Pressure Signs?

[titanxt]

I chronographed some loads yesterday and want to get your opinion. The rifle is a Remington Model 7 with a 22" barrel chambered for .223. I was shooting 50-grain Sierra Blitzkings and the average velocity was 3342. The bolt handled lifted easily and the cases extracted and ejected normally. Upon inspecting the brass, I noticed that the primers were cratered a bit. After doing dome Googling, it appears as if that may be a prevailing issue with Remington and enlarged firing pin holes - maybe my issue, maybe not. A few cases had a polished area where they made contact with the ejector, but nothing more than a slight shiny area.

With all of that having been said, is that load too stout? This gun is what I use for coyote hunting so it does not see a lot of repeated rounds.

Andy

 

[mac86951]

That load is too stout for your rifle.

We look for pressure signs not to be withing SAAMI specs only, but to also make sure our rifles are operating within their design limits.

What primers are you using? What Powder? What seating depth, and what is distance to the lands?
without further information its difficult to determine, but reasons I state above:

Primers: Some are softer than others
Powder: some are more temp sensitive than others (but it is winter so this would be a long-shot). How much of what are you using, and how are you measuring it? IE are you consistent and is your equipment working properly?
Seating Depth: Is the bullet jamming against the rifling? This will cause a pressure increase!

Finally, you say you chrono'd a load, but did you work up to that load to begin with? Did you see pressure signs at lower velocities?

Sorry, I don't mean to sound grumpy. These are the next level of questions to answer. I don't want to say use a BR4 primer for a harder cup, when there might be some other underlying issue at hand.

-Mac

 

[ShootDots]

I don't know if it is TOO stout of a load>>>BUT it is definitely a stout load. What powder are you using and how much? Are the BlitzKings jammed or set off the lands?

With one of my .223's I had, I got 3400 with 50gr Ballisitic Tips out of a 26" barrel. I was using a "stout"load of Benchmark powder when it first became available. So if you added say 30 f.p.s. per barrel inch, you would be running 3462>>> it IS a stout load, however, if your cases extract easy, no primer flattening, no shiny marks on the case head and tight primer pockets>>> you should be ok..

 

[CatShooter]

The primer signs may or may not be a sign of problems...reading primers is a "Dark Art"...

... but the ejector wipe is definitely a sign of way too much pressure, no matter what powder/bullet/primer/ or phase of the moon you have - drop a full grain, or find a slower powder.

 

[ShootDots]

The primer signs may or may not be a sign of problems...reading primers is a "Dark Art"...

... but the ejector wipe is definitely a sign of way too much pressure, no matter what powder/bullet/primer/ or phase of the moon you have - drop a full grain, or find a slower powder.

After seeing your post Cat, I saw you said he had marks from the ejector.. I went back and read the OP's posting again and there it was>>>just as you said.. How I missed it, I don't know>>but I did>>and YOU ARE CORRECT>>>TOO MUCH PRESSURE!
OP>> I am sorry I missed it in your posting.. I apologize!

 

[titanxt]

I suspected it was a bit hot and I apologize. I was home for lunch earlier when I posted the question. When I get home I will answer the other questions.

In regards to the load, it was a few rounds out of a bunch that I have loaded for a different rifle. I broke in the barrel with factory rounds that I had lying around and I grabbed these because I was starting to hunt with the rifle and needed the ammo. I will measure the distance to the rifling when I get home, but I think it is closer than I initially thought.

Andy

 

[titanxt]

I apologize for the delay. I pulled the bullet and weighed one of the charges. It was 27.2 grains of Accurate 2460 (AA2460). My Hornady manuals say that 27.1 are max for a NON-COATED bullet, but eh Accurate online information says 26.0 for the un-coated Sierra 50-grain Blitzking.

The load I had developed was for my AR-15 varmint rifle. Since the bullet were moly coated, I had to bump up the charge a bit. I am not sure why they are so hot in this 22" bolt gun over the AR, would it have to do with the gas system on the AR bleeding off some of the pressure? Nonetheless, I am working up new loads.

I will stick with the Sierra 50-grain Blitzkings. I am prepping some brass today and will load up some rounds tonight. I will probably head to the range tomorrow or Wednesday.

Thank you for the help!

Andy

 

[mac86951]

Wow, be careful Andy!

Never recommended to work up a load for one rifle, then port it to another without working up first. Best to treat each as separate entities entirely.

No it isn't the gas system, but differences in chamber cut. 223 has spec tolerances, but there are many different reamers to cut chambers, and when generating 55,000psi, 0.001" can make a big difference.

I'd recommend a reloading review before continuing. Reloading manuals seem to make it "safe," but there are lots of stories of close calls out there. A bit more research in your reloading process might be recommended. Lets see what others comment here.

-Mac

 

[titanxt]

I should not have used that ammunition for sure. I was lazy to be honest. I am now starting from the point of prepping new brass and working up a load for this rifle. I have cut and cleaned the primer pockets, removed the bur from the inside of primer hole, cleaned the case necks, and will trim and chamfer later today.

I also measured the maximum case length for my rifle, as well as the maximum bullet seating depth for the 50-grain Sierra Blitzkings that I will be using. My goal is to have a accurate round that has decent velocity, but does not need to be a screamer by any means.

Thank you all for the reminder not to mix loads and rifles. Seeing that I had several hundred already loaded rounds lying around appealed to my cheap side, not my commonsense side.

Andy

 

[mac86951]

I should not have used that ammunition for sure. I was lazy to be honest. I am now starting from the point of prepping new brass and working up a load for this rifle. I have cut and cleaned the primer pockets, removed the bur from the inside of primer hole, cleaned the case necks, and will trim and chamfer later today.

I also measured the maximum case length for my rifle, as well as the maximum bullet seating depth for the 50-grain Sierra Blitzkings that I will be using. My goal is to have a accurate round that has decent velocity, but does not need to be a screamer by any means.

Thank you all for the reminder not to mix loads and rifles. Seeing that I had several hundred already loaded rounds lying around appealed to my cheap side, not my commonsense side.

Andy

No problem Andy, we've all made our fair share, so best I can say is that we know from experience what not to do.

-Mac