Overpressure Factory ammo?

[mikeinco]

in my limited use YES as in faster velocity WITHOUT pressure.
you may see heat is shooting strings, but in the 2-5 i do no issues in my 300 win mags.


Someone at the range last week was blowing primers out of his 30-06 when using Federal ammo. Related info:

- I started playing with Reloder 26 in my 300 PRC earlier this year. I saw significantly higher velocities than expected based on the load data provided by Hornady.
- Federal started using Reloder 26 in their applicable ammo.

Is Reloder 26 in general hotter than expected?

[wbm]

._

[bigedp51]

Anybody ever consider that the factory ammo could be too short for the chamber? Round fires, primer tries to back out of the pocket and gets flattened when it hits the bolt head? Only way to correct that is to pull the bullets out a bit to increase the OAL. (to a jam) That way the case gets fire formed to the chamber.
After that, make sure you don't push the shoulder back too far again or you'll end up with the same thing.
Start with the simple stuff.:p

Very good point, many people do not realize with excess head clearance the primer backs out and becomes flatter or even mushroom shaped when the case is pushed back against the bolt face.

https://i.imgur.com/HK76WCp.jpg

Below a worn .303 British Enfield rifle at max military headspace can have .016 head clearance or air space between the case and bolt face. And your reloads with minimum shoulder bump should have approximately .002 to .003 head clearance.

https://i.imgur.com/sHgqVJR.gif

Below on this SAAMI cartridge and chamber drawing if you look at the min and max headspace and the variations in the belt thickness. The headspace on a new rifle should not vary that much, "BUT" it would not surprise me if the belt was more than .008 under minimum.

https://i.imgur.com/O3zQ5WP.png

[Rocketmandb]

In my first strings with RL 26, I loaded to what the load data was telling me I'd get ~2800 fps. First shot out of the barrel nearly missed the target high because it was going 2900 fps. By the way, aside from this fact (which you catch during load development anyway), I absolutely love this powder... except that it's nearly impossible to find. Though I placed a bunch of back orders, did daily internet searches, etc. and over the course of a few months ended up with more than 20 lbs :)

[Nor Cal Mikie]

"Very good point, many people do not realize with excess head clearance the primer backs out and becomes flatter or even mushroom shaped when the case is pushed back against the bolt face"

What LOTS of folks don't realize is, it's the little things that can cause problems. Right off, it's the GUN, needs new firing pin, head space is off, trigger is causing problems. Funny thing is, you didn't have problems till you started using THAT ammo. Hummm, could it be?? The old saying, KISS! OR, just start throwing money at it. That should solve the problem.:confused: ;)

[pescarconganas]

Here's a quick update:

Finally got results from Hornady and they said it's the underbored barrel causing the issue...still don't believe it or else there'd be a warning on all gmx bullets to not shoot them through Savages.

They were nice enough though, and agreed to send me some replacement products. They sent the replacement out that afternoon and I received 2 boxes of brass a couple days later.

Overall the customer service was great. I just don't buy the thing about Savage bores.

I did some load development with 175gr Barnes LRX and found a load with IMR 4350 that shoots 3090 fps and groups about .75 inch. Gonna try a few other powders but like what I have for hunting this season.

[CFJunkie]

Don't discount the possibility of an under bored barrel or chamber.

As I reported before, I have a Savage 12 LRP in 6.5mm Creedmoor that was bought new and would flatten and crater primers with factory ammo and even with hand loads that were loaded so light that they were 25,000 psi under Pmax. It didn't matter whose bullets it shot - Hornady, Sierra, or Berger - they all flattened the primers and flattened the head stamps on the brass. Primer pockets wore out in less than 4 reloads. I documented the results with factory ammo and with hand loads at 57,000 psi, 47,000 psi and even 37,000 psi and sent the pictures to Savage. They had me return the rifle and bored the chamber out by a few thousandths. That cured the problem and now it will shoot factory and 57,000 psi hand loads without any signs of pressure on the primers.

A worn reamer, either a chamber or bore reamer, can easily under size the bore. That raises the pressure and causes the high pressure signs. It doesn't mean that Savage's specs for the bore are under sized but that they used the reamer too long without replacing it. I have 7 Savages and that is the only one that ever had a pressure problem and boring it out a few thousandths fixed it.