Factory Berger Ammunition and two pierced primers

[spudgun]

Been there done that too.

My savage 12 F/V would crater and sometimes pierce primers CCI SRP.

Went to the CCI #41 and my issues went away.

In my case it was due to the firing pin hole just a little too large for the firing pin.

 

[Laurie]

In my case it was due to the firing pin hole just a little too large for the firing pin.

With experience of three Savage PTA single-shot 'Precision' actions, this feature varied substantially across the trio from excellent to barely acceptable.

I believe that Savage contracts out manufacture of the various bolt components and polishes / checks the dimensions only before assembling them together. The tolerances, particularly in the [separate] bolt-head, are obviously more generous than you'd expect from small production custom actions and it becomes a matter of luck whether you get a good match or not between the pin diameter and the matching bolt-face aperture. I can see why PT&G introduced its version to reduce these tolerances - assuming it does what it says on the packet, of course. At least Savage firing pins are smaller diameter than those in many competitors' rifles which helps.

Other not so good features show up too at times. I have a bolt-head for 0.473" case-heads that is so-so in pin to hole match, but also has a slightly concave face, especially around the firing pin hole. It makes it very easy to judge firing pressures through primer cup appearance. When the cup starts to produce a slightly raised centre around the pin indentation allied to a very thin and barely visible 'crater', I know that pressure is about as I high as I can happily go. That's with large primers, especially with comparatively weak-cup varieties such as the elderly PMCs (Russian manufacturer by Murom) I use in the conventional 7mm-08s rounds I fire in this rifle. I also use SRP brass (necked-down and turned 308 Win Lapua Palma) and as usual there are far fewer pressure indications except with very thin / weak primers such as the old standard PMC / Murom KVB-223 model with its bright copper colour cups. They'll flatten, but usually more robust models like Rem 7 1/2 BRs, CCI-BR4s etc transition from 'standard full working pressure' appearance to blanking without any intermediate steps.

 

[Texas10]

I see no advantage whatsoever in buying factory 6.5 CM ammo with a small primer if you're going to shoot it and not reuse the brass. Large rifle primers rarely pierce, and the main advantage of SRP's in the 6.5 CM is case longevity for hand loading. There's more brass left in the head with a SRP so it's stronger.

I suspect what with the sharp rise in gun purchases over the last months, and component shortages due to hoarding that Berger had to use second tier, less than desirable primers to keep up with ammo demand.

Your handloads will undoubtedly use better components, and your results will be better. What brass are they using? I find the Hornaday LRP brass to be very good and produces a very accurate loads in my 6.5CM.

 

[LGKLAS]

Definitely a bolt / firing pin issue then. This is a very common issue with factory rifles and high-performance / pressure cartridges with small primers. If you do a search on the forum / AS site about bolt-bushing work, there is a good size industry in the US gunsmithing trade doing remedial work - turning down the factory pin tip diameter and boring out the bolt face before fitting a bushing with a smaller dia. hole and set up for much closer tolerances. Greg Tannel was an early expert in this field, but there are now many others.

https://www.gretanrifles.com/product-page/bush-firing-pin-hole-turn-pin

Ben Chappell (@Grimstod on the AS Forum) is another who npow does this work and has had excellent reviews from other forum members. Do a search as follows:

https://forum.accurateshooter.com/search/21878/?q=grimstod+bolt+bushing&t=post&o=relevance

Bearing in mind this site was originally 6mmBR.com specialising in this cartridge and its derivatives, literally thousands of words have been written on this issue and rectifying it. In an era when Remington 700 actions and similar were far more commonly used in custom builds for the BRs, bolt-bushing was a near standard step in the build otherwise loads, pressures and MVs often had to be significantly reduced. Whilst the BR and its derivatives was the first modern SRP precision cartridge to go near mainstream, the last 15 years has seen a huge increase here with 6.5X47mm Lapua and now SP brass options on many other traditional LRP numbers such as 308 Win, 243 Win, 260 Rem etc from ADG, Peterson and with the Creedmoors and 308 Win, Lapua offering both types.

I learned the hard way about this when I had a 308 FN Special Police Rifle rebarrelled in the then near new 6.5X47L some 10 or 12 years ago. Primers cratered at every loading level / pressure including Vihtavuori's mild starting loads. Blanking (the correct name for the primer cup failing and blowing a disk out into the bolt) began at starting plus 1gn. Nobody did bolt jobs in the UK at that time (and whilst on offer now are expensive at c. £300 / $400 US) so it was a case of forced rechambering to 260 Rem to return to LRP brass use. Cratering / blanking is FAR less of a problem with LRP cartridges than with their SRP equivalents even at equal pressures.

So the answer in your case is to either have a bushing job done and / or to only buy or load ammunition in LRP brass. That's no great loss in your case as the LRP Creedmoor variant is more widespread and there are some excellent makes in this form including the Lapua LRP version.

Thank you Laurie for your detailed reply. I was aware of the bolt bushing/pin turning option but had earlier read it in conjunction with just the R-700 bolts/pins. So, saved your links and will look into having this done. I'm shooting this ammunition in because it is extremely accurate, hope to mirror it in my hand loading and for a rifle I am having built. I've fired 100 rounds of it, so can save the brass for my new rifle.

Meantime, since I last posted, I did call Berger and spoke with a Phil. He said pretty much the same thing as you. That my rifle's firing pin would pierce primers and reco'd that I contact GrayTan or anyone who could turn the pin down and install a bushing into the bolt face.

Of the now 100 (around 80 when I first posted) rounds fired , I only had two that resulted in a pierced primer. I applaud Berger's customer service and the help I always get here from members like yourself.

Thank you!

 

[LGKLAS]

Another consideration might be the firing pin hole. Too much clearance has also been associated with that type of issue, and the remedy for that can either be as simple using a different primer with a harder/thicker cup, or having the firing pin hole bushed. I think you're starting at a good place by trying to find out of anyone else has observed this issue with the same ammo. Good luck with it.

Thank you Ned. It is what Berger suggested as well as Laurie here did. I replied to Laurie with a bit more detail. Appreciate your time and help.

 

[LGKLAS]

I see no advantage whatsoever in buying factory 6.5 CM ammo with a small primer if you're going to shoot it and not reuse the brass. Large rifle primers rarely pierce, and the main advantage of SRP's in the 6.5 CM is case longevity for hand loading. There's more brass left in the head with a SRP so it's stronger.

I suspect what with the sharp rise in gun purchases over the last months, and component shortages due to hoarding that Berger had to use second tier, less than desirable primers to keep up with ammo demand.

Your handloads will undoubtedly use better components, and your results will be better. What brass are they using? I find the Hornaday LRP brass to be very good and produces a very accurate loads in my 6.5CM.

Hi Texas 10. Yes, my purpose in buying the factory loaded ammunition was to use the brass for reloading and for a rifle I am having built. Prior to this I have been shooting a rifle using and reloading all LRP brass. I started accumulating the SRP Berger loaded ammunition a couple years ago. The brass Berger is using is Lapua.

In talking with Berger today, I was told that their future factory ammunition (6.5) using the 140 gn Hybrid Targets will be with LRP brass. It was just this year that Lapua started offering the 6.5 CM brass in LRP.