Hi all, I was at the range today with a fried who was working up loads for his 340 Wby. He was shooting Barnes 175X, 225X and 180XLC. He was useing H414, IMR4831, RL19, RL22 and Ramshot Biggame. He has the Barnes no3 manual. The gun is a Mk V with 26" bbl.

All of the loads that he shot showed high pressure in that there were extruded marks on the case head from the ejector hole. This happened even with starting loads. The velocities were very close to what was listed in the books. He had Rem Brass and PMC brass. The cases were not too long. The difference between a loaded round and fired round on the casenecks were .007". He is necksizeing only.

Fed 215M primers and weighss each charge until the scale is exactly inline with the mark. He zero's the scale before use. There is about 1/4" of freebore until the bullets reach the lands.



I don't know what else to check, but think that the extruded marks on the case heads is showing very high pressure. I have some cerrosafe and will do a chamber cast just to see what the chamber looks like.



Any thoughts on this?



I ran the loads through Quickload which showed high pressure, but I don't think that it accounts for the long throat. Anybody know how to account for the long throat in Quickload?

I load for 340 wby and have used the barnes manual. The max loads can be warm but I don't think he should be having trouble with starting loads. You mention he's using rem brass. I know rem doesn't make brass for the 340 so someone must have necked up rem 300 wby brass. Had they been formed to his chamber with a previous shooting? Even though the brass is supposed to headspace on the belt I've seen excessive headspace show pressure signs befor max loads. (can't explain why for sure). Was it a hot day? What kind of chrono readings did you get with what loads?What were some of the hottest loads and the mild loads that showed pressure? Knock a primer or two out and see how ez a new one goes into some of those "high pressure" cases. Also can you measure outside to outside of the case just ahead of the belt--does it measure more than .512? Rem cases usually have a little less capacity that wby cases and can often make a little more pressure--BUT I would not think a problem with starting loads. When you say "marks" do you mean a very shiney "smeared" circle or just the outline of a circle but not shiney and smeared. Smeared is bad--just a circle outline probably not a problem. Sorry to throw a gazzillion questions but answers to these may help come up with an answer---thanks don kraky

He couldn't find 340 brass locally so bought 300brass, necked it up and fireformed before today. We checked the internal water capacity and it was right on with what quickload showed. All the loads had a circle, some of the medium loads had a raised ridge and smeared off the top. That's what first got me looking closer at the case heads is I noticed a shiney mark on one going back into the box. I don't remember what the powder charges were, but they were straight out of the Barnes manual except for the RL22 which we got out of Quickload. I remember the 175X's were going in the 3300 range and the 180 XLC's were in the 3000 range. I think the 225's were around 2850-2900ish. We wrote it all down, but he has it. All of the primers looked fine. He had a sticky bolt lift on one round. It was a cold rainy day. We got hailed on for abit, but just waited it out and shot during the clear spots.
Do you get circle spots on all of your 340 case heads?

My Brother shoots a 338-378 and gets 2 loadings out of a case before he discards them. He does it on purpose though. That's why they have 9 locking lugs right?

I'll have to get with him and see if the primer pocket friction has changed.

Personally I don't think your velocities look out of line at all. I've seen lots of circles made by factory wby ammo but we all know that stuff is loaded pretty potent at the factory. I've even seen "smeared" extractor circles and loose primer pockets on wby factory ammo from a wby rifle fired in 90 degree weather. I use a hand primer and can easily tell when primer pockets are getting loose. The sticky bolt is definately not what you want but I'm not sure that you have a problem with just lightly outlined circles on the case head. --How do primers fit back in those cases?? All I can say is I do know that max barnes loads are definately "max" in my rifle and you may be slightly over the edge using the rem brass. I've loaded brass for some wby's that look like an "audi" logo--up to five small circles and primers are still seating normally.
All I can say is procede with caution and get a feel for the primer pocket expansion.

"My Brother shoots a 338-378 and gets 2 loadings out of a case before he discards them. He does it on purpose though. That's why they have 9 locking lugs right?"

Just my two cents worth.....
-Bob F.