This morning I was testing some new loads and when I finished shooting I could barely see ejector marks on the new brass. I tried two different loads in powder weight and the marks were the same. However, I measured the brass and the lenght was .007 longer then recommended trim lenght. With the ejector marks hardly noticable could the extra brass lenght have a effect on pressure. With that said I didn't notice anything else leading to signs of high pressure and the primer looked good.

I appreciated you help.

Steve

If the throat on your chamber is at min spec, long brass could be pinched into the bullet causing high pressures. There are other items that could lead to extractor marks though. What type of rifle are you using and which caliber?

John

John

I'm shooting a .378 Weatherby Magnum which I just had rebarreled with a Shilen.

Steve

HI Steve,
If you have a chronograph check your velocities to see if you are driving your bullets a little on the fast side. Primers are sometimes suspect when trying to varify high pressure. Some are harder than others and look as though things are fine. About the third reload you'll find that the primer tension is not there any more and your brass is finished. As mentioned by John, it is possible your long brass might have caused high pressure signs. Trim your brass back and try the load again. Extractor marks are related to pressure but you should check your bolt face to make sure there isn't something there causing the marks. I had a bolt that would leave a half circle mark on my brass and had to have the face polished to fix the problem. If you know someonne with a chronograph start there.
Best of luck with your rifle
Dave

470Mbogo

I took you're advise and trimmed the brass back to recommened length (2.903) and shot the same loads and chronograghed them at the same time. Oehler 35 chronogragh.

.378 WM
111.0 H-4831SC
Federal 215 primer
C.O.L. 3.70
270 gr Barnes TSX

Muzzle Velocity 10' from muzzle 2971

.378 WM
112.0 H-4831SC
Federal 215 primer
C.O.L. 3.70
270 gr Barnes TSX

Muzzle Velocity 10' from muzzle 3003

Barnes reloading Manual uses 112.0 H-4831 for there max load with 270 gr X bullet @ 3087fps.
After shooting both loads the ejector mark was
still there and there is no difference between the two marks as fas as depth goes.

I'm trying to reach 3100 fps "IF POSSIBLE" what would happen if I changed powder and maybe tried RL-22 or IMR-7828 would that lower my pressure? Thanks for the help.

Steve

I figured these velocity's from my rifle are low considering I'm shooting from a 28 1/4" barrel.

Steve

quote:

Originally posted by Steve Lefforge:
I figured these velocity's from my rifle are low considering I'm shooting from a 28 1/4" barrel.

Steve

One suggestion is to use another chrony and see what you get. I did, while working up some .375 loads and got a velocity difference averaging 56 fps with similiar spreads and Sd's.

The Oehler 35 Chronograph has 4 foot spacing between the screens and a third screen at 2 feet as a check screen so it is about as good as chronograph get.
Did you check your bolt face to see if machining has left a raised part around your extractor?
Rl 22 is only one step slower on the burn chart rate. With a 28 inch barrel you should be able to use a slower powder yet.
Is your barrel the one that was changed from a shorter barrel to the 28 inch barrel on another post. If so ask your gunsmith if the reamer he cut the chamber with was a standard Weatherby reamer with lots of headspace or if it was a custom reamer without the headspace. That would make a big difference in pressure especially if your bullets were set out for the free bored chamber. Try setting your bullets back in another bit and see if that makes a difference. You can check your overall cartridge length with a cleaning rod that you can mark with a felt marker. Put an end in your cleaning rod so it is flat on the end even if you have to cut off an old jag to get a flat end. This is so when you check the length for a pointed bullet the tip doesn't go into the end of the cleaning rod threads. Close your bolt and put the rod down the muzzle until it is sitting against the bolt. Right at the muzzle use the marker and spin the rod to leave a circle mark on your cleaning rod. Now pull the bolt and take a 270 grain TSX bullet and drop it into the barrel and give it a couple of light taps with your cleaning rod to get it to engage in the barrel. Now take your cleaning rod and slip it into the muzzle until it is sitting on the top of the engaged bullet. The distance between the two marks will be your cartridge length from the bolt face to the rifleing. Check your rounds and see how close they are to this measurement.Make sure your set back from this distance.
Take good care,
Dave

470Mbogo

I did the cleaning rod thing earlier just to check to see how much freebore the barrel had.
The measurement between the two marks 4.485 and the cartridge meaures 3.700 the difference is .785.
I have a old book by Weatherby and they suggest the C.O.L for the .378 should be 3.680 however, that was with a factory barrel.

Yes, that was my post about the 28" barrel.
Would I be better off to have the gunsmith use a Weatherby reamer or one with more head space instead? And when reloading once fired brass and I just neck size the brass will that change anything?

Thanks Again Dave, for you're help.

Steve

Hi Steve
Your not looking for more headspace it was the freebore that Weatherby uses and it sounds like your reamer has lots of freebore. Just out of curiosity try backing the load down by lets say 5 grains and shoot it to see if you still get the extractor marks. If so then I would look into the bolt face if not then your probably looking into a pressure problem of some kind particular to your barrel. Try the loads with the once fired brass and just neck sizing them so if you have a headspace problem the cartridge will headspace on the shoulder which eliminates any headspace problem. If you have too much headspace it can cause flattened primers due to the primer moving back into the boltface. Basically it is trying to fire the primer back at the same time it's trying to push the bullet forward. I'm not sure if it could be bad enough to push the brass and leave an extractor mark. Usually by the time you get an extractor mark you have flattened and cratered primers. Your primers were in good shape so it's not really making sense. Your not using A-Square brass or some kind of soft brass are you? It might be a good idea to buy some factory rounds and try it to see if it leaves a mark. You could see what your headspace is like by taking pieces of feeler gauge and slipping it under your brass and see how many thousands it takes before your bolt get hard to close.Basically finding the differece between go and no go. Your going to have to go through a process of elimination. Since your velocity seems to be within specs have you tried to go one or more grains higher to see if the mark gets heavier?
Take good care and good luck
Dave

Hello 470Mbogo

I'm using New Weatherby brass,I'll give you're suggestion a try and go from there. I appreciate you're help.

Thanks

Steve

The ejector marks are not a problem IF your primer pockets are not loosening up or your experiencing sticky bolt lift. If you reload the same case 5 times will a primer fall out or get loose? Some weatherby brass is soft enough to show these marks even when pressures are fine. Norma brass seems to show these marks far less than Weatherby brass. Is the belt expanding .003 or more after firing? I've seen many weatherby's that do. My .460 will show these marks with factory ammo but the pockets stay tight after repeated firings so I don't worry about it.-Rob

I'm shooting 114 Grs. Rel. 22 with the 270 TSX. Pressure looks fine, primers are round and no marks. Its WBY brass. My gun will eject 3.76 live rounds so thats my O.A.L.

Rob

Are you taking that measurement from new brass compaired(sp) to once fired brass and do you measure on the belt or just in front of it. And I have been just neck sizing the brass instead of full length. By bolt lift as no sticking to it at all. And I am using Weatherby brass.


MTM

What kind of velocity and/or groups are you getting? Acorrding to Barnes you're three grains over Max however, that is with the Barnes X bullet and not the TSX. How does that 3.76 C.O.L fit down in you're magazine?

Thanks

Steve

Rob

I took a brass that had been shot before and full length resized it. Then I took brass that had just been shot in this new barrel and measured just above the belt (three times for a avarage) and the expansion was less than .001 if any, all three measurments.

I'm going to take and add two grains like 470Mbogo suggest and shoot the rifle and see if the mark get worse.

Steve

Hello 470Mbogo


I took you're advise and neck sized the brass only and trimmed back to 2.900 instead of 2.903.
I reloaded with two more grains, 114.0 grains of H-4831sc. After I shot, the bolt showed no signs of sticking when lifted. The ejector mark showed up right next to the first one but,it didn't look any worse than the first mark. These ejector marks are real hard to see, in fact if you don't hold it just right in the light you can't see them. One more thing the primer looked good again!!!

Would you say it maybe the bolt face needs machined?

Thanks again.

Steve

If your marks are barely visible, you don't have sticky bolt lift, your velocities are within the max and your primers look good, then your in good shape. I don't have the experience that Rob has with Weatherby brass so if he has noted soft brass that marks from time to time I would go with it. Usually soft brass gives you stiff bolt lift at low velocities. A-Square had this problem with my 500 A-Square brass I bought from them. Bolt was locking up at 2200 fps with a 600 grain bullet. I wonder how many guys bought loaded ammo loaded to 2450 fps with that lot of brass. Take your gun out and have a good time.
Take good care
Dave

Measure the belt itsef. I've seen them expand .003. If the belt is moving so is the primer pocket. Welcome to Weatherby spec chamber reamers too. Again, shoot your loads out of the same case 5 times. If the primers will still stay in and no sticky bolt lift issues, then just live with it. If you experience loose primer pockets or sticky bolt lift, basck down 1 gr at a time till it goes away. If no issues like I've described, its a Cosmetic problem period.
I spent alot of time on Weatherby's and admit to owning 2. I've had 10 pass through my hands and frankly don't care much for them. The ejector design is the problem as is the real high pressure factory loads and generally soft brass. Remember the average Weatherby customer doesn't reload anything period much less even look at their brass, so they can get awy with these issues. I basically like the cartridges and don't care much for the guns. If you had rebarreled a CZ550 you would not have these problems. Been there and done that.-Rob

Gentlemen

Thank you for you're help I really do appreciate the great advise and suggestions.

Rob

I'll go and shoot it a couple more times and go from there. I think you are right about the cosmetic problem only however, I didn't want to take a chance. Thanks

Steve

Steve- You are a wise man to ask these questions. I've learned to disregard all ancillary pressure signs other than loose pockets and sticky bolt lift. Sometimes as 470Mbogo said the brass is the problem. If you encounter one of those signs WATCH OUT. Otherwise the 5 case reload rule works every time. Basicall if it shoots accurately and doesn't blow primers its a keeper. If not GUN SHOW TRADE material.-Rob

Hi Steve, my load is out of the'92 Hercules handbook. It lists 115 grs. as max for 3050 at 47,200 C.U.P. My Chrono's on the fritz so no speed yet. It shoots very good.

quote:

Originally posted by Steve Lefforge:
This morning I was testing some new loads and when I finished shooting I could barely see ejector marks on the new brass. I tried two different loads in powder weight and the marks were the same. However, I measured the brass and the lenght was .007 longer then recommended trim lenght. With the ejector marks hardly noticable could the extra brass lenght have a effect on pressure. With that said I didn't notice anything else leading to signs of high pressure and the primer looked good.

I appreciated you help.

Steve

"TRIM-TO is less than the maximum allowable o/a case length that is permissible before you must trim. I doubt that the loads are showing pressure signs.


Barnes reloading Manual uses 112.0 H-4831 for there max load with 270 gr X bullet @ 3087fps.

After shooting both loads the ejector mark was still there and there is no difference between the two marks as fas as depth goes.

However, it sometimes happens that the ejector/ejector spring combination can be a little too long for the hole in the bolt face. When this happens, the ejector will not go all the way into the bolt face, and merely closing the bolt will leave a mark on the case head. To see if this is happeniong, take a new unfired empty case or two, chamber them, and close the bolt, then take out the cases. Now check them for ejector marks. IF yopu get marks w/o even firing, the ejector and ejector spring are responsible. You can fix it, or not, as you please!

Ejector marks should raise a red flag, they may not mean much but they can..I would resize to the chamber and if I got them again I would cut back a half grain at a time until I didn't get them anymore...It won't make much difference in velocity anyway...Be safe.

Your brass lengthening could be fireforming, but then it may not be so again I would shoot the properly resized brass, meaning resized to a crush fit in your chamber and if the problem still exists then your too hot and need to cut back a little..

Common since and a lot of knowledge through study, should always be your guide in reloading..Be a detective and through a process of elemination find out why these things happen, lots of reasons unfortunately...soft brass, oversize primer pockets, whatever.

I load max for the most part and I look for extractor marks (usually first), then mic my cases, then loose primers, flat primers, number of reloads..A combination of them all will tell you where your at.