18 June 2002, 00:43
NitromanLengthening The m98 To The Rear: How Far?
How much can you lengthen the m98 towards the rear if you were trying to avoid thinning the metal at the front locking lug?
Any replies appreciated.
18 June 2002, 02:55
CarnivoreI did mine and I got it to 3.49 inches without too much trouble. I also had to adjust the bolt stop and ejector a bit. It was for a 280AI. I didn't touch the front. But I do have to figure out how to get the Ackley rounds to feed without denting the shoulder on the chamber mouth
![[Mad]](images/icons/mad.gif)
. I thought the fella that did the chambering would have seen to it but it appears the ball is in my court now.
[ 06-17-2002, 18:17: Message edited by: Carnivore ]18 June 2002, 12:29
NitromanI am curious about this, I looked at one of my receivers and by making a new ejector blade I believe 0.200" could be taken from the rear of the receiver, thus sparing the front locking lug metal.
18 June 2002, 15:35
CarnivoreI don't remember what it was to begin with. It is Argentine 09 originally. I really only took off what I did to make the 280AI dummy round fit. The rifle was throated to that same round so it was what I used as a guide for lengthening the box. What are you looking to get in there?
18 June 2002, 16:03
<Don G>You can open the M98 to the rear almost until the third lug gets cut into. This is about .160 or so if I remember correctly. Then you can drop down below the level of the cutout for the third lug and cut a shelf for the rear wall of the magazine to go into. This lets the magazine sit as far back as possible. Then you can cut about .060 from the ramp at the front and get 3.60 length cartridges to fit. This is the only safe way to do this in my opinion.
The problem is that then you need a true custom magazine/bottom metal to work right. None of the Gentry/PME/Blackburn bottoms are made this way.
If you want to use one of these semi-custom magazines, get the Blackburn and cut the action opening to fit. It is further back than the rest, but not nearly as far back as the method described above. (I tried them all for fit.)
Don
18 June 2002, 20:06
aHunterThats the reason for the shoulder design of the 7 and 8x57IS, 8x68S, 9.3x62 and .404 ...
Those AI cartridges belong in such things as a Rem and not in a CRF big game rifle.
H
18 June 2002, 20:17
CarnivoreYeah well, if I had known then what I know now, things may have been different. The smith and his work came highly recommended so I trusted the fact that it would work as advertised. It does feed, it's just that the cases get dented in the shoulder area. I was told I had to massage the feed ramp a bit to give them a better shot at the chamber. Any leads on ramp work?
18 June 2002, 22:06
NitromanThanks for the replies.
Don G, I knew there had to be a way the old-time makers did it without just removing the locking lug metal. Thanks.
19 June 2002, 15:41
TGetzenCarnivore, just curious, what part of the chamber mouth is the shoulder hitting?
Todd
19 June 2002, 16:38
CarnivoreTodd,
It appears that when feeding from the right rail the shoulder hits left side about 9 or 10 o'clock and the left rail feeds it into the 2 or 3 o'clock on the chamber. It is feeding far enough to the opposite side that the bullet is doing the majority of the guiding. Then it smacks the shoulder. There is enough interference to make me realize that something must be done. Also the chamfer at the chamber mouth seems to be a bit smaller or shallower than on my other bolt rifles, ex,Sako and 7mm Mauser 98. I don't really know how deep it should be. If it was deeper it would go a long way towards fixing the problem. Or if the rounds would center up better while feeding it would be fixed. I have a couple different extractors coming as the one on it seems loose. I figured I would try whatever I could before any metal comes off. Any ideas?
19 June 2002, 16:43
<Don G>Carnivore,
Is this the top round and the last round, or just the last round?
Don
19 June 2002, 19:15
CarnivoreI'll put it back together tomorrow. Then I will take notes to post here, possibly even some pictures to illustrate the problem.
20 June 2002, 01:50
D HumbargerIs the corner on the chamber face sharp or is there any radius to it? There needs to be a little radius there.

20 June 2002, 02:14
CarnivoreThere is a little, and I mean a litttle chamfer or radius. I'll try to get pictures this after noon or early evening.