I've got a pre war mod 70 .270 Win that is my main deer rifle, and it has been giving me fits. The left rail cartridges sometimes feed properly and other times just "pop" out of the magazine and don't get picked up by the extractor. This especially occurs when the bolt is cycled slowly. If anything, if the bolt is cycled briskly, I tend not to have this problem. I am; however, hesitent to "panic-cycle" the bolt as I am afraid to push and jam the cartridge into the chamber. The right rail feeds fine no matter how slow you go.

I have another pre war mod 70 in my safe, which also shows the slow cycle "pop-ups" from the left rail. Of course my Mauser feeds fine no matter how slow I go. (Both .270s)

Both pre wars have the original springs and followers. Is this a common occurence, or do I need to stop cycling my bolts like a pussy????

Frank C, You left a clue in your description of the feed problem that invites a simple thing for you to try out. Swap Magazine spring from the Mauser to the 70 .The 70 spring is generally a little "softer" for upward pressure to the follower. This makes it cycle a little easier when all dimensions are "in the middle" per feedwell/ lip geometry. The H&H ctgs in the 70 were particularly sensitive to how much "lip" extends over the case body at the release point. As case is released it is supposed to be caught by a flat spot on the bolt face ctg rim surround and then the case is supposed to roll under this flat and up into the bolt face, simultaneously being caught by the lip of the extractor. When the feed well geometry is on the maximum opening side of the tolerances it requires more ctg tension wedging the case between the feed well upward slope and that lip. Too little tension and the ctg stutters and in the process jumps ahead of the bolt resulting in push feed. If swapping springs helps, comparison between the 70 and the Mauser "W" spring will suggest what can be done to the 70 spring to improve the shining hour. This explanation is I hope not too muddled to follow and incidentally applies also to a previous similar problem with the CZ .416 , although there the modification would be in that very skinny remnant of a flat on that rim surround on the bolt face left hand side.

Hi there (especially 'systeme 98')
I have a problem wth my CZ 416 Rigby pushfeeding from the left rail when cycling fast. I'm waiting for a new extractor to try and also a Wisner mag spring. You mention a 'similar problem' above with the CZ? Could you give some pointers for me to hand on to a gunsmith (I'm in New Zealand, and my impression is smiths here don't have the Mauser DGR experience required).

cducat, The last line of my post on the pre-war 70 indicated where the possible modification lay. If you remove the bolt and stare at the bolt face you will see the thin rim surround, and if you nudge the extractor upwards to about the 11 o'clock position you will notice that the surround which was under the extractor doesn't curl around as far down the bolt face i.e. if you imagine a line across the bolt face, 9 to 3 o'clock, left hand side surround keeps on going to almost the 5 o'clock spot whereas the extractor side surround stops closer to 8 rather than 7 o'clock position. Not symetrical.. The ctg rim at release from feed well doesn't catch the ctg rim, it bounces and shoots ahead resulting in push feed. The solution if there is to be one is to stone a flat on the thin edge of bottom of the said surround presently on your bolt face. at least 3 times as wide as the one presently on it. It will be about .010" or .25m/m if you are into metric and needs to be about 3 times that wide to commence its work. This can be done with an india stone, but there are presently PDR Chinese diamond needle files sold all over that would be better suited to the purpose. You might end up 4 or 5 times wider than it is now, but that would be a start and you will know you are on track when it only push feeds occasionally, and that will commence at about .030". It is not sinful to flatten more at the closest part to the bolt face putting that part at the very front slightly lower, thus acting as a retard. Every little bit helps. The Mauser
Werke finally got their act together in the 30's (and after constant wailing from Brit Gunmakers) and made a stepped extension of the left hand lug right out to the end and this left a lot of flat to catch the rim. It is an old problem with the biggies and really a better solution than increasing the bolt diameter taking into account the total time involved making either version feed properly. Not for nothing did the Brits alter the P13 bolt head to the P 14 shape when they switched to the rimmed .303.

Thanks. I studied the two actions after reviewing your response. The mod 70 has no "straight" edge upon which the cartridge rim is to "roll." Instead there is a double radius lip: one radius from the bolt face forwards toward the breech (in the direction in which you've described needs to be a straight edge perpendicular to the bolt face) i.e. the bottom of the bolt face there is no rim and as one goes from 5:00 to 4:00 to 3:00 (head on the bolt face, along the left) the rim is built up towards the breech. The other radius out from the bolt face laterally to the left along the left lug as part of the coned breech.

Can one cut a perpendicular on the double radius? I did cycle the rifle in a standard manner and when cycled briskly, there is no feeding problem. Only when I try to cycle the rifle in a "quiet" manner. I plan on switching springs. If this does not help, what should I do?

Should I have the extractor modified for the occasional instance when there is no CRF i.e. allow it to "slip" over a rim or should I have the bolf face modified?

Frank. Several M 70 bolts here, -pre-64 & 2 ea pre war all have a small flat lip on the left side surround bottom. It is about 3/32" up from the underside flat of the bolt lug, and this flat is parallel to the lug flat bottom. The previous posting by me on this thread was in answer to cducat from NZ and was about his CZ. He had also sent a private letter to me but I thought it better to answer in the thread inasmuch as this comes up from time to time and might be of benefit to others. No change in my recco. to you- " Swap the bloomin W spring first thing out of the chute".

Hi 'Systeme98'
Thank you VERY much for your advice re the CZ. Apologies for muddying the water, Frank C! Excuse my ignorance, but just to confirm before removing steel - you are referring to filing the rim opposite the extractor side i.e the one at 5 o'clock looking at the bolt face? In the process of filing the flat will the surround (rim) be lifted at all (i.e.closer to 4 o'clock than 5 o'clock)?
Charles Ducat
NZ