30-30 Max load differences

[gambleone]

Looking at the big differences in max loads for 30-30 using 150 gr bullet with IMR 4064. Lyman 49th edition states 31.5 gr as max. Hodgdon states 33.3 gr of IMR 4064 as max. Looking back at Lymans 44th edition has it at 36.5 gr of IMR 4064 as max. I knew there would be a difference between sources but didn't expect this. Any input would be appreciated. No pressure signs so far at 31.5 gr, but before going further wanted to see what you guys thought.

 

[jackieschmidt]

It could be that 4064 has gotten a tad hotter through the years and their test showed this.
Or it could be the work of the Legal Department. There are a lot of 30/30’s that are a lot older than most of us on this Forum.
My son loads 31.5 grns of 4895 behind a 150 with no problem in his Marlin.

 

[1lnbrdg]

It's a .30-30.

I shoot 173 gr cast lead at ~1300 fps and plant deer just fine, 6.5 gr Titegroup. Find what shoots accurate and run it.

 

[Uncle Ed]

Looking at the big differences in max loads for 30-30 using 150 gr bullet with IMR 4064. Lyman 49th edition states 31.5 gr as max. Hodgdon states 33.3 gr of IMR 4064 as max. Looking back at Lymans 44th edition has it at 36.5 gr of IMR 4064 as max. I knew there would be a difference between sources but didn't expect this. Any input would be appreciated. No pressure signs so far at 31.5 gr, but before going further wanted to see what you guys thought.

Check and see if your primers are protruding with your load, at the max pressure of 42,000 psi the chamber pressure is not great enough to push the base of the case against the bolt face. Meaning the only pressure on the bolt face is from the primer and not anywhere close to 42,000 psi on the locking bolt.

This begs the question of what is the actual chamber pressure in the chamber of the barrel. Meaning is the SAAMI chamber pressure limit of 42,000 psi for just the barrel or for the locking bolt.

My son has a Marlin 336 and I have a Winchester 94 and factory ammunition and my reloads have the primers protruding in both rifles. And I always wondered if it would be safe to load the 30-30 until the primers were flush with the base of the case????

 

[RegionRat]

Two different versions of the Sierra Manual also changed with time, but in the other direction.

The old one shows 31.8 and the newer one shows 32.2 of IMR 4064 with their 150 gr.

 

[Outrider27]

Different lot numbers of the same powder over the years could even account for much of the differences between manuals.

AS an aside, if you have load data for the TC Contender in 30-30, you will notice that the max loads for a 30-30 Contender are MUCH higher than max loads tailored to/limited by the Model 94 Winchester. Definitely wouldn't want to confuse the two when loading for a 94 or a 336.

 

[OleGreyGhost]

My son has a Marlin 336 and I have a Winchester 94 and factory ammunition and my reloads have the primers protruding in both rifles.

I also have a Winchester 94 that I purchased, used 10 yrs ago, along with some Win 150 gr factory ammo.

Upon test firing, I retrieved the brass, the primers were protruding 0.011" . I brought the gun back to Trops' gunshop where I purchased it. They said this was normal & would not take the gun back.

I was reloading for 25+ years at the time & never ran across this. Everything I read at the time pointed to an overcharge (not likely - factory ammo) or a headspace problem.

I checked around some local gunsmiths & did an internet search at the time. You are the first person that I have come across that describes the same problem.

Did you ever find out any additional info on the problem and/or this is indeed a common trait of the lever guns???

 

[1lnbrdg]

Primer protrusion:

That cartridge headspaces on the rim. Most shoulders are pushed back further than needed allowing if there is room for the cartridge to be pushed toward and the primer backwards under lower pressures.

Well documented in cast bullet loading manuals.

 

[jackieschmidt]

I also have a Winchester 94 that I purchased, used 10 yrs ago, along with some Win 150 gr factory ammo.

Upon test firing, I retrieved the brass, the primers were protruding 0.011" . I brought the gun back to Trops' gunshop where I purchased it. They said this was normal & would not take the gun back.

I was reloading for 25+ years at the time & never ran across this. Everything I read at the time pointed to an overcharge (not likely - factory ammo) or a headspace problem.

I checked around some local gunsmiths & did an internet search at the time. You are the first person that I have come across that describes the same problem.

Did you ever find out any additional info on the problem and/or this is indeed a common trait of the lever guns???

That is in all likely hood the result of a little too much headspace And a few other factors.
The 30/30 has a very shallow shoulder. Often with the pressures exhibited by many 30/30 loads, the pushback of the shoulder in the chamber is not enough to overcome the grip the case on the chamber walls upon ignition, so the primer is pushed back against the bolt face.

 

[gambleone]

I have no protruding primers so far, but I just wanted to get some thoughts on the differences in max loads. Never expected to see that big a difference, but as jackieschmidt suggests, maybe a tad hotter powder and legal team wanting to play safe. Thanks for all info.

 

[2506]

That is the reason that they have STARTING loads. Start low and work up slowly and you will find what YOUR rifle wants. I have an old Speer manual that list loads that it would be hard to get that much powder into a case with many of their calibers.

 

[Uncle Ed]

I also have a Winchester 94 that I purchased, used 10 yrs ago, along with some Win 150 gr factory ammo.

Upon test firing, I retrieved the brass, the primers were protruding 0.011" . I brought the gun back to Trops' gunshop where I purchased it. They said this was normal & would not take the gun back.

I was reloading for 25+ years at the time & never ran across this. Everything I read at the time pointed to an overcharge (not likely - factory ammo) or a headspace problem.

I checked around some local gunsmiths & did an internet search at the time. You are the first person that I have come across that describes the same problem.

Did you ever find out any additional info on the problem and/or this is indeed a common trait of the lever guns???

There is nothing wrong with any rifle if you have protruding primers, it just means low chamber pressure.

If you make a workup load starting at the suggested starting load every rifle I have ever owned had primers protruding. Then as the load is increased the chamber pressure becomes great enough to make the brass stretch back to contact the bolt face.

The same thing happens with reduced loads and the primers protruding. The reloading manuals warn you to not use reduced load cases again with normal pressure loads. This is because each time a reduced load is fired the case shoulder is pushed back increasing the head clearance. Meaning shorter cartridge headspace and increased chance of case head seperations.

Below a rimmed British .303 at 46,000 psi chamber pressure will cause the brass to stretch and contact the bolt face. And the 30-30 at 42,000 psi does not make the brass stretch and only the primer protrudes.

Below when fire forming cases for my .303 Enfield rifles I slip a thin rubber o-ring around the cartridge. This holds the cartridge against the bolt face and prevents the case from stretching. This is the same basic thing as jamming a bullet into the rifling or creating a false shoulder and holding the case against the bolt face.

Below British .303 reduced loads, .312 pistol bullets, a rubber o-ring and fire formed shoulders.

 

[gambleone]

Excellent descriptions Uncle Ed. Kinda simplifies it seeing it in pics.

 

[Uncle Ed]

Excellent descriptions Uncle Ed. Kinda simplifies it seeing it in pics.

If you add your rim thickness to the amount the primer is protruding that will be your actual headspace.
(cheap bastards headspace gauge)

 

[gambleone]

If you add your rim thickness to the amount the primer is protruding that will be your actual headspace.
(cheap bastards headspace gauge)

That's my kinda gauge.

 

[1lnbrdg]

I've never figured out how to get full length resizing on the body and proper shoulder setback with current dies. Always seem to get.004-.005" which works but shorter brass life.

With my chamber and dies, I have to bump the die against the rim to get brass at the base fitting the chamber. Pushed the shoulder back more than I want.

 

[OleGreyGhost]

There is nothing wrong with any rifle if you have protruding primers, it just means low chamber pressure.

I understand the principle behind lower chamber pressure with reduced powder reloads. I just never expected it with any "factory" ammo. This is why I suspected something was wrong.

So by your post # 14:
Rim thickness = 0.055" (just measured)
Primer protrusion = 0.011
making my head space within SAAMI spec.

just the case rim thickness is not within spec.

At least now I have something to work with. Your post has been very helpful.

 

[OleGreyGhost]

That is in all likely hood the result of a little too much headspace And a few other factors.
The 30/30 has a very shallow shoulder. Often with the pressures exhibited by many 30/30 loads, the pushback of the shoulder in the chamber is not enough to overcome the grip the case on the chamber walls upon ignition, so the primer is pushed back against the bolt face

Thanks for the explanation. It seemed everyone I queried about the problem years ago, weren't aware of the anomalies of the 30-30 cartridge.

Didn't have the heart to part with it. At least now I will have another reloading project over the winter after the upcoming hunting season.

Thank you both......

 

[Uncle Ed]

Check your rim thickness again, my Remington rims average .058-.059 in thickness.

My 30-30 cases all fail from split necks and I have never had a case head separation.

So again the max chamber pressure in the 30-30 is not high enough to make the case stretch to the bolt face.

Below is the SAAMI 30-30 cartridge and chamber drawing and it shows the MAX rim thickness of .063 and minimum rim thickness of .053. So average several of your cases and make sure you are not measuring a bur on the inside of the rim.

You can also do what they do with belted cases and let your 30-30 headspace on its shoulder. This will decrease the head clearance or the "air space" between the base of the case and the bolt face.

And on a .303 British Enfield rifle at the max headspace of .074 and a rim thickness of .058 the primer can back out .016. So remember as long as you are not having case head separations, it means the base of the case is not moving to the rear, stretching, and contacting the bolt face.

P.O. Ackley did an experiment and removed the locking bolt on a 30-30 rifle and remotely test fired it. He made sure the chamber was dry and oil free along with the cartridge. The "DRY" case gripped the chamber walls and did not move to the rear and all that happened was the primer backed out. No kaboom or damage to the rifle or case.

Below a British competitive shooter posted this photo here of 7mm Mauser cases with factory loaded ammo. As you can see the primers backed out due to the longer military headspace and low chamber pressure.

So I will tell you what a British competitive shooter said to me in a Enfield forum. "JUST SHOOT THE BLOODY RIFLE" And low pressure cartridges will always allow the primer to back out, and its not the end of the world.

 

[OleGreyGhost]

Below is the SAAMI 30-30 cartridge and chamber drawing and it shows the MAX rim thickness of .063 and minimum rim thickness of .053. So average several of your cases and make sure you are not measuring a bur on the inside of the rim.

The measurement I gave in my previous post was the average of 20 fired cases.

Post # 19 explains the measurements in more detail & shows me that the cases are within SAAMI spec.

I thank you for the additional info. The commentary puts everything into the proper perspective......