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Loading the 6.5CREEDMOOR whith diferents powders...

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12 hours ago, Leeman said:

Laurent,

certainly an improvement with the different seating depth.

I realised the figures on your loading box which I took to be velocity were seating depths,, so it would interesting to find out what speed you were getting with N560.

Richard

Hello Richard,

Happy to read You! :rolleyes:

I don't measure yet my velocity with my 2 slow powder (RS70 and N560) but I work with a friend called Quick Load...

Look at the results with 147 gr - COAL 2.903'' (Presure -Velocity)       

Presure Max 6.5 Creedmoor = 4350 Bar

 47.1gr de RS 70 et une OAL de 74,25 mm Presure : 3898 bar - V0 estimée à 854 m/s ( 2802 fps)

 47.2gr de N560 et une OAL de 74,25 mm Presure : 3833 bar -V0 estimée à 853 m/s (2799 fps) … (My good accuracy load with N560!)

I tell you when Iwill measur my velocity Richard !

A+

Laurent

 

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Well this is weird.

I previously ran a series of test loads using StarLine small primer rifle brass with N150 and 140gr Nosler Custom Competition bullets and Federal #205 primers.  The results showed a marked drop in velocity from Vhit's published loads, as expected.

Last night I ran the same loads using Murom KVB223M primers in place of the Federals

Well this is weird.

I previously ran a series of test loads using StarLine small primer rifle brass with N150 and 140gr Nosler Custom Competition bullets and Federal #205 primers.  The results showed a marked drop in velocity from Vhit's published loads, as expected having read Lauries input on the subject.

Last night I ran the same loads using Murom KVB223M primers in place of the Federals and got very strange results.  I was expecting an increase in velocity but ir reality got a decrease!, now maybe my chrono was on the wrong sensitivity setting (Magnetospeed Sporter) as it failed to register about half of the shots, I'll load more rounds and re-run the test again.

 

Here's the results.

Powder (gr)         Federal        Murom

36.0                      2528            2482

36.5                      2560            2510

37.0                      2585            2565

37.5                      2606            2584

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I had similar results. Murom KVB 223's I found a little "hotter" than their SR KVB223M siblings.  I think that the Federal 205's and Remington 7.5s for that matter, reportedly are hotter than the Muron Magnum primers.  I will never use Murom standard KVB primers again (for different reasons....see my thread yesterday on the tests) due to issues with a primer batch having multiple primer failures (splitting and pin holes forming) and gas cutting bolt face(s).  I think that for whatever the reason, the thicker cup primers definitely showed more consistent and lower SD figures but velocities were marginally down, perhaps 5 to 10fps over the standard SR primers I first tried.  What I've seen across several batches with Muroms is a lack of consistency batch to batch, especially between standard primers.

The Feds I think have a slightly higher energy "bang" and than the Murom M primers.  I have yet to try the Remington 7 1/2 primers but they are next on my list. along with the Federals.  With current sanctions in place, I wonder how reliable future sources of Muroms will be so it's probably not a bad idea to switch for that reason alone.

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I've a 1000 to get through myself before I switch to probably CCI450's.  The standard KVBs will be disposed of.  I wouldn't want anyone else experiencing those damaging their firearms, so they're scrap.

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5 hours ago, VarmLR said:

I've a 1000 to get through myself before I switch to probably CCI450's.  The standard KVBs will be disposed of.  I wouldn't want anyone else experiencing those damaging their firearms, so they're scrap.

Hi Guy ,

Yes the CCI 450 work very Right for the 6.5 Creedmoor SR Case !!!small12.jpg

(More than the CCIBR4)  whith Lapua Case for a long Range Load , I think I found my magic load with the RS 70...

But carrefuly for the cratered cup with this  Magnum primer !

small211.jpg

A+

Laurent.

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Thanks for the heads up Laurent.  What was the velocity at your accuracy node out of interest and your barrel length?  I'm finding a good accuracy node between 2630 and 2650fps with a 24 inch barrel.

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22 hours ago, VarmLR said:

Thanks for the heads up Laurent.  What was the velocity at your accuracy node out of interest and your barrel length?  I'm finding a good accuracy node between 2630 and 2650fps with a 24 inch barrel.

Hello ,

I doen't measure yet my velocity to the 46.7 gr RS +147gr Hornady ELD-Match , I prefer test it for the best accuracy at 300 m ;)

But I hope a good vellocyty for a LR use...

I look QL for this RS70's load  :

47.1gr de RS 70 et une OAL de 74,25 mm Presure : 3898 bar - V0 = 854 m/s ( 2802 fps)

I 'll share my velocity measure if you are interesting by this LR load...

wp_20110.jpg

 

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Air temperatures change velocities.unless you shot at the same temps each time your bound to get variation in fps but you already know this.when I was looking at my ball cal Sunday and from zeroing temps that was entered on the day of zeroing my ball cal was telling me with current temperatures entered there was around or over 100fps slower.i would of liked to put a couple frew the chrony to see if that was actually the case.

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That depends a lot on the powder really.  I found much larger variations with temperature using viht powders than I have done using RS powders.  I also keep my ammo out of direct sunlight when on the rare occasion it gets to tee-shirt weather :)  One of the good things about using OCW methods is that they give some leeway for those variations.

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A bit more weirdness!!

Ran some loads through yesterday on my club's day out at Otterburn.  37gr of N150, twice fired Starline small primer brass, Murom KVB223M small rifle magnum primers and Nosler 140gr Custom Competition bullets set at 2.804" (30thou" jump).

Grouping was fine but weirdly I got a lot of case sooting, but at the head (rim and extractor groove) not the neck.  No signs of pressure, no primer flattening or cratering, smooth bolt lift etc.. 

I know from comparing Vhit's data (which now says it's for small primer cases) that my velocities are quite a bit lower than theirs, so, is the load too low and giving poor case obturation?

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Have you got a photo of one of the cases with primers still in place?  If poor obituration I would have thought that you would have soot marks at the neck and main case body too?  Could it be gas blowing back through the primer edges (pockets aren't starting to get loose by any chance?)

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You'd have  a gas-cut bolt face if that was happening

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Sooted cases due to low pressures / 'funny' ignition produce a weird range of symptoms, and yes I've seen soot in the extractor groove alone on occasions.

It may not be simply overly low pressures loads that's the issue here. You may need to change primer to get one whose characteristics  suit the powder / internal ballistics relationships better. For some reason, 6.5mm cartridges seem to be more prone to this issue than others. I first came across it with N150 and 160 in 6.5X55mm many, many years ago and moved from the CCI-200 primer which was the most widely available at the time to the 250 magnum - which cured it. There was no apparent rhyme or reason to the appearance of the problem - same load  shot on the same range in apparently same temperatures would soot brass up on one weekend and not the next, alongside to the amount of soot and its nature / location being equally variable.

Despite being called a 'Magnum' that Murom primer is a mild example and has seen problems in its Wolf and Tula brand name guises in US XTC with some ball powders, even with the 223's small charges. That's why Murom introduced the thick cup, but 'hotter' brisance SR 223 REM model.

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Thanks :)

Primer pockets are nice and tight, only once fired on the ones in question.

Could well be the Muroms, I didn't have any problems using the Federal primers and as I said there's a marked drop in velocity with them.

Unfortunately my son did me a "good deed" and deprimed our days worth of cases and stuck them in the SS wet tumbler while I was having a nap!.

I still have 50 rounds loaded with the KVB223M's, we're at Ponteland range next Sunday so I'll load up a batch with KVB223's and Federal 205's and compare them.

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I had a few issues with KVB 223s....could have been a batch issue but several primers split on me so I won't be using those again.  CCI450 for me.

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Laurie Hollands review of Murom primers found that standard (non magnum)  223 Murom primers are no good over about 50,000psi of pressure....see Target Shooter website.

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Yes, I'd agree with that.  Cup thickness isn't enough for the pressures.

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1 hour ago, VarmLR said:

Yes, I'd agree with that.  Cup thickness isn't enough for the pressures.

The CCI 450 are the same Cup  thickness than the CCI 400, but the 450 work right with the high pressure! The metal cup is  harder ???

primer10.jpg

 

In my RPR, with slow powder(RS70, 47.1 gr) and heavy bullet (147 gr ELD-M) in 6.5Creedmoor LAPUA Case I use CCI 450 look at this cratered primer :

dscn0018.jpg

Do you think I'm in over pressure with this load ?

https://www.primalrights.com/library/articles/understanding-pressure

A+

Laurent.

 

 

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CCI-450 is thicker, as shown in the table you put up. 25 thou' v 20 thou' for the 400. It does make a difference, but any primer will crater / blank if the firing pin fit in its bolt aperture is poor and the pressure is high enough.

The 6.5X47L has already brought out problems with certain makes and models of rifle / action, and the advent of the small primer variant of 6.5mm Hornady Creedmoor will undoubtedly bring out many more, but at least in the Creedmoor you can buy a set of good quality LRP cases and use them instead if SRP brass causes primer problems. For the 6.5X47L, it's a bolt bushing job or a replacement calibre barrel, or a rechamber to 260 Rem. I spoke to a gunsmith recently who said that from never doing a bolt bushing / firing pin reprofile job, he has done over 20 in the last year or two, (at somewhat over £300 a time) every one through people specifying 6.5X47L barrels on a model that was traditionally offered and used in 308 only.

This issue is going to become more acute as more manufacturers offer the option of an SRP version of cases that have always been LR primed. Peterson Cartridge now offers 243 Win, 260 Rem, 6/6.5 Creedmoors, and 308 Win in both forms. Both retailers and customers have to be  aware of the differences and their implications, and any potential pitfalls. I also worry that with SRP Lapua brass (we'll have to see about Peterson in due course) able to take serious over-pressures without distress, or often even any visible symptoms, the opportunities for dangerous overloads through transfer of SRP loads to standard LRP cases, either through ignorance or a mistake on the bench by one who has both types in use, will rise. Not only is the LRP form weaker, but the substitution of the large primer can be equivalent to adding a grain or more of powder to the charge in terms of pressures generated.

Be warned!

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Your last point is very valid Laurie.  Even if you don't consider the dangers of replicating SR loads to LR cases, SR (magnum) primers of .023" or more cup thickness just don't seem to exhibit pressure signs (presumably right up to the point that they ....or something else blow) so you have to be far more attentive to case head condition and things like felt recoil....all a bit too seat of the pants. This is compounded by the fact that SR brass needs loaded up higher then its LR counterpart to get anywhere near the same velocities.

I may return to using LR brass when this batch is done and keeping loads moderate and see how many reloads I get from them.  The one advantage I do see though and one of the main arguments in the first place for SR brass is consistently low ES/SD figures.

 

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2 hours ago, Laurie said:

For the 6.5X47L, it's a bolt bushing job or a replacement calibre barrel, or a rechamber to 260 Rem. I spoke to a gunsmith recently who said that from never doing a bolt bushing / firing pin reprofile job, he has done over 20 in the last year or two, (at somewhat over £300 a time) every one through people specifying 6.5X47L barrels on a model that was traditionally offered and used in 308 only.

 

Hello Laurie, 

Yes à  bolt with excessive space between the firing pin and firing pin hole on the bolt face will allow the primer to flow into that space...and the crater primer comes!

In my RPR I measured my clearance between my firing pin and my pin hole (measured on a crater primer) 

dscn0020.jpg

I have 0.05 mm (.001968'') at clearance ! Is it to much ?

Or is a right speace between between my firing pin and my pin hole?

dscn0021.jpg

Enjoy to read you, Laurie!

A+

Laurent.

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