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Small primer Creedmoor


RPA 6mm BR

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Its just that I am exactly the sort of punter that would have missed this issue without this site, bought my (probably wrong) dies and then set about wrecking the flash holes of my £1.25 a pop Lapua brass in blissful ignorance.

 

RRP is £132.50, I am selling it at £125 because I don't want to gouge anyone

 

 

From the chats I've had with the people at Lapua, they made this brass the very best they could, and they have settled on that flash hole size for a reason.

 

Plenty of people don't think twice about modifying their gun on a whim, are happy to spend untold monies on different bullets, powders and primers, so personally I can't see the issue with dies.

You can either get the correct dies or decapping pins, or get yours modified

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RRP is £132.50, I am selling it at £125 because I don't want to gouge anyone

 

 

From the chats I've had with the people at Lapua, they made this brass the very best they could, and they have settled on that flash hole size for a reason.

 

Plenty of people don't think twice about modifying their gun on a whim, are happy to spend untold monies on different bullets, powders and primers, so personally I can't see the issue with dies.

You can either get the correct dies or decaying pins, or get yours modified

 

what bradders says , it's a non problem really and easily solvable anyway.....

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I'm not exactly sure what you're getting at about degrading performance. I simply meant that if it was offered small primer pocket with a standard sized flash hole I might be tempted. I am pretty sure you are saying that I can't appreciate or utilize enhanced precision and internal ballistics behaviors and because of which, I should stick to the inferior large primer pocket US brass.

Sigh.

Back to the Therapist.~Andrew

 

 

I misunderstood you Andrew in thinking that you were considering getting the Lapua brass and intending to enlarge the flash-holes - which some people inadvisedly do. In that case, it's almost as well to get standard cases from the outset. My apologies.

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I'm not exactly sure what you're getting at about degrading performance. I simply meant that if it was offered small primer pocket with a standard sized flash hole I might be tempted. I am pretty sure you are saying that I can't appreciate or utilize enhanced precision and internal ballistics behaviors and because of which, I should stick to the inferior large primer pocket US brass.

Sigh.

Back to the Therapist.~Andrew

 

 

I misunderstood you Andrew in thinking that you were considering getting the Lapua brass and intending to enlarge the flash-holes - which some people inadvisedly do. In that case, it's almost as well to get standard cases from the outset. My apologies.

 

I remember when I built a 6mmBr for myself, some years back.

 

That was in the days when I worried about stupidly meticulous brass prep.

 

I reamed the flash holes on a box of lapua 6mmbr brass, and it shot far better than un reamed. I cannot remember what size the reamed hole was, but it was definately bigger than the std flash hole.

 

I will shortly be stocking the new Lapua creedmoor brass, but the die problem is going to have to be addressed before its sold.

 

I only use redding dies personally, so its a simple fix, but what of the other die manufacturers ?

 

 

If it was a proper small diameter flash-hole reamer, no issue Dave and there is the chance of an improvement as you got. With the equivalent 308 Win Palma brass, I usually find a couple of 'tight' examples per box that need a lot more effort to turn the little Sinclair hand reamer tool.

 

A lot of experimentation mostly in the USA over the years with the 220 Russian / PPC and BR cases has convincingly demonstrated that if you increase the flash-hole size above a certain point, a large deterioration takes place. The 70 thou' mark seems to be critical. (Nominal out of the box sizes are 59 thou' small, and 79 thou' large, so using a large size reamer to open up the small size flash-hole will affect performance.)

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Thanks - will have a chat with spud when the time comes

 

I get it that they are making the best brass they can and have no issue with an uncompromising attitude on this frot, in fact I welcome it. I was more observing that the small flash hole and decapper issue was a new one, for me at least, and one that I could have missed resulting in waste and frustration.

 

My brother just had a really nice 6.5CM barrel made for his AI AT by baldie and I just caught him before he ran his new Lapua brass through 1.7mm decap pin dies

 

Best H

 

BTW - Thank you Bradders for your forbearance on the pricing front ;-)

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I remember when I built a 6mmBr for myself, some years back.

 

That was in the days when I worried about stupidly meticulous brass prep.

 

I reamed the flash holes on a box of lapua 6mmbr brass, and it shot far better than un reamed. I cannot remember what size the reamed hole was, but it was definately bigger than the std flash hole.

 

I will shortly be stocking the new Lapua creedmoor brass, but the die problem is going to have to be addressed before its sold.

 

I only use redding dies personally, so its a simple fix, but what of the other die manufacturers ?

And that's the point I was making. Lapua 6.5 is available here in the States but I won't seek it out do to this issue.~Andrew

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Hobbit, I remember reading The Hobbit when it was trendy stuff,easy peasy,but it was also very clear that if you wanted Tolkein as your spcialist subject on Mastermind,BIlbo Baggin's alone would not do,and you had to master the 'Lord of the RingsTrilogy'-and no movies! What a hassle,I thought..just abandoned Tolkien and went back to Maths/physics/chem etc...

So it is with shooting-dead easy to get a standard set up,rifle ammo of shelf...go shoot. Anything a little ''niche' or new,might need some homework to avoid errors-as here-glad we saved your brother (think of him as a pioneer,here.)

I do take your point-the CM was introduced with the standard small primer flash hole.This new improved Lapua version case has the even better extra small flash hole(given smll primer-therefore needs an extra small decap pin/rod. Better use the actual sizes...new Lapua CM small primer brass has 1.5mm ie .059 inch flash hole.Standard "small primer' flash holes are .0625 inch (and standard large are .079 inch.

Clearly you need this new 'extra small' size. Not expensive,per se.

The main more umarket brands will have them...Forster/Redding eg and more will come on line PDQ as this brass will sell...most won't see much benefit...except in case life if warm( (ie hot) loaded. Premium niche accuracy makers-like the excellent Whidden John MH rightly recommends,are well worth considering if you are serious...though they will cost more and won't be 'off the shelf' probably at your local dealer.($184 last time I looked)....You might well get into all this seriously (an AI switch barrel isnt often a basic kit choice!) and the question to ask is ..Is the premium price worth it,for a bit more precision,usually not much unless you are at the top of the competition pyramid,and in a discipline where differences are very fine (100y Bench Rest eg is second decimal 5x5 shor aggregates......240 hero,.270 zero).but they don't even weigh charges....go figure-the reason is for another time. Often I've found the upgrade-remember its 'how much more did the premium gear cost-it might be 5xthe price,or 'just $150"-is a pleasure for it's accuracy/design...eg seating dies...basic depth you can adjust by trial and error turn on the die-crude...some seaters have "micro' heads,so you can set to eg "10" but what "10" is...well,who knows...and 20 might not be twice as much as 10...classy stuff like whidden-in this example-means 10 means 10 thou',and 24 means 24 thou etc-pure joy to use,big feel good/confidence factor. But I honestly don't think I missed anything in early days because I had more basic dies....but I wasn't then into Bench Rest etc (or 1000y where a little bit starts to matter...it's a bigger bit by that distance!)

 

Advice_ ask,as you've done here-there is a lot of practical experience and knowledge,freely offered.We've often l been there,and it's nice to help others make informed choices and avoid blunders....doing your homework helps:

Look at "Accurate Shooter' site for any cartidge you are thinking about-before you commit-of course nothing could foresee the Lapua CM variation (esp as the CM rather undercuts Lapua's own 6.5x47 ),but not much is really new-Norma eg improved the US Rem BR case,with the (Norma) 6BR and it had the extra small flash hole-not realy an issue as it wasn't the near moribund original Rem case anyhow...the PPCs too,as I recall-but all new,so no chance of older dies not fitting ...and look what the extra small flash hole helped do-more wins and records than most any other case...it proved not to be a nuisance /sales gimmick....au contraire...though there is still choice-other CM brass is standard flash hole...isn't it?

 

Get used to it....a glance at cartridge names should indicate there are several incompatible calassification systems in use....and not just metric/imperial either.

 

So ask in advance,do some research...part of the fun......hope it's more interesting than Tolkein was for me,though Smaug was OK...Mind you di/trichlorohexamine wasn't very sexy either ....never pee'd in the swimming pool again..despite olympic medalists 'fessing up on that "so as not to interupt their training session." Naughty practise from the best happens sometimes. :-)

 

gbal

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Hi, I have just purchased 200 Lapua 6.5 creedmoor cases which have the small rifle primer as opposed to the standard large rifle primers in other creedmoor brass.

Obviously my resizing die has a standard 2mm decapping get pin and the Lapua brass has a 1.5mm flash hole. What do people recommend to easily get over this as I would think it would take weeks to get a small decapping pin for my crappy Hornady die.

 

You can buy just the decap assembly here and select the right pin for the job:

 

http://www.whiddengunworks.com/product/decap-assembly

 

Martin

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gbal

 

Thanks for the thoughtful post - no arguments here - I'll get the right kit from Spud - I'm a 'buy once - cry once' guys so will look into the good stuff

 

Agree organic chemistry was tedious too!

 

Cheers

 

H

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Looks like it was a good job I brought this issue up, it may have saved some broken decapping pins across the country lol

 

True, but I assumed that being a small rifle primer the case also had the small flash hole. I haven't come across a SR case with a large hole yet. Am I wrong?

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The issue was /still is for the unwary..that the LAPUA new CM brass has a regular,small primer pocket BUT a smaller than normal 'small primer' flash hole-so it needs a correspondingly smaller decapping pin ( 1.5mm/.059) not the usual 'small pin" (.0625),which will stick,jam,break etc.

Large rifle pin size is .079,and there are not any other sizes for flash holes-so not a problem.....yet.

 

Large primer,small primer,yes. But now (actaully not very new 6BR,maybe 6PPC) three sizes of flash hole,one for large primers,two for small primers.

Simples,though not as simples as just one sizes for LR ,and one sizefor SR.

Think of it as the price of improved performance (like different grades of the same size primer).

 

(and yes,I am sure the two interact-extra small flash hole will do better with some primer grades -I mean BR /'magnum' versus 'standard'. Lapua etc have recommendations based on their testing...it's all about optimum flash depth and temperature,and suchlike for powder burn efficiency/performance and suchlike.

Plan B,just get the original LR brass,or wait for standard SR primer brass with standard SR flash holes..... or ream them all to your custom wildcat preferences,and prove Lapua is misguided...if you survive. ;-)

 

But it has to help to make this sort of thing more widely appreciated,or at least known.

 

gbal

 

 

gbal

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Ah, I completely missed that point George. Thanks clarifying it.

Having said that, and not being aware of the smallnest of the flash hole, I would honed down the decapping pin on my Creedmoor die to fit the case anyway (something I will do when I transition over to Lapua cases). I gave up resizing Lapua Palma brass as I found it to laborious for the potential reward.

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The groups I get using plain old Hornady CM brass are so small, and the numbers so good, that I seriously doubt if I could improve on them to any degree. Certainly not to any degree that could be seen on a hill top swept by 30 mph winds while staring down targets out past 1000 yards. My Tikka is currently delivering sub half MOA groups. Even if I could shave a few thou off of that, the gods of shooting would take it all back. I love spending money on reloading but there is always a point of diminishing returns.~Andrew

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To take Andrew's point, I get optimum accuracy of my Creedmoor with 140 - 142 grain bullets at 2850 fps, give or take 10-15 fps. It I push them faster the groups open up and the primer pockets start to open up after only a couple of shots from the brass.

In an ideal world I would hope the use of Lapua cases would enable me to increase MV without wrecking the brass whilst retaining accuracy.

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Brillo,than's an option,esp if the new size isn't readily available-they usually are,and at not much cost.

 

Andrew,yes indeed-the diminishing gains probably asymptote out at some point...then there is no observable/measureable gain.

 

This will vary though with the precision of the rig(rifle/ammo/scope etc) and the accuracy of the shooter (firing solution,shooting skill etc) and even target size ( when a hit is a hit,perfect or not,every time-it's good enough for purpose).

Cost is another,different kind of issue,though relevant to most hobbyists.

 

So where the cut off occurs will indeed vary for different shooters.

 

Needs a new thread...coming soon.... :-)

 

gbal

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True, but I assumed that being a small rifle primer the case also had the small flash hole. I haven't come across a SR case with a large hole yet. Am I wrong?

 

Yes, you're 'wrong'. Lots of SR cartridges have the 2mm dia. flash-hole - everything based on the 222 Rem for instance (222 / 223 / 222 Magnum / 204 Ruger, 221 Rem Fireball etc). All the small 17s and 22s with SR primers such as 22 Hornet etc have the larger diameter aperture.

 

Until recently, it was easier to say what didn't have a small flash-hole as it was restricted to the 220 Russian / PPC and BR cases plus some special thin-wall Remington UBBR 308 Win (for reforming to BR) yonks ago, but which still turns up in the USA surprisingly frequently these days. In the last 10 years, we've acquired Lapua Palma 308 Win, 6.5X47mm Lapua, and now 6.5 Creedmoor.

 

A few cases use either size of primer (6.8mm Rem SPC which can have either depending on make) and some US made 7.62X39mm is SR, but they all have the 2mm / 0.079" dia. flash-hole.

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+1 thanks Laurie

 

Does a small flash hole have any implication for the preferred primer?

 

What primer would go well with this new SRP small flash hole 6.5CM Lapua brass? Would you get better results with a magnum SRP?

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Hobbit-probably,one kinof primer will have advantage-not much hands on experiencehere,yet-unless Laurie has done the work.IN US,read with care-temperatures there can be rather low....

 

AccurateShooter Nov 23 2016 carried the announcement-and from Lapua:

 

"New 6.5 CM brass from Lapua'',and read the comments too-and the editor's on decapping.This is hardly a new issue,just new in CM!!

Google similarly "CM small primer brass" and see the range of comment on forums from the ***** to the ^^^^-fill in according to choice.

What is surprising is that potential/actual customers didnot know.....let alone understand,or accept.Not very informed pursuers of excellence!

 

Couldn't happen here. :-)

 

gone shooting (243 Sako,LR primers-need to get the old girl worn out,then it's cosmetic surgery,I think.)

 

gbal

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