Is SRP in anything larger than .223 unsafe?

[JC0352]

http://www.shootingtimes.com/ammo/starlines-6-5-creedmoor-brass/

“...but the small primers almost always delivered reduced standard deviations and improved accuracy. I consulted Dave Emary, Hornady’s chief ballistician and originator of the 6.5 Creedmoor, to share the good news.

He promptly poured cold water on my results.”

“Typical 6.5 Creedmoor powder charges are simply too large to reliably ignite with Small Rifle primers under all conditions. They’re just fine for .223 and similar capacity rounds; however, we’re talking about nearly twice as much propellant. A Large Rifle primer is definitely needed to assure reliable and consistent ignition. If the throat is eroded and a round hang-fires, the bullet will plug the bore, and the reigniting propellant will likely fully burn before the bullet can began moving again. Skyrocketing pressures may damage the rifle and possibly injure the shooter.”

“Ron Reiber, Hodgdon Powder product manager, added even more cold water.”

“Many propellants are sensitive to temperature variations,” Reiber said. “If the ammo gets too cold, it’s harder to ignite. Small primers contain less energetic material, so the risk of experiencing a dud round or hang-fire increases in cold conditions. And the 6.5 Creedmoor can achieve excellent ballistic performance loaded with a double-base propellant containing nitroglycerine. That type of propellant is more difficult to ignite than single-base, nitrocellulose powder, which only exacerbates the critical ignition process.”

H4350 is a single-base propellant and it’s what I use, but could certain conditions also make this a dangerous combination? I’m worried because this article is the first time I’ve heard of any of this. New to Creedmor, and I’ve never fired my rifle in colder temps yet.

 

[TEDean]

I read the same article. I simply have not experienced any issues using small primers (CCI Magnum, LaPua, 6.5CM H4350) in my short 2 years of reloading. I have shot several thousand rounds in 100 to 30F and had no issues, granted most are in temperate conditions. I am most curious what the more experienced shooters will say.

 

[Skunkworx]

the man has a point; but with the millions of rounds of SRP 6cm, 6.5cm, 260 REM, 6 dasher, and etc going down range each year if it was an issue we’d have heard horror stories by now.

 

[JC0352]

the man has a point; but with the millions of rounds of SRP 6cm, 6.5cm, 260 REM, 6 dasher, and etc going down range each year if it was an issue we’d have heard horror stories by now.

That’s exactly what I was thinking! I can’t question the experts cited in the article, but why hasn’t this come up more?! Are they just being SUPER conservative?

With another kiddo on the way, I’m not willing to make time to get into reloading right now. My Dad loads my ammo and he’s been reloading for over 30 years. When a friend of his at work showed him that article, it gave him pause.

 

[JC0352]

I’m also wondering about our choice in primer. My dad and I both use CCI BR4. After he sent me this article, I’m trying to read about this everywhere, and other sources indicate CCI 450 would be a better choice? To date, we both have not had any issues with pierced primers on the hottest Louisiana days.

We’ve not had any ignition issues with BR4 like Jim Kauber mentions in this blog:
http://alphamunitions.com/kaubers-corner-large-vs-small-rifle-primers/

 

[Stpilot12]

You'd think we would've heard about someone blowing themselves up...

 

[Stpilot12]

I’m also wondering about our choice in primer. My dad and I both use CCI BR4. After he sent me this article, I’m trying to read about this everywhere, and other sources indicate CCI 450 would be a better choice? To date, we both have not had any issues with pierced primers on the hottest Louisiana days.

I did some load work to compare CCI BR4 and 450's in Lapua 6.5CM, really not much difference other than the 450's seem to have slightly better SD.

 

[JC0352]

I did some load work to compare CCI BR4 and 450's in Lapua 6.5CM, really not much difference other than the 450's seem to have slightly better SD.

I’ve read they’re the same, except for the 450 having a thicker cup... Is that right?

Would it be a fairly safe move to keep rolling with these if we haven’t had any issues over hundreds of rounds through 2 rifles in ballz hot weather?

 

[Supersubes]

I’ve read they’re the same, except for the 450 having a thicker cup... Is that right?

Would it be a fairly safe move to keep rolling with these if we haven’t had any issues over hundreds of rounds through 2 rifles in ballz hot weather?

No, they’re actually identical in every way except for the “b” on the cup of the BR4’s

 

[JC0352]

Oh... Wow, didn’t know that

 

[Supersubes]

The Hornady guy’s explanation seems a little far fetched and theoretical to me. Simply too many of these combos being run, with zero Kb’s, for it to be an issue. Lapua has been making the .308 palma brass for quite a while. 6.5x47 has always had a small primer, then Lapua doubles down on the creedmoor brass with a small primer. Between 6.5x47 and Lapua creedmoor, I’m probably around the 7500 round mark using br4/450 primers. Not one fail to fire, or hang fire. I did experience several hang fires in the 47 using Wolf SRM’s and Varget. None of those exhibited excessive pressures, quite the opposite actually. ~100 fps slower and a low impact on Target, which is why Im not buying the Hornady explanation.

 

[JC0352]

Thanks all for relieving my paranoia! My gunsmith told me to relax, too, lol

 

[Mike Casselton]

Could it be that Hornady makes their brass with the LRP instead of the SRP because they already had tooling for it?
Much larger cases have been successfully used with the SRP as pointed out above

 

[Supersubes]

Could it be that Hornady makes their brass with the LRP instead of the SRP because they already had tooling for it?
Much larger cases have been successfully used with the SRP as pointed out above

I can’t imagine the punch or forming tool for the pockets being the big expensive part of case forming. Peterson brought out their large primered cases, then very quickly brought the small primer variants to market, and now they’re available simultaneously. Certainly they have less resources than the Hornady.

With the main fail point of Hornady brass being the primer pockets, seems to me they could remedy that easily by switching to a small primer pocket. Might make their brass more relevant with all the small primer offerings in the market. Not gonna happen though, given their stance on the matter.

 

[spife7980]

With the main fail point of Hornady brass being the primer pockets, seems to me they could remedy that easily by switching to a small primer pocket. Might make their brass more relevant with all the small primer offerings in the market. Not gonna happen though, given their stance on the matter.

I imagine a lot of that is due to many people shooting the now immensely popular chambering having large, sloppy fitting firing pins and thus the potential to pop more primers. Factory ammos always seem to cater to the lowest common denominator for liability I imagine. Small primers could puncture.

 

[rockywlw]

I have shoot almost 1000 rounds with Alpha 6.5 Creedmoor small primer brass and zero issues. I have yet to see any sign of n ignition problem, I'm staying with SRP for my 6.5.

 

[nexusfire]

CCI450's fo life. I wont shoot a cartridge that I am reloading that's not SRP.

 

[MarinePMI]

Could it be that Hornady makes their brass with the LRP instead of the SRP because they already had tooling for it?
Much larger cases have been successfully used with the SRP as pointed out above

I'm thinking this is the winner. Nothing against Hornady mind you, but I'd hardly expect them to endorse a type of product they don't offer. And one that a competitor has, that would compete with theirs.

Same thing was going on with Lee and CCI/RCBS a while back IIRC...all about primers and potential sympathetic detonation. Marketing hype, with some overly cautious warnings to solidify their stance (which encouraged use of their product). Just good business practice, that has no real potential to hurt anyone.

 

[MarinePMI]

WRT to the tooling, it would require more than just a simple tooling (rifle pocket swager) change, it'd require the tooling for drawing to also change, as the case head is drawn in the initial phase of forming. Small rifle pockets would change how thick the case head is at a certain point in the drawing process, as the SRP would displace less material. Hence the tooling that supports the case (internally) when the rifle pocket is swaged would have to account for the increased thickness of the case head. Or...the drawing process up to that point would have to change to ensure the less displaced material was accounted for. Or, the basic material stock used for the brass would have to change in thickness.

A lot of different ways to skin the cat, but all would require a change that wasn't planned for when the initial process was created. Hornady (or Frontier, I should say) makes a lot of brass. I can only imagine what it would do to their manufacturing schedule, if they were to introduce a change like this (for probably very little profit and additional market share). A major PITA for little to no added benefit to them.

JMTCW...

 

[Mike Casselton]

WRT to the tooling, it would require more than just a simple tooling (rifle pocket swager) change, it'd require the tooling for drawing to also change, as the case head is drawn in the initial phase of forming. Small rifle pockets would change how thick the case head is at a certain point in the drawing process, as the SRP would displace less material. Hence the tooling the supports the case (internally) when the rifle pocket is swaged would have to account for the increased thickness of the case head. Or...the drawing process up to that point would have to change to ensure the less displaced material was accounted for. Or, the basic material stock used for the brass would have to change in thickness.

A lot of different ways to skin the cat, but all would require a change that wasn't planned for when the initial process was created. Hornady (or Frontier, I should say) makes a lot of brass. I can only imagine what it would do to their manufacturing schedule, if they were to introduce a change like this (for probably very little profit and additional market share). A major PITA for little to no added benefit to them.

JMTCW...

Most people have never seen ammunition being made commercially.
It's amazing how much down time is required for basic cleaning or minor repairs on these machines.

Add in punch and draw changes and the required testing and you could be down for days.
They aren't willing to lose that much production

 

[Milo 2.5]

“Many propellants are sensitive to temperature variations,” Reiber said. “If the ammo gets too cold, it’s harder to ignite. Small primers contain less energetic material, so the risk of experiencing a dud round or hang-fire increases in cold conditions. And the 6.5 Creedmoor can achieve excellent ballistic performance loaded with a double-base propellant containing nitroglycerine. That type of propellant is more difficult to ignite than single-base, nitrocellulose powder, which only exacerbates the critical ignition process.”
I think the powder choice has way more to with it than srp. .223 cases have a large flashole, Lapua made great strides with 6BR brass, and 6.5x47 utilizing small primers and smaller flasholes.
I necked down Lapua 6.5 creed srp brass to 6mm, and had hangfires using Norma MRP with a 110 Sierra. But I cannot make assumptions on srp-slower powder because the barrel had an ungodly amount of freebore for the 110. Not really being smart enough to figure the problem out, I just gave up on it, but in my head a larger flashole may have solved it.
I do tend to agree with the wisdom the case is getting a little big for srp and small flashole, but there are thousands of people making it work everyday, tough point to argue.

 

[OzzyO20]

Do Federal GMM 205M's stack up with the CCI 450's for ignition? I'm using H4350 and have never had a single issue, but I've also not tried BR4 and 450s. They're certainly easier to find and if they are a better component, I'll give them a try.

Edit:I saw in the Alpha article the author suggested not using a SRP match primer in the 6.5CM. My last 10 shot string had an SD of 10 and ES of 35 and this load is a solid .5 MOA load, but if it's not safe I may go away form the 205M's.

 

[Supersubes]

Peterson and alpha make both primer sizes in every .473 sized cartridge they make. When Peterson introduced the creedmoor SRP brass, the rest of the line got it almost immediately. They either made a large investment in tooling, or there is some Interchangeability of tooling making it easier to do same sizes cases with small primers. I vote the latter.

 

[MarinePMI]

I'd suspect it was planned from the outset.

 

[kujuak]

Could someone explain to me why this is not a problem with Lapua 308 palma SP brass.It's been used for years hasn't it. I use it with Varget from 20 degrees to 90 degrees with no issues???

 

[Supersubes]

Could someone explain to me why this is not a problem with Lapua 308 palma SP brass.It's been used for years hasn't it. I use it with Varget from 20 degrees to 90 degrees with no issues???

Yes, because it isn’t a problem at all.

 

[mdmp5]

I imagine a lot of that is due to many people shooting the now immensely popular chambering having large, sloppy fitting firing pins and thus the potential to pop more primers. Factory ammos always seem to cater to the lowest common denominator for liability I imagine. Small primers could puncture.

I've punctured a ton of SR primers when I rechambered my 308 to 47. Ended up bushing the firing pin and problem solved.

I had a ton of hang fires in the caliber too afterwards, but that was simply because of the primers I was using. Switched to remington and no more hang fires. That writing about dangerous pressure with hang fires sounds like theory or rare occurrence to me. I've experienced enough of them that I can say it doesn't happen

 

[flyer]

I think I remember seeing a Hornady PDF suggesting that their 147 grain TAP 6.5 Creedmoor ammo would have small primers.

Maybe that was a screw up and this is an overreaction?

I don't think SRP is a problem if you use the right primers and your firing pin/hole is appropriate. On the other hand, if you look at the data Alpha Munitions put together on their LRP and SRP 6.5 Creedmoor brass, if SRP has a consistency advantage, it is very small.

Bottom line, I'm going to go with LRP brass but only because I don't have to worry about firing pins.