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CCI BR4's


No i deer

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I'm completely out of BR4's. I either buy some more or try the CCI 450 magnums that are half the price hoping that the accuracy is exactly the same so I don't have to bother redeveloping the load. Whats the difference between them as there both magnum primers....?

If any knows they will definately change the accuracy then I will stick with the BR4's.

My 139gr scenar load shoots that well I'm not prepared to risk it changing on a guess....

Who is likely to sell them at Bisley....

Cheers No I deer 

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I have back to back tested them in 6.5x47 Lapua over RS62.

Both have the same thick cup and therefore avoid most pierced primer issues. Officially however the 450 is a magnum primer and the BR4 a standard primer with the thicker cup.

In back to back testing over 10 shots of each with very carefully prepped brass, loads measured to 0.02 grains and the same bottle of powder the BR4's gave me an additional 9 fps and an SD of 5.3 vs the 450's SD of 14.2.  I could understand the SD but the additional velocity confused me.

No guarantee that you will get the same results with your powder/rifle but I am sticking with the BR4's.

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In my testing in .223 with 80gr and 90gr bullets I found that both can provide similar ES and accuracy with appropriate load development and care when weighing charges - however the BR-4s consistently provided velocities 15-20 FPS higher for a given charge weight. This velocity difference was similar to what Laurie Holland found in his small rifle primer test IIRC.

In short I would (and do) happily use either depending on cost/availability with appropriate loads for each .

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9 hours ago, No i deer said:

You would expect the magnum primer to be hotter and produce a higher velocity.....

Even more confusion.....

It's most likely to do with how the primer output pressurises and ignites the propellant bed. Pressurisation of the bed, before full ignition, affects the projectile's initial motion, its debulleting from the case, and its initial motion into the bore.

The US Army Research Laboratory (ARL) has been doing an awful lot of fundamental research into this sort of thing. Most likely to do with the development of their new small arms cartridge.

It's all pretty complex and I don't profess to fully understand it enough to explain it more than I have already. It's covered in a load of non-classified papers that the ARL have released to the public. I've listed a few papers below for people who are interested in reading about it.

A Study of the Engraving of the M855 5.56-mm Projectile - ARL-TR-4743 (2009)

Experimental Studies of the No. 41 Primer and Ignition of 5.56-mm Ammunition (ARL-TR-3922)(2006)

In-Chamber Primer Force and Case Pressure Measurements of the 5.56-mm Cartridge - ARL-TR-5862 (2012)

Novel Diagnostics of 5.56 Ammunition Interior Ballistics (2012)

Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition - ARL-TR-7479 (2015)

Progress Toward a Multidimensional Representation of the 5.56-mm Interior Ballistics (ARL-TR-4903)(2009)

I have all these and more in my technical documents library if you can't find them online or what more data on the subject.

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2 hours ago, BlueBoy69 said:

It's most likely to do with how the primer output pressurises and ignites the propellant bed. Pressurisation of the bed, before full ignition, affects the projectile's initial motion, its debulleting from the case, and its initial motion into the bore.

The US Army Research Laboratory (ARL) has been doing an awful lot of fundamental research into this sort of thing. Most likely to do with the development of their new small arms cartridge.

It's all pretty complex and I don't profess to fully understand it enough to explain it more than I have already. It's covered in a load of non-classified papers that the ARL have released to the public. I've listed a few papers below for people who are interested in reading about it.

A Study of the Engraving of the M855 5.56-mm Projectile - ARL-TR-4743 (2009)

Experimental Studies of the No. 41 Primer and Ignition of 5.56-mm Ammunition (ARL-TR-3922)(2006)

In-Chamber Primer Force and Case Pressure Measurements of the 5.56-mm Cartridge - ARL-TR-5862 (2012)

Novel Diagnostics of 5.56 Ammunition Interior Ballistics (2012)

Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition - ARL-TR-7479 (2015)

Progress Toward a Multidimensional Representation of the 5.56-mm Interior Ballistics (ARL-TR-4903)(2009)

I have all these and more in my technical documents library if you can't find them online or what more data on the subject.

I've just finished reading "Experimental Studies of the No. 41 Primer and Ignition of 5.56-mm Ammunition (ARL-TR-3922)(2006)".  Very interesting and worth the read for those of a technical mind.  One quick take-away finding was that the primer combustion only penetrated into 40% of the powder charge and (later in the paper) that powder compression close to the seated bullet impedes full combustion.  Compressed loads are sub-optimal in their experimental findings.

The findings that it's the primer that propels the bullet forward into the lands is very interesting:

Abstract From "Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition - ARL-TR-7479 (2015)"

"A novel technique for quantifying the initial motion of projectiles in unmodified small-caliber ammunition (5.56 and 7.62 mm) is demonstrated. Evidence that the primer launches the bullet into the engraving process prior to propellant burning is presented. The impulse resulting from the primers' (Nos. 41 and 34, respectively) output is measured and compared with the bullet momentum"

 

Thanks for digging those papers out BluBoy

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1 hour ago, No i deer said:

A new Laurie Holland on the block.....

It will be nice to get Laurie's opinion..

 

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On 8/21/2019 at 7:14 AM, No i deer said:

I'm completely out of BR4's. I either buy some more or try the CCI 450 magnums that are half the price hoping that the accuracy is exactly the same so I don't have to bother redeveloping the load. Whats the difference between them as there both magnum primers....?

If any knows they will definately change the accuracy then I will stick with the BR4's.

My 139gr scenar load shoots that well I'm not prepared to risk it changing on a guess....

Who is likely to sell them at Bisley....

Cheers No I deer 

I don’t know how I missed this post Neil. I suggest you try Murom KVB223 primers.

I changed over to them for my 47L and my ES dropped. I use them for all my SR cartridges now.

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9 hours ago, No i deer said:

A new Laurie Holland on the block.....

 

New? I've been here for for some time (2015), but I normally just get ignored. This even though doing this sort of has been my job for years.

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1 hour ago, Brillo said:

I don’t know how I missed this post Neil. I suggest you try Murom KVB223 primers.

I changed over to them for my 47L and my ES dropped. I use them for all my SR cartridges now.

I had an issue a few weeks back with KVB223 primers in a Peterson SRP 6XC Case, one miss fire out of about 70 rounds fired that day. When I pulled the bullet the powder was scorched (some of it had a brown tinge) but had failed to ignite, load was 39.5 grains of RL17 and a 115 DTAC, powder was not compressed.

I'm going to try BR4 and CCI 450 next, been told that BR4 should be ok by several other users.

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I've only ever ran my 6.5x47 on BR4's...

The last time I checked the ES was years ago and they were single figures with a standard Forster BR die set with 2 to 3 thousanths neck tension...

I must be near OCW  to get a good ES like this not that I tried.

I went by what others were doing and it just worked, the throat has grown somewhat since then and I've kept the same jump and it shoots great.....

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2 hours ago, BlueBoy69 said:
 

New? I've been here for for some time (2015), but I normally just get ignored. This even though doing this sort of has been my job for years.

You have to upset other posters by disagreeing to get an answer 😁🤣

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2 hours ago, John MH said:

I had an issue a few weeks back with KVB223 primers in a Peterson SRP 6XC Case, one miss fire out of about 70 rounds fired that day. When I pulled the bullet the powder was scorched (some of it had a brown tinge) but had failed to ignite, load was 39.5 grains of RL17 and a 115 DTAC, powder was not compressed.

I'm going to try BR4 and CCI 450 next, been told that BR4 should be ok by several other users.

John, are you talking about the standard KVB223 or the magnum KVB223M? I was using the BR4s but after a period of time which much too high a misfire rate I’ve moved over to the Russian magnums and found them to be excellent 

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8 minutes ago, furrybean said:

Have you tried the magnums John?

Im at Bisley a bit over the next few weeks if you want to try a few 

Not tried the KVB223M, I have 18k of the KVB223 that I’ll keep for the .223 and try CCI 450 and BR4 in the 6XC with Peterson Brass.

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6 hours ago, Popsbengo said:

You have to upset other posters by disagreeing to get an answer 😁🤣

It does seem that way?

Look for 'ullage' if you want to see one of my rants, that or 'reloading data RS60 flame temperature'.

On 8/22/2019 at 10:25 AM, Popsbengo said:

I've just finished reading "Experimental Studies of the No. 41 Primer and Ignition of 5.56-mm Ammunition (ARL-TR-3922)(2006)".  Very interesting and worth the read for those of a technical mind.  One quick take-away finding was that the primer combustion only penetrated into 40% of the powder charge and (later in the paper) that powder compression close to the seated bullet impedes full combustion.  Compressed loads are sub-optimal in their experimental findings.

The findings that it's the primer that propels the bullet forward into the lands is very interesting:

Abstract From "Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition - ARL-TR-7479 (2015)"

"A novel technique for quantifying the initial motion of projectiles in unmodified small-caliber ammunition (5.56 and 7.62 mm) is demonstrated. Evidence that the primer launches the bullet into the engraving process prior to propellant burning is presented. The impulse resulting from the primers' (Nos. 41 and 34, respectively) output is measured and compared with the bullet momentum"

 

Thanks for digging those papers out BluBoy

Glad the reading suggestions were of interest.

For more on the previous subject and ullage effects, try these.

Flame-Spreading Processes in a Small-Caliber Gun (ARL-TR-4181)

Simulation Of Asymmetric Shot Start In Small Caliber Ammunition

Spit-Hole Effects on the Ballistics of a 7.62-mm Cartridge (ARL-TR-6785)

The Effects of Propellent Position on Small Caliber Ballistic Performance

 

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9 hours ago, John MH said:

I had an issue a few weeks back with KVB223 primers in a Peterson SRP 6XC Case, one miss fire out of about 70 rounds fired that day. When I pulled the bullet the powder was scorched (some of it had a brown tinge) but had failed to ignite, load was 39.5 grains of RL17 and a 115 DTAC, powder was not compressed.

I'm going to try BR4 and CCI 450 next, been told that BR4 should be ok by several other users.

Very interesting and bizarre. I’ve shot well in excess of 5000 and not had one misfire.

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I've only ever had 2 misfires, one was a factory load and the other was a soft strike or a dodgy primer as it fired the next time

I've predominantly used CCI primer over the last 20 years.....

Mainly BR2's and BR4's until we had a shortage 5 ish years ago and I bought some seller and belliot lr primers as a back up which I used in my 308 for a while, I only used them for barrel foulers now.

In recent times I've started using muroms competition large rifle primers as my 7mm saum didn't like BR2's.... great Es's figures with them like 4fps but accuracy was crap, I couldnt get better than 3/4 of an inch at 100yds yet the same load with muroms want to shoot in the same hole 🤔....

I've got some BR4's to pick up Sunday 👍.

Maybe you do need magnum primers in your 6xc...!

Have you had a problem with the kb's before in your 6xc or have you recently started using them...?

It might be a dodgy batch of primers. Again a process of elimination...

I was very surprised how much difference primers change the accuracy.....

 

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I have 15k Murom KVB-223m (magnums) and used them since I found they dropped my ES/SD values to single digits, compared to the CCI 450s which were just horrible.

In a few thousand rounds with perfectly fine ignition, I found 2 or 3 had a ‘delayed’ ignition when using RS52 powder. Not had any issues with VARGET, RS62, N140 or Lovex SO70. Only the RS52. 

I’m unsure about the non magnum version (KVB-223) but it could just be the combination of the primer with THAT powder in THAT case volume/design. 

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Maybe the (KVB223) tells it's own story as it was designed solely for the 223 but can/does work in other small capacity cases but only up to a certain grainage,powder column and load density 🤔

Just a thought 🤔

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On 8/23/2019 at 9:32 AM, John MH said:

KVB223

What case and load were you getting misfires with and were they failure to ignite the powder (scorched powder) after ‘firing’ or a failure of the primer to go ‘bang’; tow different things.

I've had that problem with Murom SRP magnum primers with 34gr Hodgdon 4895 in 6,5 Creedmore. I've gone over to Viht 150 now.

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