load.
 
From what i have seen with many cartridges, Federal brass weigh more than others so the internal volume is smaller which in turn can lead to higher pressure faster than with other cases. The best way to check for excessive pressure is to use a micrometer($60-$90). When one has ejector marks or heavy bolt lift, the pressure is way higher than accepted for the cartridge. I always use a micrometer and chronograph for load development. Just my 2 cents...
 
Wish I did have a chrono. When I load develop I always stick with the min/max listed in the books. The brass looks fine but I am going to pitch it and go with new. I always tell myself to start with new brass but with the shortages and price of things I have been cheating out lately.
 
powder gun - I do not think there is a "book" with pressure tested results for Federal brass and that powder - you are "hoping" what you found will give similar results. My only caution is what you did - start low and work up - with your stuff. You just have to experience once, where your load locked up that bolt tight and can not get it open without pounding on it with 2x4 - if unfortunate enough to have a Rem 788, then have extra spice when that bolt handle breaks off - so still have bolt frozen shut and have to go find the damn handle - after all that gets fixed, makes one fairly "shy" about not having time to "work up" a loading ...

From my own perspective, working up load and firing through chronograph is best. If that is not possible, is bolt getting tight to open? Finally, what do primer shoulders look like? Last two have been shown many times in many articles not to be "proof" - they can be false negative - but I have not read of instance where tight bolt to open was a "false positive" for pressure.

Is somewhat confounded that some factory actions notorious for bolt handle installed "out-of-time", so is NO primary extraction on opening that bolt.
 
Last edited:
powdergun said:
Wish I did have a chrono. When I load develop I always stick with the min/max listed in the books. The brass looks fine but I am going to pitch it and go with new. I always tell myself to start with new brass but with the shortages and price of things I have been cheating out lately.
Click to expand...

Look at a low end magnetospeed or the next time you're at a gunshow, look for a used Chrony.

Chrony types work well enough for load development and at the last two shows, the vendors couldn't give them away.
 
You must log in or register to reply here.
Back
Top Bottom