I have a custom 338 Lapua Magnum that I have put just over a hundred rounds down range. I bought 100 rounds of Lapua brass and selected 50 to do initial load development. I found a the load of 92gr H1000, Fed 215M primer, 300 gr Berger .015" off the lands to hold less than 1/2 MOA with no pressure signs. This load worked well until I bought a new lot of powder and started to notice a stiff bolt lift after firing. I figured this had something to do with newer lots of powder burning hotter. The bolt lift wasn't too bad, but still was stiff so I bought an 8lb jug and decided to redevelop a load. I have no chrono results, but am getting a new one soon. I started at 88 grains and worked up to 90 grains, however, every round had the same stiff bolt lift. This didn't seem right to me so after I FL sized the brass with a Forester benchrest sizer, I decided to run one in the gun. After being sized it gives me the same stiff bolt lift as if it were fired. New brass has no issue. I bump the headspace back .002" when resizing. I even bumped the headspace back to what the new brass is, which was approx .004" and it still has a stiff bolt lift. The only time I had a stiff bolt was with once fired,resized brass. The last 10 rounds were on their third firing and these have had the stiffest bolt lift yet, with a reduced load of 90 grains.
Inspecting the brass further, about a half inch above the extraction grove it measures .005" wider than factory new brass. I marked a case with a sharpie. When I chambered it, it showed a rub mark at this same area. Obviously it is contacting there.
My question, is my sizing die not sizing the cases enough? The only real resitance I feel is the mandrel going through the neck. The other possibilty I've been told is that I might have an oversized chamber. Has anyone had anything like this happen to them? I would appreciate any ideas. Thanks.
If you have a oversize/larger chamber, the sizing dies should take care of that. It,s the tight
chambers that sometimes dont get sized enough because the dies are not small enough.
I would look at the neck diameter, case length compared to chamber length and bullet
Anyone of these can cause pressure even with reduced loads.
If the case necks are nor releasing the bullet enough, You will have pressure.
If the case length is longer than the chamber, they tend to crimp and cause pressure. (A simple test
is to try to stick a bullet in a fired case), if it does not want to go the case needs to be trimed.
If your bullet is touching the lands or very close this can also cause Pressure in full house loads.
Sounds to me like you are not sizing them enough, I have no experience with forester dies though. they may have been over pressured and the head expanded too much, but I dont think so. my loads in my 338lm are very hot but I have not had a problem and I am on my 7th load with this lot of brass.... My guess is you dont have your dies set up properly, it happens.
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The neck is tight, but a bullet will slide into the neck on a fired unsized case. I was thinking maybe the cases were too long, but I trimmed them down to the factory brass length that was chambering fine. Next time I load, I will back the bullet off the lands more to see if that helps. I would think the die would resize the case if it expanded in an oversized chamber also. That's why I think maybe the Forester isn't sizing it enough. I ordered and Redding S type bushing neck sizer and a redding body die to see if these will do the trick.
I'm bumping the headspace back .002 when I resize it, even more when I tried to match the factory new brass. There is no way I can size it more since I'm already camming over a good bit to get it back to the factory headspacing measurements. I could try a different shell holder, but I don't think its a headspace issue. The body just isn't getting squeezed back enough.
There are no other pressure signs on the case. Primers look good, no extractor marks. Has anyone had a die that hasn't sized enough?
Snapper26, As we talked before, the reason I suggested the posibility of an oversized chamber was this. I once picked up a couple once fired (Lapua) 338 LM cases used. When sizing these cases in my Redding body die they almost stuck. More lube was needed as they were tight above the rim about 3/8 to 1/2". Same as yours. Checking with the mic. proved these cases to be swelled about .005" in this area. Even after sizing a couple times and moving the shoulder back they would not chamber in my rifle. So sizing dies will not always size enough if the case is out too far. After working with these a while I tossed them away and wrote it off. I figured the rifle they had been fired in had a larger chamber than mine. I should also note that these cases didn't show much other sign of over pressure. Only the swell and a shadow of an ejector pin mark. This I have seen before and even with my rifle on a hot day. But the brass still sized perfectly and the brass is still in use. I have loaded extensively for the 338 LM with several powders and bullets. My current load is slightly above your accuracy load with H-1000 and also seated -.015" off the lands with a 300 Berger. Since you stated that you feel the resistance on close and lift of the bolt of a freshly sized case I feel it boils down to things. A chamber that s a little large or a die not sizing enough. I will be interested to see if the redding body die cures the problem. I do not feel you are over pressure, especially at the reduced test load of 88 gr.
Make sure you lube the tight area of the case well with your new die. If it is indeed doing more work a little extra lube will be a good thing.
Also, I set my Redding body die up to fully camover. Then I use the Reddig stepped shell holders to adjust the amount of shoulder bump. (.0015 ~.002")
This was recommended by Redding Tech and works great.