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Blown Primers

That load is simply too hot for the conditions for several reasons. First, you're trying to hit the high node with the 200.20X bullet and Varget. In Lapua Palma brass, that means pressures predicted to be well above SAAMI max for a .308, probably in the 63-64K psi range, or even higher. According to the folks at Alpha Munitions, their SRP brass has an average water capacity of 54.8 gr, which is more than a full grain lower than Lapua brass runs on average. Add in the elevated temps and excessively large firing pin hole on a Savage rifle, and what you observed shouldn't be too surprising. If you dial that load back to the 2640-2660 fps node for that brass/powder/bullet combination, it may not be necessary to have the firing pin hole bushed immediately, even though it's probably a good idea to have it done anyhow. Typical Varget charge weights to hit the lower node with Lapua brass and the 200.20X usually end up somewhere in the 43.2 to 43.6 gr range.

FWIW I measure Lapua to be 56.15 (fired) and Alpha SRP to be 55.49 (fired)
 
2 cents.

I have a Blue Printed 700 SA with Small Firing Pin , 30" 1-10 Brux .
Peterson SP Brass CCI 450

I can not shoot that load . 43 gr. Varget . lot 5553 . 200-20's or HB .
 
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Bushing the firing pin hole just hides the signs of pressure. The loads are hot regardless of fps.

Agree on that, BUT, bushing the bolt for a proper firing pin fit is not a bad thing, if the work is done correctly.

Danny
 
Getting your bolt bushed only costs around fifty bucks. I would strongly urge you to get it done. He will turn your firing pin down to the right size and adjust the spring tension to where it should be. Best money you can spend on your Savage. And I know because I have been there, done that. (and the guns I have had done both shoot smaller now too)
 
Checked my whole batch, they're all .4700 (Mitutoyo Vernier)


Thought about that. I wanted a little more advantage over the Juggernauts if I'm going to put the time/energy into making the 20x work.






That's proper protrusion for Savage, .065. I would send it to Grimstod and while it's being bushed have him to a lift kit job on it. Do you know you can start at the muzzle with the 185 running a bit faster than the 200, but when they go thru the target at 600 and out the 200 retains more speed, significantly. =BC.

What should my firing pin protrusion be? At maximum poke it's about 65 thou - seems like a lot.
 
Couple of ideas to add, quickest/cheapest to most expensive/time consuming.

Switch to 205M-AR primers that have a harder cup. Or go with CCI 450

Explore a slightly reduced charge for hot weather. I had to do this recently on my 223 using Varget. Same issue.

Buy several new firing pins from Savage and hand pick the one the fits the bolt head best. This was the fix I used one of my model 12's and they were happy with me buying 6 new firing pins.

Send your bolt to Grimstod and have it bushed. Probably the best long term solution.
 
I'm not a 308 shooter but looking at different loading manuals and running the numbers through QL anything above about 43gr Varget w/200gr bullet is reaching max pressure and if you are seating your bullets to where they are just touching or even slightly off, that's going to spike up the pressure well above max.

From looking at your brass with multiple ejector marks, you've been running above your guns max before now.
 
Bushing the firing pin hole just hides the signs of pressure. The loads are hot regardless of fps.

This is not always true, I know it's not a 47L but that is the best example. Often times the only way you can run a 6.5x47L at max (63.000 psi) is with a small pin tight fit. I've seen factory actions large pin excessive slop and weak spring, blank primer at lethargic starting load charges.

So yes it will "hide" pressure sign, but often it will allow it run where it should be. And by small pin and bushing you can look at other pressure indicators that are more reliable than the often false signs you get from big hole, slop and weak springs
 
I think it's pin/ pin hole/bolt issues.
Those primers aren't flattened. Matter of fact they look great except for the pin strike.
Something like the pin is going in too far and the primer cup material has to go somewhere so it's riding up the pin.
 
Checked my whole batch, they're all .4700 (Mitutoyo Vernier)


Thought about that. I wanted a little more advantage over the Juggernauts if I'm going to put the time/energy into making the 20x work.


What should my firing pin protrusion be? At maximum poke it's about 65 thou - seems like a lot.

0.065 is a bit much. I set them to .055 and some people do .040. Its hard to set them to an exact depth as they have those crown washers that permit only quarter turn adjustments.

If there is not case head expansion then you are not to hot on your load. Bushing it would fix it and let you shoot a good node there.
 
If the pressure is too much, why are the primer shoulders still so round? It seems like every time I have seen signs of over pressure, the primers become flattened.
You are correct. Most loads that are to hot have flat primers. Its very rare to not see that symptom with a hot load.
 
FWIW I measure Lapua to be 56.15 (fired) and Alpha SRP to be 55.49 (fired)

Our Lapua measurements are pretty close; my latest Lot runs at 56.10 gr. So the Alpha is only a little more than half a grain less capacity than Lapua. Nonetheless, it's likely that difference in case volume made some contribution to your pressure issues. 44 gr of Varget is a stout load for a 200 gr bullet. Not to worry, a little more charge weight testing carried out at the higher temps (90s), or backing off the load to the slower node ought to do the trick.

FWIW - I have talked to a few F-TR shooters at matches this year that really know what they're about on the topic of running the high node with SRP brass, Varget, and the 200.20X. Some of them have decided to go back to using the slower (~2640-2660 fps) node for a number of reasons such as pressure, brass life, recoil management, etc. They seem to be very pleased about making the decision to run the 200.20Xs at slightly less velocity. The amount of performance that is given up when reducing the velocity by ~50 fps is pretty small.
 
If you are certain that the powder load was the same as those that did no primer damage, then the culprit is most likely wall thickness of the brass. I had this happen on some LC .223 brass. When loading did you notice that the powder charge was higher in some cases than others?
 
I was blanking primers in my 6Creed RPR with average loads before I sent my bolt out to be bushed. Never had cratering, let alone blanking after the modification. All primer strikes are perfectly centered and I believe it is a bit more accurate. I am now a firm believer in bushing the FP hole.
 

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