I have a .38-40 rifle and revolver. I wish to handload a round that is compatible in each. From what I have read, it seems to me that the difference between a rifle and pistol primer is that it takes less force to detonate a pistol primer than a rifle primer. I am surmising that there may be greater pressures generated with a rifle primer than a pistol primer, but is this true, or not? And, even if it takes more force to detonate a rifle primer than a pistol primer, why would this matter? I cannot think of any time I would pull the trigger on a rifle and NOT want the round to discharge, so why would it matter if it takes more or less force to detonate it? So, I guess my question is two-fold: Why is there a distinction between pistol and rifle primers (in that if rifle primers do not always detonate in a pistol, why are not all tolerances that which are found within pistol primers?); and, should I still handload identical loads, compatible with my revolver and rifle, EXCEPT for different primers, OR can I reload using pistol primers for both? Incidentally, when I first started handloading, I did NOT realize there was a difference between pistol and rifle primers and I loaded, and fired, 100 .41 Long Colt rounds in a Colt 1895 revolver and had NO problems whatsoever. It was only after I fired all 100 rounds, I discovered there was a distinction between the two types of primers. Lastly, for those more technically oriented, what is in a rifle primer that makes it inherently different from a pistol primer?
Rifle vs pistol primers
- Thread starter orpington
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onegunred
Member
A rifle primer is taller than a pistol primer. And it may be hotter.
Large rifle primers are, as you say, taller than large pistol primers. Small primers are the same.
Rifle primers have harder/thicker cups to resist 70000 psi pressure.
Any time you change primers there will be some variation in pressure; however, firing small rifle primers in the my .38 Super produced no higher pressures than small pistol primers.
Rifle primers have harder/thicker cups to resist 70000 psi pressure.
Any time you change primers there will be some variation in pressure; however, firing small rifle primers in the my .38 Super produced no higher pressures than small pistol primers.
Magnum Shooter
Member
Small rifle and small pistol primers are the same size. If you pistol hits hard enough to set off a rifle primer its OK to use them, if you rifle doesn’t pierce a pistol primer its OK to use them. It doesn’t matter what you use if you work up a load that functions properly and safely in both guns.
Lloyd Smale
Member
Like what magnum said, with ccis anyway a standard small rifle primer and a magnum pistol primer are the same thing. that said for a mild round like the 38/40 id stick with standard pistol. Your no doubt going to get better accuracy
oldpapps
Member
So many things to address.
As stated above large Rifle primers have longer skirts than large pistol primers, but not all that much longer.
Rifle primers are normally made of stiffer stuff for the higher pressures. Further more, they generally have a longer and or hotter burn.
As you are loading for a classic old black powder round, this would tell me that you are not routinely loading for that rouge elephant, don't.
The practicalities for interchangeable rounds.
The brass you use will determine if rifle length primers will seat properly. I suspect they do.
Next up is hammer or firing pin fall. The primer cup must be crushed well enough to set off the priming mixture. A weak hammer or firing pin fall will make for erratic ignition and possible hang fires or miss fires. As I don't know your weapons, I can't make a blanket statement on this.
To the loadings themselves. Always start with the book beginning loads. Try these in both your pistol and rifle. Work up to your desired level in both.
One other item. A loading that is great in a short/er barrel pistol will normally be good in a longer barreled rifle. Exception being a load that doesn't lead in the pistol may lead in the rifle. Velocities will increase in the longer barrel, but not much.
Enjoy your classics. Load with safety.
As stated above large Rifle primers have longer skirts than large pistol primers, but not all that much longer.
Rifle primers are normally made of stiffer stuff for the higher pressures. Further more, they generally have a longer and or hotter burn.
As you are loading for a classic old black powder round, this would tell me that you are not routinely loading for that rouge elephant, don't.
The practicalities for interchangeable rounds.
The brass you use will determine if rifle length primers will seat properly. I suspect they do.
Next up is hammer or firing pin fall. The primer cup must be crushed well enough to set off the priming mixture. A weak hammer or firing pin fall will make for erratic ignition and possible hang fires or miss fires. As I don't know your weapons, I can't make a blanket statement on this.
To the loadings themselves. Always start with the book beginning loads. Try these in both your pistol and rifle. Work up to your desired level in both.
One other item. A loading that is great in a short/er barrel pistol will normally be good in a longer barreled rifle. Exception being a load that doesn't lead in the pistol may lead in the rifle. Velocities will increase in the longer barrel, but not much.
Enjoy your classics. Load with safety.
witchhunter
Member
The 38/40 is a pistol round. Use large pistol primers for it. It does not generate enough pressure that a rifle primer is needed. A large rifle primer is too deep to seat properly in the case. When using a cartridge for both rifle and pistol and you are loading the same load for both, I would go with the pistol load as it will be safe in the weakest gun. Depending on the pistol, a load that is good to go for your rifle may be too hot for an older revolver. Why take chances.
rcmodel
Member in memoriam
This is the correct answer.
LR primers are slightly taller, and may not fully seat in some brands of pistol brass.
This can cause higher drag turning the cylinder in revolvers, and a higher risk of a round going off from recoil in the mag tube in lever actions.
If that isn't enough, every reloading manual ever printed says to use LP primers in the 38-40 WCF.
rc
Sunray
Member
Both a .38-40 rifle and revolver use the same cartridge, that uses the same primer. You don't use a LR primer(that has a different priming compound than a LP primer) just because you're shooting one or the other.
Anyway, you really need to work up a load for each firearm. The chances of finding one load that shoot well in both are slim. Despite what was done in the past.
Anyway, you really need to work up a load for each firearm. The chances of finding one load that shoot well in both are slim. Despite what was done in the past.
As you can see the large rifle primer is .008" taller than the large pistol primer. While .008" isn't much, it's enough to cause problems standing that much above the case head...
DRAT! Having trouble attaching a chart to my post. Anyway a large rifle primer, by SAAMI standards is .123"-.133" tall. A large pistol primer is .115"-.125" tall...
DRAT! Having trouble attaching a chart to my post. Anyway a large rifle primer, by SAAMI standards is .123"-.133" tall. A large pistol primer is .115"-.125" tall...
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http://www.thehighroad.org/attachment.php?attachmentid=183473&d=1367342906 again?
Seems like if something is posted/uploaded in another thread, it cannot be posted again in a different thread. At least I can't. So, see post #9 here...http://www.thehighroad.org/showthread.php?t=714886
Oh well, sorry to waste space..
Seems like if something is posted/uploaded in another thread, it cannot be posted again in a different thread. At least I can't. So, see post #9 here...http://www.thehighroad.org/showthread.php?t=714886
Oh well, sorry to waste space..
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Don McDowell
Member
The 38-40 is a rifle round, it began life about 1880 as the 38wcf, and became one of the most popular chambers in the 1873 and 1892 rifles. Colt and Smith both chambered it in handguns.
In the Winchester , Western and Remington and Peters cartridges, from as recent as the 1950's and 60's they did use pistol primers in factory ammo but they are crimped in. So when using those cases a person can remove the primer pocket crimp and seat either a rifle of a pistol primer.
So a simple check to see if the cases you have will allow a rifle primer to seat flush or a tad below the case head, you are good to go. A good mainspring in the revolver will fire those rifle primers with no problems.
It's not to hard to find a single load that will work in both guns, unique, bludot,2400 and 4227 are all good powders in either. The faster powders unique and bludot will give more efficient use in the handgun than the slower powders.
2 f Olde Eynsford blackpowder, or 3f Goex both work rather well also.
In the Winchester , Western and Remington and Peters cartridges, from as recent as the 1950's and 60's they did use pistol primers in factory ammo but they are crimped in. So when using those cases a person can remove the primer pocket crimp and seat either a rifle of a pistol primer.
So a simple check to see if the cases you have will allow a rifle primer to seat flush or a tad below the case head, you are good to go. A good mainspring in the revolver will fire those rifle primers with no problems.
It's not to hard to find a single load that will work in both guns, unique, bludot,2400 and 4227 are all good powders in either. The faster powders unique and bludot will give more efficient use in the handgun than the slower powders.
2 f Olde Eynsford blackpowder, or 3f Goex both work rather well also.
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