30-30 popping primers

[coyoteking]

I’ve got a Winchester 1894 in 30-30 that was manufactured in 1895 and rebarreled at some point, the date stamp on the barrel is 1946.

I finally got around to shooting it for the first time a couple days ago. After firing 4 rounds I picked up a case to inspect it and found the primers were pushed halfway out of the pocket. I was shooting federal 170 gr factory ammunition.

What could cause this? Fwiw, I measured the shoulder of the fired case and compared it to the shoulder of a loaded round and found the shoulder has moved forward .024” on the fires cases. As the 30-30 headspaces on the rim, this couldn’t be the issue, right?

 

[jethunter]

The primers backing out, and the shoulder moving forward both point towards headspace issues. 30-30 doesn't headspace on the shoulder but having it move forward that much tells you there's probably extra room in that chamber. Backed out primers say the same.

If you fireform brass to that chamber you could use it. You would need to use the o-ring method or something similar to get the brass positioned in the chamber properly so it will fireform properly. .303 British rifles commonly have the same problem with excess headspace and using brass that has been fireformed to the individual chamber solves it.

 

[tjhaile]

It could be excess headspace, but it could also be a sign of low pressure or a combination of the two. Sometimes, at low pressures, there isn't enough rearward thrust to push the case head against the bolt face, but the primer gets pushed out until the bolt face stops it.

.30-30 factory ammo tends to be loaded pretty conservatively and it isn't unusual to see primers backing out to some extent.

 

[billdick]

Head space is your issue. The firing pin is pushing the case ahead and when it fires the brass sticks to the chamber and the primer slides out until it touches the bolt face. They head space on the rim so the rim should fit tight between the barrel and bolt face.

 

[jethunter]

It could be excess headspace, but it could also be a sign of low pressure or a combination of the two. Sometimes, at low pressures, there isn't enough rearward thrust to push the case head against the bolt face, but the primer gets pushed out until the bolt face stops it.

.30-30 factory ammo tends to be loaded pretty conservatively and it isn't unusual to see primers backing out to some extent.

I wouldn't expect low pressure with factory ammunition.

 

[mbogo3]

Barrel could be set back and chamber refreshed or if it don't bother you have the bolt face plated to take up the slack.

 

[jethunter]

Barrel could be set back and chamber refreshed or if it don't bother you have the bolt face plated to take up the slack.

Is there any hope a new bolt would tighten things up?

 

[John Y Cannuck]

Is there any hope a new bolt would tighten things up?

If it's been re-barreled it's most likely a new barrel was just screwed on and never checked, possibly by the last owner himself. The barrel should be set back to properly headspace the rifle. The chances of a new bolt accomplishing a fix for the headspace issue indicated by the op are pretty low IMO.

 

[bigedp51]

Measure the case rim thickness and the amount the primer is protruding and this will be your actual headspace.

The primers backing out is normal, the 30-30 max chamber pressure of 43,000 psi is not great enough to push the case back against the bolt face.

The primers on my Winchester 94 30-30 and my sons Marlin 30-30 back out all the time, and the amount they back out is your head clearance.headspace

Below depending on your rim thickness on average the primers can back out .007 to .009 maximum. If you have a vernier caliper you can measure your primer protrusion and rim thickness to get your rifles actual headspace reading.

With lower chamber pressure like starting at the suggested start load or reduced loads any cartridge will have backed out primers. And the amount the primer backs out is your head clearance. And with a resized case with .002 shoulder bump you would have approximately .002 head clearance.

Below is the cheap bastards headspace gauge with rimmed cartridges.

1. Take a new or full length resized case with the primer removed and measure from the case mouth to the base of the case and write it down.

2. Now take a fired spent primer and using your fingers just start the primer into the primer pocket.

3. Now chamber the case and slowly close the bolt and let the bolt face seat the primer.

4. Remove the case and measure again from the case mouth to the base of the "primer" and write it down.

5. Now subtract the first case measurement from the second and this is your head clearance and the amount the primer is protruding.

6 Now measure your rim thickness and add it to your head clearance and this in your rifles actual headspace. And the max field gauge 30-30 Win headspace is .070.

NOTE, if the rifle is over .070 you should get a gunsmith to set the barrel back to GO and NO-GO headspace limits to be safe.

 

[bigedp51]

Below is how far the primer backed out on a worn WWI No.1 Enfield rifle that is over maximum head space. This rifle was being safely fired with reduced loads and cast bullets even with it being over maximum headspace. Normally with a rim thickness of .058 and at the max headspace of .074 you would have .016 head clearance. You can see the primer still has rounded edges and the sides of the primer have not expanded with the primer becoming mushroom shaped. The danger is at higher pressures when the primer sidewalls expand outward there is the danger of the primer letting go and rupturing. (mushroom shaped fired primers)

 

[mbogo3]

There you go a detailed explanation.

 

[coyoteking]

Thanks for the reply’s everyone. I’ll be using Bigedp’s excellent advice to take some measurements tonight. Here’s a pic of one of the spent cases. I’m guessing I’ll have to find a gunsmith to set the barrel back judging by how far the primer has backed out.

 

[maynard]

Try something other than Federal ammo.

 

[bigedp51]

Thanks for the reply’s everyone. I’ll be using Bigedp’s excellent advice to take some measurements tonight. Here’s a pic of one of the spent cases. I’m guessing I’ll have to find a gunsmith to set the barrel back judging by how far the primer has backed out.

View attachment 239923

Do my test backwards and measure the fired case with the protruding primer first. Then remove the primer and measure the case again and do the math. Then measure your rim thickness and add the two figures for your rifles actual headspace.

And remember when only the primer is touching the bolt face the force on the bolt or bolt trust is extremely low.

 

[coyoteking]

Do my test backwards and measure the fired case with the protruding primer first. Then remove the primer and measure the case again and do the math. Then measure your rim thickness and add the two figures for your rifles actual headspace.

And remember when only the primer is touching the bolt face the force on the bolt or bolt trust is extremely low.

It looks like I’ve got 0.075” of headspace.

 

[bigedp51]

It looks like I’ve got 0.075” of headspace.

The 30-30 Winchester headspace gauges below.
GO = .063
NO-GO = .067
Max Field = .070

Forster offers three lengths of headspace gages per rifle caliber. In order from the shortest to longest, they are: GO, NO-GO and FIELD:

GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gage, the chamber will accept ammunition that is made to SAAMI’s maximum specifications. The GO gage is essential for checking a newly-reamed chamber in order to ensure a tight, accurate and safe chamber that will accept SAAMI maximum ammo. Although the GO gage is necessary for a gunsmith or armorer, it usually has fewer applications for the collector or surplus firearms purchaser.

NO-GO: Corresponds to the maximum headspace recommended for gunsmiths chambering new firearms. This is NOT a SAAMI-maximum measurement. If a rifle closes on a NO-GO gage, it may still be within SAAMI specifications or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gage. The NO-GO gage is essential for checking a newly-reamed chamber in order to ensure a tight and accurate chamber.

FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gage, its chamber is dangerously close to, or longer than, SAAMI’s specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gages are slightly shorter than the SAAMI maximum in order to give a small safety margin.

 

[coyoteking]

The 30-30 Winchester headspace gauges below.
GO = .063
NO-GO = .067
Max Field = .070

Forster offers three lengths of headspace gages per rifle caliber. In order from the shortest to longest, they are: GO, NO-GO and FIELD:

GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gage, the chamber will accept ammunition that is made to SAAMI’s maximum specifications. The GO gage is essential for checking a newly-reamed chamber in order to ensure a tight, accurate and safe chamber that will accept SAAMI maximum ammo. Although the GO gage is necessary for a gunsmith or armorer, it usually has fewer applications for the collector or surplus firearms purchaser.

NO-GO: Corresponds to the maximum headspace recommended for gunsmiths chambering new firearms. This is NOT a SAAMI-maximum measurement. If a rifle closes on a NO-GO gage, it may still be within SAAMI specifications or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gage. The NO-GO gage is essential for checking a newly-reamed chamber in order to ensure a tight and accurate chamber.

FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gage, its chamber is dangerously close to, or longer than, SAAMI’s specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gages are slightly shorter than the SAAMI maximum in order to give a small safety margin.

Thanks Ed, this has been incredibly helpful. I’ll be taking this rifle to a gunsmith before firing again.

 

[bigedp51]

Thanks Ed, this has been incredibly helpful. I’ll be taking this rifle to a gunsmith before firing again.

They make oversized locking blocks that decrease the headspace on the Win 30-30 from plus .005, .010, .015 to plus .020. A plus .010 will put your 30-30 between the GO and NO-GO gauges without setting the barrel back. .Meaning a new plus .010 locking block would put the headspace at approximately .065 and you will be good for another 100 years.

NOTE, the military headspace for the .303 British is min .064 and .074 max and at 49,000 psi the .303 case will stretch. And at 43,000 psi the 30-30 cases do not stretch and the primers always protrude. I have Enfield rifles that are over max headspace that I shoot with lower pressure loads with no ill effects.

I would ask the more senior and more experienced forum members here that know a lot more about the Winchester 30-30 if .005 over max headspace will hurt anything other than backed out primers.

On my No.4 Enfield rifle below I have adjusted and set the headspace .006 below minimum and .010 over maximum (.084) to see the effects. All that happened was the cases stretched more as the headspace increased. But all that happens on a 30-30 is the primers back out further without any case stretching. And in your photos your primers show no bulging or distortion .

Where is Ganderite when you need him the whole world wonders.

 

[just having some fun]

My first center fire rifle was a win 30-30
first range visit primers were backing out

took it to a gunsmith with fired cases in hand

at that point in my life I knew 0 about guns

he took one look at it and said leaver is bent ... left it with him ... he fixed it

He re-bent the leaver / heat treated it ?????

still have rifle

 

[bigedp51]

My first center fire rifle was a win 30-30
first range visit primers were backing out

took it to a gunsmith with fired cases in hand

at that point in my life I knew 0 about guns

he took one look at it and said leaver is bent ... left it with him ... he fixed it

He re-bent the leaver / heat treated it ?????

still have rifle

I don't know if I would let a Gunsmith tell me to get bent.