Zastava stainless M70 bedding issue

[jbmauser]

After hunting season was over I took my Zastava apart to clean it up and when putting it together I noticed that there is play at the rear between the action and stock when both action screws are fully tightened. I've put a hundred plus rounds through it previously and had it apart multiple times but some how never noticed it before. It's amazing it shoots as good as it does.

When the screws are tightened up fully there is a gap between the bottom metal and receiver as is correct. If I remove the rear pillar all together and tighten up the screws then there is no play and there still is a nice even gap between the trigger guard and receiver. I'm thinking I should shorten the rear pillar? I measured the pillar in my Zastava and it measures 1.199". I compared it to 4 original military pillars and they range from 1.150-1.170 in length.

So am I correct in my assumption that the rear pillar is to long? The only other option I can see is building up the stock with bedding compound but I don't think that's going to yield good results with the plastic the stock is made out of. Also if the stock bedding was incorrect, I would think that the gap between the trigger guard and receiver would not be present with the pillar removed.

Opinions? Suggestions?

See pics below. Top pic is of the pillar protrusion with the action fully seated into the stock. You can see it sticks out quite a bit.

Next pic is of the gap between the trigger guard and action with the pillar installed. Play at the rear.
Next pic is of the gap with the pillar removed. No play.

 

[liberty]

I would bed the action and floorplate,,if you go and cut that rear pillar when you reassemble the gun the floorplate will flex/spring.
I believe on the mauser action, the lengths of the pillars (front and rear) keep the action, box and everything straight, so make the stock fit the pillars...

JMO, but that's what I do to mine,

 

[Mauser98]

When I'm bedding a Mauser, I pre-fit the barrelled action to the bottom metal so that there is a +/- 1/16" gap between the top of the mag box and the bottom of the receiver. I use a piece of threaded lamp rod for the rear pillar and adjust it's length until things are just right.

The Mausers front pillar is usually just right.

I pretty much always bed the front and rear tangs of the bottom metal along with the Barrelled action. I have had enough practice that I can do it all with one pour.

 

[jbmauser]

I would bed the action and floorplate,,if you go and cut that rear pillar when you reassemble the gun the floorplate will flex/spring.
I believe on the mauser action, the lengths of the pillars (front and rear) keep the action, box and everything straight, so make the stock fit the pillars...

JMO, but that's what I do to mine,

It's a good suggestion for sure and normally what I would do as well except that this pillar is substantially longer than all the others I measured and I know the bedding isn't going to bond very well to the plastic stock. I could make mechanical locks for the bedding by drilling holes, etc., in the stock but it's going to be a pretty thin layer of bedding compound in areas and in my experience it's not going to work overly great.

I put a shorter pillar in between the trigger guard and action and snugged up the screws. The gap between the two parts is nice and even all the way along still. I wouldn't have to shorten it much to provide a bit of a crush fit on the stock. I would have to go from approx 1.2" to 1.185 from my measurements.

 

[jbmauser]

When I'm bedding a Mauser, I pre-fit the barrelled action to the bottom metal so that there is a +/- 1/16" gap between the top of the mag box and the bottom of the receiver. I use a piece of threaded lamp rod for the rear pillar and adjust it's length until things are just right.

The Mausers front pillar is usually just right.

I pretty much always bed the front and rear tangs of the bottom metal along with the Barrelled action. I have had enough practice that I can do it all with one pour.

Thanks. So as long as I have an even gap from front to back, I should be ok then. I think I'm going to shorten the rear pillar the required amount and give it a shot.

I normally have no problem doing a full length bedding job including the bottom metal like you do but I just don't like doing it in cheap plastic stocks.

 

[bigbull]

You are correct, the pillar(s) is too long shorten it up until there is no gap between th metal and the stock surfaces,
those stocks can also take a little compression without any ill efects, minimize the bedding with injection molded stocks
since it will often flake off especially when it is very thin, go slow and don't take off too much pillar material, go flush with the stock
surface or a touch below, as long as there is still a gap between the mag box and underside of reciever you won't get any binding, if
you do just file off enough to get your gap back you don't need much of a gap either especially with a synthetic stock.
Good Luck

 

[jbmauser]

Ok. I carefully removed small amounts at a time from the pillar until it was just slightly below the stock to provide a slight compression fit between the metal and stock. There is still a nice even gap between the trigger guard and receiver and NO play now.

Now the big question is, how much will this affect accuracy and the poi? I'll have to make a trip to the range in the near future and find out. I'll update this thread for any one interested with the results. Could be a while though as it's pretty darn cold here.

 

[rgv]

You've probably got it licked, but before shooting it, I would mark the top edge of the magazine box with lipstick or carbon black, then reassemble and disassemble to see if there is ANY contact. If there is, carefully draw file it down. I even like to have clearance side to side around the rear of the box that extends up into the receiver.

I've found the mag box being pinched to be a common cause of accuracy problems in 98's

 

[jbmauser]

You've probably got it licked, but before shooting it, I would mark the top edge of the magazine box with lipstick or carbon black, then reassemble and disassemble to see if there is ANY contact. If there is, carefully draw file it down. I even like to have clearance side to side around the rear of the box that extends up into the receiver.

I've found the mag box being pinched to be a common cause of accuracy problems in 98's

Thanks. That's a great suggestion.

I am able to slip a piece of thin cardboard (about .020) between the top edge of the mag and the receiver with no resistance for the full length on both sides. I can see the top of the extension on the rear of the mag box has similar clearance at the top as well. It's hard to see the sides though so I may have to try your method to check it out.

 

[bigbull]

Check also that the tip of the trigger does not bind into the trigger guard when you pull to fire,
if it is too close a little filing will be required.
BB

 

[jbmauser]

Check also that the tip of the trigger does not bind into the trigger guard when you pull to fire,
if it is too close a little filing will be required.
BB

Thanks BB. There is plenty of clearance there as well. I can't wait to try it out and see how it shoots now that it's tight in the stock. I can't believe I didn't have accuracy issues or poi changes the way it was before. I just don't feel ambitious enough to go shooting in -33C weather.