Ammo is too Hot. What to do?

Ganderite

Ganderite

CGN Ultra frequent flyer
Rating - 99.7%
355   1   0
Location
Farm south of North Bay
Usually, I just take it home, pull bullets and re-load with less powder.

But sometimes that is not a real good option. You might be on a hunt or competition and because of hot weather suddenly find you are blowing primers. You don't want to ruin your brass, or worse, but going home is not an attractive option.

I have 500 pieces of new Lapua 260Rem brass to be fire-formed in my Ackley chambered F Class rifle. I have found that 45 gr of 4350 forms the cases perfectly and also shoots very, very well, so I always use this ammo for the short range shooting of 300 to 600 yards, where the reduced velocity is not an issue.

Last week I tested some Sierra and Lapua bullets in this new brass and found that the Lapua bullets shot the best, and they did best with the bullet hard into the rifling. Also found that 46.5 gr was the best. So I loaded up 200 of them for upcoming shoots.

On the weekend I used some of these in a match. Excellent results. Less than 1" at 300 yards. Last night I decided to reload some of the fire-formed fired cases so I could do some load development with these new cases and the Lapua bullets.

Horrors! The primer pockets do not seem very tight. The load is too hot! But I have already made 200 of these!!!

I just tested this ammo, using a trick I have used before as an emergency field fix for hot ammo. I smeared some grease on the bullet, including the ogive. This dropped the velocity a full 100fps. The primer pockets are tight. Now I know how to be able to shoot the remaining 200 rounds, without having to pull bullets and re-weigh powder charges.

I have tested this in the lab, with 308 ammo, and greasing the bullet dropped pressure about 6,000 psi. With military ball ammo, it also improved the SD.

So if you are ever stick with too hot ammo, use some of the grease you carry for lubing your bolt lugs (if you don't have any, someone else will) to smear some grease around the bullets.
 
Great tip. I have always wondered about the effects of lube in the bbl or on a bullet. Heard that excessive lube in the bbl can hydraulically open up the bbl causing a larger bore. Don't know if that one is true.
 
I was going to suggest seating the bullets deeper if they are jammed into the lands, but grease would certainly be a better and easier trick.
 
Republic of Alberta said:
Great tip. I have always wondered about the effects of lube in the bbl or on a bullet. Heard that excessive lube in the bbl can hydraulically open up the bbl causing a larger bore. Don't know if that one is true.
Click to expand...

As it happens, having had access to a ballistics lab, i have played with many different ideas to see what would happen. The lab rifle would handle up to 120,000 psi without breaking a sweat, so that was the place to play.

If a barrel has a big gob of cosmoline in it, it is a problem, especially if the gob is more than 1/3 of the way down the barrel.

When it comes to greasing the bullets, after awhile if you shoot a lot of them, the entire chamber is greased. I never saw any ill effects from this.

In my Rem260 Ackley, the velocity dropped 100 fps. That is about the same as dropping the powder charge about 1.5gr. A useful reduction.
 
Trinimon said:
Seating the bullet deeper would increase the CUP.
Click to expand...

Well if I understand things correctly having your bullet jammed into the rifling causes a pressure spike. Whether or not the increased pressure from seating it deeper would be the same as the pressure spike from being jammed into the rifling would be the same or less I'm not sure, but I suspect it would be less.
 
Spawn-Inc said:
Well if I understand things correctly having your bullet jammed into the rifling causes a pressure spike. Whether or not the increased pressure from seating it deeper would be the same as the pressure spike from being jammed into the rifling would be the same or less I'm not sure, but I suspect it would be less.
Click to expand...

Ya, neither being jammed up into the lands or seated deeper would be a good thing I'm guessing. If it were me, I'd rather not take chances with hot ammo and just pulled 'em. But I'm chicken like that. Good to know lubing up the bullets can reduce pressures.
 
Before you all go galloping off and greasing your bullets read Hatchers Notbook starting on page 337 through 343, pay attention to the words chamber pressure and bolt thrust.

Murphy's law: Anything that can go wrong will go wrong.

http://worldtracker.org/media/library/Law%20Enforcement/Firearms/Hatchers%20Notebook.pdf

dontlube-1_zps229e411c.jpg


Below is from the H.P. White ballistics testing laboratory.

Overpressure-boltthrust_zpsa268b012.jpg
 
bigedp51 said:
Before you all go galloping off and greasing your bullets read Hatchers Notbook starting on page 337 through 343, pay attention to the words chamber pressure and bolt thrust.

Murphy's law: Anything that can go wrong will go wrong.

http://worldtracker.org/media/library/Law%20Enforcement/Firearms/Hatchers%20Notebook.pdf



Below is from the H.P. White ballistics testing laboratory.
Click to expand...

Based on that safety bulletin, all the problems come from a lubed casing, not a lubed bullet.
 
I am familiar with Hatcher. As a matter of fact, it was one of the books given to me when I joined CIL. It was 'required reading".

I have never seen any sign of an issue caused by greased bullets, other than reduced chamber pressure and velocity. I shared it here as a trick to have up your sleeve if you have to shoot hot ammo.

When we compete in some target rifle competitions, we are issued ammo that we have to use. Sometimes the ammo is incompatible with our rifles. The British issue ammo that is sometimes of dubious quality and there are some shooters who routinely use grease on the bullets to improve accuracy. Greasing seems to improve the SD.

The ammo company lab over there ran tests to see if the shooters were flirting with danger. Their conclusion was that it was safe and they also confirmed a drop in pressure and SD.

Logic says that bolt thrust would increase. Maybe lugs are bigger now.

I am reducing the powder charge in my fire forming ammo, but the 200 I already have on hand will get greased as I shoot them.
 
saskgunowner101 said:
I believe he's talking about lubing the bullet only, not the entire cartridge case.
Click to expand...


Spawn-Inc said:
Based on that safety bulletin, all the problems come from a lubed casing, not a lubed bullet.
Click to expand...

If you take the time to read the pages I stated you will find the Americans were just greasing their bullets and not the case and over pressure and increased bolt thrust was the result. "NO" grease or oil belongs in the bore or chamber when shooting a firearm and this is a "VERY" bad idea.

You are to remove any grease or oil in the chamber and bore before shooting, failure to do so will cause an increase in chamber pressure and bolt thrust.
 
yomomma said:
Unless you shoot a Ljungman where it is prescribed to oil the cartridges.
Click to expand...

that was a stop gap measure so the swedes could use 160 grain ammo when the 140 stuff wasn't available , to keep from ripping the rear of the case off the round from too much gas pressure .

the proper fix is to copy the hakim gas system .

greasing the brass is very very bad juju in any rifle .
 
I think the 'Don't grease the chamber bulletin' should be given the same credence as the 'Wandering zero' issue in No. 5 LE's. A major power found something to be problem enough to conduct investigations and issue results on it.
But an amateur ( OK semi-pro, don't mean to offend, lol) ballistics aficionado or Gun Plumber will pronounce the findings of the United States Armed Forces or British Army poppy ####? Sorry to break it to anyone, I'll go with the superpower's findings.
It's not unlike the Shadetree Mechanic tearing out "all that pollution crap" on those 70's and 80's auto mobile engines. Ford or GM probably spent millions developing it, but no I can do better?
Some things are best let alone IMO
But hey, what do I know?
 
This does make sense, and I doubt if it poses any danger to the shooter; probably being analogous to shooting moly coated bullets, with similar results. By now, most of us who have used coated bullets know you have to tweek the loads to get top performance. This is an interesting tip that I intend to explore and add to my repertoire. Now the only question is, Lubriplate 130-A or Imperial Sizing Wax?
 
If your ammo is too hot due to temperature, what range of temperature can be compensated for by lubing the bullets? Do you get equal results with other powders? The 1.5 grain reduction seems a bit too "general" to be taken as gospel. I hope you do more research, interesting as it is.
 
bigedp51 said:
If you take the time to read the pages I stated you will find the Americans were just greasing their bullets and not the case and over pressure and increased bolt thrust was the result. "NO" grease or oil belongs in the bore or chamber when shooting a firearm and this is a "VERY" bad idea.

You are to remove any grease or oil in the chamber and bore before shooting, failure to do so will cause an increase in chamber pressure and bolt thrust.
Click to expand...

You do realize that anyone looking at the page you posted would assume you didn't know the difference between bullet and cartridge case. Are you saying the OP and his observations are wrong?
 
There was a write up in one of the Gun Digest books about the US shooters using a lube on their bullets for the 1903 Springfield, and the Swiss had a implement (can) to grease their GP11 for target shooting. Information for the Swiss can be found at one of the Swiss rifle forums. i.e. http://swissrifles.com/
 
You must log in or register to reply here.
Back
Top Bottom