Small rifle primers and extended firing pin - Shadow 2

[jejb]

I have been using SRP's in 9mm for a few months. All Federals, normal ones and gold medal. Work fine with my S2 Orange. Stock firing pin, 10lb CGW recoil spring and the strongest of the 3 hammer springs that it came with (16lb, I believe). Totally reliable. So I found some more SRP's the other day at Bass Pro, Win SMRLP, and bought 2000 of them. They say on the box specifically for 5.56 so I did some research on them before buying and read a review from a person that said they worked great in his 9mm handgun. Well, they didn't work in my S2 or P229. Some would go bang, some only after repeated hammer strikes, some not at all. 

 

Figured it was time for the CGW extended firing pin. They advertise that if you use it with the blue 13# hammer spring, it'll ignite "even the hardest primers". Got that in today, installed it, and no change in performance. That was disappointing. Called CGW and talked to one of the smiths to confirm I had the correct setup for the hardest hit. He'd never heard of this issue before, but I think these are not common primers.

 

I'm pretty sure I can get rid of them at my local range, but wondering if I should send the extended firing pin back or keep it. So my question is, why do people use it? My S2 lights SR primers with the stock spring very reliably, so having trouble understanding their value. 

Edited April 19, 2021 by jejb

[Squirrel45]

Ill be interested in what you find out here, I picked up some Win #41 myself hoping to use them in my S2 and Czechmate. I thought they would be the same as a SRP

[rowdyb]

You're likely not seating the small rifle primers deep enough. People run extended firing pins because they run light main springs. In their search for low DA numbers the suffer ignition problems and running an extended firing pin is part of dealing with these issues.

 

Previous set up in my Shadow 2 Orange: stock firing pin, stock fp spring, 10lb CZC main spring. If my CCI small rifle primers were even flush this would only set them off 75% of the time.

 

Current set up in same gun: CZC extended firing pin, 2075 firing pin spring, 12lb CZC main spring. Lights off 100% of my different small rifle primers, even if flush.

 

If you have a 16lb main spring and an extended firing pin and you're not lighting them off 100% it isn't the gun that is the issue, it is the ammo.

Edited April 19, 2021 by rowdyb

[GeneBray]

3 hours ago, rowdyb said:

You're likely not seating the small rifle primers deep enough. People run extended firing pins because they run light main springs. In their search for low DA numbers the suffer ignition problems and running an extended firing pin is part of dealing with these issues.

 

Previous set up in my Shadow 2 Orange: stock firing pin, stock fp spring, 10lb CZC main spring. If my CCI small rifle primers were even flush this would only set them off 75% of the time.

 

Current set up in same gun: CZC extended firing pin, 2075 firing pin spring, 12lb CZC main spring. Lights off 100% of my different small rifle primers, even if flush.

 

If you have a 16lb main spring and an extended firing pin and you're not lighting them off 100% it isn't the gun that is the issue, it is the ammo.

 

7 hours ago, jejb said:

I have been using SRP's in 9mm for a few months. All Federals, normal ones and gold medal. Work fine with my S2 Orange. Stock firing pin, 10lb CGW recoil spring and the strongest of the 3 hammer springs that it came with (16lb, I believe). Totally reliable. So I found some more SRP's the other day at Bass Pro, Win SMRLP, and bought 2000 of them. They say on the box specifically for 5.56 so I did some research on them before buying and read a review from a person that said they worked great in his 9mm handgun. Well, they didn't work in my S2 or P229. Some would go bang, some only after repeated hammer strikes, some not at all. 

 

Figured it was time for the CGW extended firing pin. They advertise that if you use it with the blue 13# hammer spring, it'll ignite "even the hardest primers". Got that in today, installed it, and no change in performance. That was disappointing. Called CGW and talked to one of the smiths to confirm I had the correct setup for the hardest hit. He'd never heard of this issue before, but I think these are not common primers.

 

I'm pretty sure I can get rid of them at my local range, but wondering if I should send the extended firing pin back or keep it. So my question is, why do people use it? My S2 lights SR primers with the stock spring very reliably, so having trouble understanding their value. 

My understanding is AR style SR primers are they either very hard, thicker cup material,  or both. Since ARs don’t have a firing pin spring, softer primers were subject to slam fires — firing pin slams forward as the bolt hits forward travel and begins to rotate to lock up. Result is firing pin moving forward and striking primer hard enough to detonate primer. ANd, you get a slam fire. The firing pin may have been modified to make it heavier so it has more inertia to over come when bolt stops. The other change were primers that are harder to set off than normal primers. That is the reason the box says for 5.56 which is considered a military round intended for use in AR/M-16 rifles.  If the more difficult primer to set off was part of the fox, I think you will find it difficult to find a set up for those primers to work reliably and a trigger pull you want for your pistol. I would swap or use in your AR/buy an AR and use them. 
 

I have used SR in my SP01 reliably. But not 5.56.  Believe with 11/12 lb. main spring. Maybe 13. Tula/Wolf SR were a nightmare in the pistol and never did find suitable fix. People told me those primers are hard and they never haven’t issues with them in ARs. 
 

I never tracked down the history of

slam fires in AR style rifles so don’t really know if true.  If it is true, shouldn’t be too hard to find on internet. 
 

Hope this is helpful. 

[GeneBray]

Make that Tula/Wolf SP not small AR in my SP01.   And, comment on using those brand primers in ARs were SR not SP. 

 

Sorry in my cell and couldn’t find the “edit post.”

[jejb]

11 hours ago, rowdyb said:

People run extended firing pins because they run light main springs. In their search for low DA numbers the suffer ignition problems and running an extended firing pin is part of dealing with these issues.

Thanks, that makes sense.

Quote

If you have a 16lb main spring and an extended firing pin and you're not lighting them off 100% it isn't the gun that is the issue, it is the ammo.

CGW says to never run more than a 13# hammer spring with their extended firing pin. So that's what I tried. The 16# spring was used with the stock pin. 

[jejb]

7 hours ago, GeneBray said:

 

My understanding is AR style SR primers are they either very hard, thicker cup material,  or both. Since ARs don’t have a firing pin spring, softer primers were subject to slam fires — firing pin slams forward as the bolt hits forward travel and begins to rotate to lock up. Result is firing pin moving forward and striking primer hard enough to detonate primer. ANd, you get a slam fire. The firing pin may have been modified to make it heavier so it has more inertia to over come when bolt stops. The other change were primers that are harder to set off than normal primers. That is the reason the box says for 5.56 which is considered a military round intended for use in AR/M-16 rifles.  If the more difficult primer to set off was part of the fox, I think you will find it difficult to find a set up for those primers to work reliably and a trigger pull you want for your pistol. I would swap or use in your AR/buy an AR and use them. 
 

I have used SR in my SP01 reliably. But not 5.56.  Believe with 11/12 lb. main spring. Maybe 13. Tula/Wolf SR were a nightmare in the pistol and never did find suitable fix. People told me those primers are hard and they never haven’t issues with them in ARs. 
 

I never tracked down the history of

slam fires in AR style rifles so don’t really know if true.  If it is true, shouldn’t be too hard to find on internet. 
 

Hope this is helpful. 

Thanks. I'm not looking for an answer on being able to use these 5.56 primers in 9mm. I'm convinced that are not going to work for my guns. I do have an AR and have given some thought to setting up one of my loaders for it. But we just don't shoot it enough to justify the expense for dies and plates. If I can't get rid of these primers though, it may push me over the edge on that one. 

[Steve RA]

I run Tula SRMPs in 9mm, .45 and .223/5.56 and have never had one not go off.  I think it is very important to be sure the primers are seated fully.

[Sarge]

Just now, Steve RA said:

I run Tula SRMPs in 9mm, .45 and .223/5.56 and have never had one not go off.  I think it is very important to be sure the primers are seated fully.

Seeing as you have been posting this for years, you must have bought a metric ton of these when they were available.

[Steve RA]

I did, still have about half a ton.  Not shooting matches anymore so they will last a lot longer.   

[Darqusoull13]

You can get most anything except Small Rifle Magnums to reliably ignite with either a Shadow / Shadow 2 with the extended firing pin and ~13-15 lb main spring or a Tac Sport with the same. Once you drop the main spring under 13 or get a weaker 13 () you need to even select softer small rifle primers. 

Seating depth is also critical. You MUST be below flush. 

[18111811]

How are you seating below flush with a xl750

[jejb]

9 hours ago, Steve RA said:

I run Tula SRMPs in 9mm, .45 and .223/5.56 and have never had one not go off.  I think it is very important to be sure the primers are seated fully.

Yeah, I've had good luck with other SRP's. But these Win WMSRL's are a different story. 

[Steve RA]

As mentioned above, it's important to have them firmly seated.  If you have a hand seater, do some and try them again.