To the group

Several months ago I picked up a Winchester model 70 in 338 imperial magnum. I was very optimistic that I could use my collection of 375 Remington Ultra mag cases. Things went well until I loaded a few hunting loads that brought the velocity up close to a 338 ultra mag. I attempted to extract the first case after firing this warmish load and the extract or pulled off the rim and left me with a rifle and a stuck case. I was able to remove it at home and I attempted to study the problem in detail. I have posted a photograph of the 2 cases side-by-side the one with the blue tape on it is the modified Remington ultra mag case that became stuck in my rifle. I do not know where the gunsmithing worker occurred since I purchase to this rifle off of the classified form I think it's passed through a couple of different hands over the years. To the best of my knowledge the rifle started out life as a 300 Weatherby Winchester Model 70 Classic CRF and was modified to work with 404 Jeffrey cases fire formed into a 338 imperial magnum. I may have a line on some 404 basic brass however ultimately I would like to find a more reliable source of brass such as the 375 Remington ultra mag case. Does anybody know if it would be possible to fix or modify with a new extract or my bolt so it could work with the ultra mag cases? I was told by redneck on the 24 hour Camp Fire form that correcting the bolt to accept ultra mag cases would be a lot of work. I noticed that Brownell's stocks replacement extractors for Winchester model 70 magnum rifles. Any help with this question would be wonderful if it's too much work to fix the bolt I will just try and find some 404 cases. I was half tempted to try my 300 RUM bolt from my other Winchester model 70 classic rifle but know that this is probably a no-no swaping bolts that is.



Thanks

Brad

If your extractor pulled the rim off, you don't have an extractor problem; sounds like it did it's job. You have a pressure/sizing/soft brass problem; one of those.
If the rifle was a 300 wby to start with, the bolt face and extractor should also work with RUM cases, they are the same diameter. I just measured some RUM rims (.535) and some .404s (.540) Close enough. You just got your loads too warm. RUM brass and 404 brass are basically interchangeable. Your wildcat chamber and throat just won't handle the pressure with that brass. Sounds like to me. Whoever told you about a "lot of work", I would question. I converted a standard 7mm mag M70 to 338 RUM with no change to the bolt face at all.

Rim diameter should not be an issue.

How much do your cases expand at the web?

How much velocity?

Good questions. OP posted the pics to show us the wider extractor groove on the .404. That has no bearing on this problem; your extracgtor is getting a good grab onto your case; otherwise it could not pull the rim off. Extractor too.

Mic a new RUM case and a 404 case right in front of the extractor groove. (HINT)

I can't use 375 RUM brass in my 416 Dakota either.

I did; RUM is .547; .404 is .542. That is not an extraction problem. In this case, if the solid head is getting stuck (I don't see any marks in his picture) I would polish out the chamber rather than get new, hard to find, brass. That's only two and a half thousanths difference.

OP said he fired a "warmish load". What happens when he fires a normal load, or chambers a piece of sized brass? OP, please come back and tell us more.

Rereading the first post did the extractor slip off the rim? Or did the extractor pull the rim off the case?

I first took it as pulled the rim off but now I'm not sure.

He says, "pulled off" the rim, which I guess I assumed was pulled through. Could mean pulled over too. OP needs to come back on and tell us more. Looking at the pics, there is no evidence of pulled through, is there? So he might not be actually sticking a case after all? Need more info to diagnose this. But he says that "things went well" until he tried "warmish loads". Could be his extractor, not a brass issue at all.

300 RUM Bolt 404 Jeffery Cartridge 338 Imperial Bolt 404 jeffery cartridge



300 RUM Bolt 338 Imperial Bolt

Top 300 RUM Bottom 338 Imperial


Left 300 RUM Bolt with RUM Case Right 338 Imperial Bolt with 404 Jeffery Case on it.


After taking the photos and looking at them side by side I think that the 338 Imperial Bolt is messed up at least to my eye the extractor doesn't look right for some reason. The bolt face looks a little opened and polished any thoughts?

Brad

Looks to me like the extractor is bent.

Looks to me like the extractor tongue is not riding in the groove in the bolt properly hence is bending the claw away from the bolt face and cartridge rim. Mis-matched extractor?????

quote:

Originally posted by ramrod340:
Looks to me like the extractor is bent.

+1

954-000-020WB
Magnum RH Extractor
Mfr Part: WFC604207
Would this work ?
Brad

Brad
These other gentlemen are correct, the claw end of your extractor is bent and useless, likely the original OEM cast extractor which is pretty lame even in new condition. You will need to properly fit a replacement extractor to what ever case you plan to use.

Lip is also rounded over on the rim side which would explain the slipping over the rim.

Thanks for all the Help Brownell's has a one day free shipping TODAY! should I order the William extractor shown and send the bolt off to have it fit? Any thoughts would be great I'm happy I'm getting to the bottom of this issue finally.

Brad

Might work as is. Try it and see. Mag and RUM rims are the same.

I think I'll try it a bird in the hand is worth two in the bush.


Update just placed the order !!

Brad

Here's a very informative article by D'Arcy Echols on claw extractors that may be of interest: http://www.tecomate.com/conten...claw_extractors_101/

Great Info. Thanks