Jump to content
bowhunter-tw

Loose primer pockets

Recommended Posts

1 hour ago, L Cazador said:

Simply put the cartridge head has expanded due excessive pressure. Back the load off two grains and start over with new brass. Trying to whip a dead horse to life is a waste of time. Look for new node in .5 grain increments. I'm going to say the problem is the Hornady bullet which has a secant ogive and you have it seated a bit too close to the lands. Especially on the first firing you should always shoot a middle load to fire form brass and than try your maximum load. Going to Reloader 19 is not a good idea as it is a much faster burn rate. Buy Norma brass.

Ive got some norma brass I can use. Should I seat the bullets a little deeper? Im seating them a little long of the cannelure (about .010-.015 short of it) I was going to back off a grain an see how that looked

Share this post


Link to post
Share on other sites
2 hours ago, bowhunter-tw said:

Ive got some norma brass I can use. Should I seat the bullets a little deeper? Im seating them a little long of the cannelure (about .010-.015 short of it) I was going to back off a grain an see how that looked

Is the Norma brass new? If it is, back off two grains and fire form. Don't look for a load until you have fireformed brass to your chamber. Most brass is made short of chamber length so it will fit all chambers. Firing a maximum load with brass that is short for your chamber can overstretch not only the head diameter but also the body length. Start with 10 pieces of new brass and be aware of case length, case head diameter, and overall cartridge length. I would not continue using the brass that has loose pockets. Loose pockets create a poor gas seal. Escaping gases can damage bolt and trigger. Not worth it. On your question regarding seating length, I'd start at the cannelure for fire forming then go out further with test loads. Measure head diameter at the belt with a micrometer with .0001" resolution so you have an idea of pressure. Any expansion of more than .001" at the belt is not good. You should be under this number after fireforming.  Generally after fire form you should have .0005-.0008" expansion at the belt. 

  • Like 1

Share this post


Link to post
Share on other sites
On 9/18/2023 at 1:19 PM, bowhunter-tw said:

All the brass I have is once fired, but not in my chamber. When you say at the belt do you mean the diameter of the belt or diameter right above the belt where the case meets the belt? 

Measure at the belt and just forward of the belt since this brass was fired in another chamber. Hopefully that once fired brass is within SAMMI dimensions. I'd back off 2 grains and go up 1/2 grain at time till you see the belt increase in size.

Share this post


Link to post
Share on other sites

I just measured random pieces of once fired brass from low end loads to the upper end, factory once fired, and factory loaded ammo. All the once fired brass measures within .0002”-.0003” of each other at both the belt and in front of the belt. But from the factory new ammo vs any once fired the case right before the belt has grown .005” no matter the load?

Share this post


Link to post
Share on other sites

I find very hard to believe that you have loose primer pockets on the 2nd firing. (unless is a very bad batch of brass?)

Maybe you need back out and start at 62 grains of powder instead of 65? check your velocity, sd and es and of course how well they group. Then 62.3, 62.5, 62.8, 63.1, 63.4, 63.7 and so on. Load 5 rounds of each load. Check every piece of brass after every firing and look for sings of pressure. If on a specific load you start to see sighs of pressure Stop rigth there! Write down all your info and choose the best load with the best sd, es and of course the best group.

If the brass wasn't  fired on your rifle, I'll bump the shoulder 1 to 2 thousands and go from there. Don't forget to anneal your brass before rezising. Im sure some where in the 2900 to 3000 fps there is a happy recipe for your rifle and brass. Good luck and keep us posted.

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, bowhunter-tw said:

Pressed a fed primer into a case, went in with expected amount of tension vs the win primers. Maybe the brass isnt over pressured its the primer size

Something a little small about the win primers. Never have liked using them. Hopefully the fed primers are the fix!

  • Like 1

Share this post


Link to post
Share on other sites
21 minutes ago, Ernesto C said:

I find very hard to believe that you have loose primer pockets on the 2nd firing. (unless is a very bad batch of brass?)

Maybe you need back out and start at 62 grains of powder instead of 65? check your velocity, sd and es and of course how well they group. Then 62.3, 62.5, 62.8, 63.1, 63.4, 63.7 and so on. Load 5 rounds of each load. Check every piece of brass after every firing and look for sings of pressure. If on a specific load you start to see sighs of pressure Stop rigth there! Write down all your info and choose the best load with the best sd, es and of course the best group.

If the brass wasn't  fired on your rifle, I'll bump the shoulder 1 to 2 thousands and go from there. Don't forget to anneal your brass before rezising. Im sure some where in the 2900 to 3000 fps there is a happy recipe for your rifle and brass. Good luck and keep us posted.

An annealer is one of the last pieces of reloading equipment ive yet to get

Share this post


Link to post
Share on other sites
11 hours ago, bowhunter-tw said:

An annealer is one of the last pieces of reloading equipment ive yet to get

In the mean time..a cordless drill, a socket and a torche will do the trick. 

Share this post


Link to post
Share on other sites
Just now, Ernesto C said:

In the mean time..a cordless drill, a socket and a torche will do the trick. 

I have done this! Works well enough for now! Does it make sense to anneal before or after sizing? After would relieve work hardening stress after sizing but before would probably prevent splitting? 

Share this post


Link to post
Share on other sites
34 minutes ago, bowhunter-tw said:

I have done this! Works well enough for now! Does it make sense to anneal before or after sizing? After would relieve work hardening stress after sizing but before would probably prevent splitting? 

 

34 minutes ago, bowhunter-tw said:

I have done this! Works well enough for now! Does it make sense to anneal before or after sizing? After would relieve work hardening stress after sizing but before would probably prevent splitting? 

What Ernesto C says but I would only do load test with 3 instead of 5. After you get close then shoot 5 to verify. Anneal before sizing. Sounds like you may have a brass issue instead of overexpanding. 

Share this post


Link to post
Share on other sites

I have seen loose primer pockets on federal brass in 7mm rem mag as well as my 300wsm. Some of each caliber had loose primer pockets after firing the factory loaded ammo. So they were loose after 1 single firing from factory loaded ammo and some i got 1 load out of them, now if i end up with fed mag brass i just throw it in my scrap brass bucket. I use the ballistic tools primer pocket go/no-go gauges for all of my rifle brass as well. Great for a quick check after decapping. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×