.270 win help. Cratering primers update Page 8 post 78

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bobjoe

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I have an unusual problem that is perplexing me. I have been reloading for years. I am trying to find a load that would work for two different .270 win bolt actions that I have. I planned on using a 130 gr barnes ttsx. Doing proper development I started at 54gr with max being 58 using IMR 4831 according to the barns book. I also had 215mag GMM primers. I went out and shot and found that 55gr was the most accurate load for both but I had some concern as the primers were cratering/flattening/backing out and I had some marks on the head of the brass. Crony was showing 3150 fps. Which is fast for 55gr but within the range of the barns book. Seating was at 3.300 originally.

Wanting to be safe I back the load off down as low as 52gr and seated the bullet into 3.230 I tired CCI 250 primers and even tried a Speer 130gr BT that I had on hand. No matter the type of brass, primer ect that I use the primers crater and are starting to flow out of the brass leaving a ring on the bottom of the primer. 52gr is well below the starting load. I’m at a loss. Bolt hasn’t been hard to open at all. Brass measure proper after firing in all aspects except the primer pockets. They start at .205 and after firing some of them are .207 up to .214 for one and it had gas escape from it on firing.

Is this a head space issue? Rifle is a savage 111.
Some pictures to show what is happening
OkWg20X.jpg

FzEtVPm.jpg
 
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That is extremely odd I use 59.5gr of H4831 (which does burn a bit slower than IMR) with federal 215M with no issues and not getting the speed you are getting. Seems to be a rifle issue as I have this load in 4 rifles no issue.
 
sbe said:
That is extremely odd I use 59.5gr of H4831 (which does burn a bit slower than IMR) with federal 215M with no issues and not getting the speed you are getting. Seems to be a rifle issue as I have this load in 4 rifles no issue.
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See I was wondering if it was a rifle issue but it was doing the same thing with both rifles.
 
Why are you using magnum primers with IMR 4831? This is not what Barnes recommends....Your 55 grains load is too hot obviously. Barnes recommend 50.7 to 56.3 grains. Start low, go up slow with non magnum primers (Rem 9 1/2 is excellent for the 270 win). Winchester brass has the largest case capacity for the brass you have.
 
It's possible you're pushing the shoulder back too far, which creates excessive headspace. When the round fires, the primer has room to move out of the pocket. That doesn't explain marks on the case head, however. Have you tried factory ammo in both rifles?
 
mimile said:
Why are you using magnum primers with IMR 4831? This is not what Barnes recommends....Your 55 grains load is too hot obviously. Barnes recommend 50.7 to 56.3 grains. Start low, go up slow with non magnum primers (Rem 9 1/2 is excellent for the 270 win). Winchester brass has the largest case capacity for the brass you have.
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I hunt in the far north where it is often very cold. I prefer to have the higher heat of the mag primers to ensure fast ignition. I build all my loads with them. (I don’t have any rem primers to try.
 
Chilly807 said:
It's possible you're pushing the shoulder back too far, which creates excessive headspace. When the round fires, the primer has room to move out of the pocket. That doesn't explain marks on the case head, however. Have you tried factory ammo in both rifles?
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That’s an interesting thought. I full length resize them in Lyman dies. I will measure the sized brass to see what the difference is. As for factory ammo, Shot some in both. Just never paid attention to the primers on them.
 
The brass is flowing enough to leave a mark from the ejector hole. High pressure. The flattened and leaking primers are sending the same message.
 
Janeau said:
Loud and clear overpressure.
Do you have a chrono ? Time to stop when published velocities are reached.
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I do have a chrono. With 55gr which is under published max they are doing 3150. I went down to 52gr but did not chrono them. They still had flattened primers at 52. Which is a starting load. This is why I am confused. Everything is showing over pressure when all well under published loads.
 
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That bullet is moving I’d say.
try at a lower gr weight it’s not about speed it’s about accuracy someone told me this years ago when I started and I have loaded down in speed and I have found some tight groups shooting at slower speeds
But hey to each your own
The 220 swift is a screamer (lol) coyotes can’t run fast enough...... lmao
 
Too hot I can see ejector pin imprint on the brass a Wilson Case Gauge would be good to have/use to make sure that the brass is sized perfect. Try shooting some factory loads and see what results you get. If you get the same then it's the rifle.

You will also have 20 rounds of 1 fired brass for your load development
 
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