Beretta Mobilchoke tubes (steel proof).

[Cranfield]

My Beretta AL391 has Mobilchoke tubes, how do I know if they are "Steel Proof", should they be marked in some way ?

[njc110381]

Have a look on the outside of the tube. It has some fine engraving on it (although you'll need to get a reflection of light on it to see it probably) which should read....PB-F-SP....That means PB=P. Beretta, F=Full (or whatever it is, IC, IM etc), SP=Steel proof

 

hope this helps :yp:

[webber]

Cranfield

 

As above, also I recall the beretta manual being specific about the use of certain hokes for steel. My copy is in the loft, but unfortunatley I can't get up there at the moment. If you are still stuck later on I will ask Martin to go up there and find the manual for me. I recall nothing tighter than 1/2 choke for steel, but can't be certain.

 

webber

[Cranfield]

Thanks njc, I did have a look at one tube, but that only had "PB*F*gp" (gp is as best I can tell) .

Having looked at the others , they clearly have "PB*SK*SP" , for example.

[njc110381]

I do recall (as webber has said) that only 1/2 or less should be used with steel. That said, my full tube has SP on it so maybe it just doesn't help the patterns to go any tighter than half? I would stick with CL, SK, IC or M, assuming that the tubes also have SP on them.

[Chard]

My gun shop (Bamfords in Lancashire) told me not to use steel in anything tighter than half choke.

 

I assumed they were referring to safety, by the manner in which he said it, due to there being no give in steel shot, but I suppose he could have been referring to pattern problems with tighter chokes :yp:

 

Interesting that your full choke had SP on it, njc110381 - I must have a look at mine

Edited May 26, 2008 by Chard

[Cranfield]

My choke "set" is a group that I have gathered together through owning various Berettas, so that is why there could be some differences in the markings.

 

I did download a Beretta AL391 handbook and that indicates that steel is "not recommended" in Full or Improved Modified chokes, but the "steel proof" chokes in these sizes are available.

[chrispti]

The optima chokes are not recommended for use with steel shot over 1/2 choke.

 

Even though they are all steel proofed?

Edited May 26, 2008 by chrispti

[njc110381]

I've heard several versions of the reason heavy choke is no good for Steel. The first one (and the one I tend to believe) is that it blows patterns. There's little point using a tighter choke if it actually reduces the effective range of the pattern due to gaps. The second is that in time the chokes can actually be forced to expand with the pressure, making a multi stick in and a fixed gun have less choke. If you look at it as a mass of small balls in a cylinder, if the sides are compressed they will move and make the cylinder longer and narrower to fit the tube.

 

I'd say all the Beretta SP chokes are safe for steel use, but the tighter ones are not an advantage. They may even be a disadvantage.

[garyb]

Yes no more than 1/2 choke for steel

 

This is also the reason (so I'm told) that the fixed game Beretta's, which are steel proofed come out with 1/4 & 1/2

[BlaserF3]

Steel shot should not be shot through a choke tighter than half as it does not get deformed like lead. If your tube has sp stamped on it it's OK to use with steel.

 

This has nothing to do with chokes but it's full of useful information for Beretta auto users.

 

http://www.shotgunworld.com/bbs/viewtopic.php?t=101242