Is Reloading below min recommended safe ?

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Chris Fett

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Hello

I am fireforming new 30.06 cases with the RCBS 100 gr Plinker.

I chose this bullet because it's a relatively inexpensive jacketed projectile. I wanted copper jacket and not lead.

I should have followed the manual's recommendation (RCBS #11 - see photo attached) to stay within min-max parameters (56gr - 60 gr of Wi 748) but I thought since it's only to fireform, 50 gr of 748 would be sufficient. I arbitrarily chose this weight...didn't want to go too low so that the primer would fire across the powder in the case rather than into a wall, albeit sloped and of smaller area.

I wrote to RCBS asking if it's safe to shoot this load but they wouldn't answer....didn't think they would.

I would play it safe and pull them all, but I rolled (200) rounds.

If have to pull them, I will, but those in the know...is a 50 gr load of Win 748 dangerously low when a 56 gr load is considered minimum ?

Rifle: Remington 721 bolt.

Cases: Winchester (same batch)

Powder: 50 gr Win 748

Primers: Fed 210
 

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It depends on the powder. Often NO. However, the so-called "minimum" charge is really a starting load where you should not over pressure with a tight chamber, short throat, and a fast lot of powder. Most rifle powders are not tested for consistency at low pressures and charge weights. Somehow, a light charge of slow burning powder can spike in pressure enough to blow up a gun. No one is 100% sure how it happens but it does happen. However, faster rifle powders are somewhat safer for reduced loads. For example, Hodgdon says you can safely go down to as low as 60% of max charge with H4895 (NOT IMR 4895). Also, IMR 4198 (among other powders) is shown in the Lyman manuals at quite reduced loads and pressures for cast lead bullets. It will probably be fine with jacketed bullets, too. Some internet heroes use Blue Dot for light rifle loads and Red Dot for even lighter subsonic loads. It seems that the faster a powder burns, the less likely it is to explode. Many cowboy action loads for revolver cartridges are under 50% case fill with these fast powders.

Long story short: I'd say it's perfectly safe (and I do it myself) with the 60% H4895 rule and with any powders listed for light cast bullet loads. Such as IMR 4198, IMR 3031, IMR 4227, and SR 4759. Lyman even shows 30gr of Varget for a 200gr lead bullet. That's the slowest rifle powder I've seen listed for any kind of reduced loads. I also haven't seen ball powders listed for reduced loads. Quickload says you'll be at 80% case fill and 35,000 psi with 50gr 748. That's getting pretty low for pressure and ball powders are harder to ignite. I wouldn't do it.
 
Try in the reloading subforum, but to help you now..
Speer has data for two different 110gr projectiles, one which has a fragile jacket and shouldnt exceed 2900fps I believe. They load it with 44.5 to 48.5gr of win 748. The data is freely available from the speer website.

You should be safe from the feared undercharge detonation.
 
IMHO, you are wasting a lot of powder and bullets.. For fireforming, i have used a light charge of a fast pistol powder ( like 7 grs of Unique or Universal), topped with cream of wheat or ground corn flour ( polenta) to fill the case, and a molten bees wax plug. I do not use a bullet. Just fire them in your rifle, and the cases will be perfectly fireformed to your chamber. I have done this to fireform 8x57 cases to 9.3x57 with good results.
 
9.3mauser said:
Fireforming them into what? If they're .30/06 cases being fired in a .30/06 rifle, there should be no need to fireform anything, just load and shoot.
Click to expand...

Perhaps he's got an improved chamber, although he doesn't say that, but I agree there is no benefit to soft load the .30/06 for fireforming. Even when I made 9.3X62 out of .30/06 brass I didn't bother with a light fire forming load. I just expanded the case mouth to .40 to produce the false shoulder, ran it through a 9.3X62 full length die, and loaded the appropriate charge for bullet weight, per Ted Wagner's advice. That said, reduced loads using pistol or shotgun powders are useful for cast bullet shooting, plinking, and small game hunting with a .30/06. Trailboss seems to be the go to reduced load powder now since the demise of SR 4759.
 
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Ganderite said:
It would be safe, however it may hangfire and/or be erratic. A ball powder, light bullet and a non-magnum primer is a very poor combination.

The ES should be very poor.
Click to expand...

I'll say they don't fire at all, and he ends up having to pull them...
 
pacobillie said:
IMHO, you are wasting a lot of powder and bullets.. For fireforming, i have used a light charge of a fast pistol powder ( like 7 grs of Unique or Universal), topped with cream of wheat or ground corn flour ( polenta) to fill the case, and a molten bees wax plug. I do not use a bullet. Just fire them in your rifle, and the cases will be perfectly fireformed to your chamber. I have done this to fireform 8x57 cases to 9.3x57 with good results.
Click to expand...

This
 
No...same calibre but older used rifle...I figure the chamber may not be as concentric as one fabricated today using CAD.
 
First of all, if your rifle is a 30-06, it must be a Model 721, not a 722
Those rifles were known for accuracy, and I would doubt you will find any
chamber irregularities with yours. I would just develop a hunting load
and enjoy my older Remington. Dave.
 
9.3mauser said:
Fireforming them into what? If they're .30/06 cases being fired in a .30/06 rifle, there should be no need to fireform anything, just load and shoot.
Click to expand...

I always fireform cases even when the chamber is the same caliber as the case. Wouldn't do it if they were Lapua cases, but these are bulk Winchester...good quality for sure but there are inconsistencies, even in the same batch, so I always full-body size first time, then fireform and for subsequent reloads I only resize the neck and trim & outside turn the neck as req'd.

Also, the rifle is a Rem 721BDL...manufactured 1955 - 57. Although it's a really accurate rifle, new cases are manufactured to SAAMI specs and that may not be what the chamber was bored out to, especially with a rifle that was manufactured over 60 years ago. I wouldn't fireform with a current new rifle, one that's benefitted from a CAD fabrication process, but I think fireforming for the 721 would squeeze just a bit more accuracy out of it.
 
Eagleye said:
First of all, if your rifle is a 30-06, it must be a Model 721, not a 722
Those rifles were known for accuracy, and I would doubt you will find any
chamber irregularities with yours. I would just develop a hunting load
and enjoy my older Remington. Dave.
Click to expand...

Correct..it's the 721.
 
Chris Fett said:
I always fireform cases even when the chamber is the same caliber as the case. Wouldn't do it if they were Lapua cases, but these are bulk Winchester...good quality for sure but there are inconsistencies, even in the same batch, so I always full-body size first time, then fireform and for subsequent reloads I only resize the neck and trim & outside turn the neck as req'd.

Also, the rifle is a Rem 721BDL...manufactured 1955 - 57. Although it's a really accurate rifle, new cases are manufactured to SAAMI specs and that may not be what the chamber was bored out to, especially with a rifle that was manufactured over 60 years ago. I wouldn't fireform with a current new rifle, one that's benefitted from a CAD fabrication process, but I think fireforming for the 721 would squeeze just a bit more accuracy out of it.
Click to expand...

I am willing to bet twenty 308 Match bullets that you are wrong in thinking that, and this is the perfect time to check it out. Load 10 rounds with fire-formed brass and ten with exactly the same load in the other brass. Shoot two five shot groups at 200 yards, one from each batch. Then do it again on another day, Compare the two sets of groups for both group size AND point of impact.

My bet is there will be so little difference in group size or POI that you won't bother doing it any longer. If you win, send me your mailing address. If I win, you can take a kid or a new shooter to the range and burn up a brick of 22 ammo while teaching them sight picture and trigger control. :)

Ted

PS: I have won this bet many times.
 
Ganderite said:
It would be safe, however it may hangfire and/or be erratic. A ball powder, light bullet and a non-magnum primer is a very poor combination.

The ES should be very poor.
Click to expand...

This. Ball powder is harder to ignite and winchester used to and maybe still does caution against downloading. Would be better to use an extruded powder
 
I've read alot about fireforming. In the end I decided to not waste the components. Whether virgin brass or once fired factory, I just take a known load, back off 0.5%, load and shoot. I won't use these bullets in competition, but they are perfectly suited for practice. I have never noted more than a marginal change in average velocity or group size, which is typically resolved by dialing the load back in after the downloaded first shot.

I was never convinced that 'fireforming' was all that important is not using a full pressure charge, unless you were wildcating a case into a chamber other than what it was made for.

danger of sub-minimum charges, it seems to be more folklore than science, but if there is something to it I suspect the problem lies in the primer igniting powder at the far end of the case which causes the explosive train to work backwards towards the case head rather than forwards towards the bullet.

A simple solution here is to take a wadding material like a cotton ball and wad the powder down against the case head. buy the smallest ones you can find and for a .308 you will probably still need to cut it into halfs or quarters. You can pack it down gently with a roll punch. You aren't packing the powder so much as simply pressing the cotton down so that it holds the powder in place when you tip the case on its side to load it into the chamber.

Ive done this hundreds of times with low powered .50 bmg and 14.5mmR loads, and found that not only is there is no concern with safety, but the wadding ensures better consistency in powder burn and velocity. Youd be surprised the effect on velocity if you shake all the powder to the top of the case vs bottom
 
rifleman762 said:
It depends on the powder. Often NO. However, the so-called "minimum" charge is really a starting load where you should not over pressure with a tight chamber, short throat, and a fast lot of powder. Most rifle powders are not tested for consistency at low pressures and charge weights. Somehow, a light charge of slow burning powder can spike in pressure enough to blow up a gun. No one is 100% sure how it happens but it does happen. However, faster rifle powders are somewhat safer for reduced loads. For example, Hodgdon says you can safely go down to as low as 60% of max charge with H4895 (NOT IMR 4895). Also, IMR 4198 (among other powders) is shown in the Lyman manuals at quite reduced loads and pressures for cast lead bullets. It will probably be fine with jacketed bullets, too. Some internet heroes use Blue Dot for light rifle loads and Red Dot for even lighter subsonic loads. It seems that the faster a powder burns, the less likely it is to explode. Many cowboy action loads for revolver cartridges are under 50% case fill with these fast powders.

Long story short: I'd say it's perfectly safe (and I do it myself) with the 60% H4895 rule and with any powders listed for light cast bullet loads. Such as IMR 4198, IMR 3031, IMR 4227, and SR 4759. Lyman even shows 30gr of Varget for a 200gr lead bullet. That's the slowest rifle powder I've seen listed for any kind of reduced loads. I also haven't seen ball powders listed for reduced loads. Quickload says you'll be at 80% case fill and 35,000 psi with 50gr 748. That's getting pretty low for pressure and ball powders are harder to ignite. I wouldn't do it.
Click to expand...

Thanks for the explanation. Are you saying that there's a possibility the 748 will NOT ignite because of the low pressure (35 ksi) or because of the 80% case fill ? What if the 748 ignites ? No issues, correct ? SAAMI says 60 ksi MAX pressure...there isn't a chance that detonation would be latent to bring that pressure over 60ksi , would there ?
 
Chris Fett

If you look at the reloading data you posted for the 110 grain bullets you will see all the ball powder loads use a magnum primer.

And if you go to Hodgdon's website and look at the 30-06 loads they only list 52.7 grains of 748 with a 110 grain bullet and no start load.

I use 748 in my 30-30 that has a 16 1/2 inch barrel and use a magnum primer. And if I do not use a magnum primer I will have grains of unburnt powder in the bore.

There is a very good possibility with your 50 grain load of 748 of poor ignition with a standard primer and unburnt powder and possibly other low pressure problems. On top of this the low chamber pressure will not push the rear of the case back against the bolt face. Meaning the case will not be formed to the chamber. And the amount the primer is protruding is how short the case shoulder is from being formed to the shoulder of the chamber.

If you want to form your cases then use your standard high pressure load so the case does form to your chamber. And even after the first firing with a high pressure load the cases will not be fully formed. And your mouse fart load of 50 grains will not form the case and you will have the primers protruding from the base of the case and gain nothing.

I prefer to full length resize and give the case a little wiggle room for the bullet to self align with the bore. Below is Kevin Thomas who worked at the Sierra ballistic test lab and now shoots for Team Lapua USA. Please note the funny comment what the late Jim Hull of Sierra bullets said below. "The cartridge should fit the chamber like a rat turd in a violin case." In simple terms, this just means the full length resized case body does not touch the chamber walls and has no effect on the bullet alignment with the bore.

Y3IiYL5.jpg
 
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Below some followup, the photo below shows factory loaded 7mm Mauser cases that were fired in an old surplus Mauser rifle. The chamber pressure was not high enough to push the case back against the bolt face. And this allowed the primers to protrude and the case shoulder not being formed to the chamber. You will see this if you make work up loads starting at the suggested start load and working up. And at the lower loads the primers will protrude until the pressure is high enough to push the case against the bolt face. And if the pressure were high enough to push the case to the rear the case has to stretch and thin by the same amount that the primers are protruding. And this is why to form cases you use a bullet jammed into the rifling or a false shoulder to hold the case against the bolt face.

And my 30-30 primers at the max load and pressure of 43,000 psi always have the primers protruding .004 to .006 depending on the rim thickness.

Bottom line you do not form cases with low pressure loads and you also run the risk of this actually pushing the shoulder back a thousandths or more each time the case is fired. In most reloading manuals you are warned to never shoot cases used for reduced loads with high pressure loads. This is because each time the case is fired at low pressure the shoulder is pushed back by the force of the firing pin hitting the primer.

YLNgBO6.png
 
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