Occasional pierced primer with Lapua SP

[jb1023]

I have a Howa 1500 chambered in 6.5 Creedmoor. I recently took a LR class and needed to buy some brass in a hurry so I would not have to go home after day one and reload for day 2. Anyway, the only thing I could get at the time, and have it in time, was Lapua SP or Hornady. I went with the Lapua SP. Because these were virgin and I had never used Lapua brass before I reduced my load from my normal load with ADG and Hornady 147 eld-M. I don't have my book in front of me but I was getting ~2630 fps with the reduced load, so not a stiff load by any means. This rifle has never pierced a large primer, even when I was doing pressure tests and probably went way hotter than I should have, 3k, granted that was with Unicorn Dust so it was okay. Anyway, shooting the new Lapua brass with reduced loads I've gotten several pierced primers. I've used both CCI 400 and Winchester WSR and both have been pierced. The primers are not flattened at all. If I shoot one of my normal loads with the large primers, CCI 200, on the same range trip, no pierced primers. I've seen some others mention replacing the firing pin with a small pin but when I do a search for a small pin for a Howa, nothing comes up. Is that the avenue I need to research or is there something else going on? Do I just sell my once fired Lapua brass and buy more ADG?

 

[Dmagna]

I use the cci 450. Seems to be a little less prone to pierce. But depending on your powder you might be over pressure.

 

[25WSM]

Plus one on the cci450s. You won't find a small pin for the howa it would need to have a bushing installed and the original pin ground down. The 450s have a thicker cup and should be good to go for you.
Shep

 

[Tripodmvr7]

As 25WSM mentioned above about the 450 cup thickness, have a look at the attached image.

 

[jb1023]

I use the cci 450. Seems to be a little less prone to pierce. But depending on your powder you might be over pressure.

I will def see if I can get some 450's.

I don't think I'm over pressure though, according to QL I'm running about 50k psi based on the virgin h2o case capacity with 41.6 RS Hunter with the Hornady 147 eld-M loaded to 2.860" at 2641 (2630 actual).

 

[jb1023]

As 25WSM mentioned above about the 450 cup thickness, have a look at the attached image.

View attachment 226171

Based on the diagram, should I also look for Remington 7 1/2 since they are the same thickness as the 450's or is there a reason to avoid those?

 

[Tripodmvr7]

The QL data uses a Weighting Factor of 0,5. With practical test results it seems that 0,65 is better to use to check actual pressure. This causes the pressure to reflect higher and fits with the practical experience where 2700fps is a safe load with 140gr bullets.

 

[MagnumManiac]

Federal 205 Magnum primers also have thicker cups, adjusting your load may/may not be required.
I pierced a couple of primers in my Lapua SP brass in 6.5x47 and 22-250AI.
I switched to these due to the CCI 450 being unobtainium, luckily I bought 3k at the time cuz there are hardly any primers available here other than Federal LP 210/215.
Haven't pierced a single primer using the 205M.

Cheers.

 

[TRG65]

You should look at having your firing pin and bolt face bushed. I used GreTan but other gunsmiths do the same service. It eliminates the pierced and even cratering associated with using SRP brass in some actions.

 

[jb1023]

You should look at having your firing pin and bolt face bushed. I used GreTan but other gunsmiths do the same service. It eliminates the pierced and even cratering associated with using SRP brass in some actions.

If I were to do this process, would that then potentially cause issues when shooting a LP? What would a ballpark $ be for this?

 

[TRG65]

No issues shooting LRP. I've done it with 3 rifles (rem 700) and fixed the problems in all of them. About $100

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[Deleted member 103481]

This is pretty common with small primer brass and factory rifles and that^^^^ (bushing fp) is usually the answer.

no negative effects that I've ever heard of

 

[zr600]

What primers where you using in adg brass small or large?

 

[jb1023]

What primers where you using in adg brass small or large?

Large, CCI 200.