I have read that there is no difference between a Small Pistol Primer and a Small Rifle Primer, is that the truth? What is the main purpose of a Small Pistol Bench Rest Primer and a Small Rifle Bench Rest Primer? If there is no difference can you use a Small Pistol Primer instead of a Small Rifle Primer or Visa Versa?? Can you use a Small BR pistol primer for a Small BR rifle primer? Just seems strange that they are the same but they come in different boxes. Just a question I ponder after reading that they are the same size and I wonder if they have the same components, seems that they do have the same components and measurements. I personally only use the primer that the reloading book says to use, not necessarily the brand, but the size, small pistol for pistol, small rifle for rifle.
PRIMER QUESTIONS???
- Thread starter 74man
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AJC1
Member
No the cups are designed to handle different pressures. A spp at 62kpsi is no good.
sparkyv
Member
SRP are the same size as SPP, but SRP are harder and more difficult to ignite. Usually, SRP have a higher brisciance. Not a good idea to interchange.
If you have a hard hitting firing pin and are not running max loads srp work fine in pistol cases.
Otherwise you can have failure to fire or possibly high pressure if you are loading hot already and switch to srp.
Definitely don't want to run spp in rifle cartriges you will get blown primers and gas cut bolt faces.
Otherwise you can have failure to fire or possibly high pressure if you are loading hot already and switch to srp.
Definitely don't want to run spp in rifle cartriges you will get blown primers and gas cut bolt faces.
The SRP have a thicker cup to handle the extra pressure. You can put SRP in pistol rounds but your pistol may not set them off. But you can't run SPP in rifle because of the thin cups it will burn through or just blow the primer out.
ArchAngelCD
Member.
Benchrest and Match primers are usually assembled by the company's most experienced workers usually resulting in a more consistent performance over the box of primers when shot.
N555
Member
Some hand guns, mainly striker fired don't hit rifle primers hard enough to set them off reliably.
jmorris
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No, there are even differences between different brands, of SPP.
If they were all the same we would just buy them by size.
FROGO207
Member
All good answers in above posts. As you get more experience reloading you will learn lots of the newances of the craft. At the start following the manufacturers instructions will keep you as safe as possible while making ammo. Firstly I have subbed different brands of primer of the same type (SPP for SPP) and as far as I can tell I can not shoot the difference.
The composition and thickness of the primer cup material will allow them to be used at different pressures and with different firing pin strikes. With small primers they are all physically the same size. Federal primers have the thinnest cups and are the most sensitive of the brands. Brissance was also mentioned above. It is the amount and duration of the "spark" when the primer is hit.
Due to recent events a lot of long time reloaders have substituted primers because of lack of availability. After you have made some ammo and shot it you will figure out how the componants are supposed to act. Then it is possible to substitute different primers and see what the differing results end up being with regards to felt recoil, velocity, and accuracy. When subbing anything always start at 10% below max and work up. I still do this after 40+ years reloading.
By the way, large rifle primers are made deeper than large pistol primers and are not interchangable physically.
The composition and thickness of the primer cup material will allow them to be used at different pressures and with different firing pin strikes. With small primers they are all physically the same size. Federal primers have the thinnest cups and are the most sensitive of the brands. Brissance was also mentioned above. It is the amount and duration of the "spark" when the primer is hit.
Due to recent events a lot of long time reloaders have substituted primers because of lack of availability. After you have made some ammo and shot it you will figure out how the componants are supposed to act. Then it is possible to substitute different primers and see what the differing results end up being with regards to felt recoil, velocity, and accuracy. When subbing anything always start at 10% below max and work up. I still do this after 40+ years reloading.
By the way, large rifle primers are made deeper than large pistol primers and are not interchangable physically.
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TacticalJanitor
Member
What about a J frame with factory springs? Would SRP work with .38 Special running at about 800 fps (pretty mild)?
I ask because my LGS currently has 5000 "small rifle" primers. I didn't notice the SRP marking.
Edit: Duh. I just realized what SRP stood for.
You probably did not read that. You misunderstood what some folks have said
The have said that the used a srp in place of a spp as they ran out. BUT NOT the other way around,
Some handguns will set them off, others will not.
Riomouse911
Member
They may be just fine or they may be unreliable, it all depends on the weight of the hammer fall.
Since the gun is stock, you will probably be ok if you seat the SRP fully and be sure the cartridge fits in the cylinder without any friction holding it up. The case can be driven forward if the rim doesn’t lie fast against the cylinder, softening the firing pin blow. (I have had this happen a couple of times, especially shooting DA.) I’d load 10 or so and give them a try. If they all fire you should be ok, if they are spotty then you haven’t wasted a bunch of primers.
I load SRP in my .32 H&R and .327 Federal loads because the firing pins on my Rugers (Single Six .32 and SP 101 .327) are long enough to pierce small pistol primer cups. When I went to SRP I haven’t had an issue.
Stay safe.
TacticalJanitor
Member
Thank you sir. I might pickup a thousand to play with.
Basically, all small primers have pretty much the same physical size. As apposed to large rifle primers that are taller (.008") than large pistol primers. Yep, cups and compounds differ, but outside all small primers are very close...
Decent post about primers. https://www.sksboards.com/smf/index.php?topic=56422.0
Decent post about primers. https://www.sksboards.com/smf/index.php?topic=56422.0
N555
Member
Other smith revolvers set them off just fine. I have heard one of their hammer less DAO revolvers won't set them off reliably.
Prime a dozen brass and fire them DAO and if they all fire then you know single action will definitely fire them. Small pistol primers are hard to find.
TacticalJanitor
Member
Excellent info sir. My J frames are DAO, so I'd rather not gamble a C-note on it.
Thank you.
GooseGestapo
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- 6,153
Because of operating pressures, the .327Magnum and .30 Super Carry are spec to Small Rifle Primers.
For upper end loads in the .327 I use SRP, likewise the .30Super, which can then be loaded to 100fps faster than factory loads. (Hodgdons data @ Hodgdons.com).
However for.32H&R, I find regular SPP to be fine.
For upper end loads in the .327 I use SRP, likewise the .30Super, which can then be loaded to 100fps faster than factory loads. (Hodgdons data @ Hodgdons.com).
However for.32H&R, I find regular SPP to be fine.
Fooey
Member
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Here you can find all the SPP you want. Primers small pistol | Best Primers small pistol - AmmoSeek.com 2023
Fooey
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TheKoba49 has been testing SPP of foreign manufacturers and has his results here. Interesting view. I have several K of US made on the shelf but think I am going to order a couple thousand and try them out as they are some cheaper than US made. Here is his YouTube link if you haven't seen him.
N555
Member
I hope US primer manufacturers are putting some of this gouge money back into expanding primer manufacturing lines or R&D to make lead free primers.
Jim Watson
Member
All I have is a chronograph so I went with it.
Different brands of Small Pistol, Small Pistol Magnum, and Small Rifle all delivered the same velocity with my usual 9mm load within less than one standard deviation. Except Remington 1 1/2 Small Pistol, they were a bit faster.
CCI BR4, their Small Rifle Match was very difficult to seat, I had to seat them off the Dillon to get them flush or below.
That made me think they were in SR Magnum or military cups. They all went off, though.
Different brands of Small Pistol, Small Pistol Magnum, and Small Rifle all delivered the same velocity with my usual 9mm load within less than one standard deviation. Except Remington 1 1/2 Small Pistol, they were a bit faster.
CCI BR4, their Small Rifle Match was very difficult to seat, I had to seat them off the Dillon to get them flush or below.
That made me think they were in SR Magnum or military cups. They all went off, though.
Bcwitt
Member
If it wasnt nessesary they wouldnt make both types. Put some diesel feul in your gas tank , you will see what i mean.
Jim Watson
Member
True, but we are talking about shifts and adaptations to overcome "supply chain issues."
And, before Federal started making magnum primers, they recommended their small rifle primers for .357 magnum so it is not completely cut and dried.
And, before Federal started making magnum primers, they recommended their small rifle primers for .357 magnum so it is not completely cut and dried.
