Some of the 224 VAL shooters have been having problems with the Primers blowing out. One of the things to check for with this problem is proper Gas Block Adjustment. Not opened enough and rifle will not cycle, opened too much and primers will blow. This is FYI ONLY please contact Savage if you are having problems shooting 224 VAL ammo in your Savage MSR. The Gas Block Adjustment corrected the Primer issues with one of the guys at my Local Gun shop.
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The gun shop guy was shooting Federal Premium 90 Grain SMK Factory Loads. Once he contacted Savage and adjusted the gas block for that SPECIFIC ammo his primer and cycling issues disappeared. The Savage attachment states the gas block is adjustable for each specific type of ammo you are shooting.
You did list very common issues that will cause primers to blow out of pocket.
I fail to see how overgassing the action can cause a blown primer. The bullet has left the barrel and the barrel depressurized before the carrier even moves. The gas is forced into the gas key, not through the chamber. "Blown primers" are from a serious over pressure event in the chamber where the seal around the primer is the weakest point for excessive gas to escape and either the pocket wall is expanded to the point it will no longer hold the primer or the primer cup is compressed, or both. The primer doesn't physically fall out of the case until ejection occurs. Think about that and then ask yourself how opening up a gas system which only reduces barrel pressure if anything can cause a high pressure event in the chamber. It can't. I pretty much guarantee you that these rifles either have a way short headspace or a short throat where the bullets are jammed.
If a gas key adjustment was the issue with Savages they wouldn't have peoples rifles still sitting there for months with no explanation or ETA other than "we're waiting on parts". If this was the case they would have sent them back out and would not need parts.
If a gas key adjustment was the issue with Savages they wouldn't have peoples rifles still sitting there for months with no explanation or ETA other than "we're waiting on parts". If this was the case they would have sent them back out and would not need parts.
"It's long been accepted that a primer popping out of a case when a round is fired is an absolute indication of high pressure. This is usually referred to as "blown" primer. However, it can also occur because a gas-operated, semi-automatic rifle is not properly timed. In other words, the bolt unlocks before the case releases its hold on the chamber, and the primer pops out. It's not an entirely unusual occurrence with AR-10s. Jeff Hoffman with Black Hills Ammunition refers to these as "dropped" primers."
Yeah. was going to say this - blown primers are more frequently a timing issue on a gas gun than a headspace problem.
On a bolt gun it’s not the same action operation and blown primers there are always bad pressure/case metallurgy/headspace.
Seen blown primers on dozens of high pressure ARs.
On a bolt gun it’s not the same action operation and blown primers there are always bad pressure/case metallurgy/headspace.
Seen blown primers on dozens of high pressure ARs.
Yeah, I concur with too much gas causing the bolt to start moving early is usually my first guess with blown primers in an AR. Unsupported cases are very prone to expanding to the point of losing primers. I've run into this issue a few times with different caliber AR's that function fine with a flash hider and then suddenly start blowing primers with a suppressor attached until the correct gas is dialed in.
Now whether or not this is indeed Savage's issue... I have no idea. I don't own one nor do I own a single Valkyrie.
Sure seems odd though... to say "waiting on parts" when adjusting a gas block only takes seconds and no parts are needed. I could understand "we're working through the back log" for the gas block adjustment, but "waiting on parts" might indicate a chamber/barrel pressure issue?
Or it may indicate that at the bottom of the gas adjustment range its too course.
So maybe the adjustable gas block only has "full closed - .010 - .020 - .030" settings for example - and proper gas for the 90grainers was .005.
This is a thing on click detent gas blocks at least - not sure what the savage has.
So maybe the adjustable gas block only has "full closed - .010 - .020 - .030" settings for example - and proper gas for the 90grainers was .005.
This is a thing on click detent gas blocks at least - not sure what the savage has.
Unless there are a shitload of "swipe-marks" on a case rim the above is not true. Excess gas coming back through the system can unlock the bolt befoe it should be, but there will be massive case swipes on the rim, if that happens.
In short, I call bullshit. Savage knows how an AR works by this time of introduction of the .224 Valkyrie. Which, they don't even build the ammunition for. The .224 Valkyrie has already been tested in multiple various forms and nothing here is a mystery. The blown primers are A. headspace or B. high pressure.
In short, I call bullshit. Savage knows how an AR works by this time of introduction of the .224 Valkyrie. Which, they don't even build the ammunition for. The .224 Valkyrie has already been tested in multiple various forms and nothing here is a mystery. The blown primers are A. headspace or B. high pressure.
Only playing devils advocate as I haven't followed the MSR issues at all, but you're poo-poo'ing (yep, that's a non-subtle play on your "bullshit" theme
) the idea of over gas cause there will be "swipe-marks". Then turn around and say that over pressure is more likely... really?!... Wouldn't several different rifles all blowing primers from high pressure exhibit other signs of pressure on the case as well? Playing devils advocate is a good thing. It makes us go back and look at what we say and do.Only playing devils advocate as I haven't followed the MSR issues at all, but you're poo-poo'ing (yep, that's a non-subtle play on your "bullshit" theme
To be clear, which maybe I wasn't before, high pressure in either bolt or gas-gun will cause blown primers. Case swipe WITHOUT blown primers in a semi-auto/auto shows too much gas in the system. The question then is what do the primers look like with case swipe? Flat to the edges and dimpled could well mean, that while getting case swipe, but not blown primers, still shows too hot of a load. Rounded edges of the primer and a regular dent in the primer, but "swiped" would show too much gas.
I ran into this with AA2520 in extreme cold with my 6.5 Grendel. At first I thought "hot loads" because the cases were swiped. Then I realized the primers weren't fully flattened. Reducing loads from where I started only made it worse.
But, blown primers is either caused by too hot of a load, or excessive headspace.
You're right. Primers that fall out due to pressure are "blown" and primers that fall out because the bolt starts moving too soon due to over gassing are "dropped" primers. I tend to use the term "blown" to refer to all primers that have fallen out even though I know I shouldn't.
I think our experiences differ a little as I've experienced both dropped primers on 4 separate AR's and blown primers on more rifles than I care to admit as I used to be a foolish subscriber to the philosophy "always run the ragged edge" on every cartridge I loaded.
"Swipe" marks as you suggested were indeed evident in each instance I dropped a primer, but I couldn't tell that they looked any different from swipe marks from over pressure. There might have been evidence I missed such as primer shape, but the two distinctions that really stood out to me from the dropped primers were: 1) The primer pockets were completely covered in powder residue 2) The primers did NOT fit back into the case. With blown primers from pressure I've always been able to put the primer back into the case fairly easily by hand and the primer pockets are always pretty clean.
Now whether any of my dropped primer observations are anecdotal to my experiences to date or apply to all instances I don't know. Nor do I know if they have anything to do with the MSR issues...
We might be talking in circles here, but I will say this. At initial pressure peak in a case with too much pressure, the case will swell too much and expand backward until the primer is loose. i've done this enough to know, like in a bolt gun, that pressure is the issue. Sometimes to the point, it will go right in and fall right back out.
I've also oversized cases to the point there is play between the shoulder of the case and chamber, and the case is pushed forward when firing but is not not pushed forward so much that the primer won't ignite. These cases, even with light loads, exhibit the classic high pressure loads because the case is suddenly rammed backward to the face of the bolt.
I have never had a gas system type rifle, with properly sized ammo, get slammed back so hard the primer pocket opened up. I've had many a 'swipe' because the pressure at the port (and back through the system) was high. While firing, the case is held tight to the chamber walls. If there is enough pressure to unlock the bolt early, then there is a swipe on the case. But, I have never seen enough pressure from unlocking the bolt early to blow the primer pocket out. The case itself can expand more than expected., but there is nothing to make the primer pocket expand, that wouldn't have already made it expand initially, except over pressure.
The excess throat as described in the pdf would be more inclined to alleviate pressure. Rather than take the 10k pressure from the port and blow primers out. A short throat on the other hand would be more inclined to increase initial pressure.
Could it be these are actually 'undersized cases?' That show swipe because the gas coming back has nothing stopping it, AND, its' moving early due to the gas burning too slow for the load and there is too high pressure at the port?
