loading a rifle subsonic with pistol powder?

[stoney1666]

do you use a rifle primer or a pistol primer?

 

[kingmt]

I've used both but I'd suggest rifle. I'd use soft pistol until I started seeing signs of pressure.

 

[jmorris]

What round?

 

[berettaprofessor]

What powder? You would use a rifle primer in a rifle case, but for the powder, other than trail boss, it's pretty dangerous to use most pistol powders in rifles....pressures spike fast!

 

[7mmb]

A large rifle primer is taller than a large pistol primer. If the rifle case you are downloading uses a large rifle primer then you cannot substitute a large pistol primer. Small rifle and small pistol primers are the same size in every dimension and could be substituted. Published data for downloading rifle cartridges use rifle primers though. I would just stick with them and call it good.

 

[kingmt]

A large rifle primer is taller than a large pistol primer. If the rifle case you are downloading uses a large rifle primer then you cannot substitute a large pistol primer. Small rifle and small pistol primers are the same size in every dimension and could be substituted. Published data for downloading rifle cartridges use rifle primers though. I would just stick with them and call it good.

Well actually you can. I've been doing it for years. As soon as this ammo is used up I'm going back to rifle primers tho. I did it to know the round apart at quick glance.

 

[rfwobbly]

This is done all the time. Trail Boss powder is a favorite. With TB, just be sure the case is not completely filled. Leave a 1/4" air gap between the top of the powder and the bottom of the seated bullet.

 

[Walkalong]

100% load density is OK with Trail Boss, assuming you haven't gone over the max charge in the data, the only thing Hodgdon warns about is not to compress it.

http://www.imrpowder.com/PDF/Trail-Boss-data.pdf

The pressure determines whether you need a small pistol primer or a small rifle primer, not the powder choice.

As posted, large pistol primers are not quite as tall as large rifle primers and when seated properly to the bottom of the primer pocket in rifle brass the firing pin may not reach them well enough to set them off reliably.

 

[jmorris]

I asked because some rifle rounds actually use pistol primers. So if you are working up a subsonic round for 458 socom for example you would use a pistol primer.

I have also never had a problem with LPP going off in rifle cases I have converted for use in pistols, despite them being deeper in the pocket.

The question is kind of like "do I need an umbrella today?" To correctly answer we need more information.