Primers falling out of NEW brass?

[corey006]

I have a friend that called me last night.

He is NEWB to reloading.

He is loading 7mm Rem Mag.

Winchester Brass(NEW)

Fed 215 Primers.

63 gr of Reloader 22

160gr Accubond.

He says that some of his primers(not all of them 50%) are falling out upon ejecting the fired round?

He says no other pressure signs and that on the cases in which the primers stay in they are not flattened, pierced or cratered.

He says his OAL is fine...

He has double checked his scale and he trickles every load.

The only thing I could tell him was to back off on the charge.....

The only other thing I could think of is a bad batch of brass or primers are inconsistent size???

 

[snuffy]

According to my Lyman 48th manual, he's right in the middle of the recommended loading for RX22, 60.0 to 66.0. That would be where I would start load development with a rifle that I had loaded for before. A new rifle or new to me used rifle, I would start at the 63.0 level. You never know if you have a tightly chambered, or a tight bore that will raise pressure. That 63.0 grain load MAY be over max in that rifle, it happens.

Primers don't fall out of pockets unless there's a very high pressure developed in the shell. Have him mike the area just in front of the belt. Then compare that to a factory loaded shell. I'd bet it will be bigger by at least .0001.

 

[Walkalong]

Gotta go with snuffy here. Primers don't just "fall out" for no reason.

 

[Lone_Gunman]

I'd bet it will be bigger by at least .0001.

Do you mean .0001 or .001?

What do you use to measure to 1/10,000th of an inch?

 

[Werewolf]

What do you use to measure to 1/10,000th of an inch?

A Micrometer. Looks kind'a like a C Clamp. Has a fixed cylindrical post and a movable post. They come in various sizes and good one's aren't cheap.

Some people have trouble interpolating the dials on manual ones. I imagine most now are digital though so that shouldn't be a problem.

 

[snuffy]

Opps, I did mean .001 not one ten thousandths. But I do have a non-digital micrometer than can read down to 1/10,000ths.

What I was referring to is called case head expansion. It occurs when pressure is exerted on the inside of the case by the burning powder. It is entirely normal and happens to some degree in all brass cased ammo. When primers fall out, the case head has expanded AWAY from the primer pocket to allow it to become so loose that it won't hold onto a primer.

The amount it takes for this to happen varies from caliber to caliber. But it should be around .001 OVER normal factory shells fired in that rifle,(measured before the case is full length resized).

 

[Sunray]

"...good one's aren't cheap..." Neither are the poor ones.
Sounds like a bad batch of brass to me. It happens, albeit rarely. Either that or your buddy has mixed up his primers.

 

[jrumsey]

Ask him if it was hard to lift the bolt on the ones with loose primers (if it was a bolt action rifle) if it was he is over pressure for sure. I would next look at how the scale is set up for zero and then use check weights to see how accurate the scale is in ten grain increments up to the charge weight for the load he is using. With belted cases you can also push the belt back and have a head space condition which might cause a primer issue and allow gas back into the primer pocket.

Joe

 

[Ol` Joe]

Here a quick artical on measureing head expansion as a pressure JUDGEING method. I personally don`t trust it much but it much better then looking at a primer and trying tell where you are.

http://www.reloadingroom.com/page7.html

 

[corey006]

RCBS 505 Scale has been double an triple checked....accurate and working fine.

Primers are not mixed up...as he has just started so he is using Federal Large Rifle Mag only

I asked if the bolt was sticky at all....and he said NO.


I will get him the measure case head expansion.

 

[Walkalong]

What do you use to measure to 1/10,000th of an inch?

A Micrometer. Looks kind'a like a C Clamp. Has a fixed cylindrical post and a movable post. They come in various sizes and good one's aren't cheap.

This one is for inside measurements. A regular one is flat faced where the ball is on this one. I had a pic of this one, and not the other.

 

[flashhole]

Did your friend use a primer pocket uniformer on his brass before he loaded them? If yes, he may have been too aggressive with the uniformer and enlarged the primer pocket. How do I know this......had to trash about fourty 25-06 cases when I got too aggressive and had the same thing happen to me. The primers would become dislodged after firing and some were so big they wouldn't hold a newly seated primer.

 

[corey006]

Nope,

Virgin brass.

No primer pocket uniforming done.

 

[PsychoKnight]

Easy Test:
Try another batch of brass.

 

[jeepmor]

Anyone measure the primer pocket yet, lets look at that pre and post firing and across the batch before we go diagnosing pressure. Same goes for the primers themselves.

If anything it out of spec or varying significantly, contact the manufacturer with some lot numbers.

 

[KI.W.]

Primers falling out..

The same has happennd to me witch Sako cases. When they makes cases it must make soft neck and shoulder witch heating. I do´nt know the right word. It is like "anlening". Ok, there was too much "anlening". Cases was in the wrong positions in the heating.

 

[Eagle103]

I've never reloaded 7mm Rem Mag but the only time I've seen primers back out was on a low charge, not a high one. I was told it's due to insufficient pressure to push the case back and reseat the primer after ignition. Actually falling out may be a totally different scenario though. Someone needs to invent and manufacture a primer that could make more accurate pressure estimations possible by appearance. Sort of like a plastiguage. It would be great for relative noobs like myself. I suppose the lawyers would have a problem with it though.

 

[Ol` Joe]

Primers backing out without pocket expansion is normal with low pressure loads. Primers falling out and pockets enlarged is a sign the pressure is too high for the brass being used. It doesn`t matter if the loads charge is starting, mid of the road, or over book max, it is too hot for the components being used. The load may be OK with a change in brass or bullet brand/style, but as is I would drop a couple grs and call it good. Brass flow begins at around 70K with good cases, your friend is obviously over this.

BTW, 63 gr of R22 with a 160 gr bullet is max in the Nosler #5 manual for the 7mm Mag. Your friend is at max according to the bullet maker. Nosler BTs and Accu Bonds are long for wgt and they have a larger bearing surface then other bullets. One of the reasons to use data for the bullet and not by generic bullet wgt.

 

[ADKWOODSMAN]

Could the overall legth of the loaded round be way too much and therefore pressure to high with the bullet jamed into the lands??

 

[GooseGestapo]

I second Adkwoodsmans assessment.

Having loaded for several 7mags, I can tell you that the throats in the barrels are "all over the place".

I had a similar situation with a friends Savage M110 in 7mmRemMag. I found that I had to seat a Sierra 140gr PtdSpt well under the manual recommendations to get a similar load of H4831SC to "behave". In fact,the initial loadings would not even chamber due to the over length of the seated bullets to "normal" seating depths in most manuals 3.275" oal and 3.290" max. I had to seat to 3.210" to get peak accuracy and 3.230" was "touching" and would give over pressures with a normal "starting" load ...............in this rifle.

Advise your friend to start lower and shorter and "work UP" the load................... Also determing the oal to "touch" the throat and start at least .030 under and again, work up, not "down" as necessary.

I've picked up a lot of previously fired cases from public ranges. Most of the cases exhibit "excessive" pressure signs and are far "hotter" than I would load my own ammo in this cart............

 

[KI.W.]

If You will to measure the headspace and if it is the plunger on the boltfase, put primer to case and shot. Primer goes out so long than the headspase is. Can somebody understand what I was telling?

 

[alsaqr]

"BTW, 63 gr of R22 with a 160 gr bullet is max in the Nosler #5 manual for the 7mm Mag. Your friend is at max according to the bullet maker. Nosler BTs and Accu Bonds are long for wgt and they have a larger bearing surface then other bullets."

Bingo. A lot of new re-loaders ignore the standard admonition to reduce max laods by 10 percent and work up. Then they substitute bullets primers and cases, and wonder why primers fall out.

 

[corey006]

He did start at 59 gr and work up...

The 63 gr must be a max load for his rifle..

The bullet was seated .030 off the lands.

I told him a few days ago to be safe back off about 1 grain for sure...