NitroX
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| (.700 member) |
| 20/08/12 12:06 AM |
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Pump action shotgun - choke modification questions?
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I may have to buy an old Mossberg Pump action shotgun equipped with a vari-choke "bulbous" adjustable abortion on the end of the barrel.
So the plan is to cut off the choke and have fitted a proper removable choke system like Briley.
My question is it worth considering a system which also has rifled chokes? Does Briley do these as well?
(I have the appropriate licence for the shotgun, don't worry about it.)
| Paatti |
| (.333 member) |
| 20/08/12 01:39 AM |
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Re: Pump action shotgun - choke modification questions?
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Theoretically those rifled chokes are good but in the real life i have found them unnecessity.
Normal cyl-mod choke shoot proper slugs accurate enough.
| DarylS |
| (.700 member) |
| 20/08/12 02:15 AM |
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Re: Pump action shotgun - choke modification questions?
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I don't think I'd shoot slugs out of a screw-in choke that is tighter than IMP cylinder. You may find the IMP Cylinder gives up 3" to 5" groups at 50 yards, with decent, full sized slugs. I've not tried screw-in "rifled chokes". I've never checked them out and cannot say if they have lands tighter than the actual bore and bore-sized grooves or not. Since shotguns vary so much nowadays in size, the dimension of the screw-in chokes will vary. For example, the bore of my 12 bore Mossberg M835 pump's smooth barrel is .740". The rifled barrel has a .724" groove diameter.
If you want to shoot the newer sabot shells with their undersized, jacketed bullets, you'll need some form of rifling. I would check out Ed Huble's extensive thread on using various bullets in shotshell wads. A very good one, found to shoot well in 12 bore wads, is the Lyman sabot. It is .69 cal. and is said to shoot quite accurately from a smoothbore. Your mossy should be able to drive that 500gr. at over 1,700fps with carefully loaded ammo. No factory slug I'm aware of, can match that.
The standard 'rifled' slugs (Foster- no the rifling does not spin them in flight) have not shown in magazine writer's testing to benefit from rifling to any extent. Since they are comprised of pure lead, the do not seem to do penetrate well on heavily constructed animals. They will work (have worked in the past) on Grizzlies at very close range, but that is not recommended except at spitting distance.
| albertan |
| (.333 member) |
| 24/01/13 06:53 PM |
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Re: Pump action shotgun - choke modification questions?
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Mossberg makes many replacement barrels. Indeed, they make them for the Remington 870. It would be cheaper just to replace the barrel, and you know it will work.
| elvas |
| (.275 member) |
| 02/03/13 10:35 PM |
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Re: Pump action shotgun - choke modification questions?
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NitroX,
If you can find a rifled choke tube that its groove diameter matches the bore of your barrel go for it. Otherwise leave it as it is or cut the barrel and use it for smoothbore slugs only.
Lefteris
www.europeancartridgeunlimited.com
| 9.3x57 |
| (.450 member) |
| 03/03/13 12:41 AM |
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Re: Pump action shotgun - choke modification questions?
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Nitro; RE: Polychokes, we've had a few over the years and unless looks is the thing...which on a Mossberg is a ship that's passed as you know...I'd keep the Polychoke. I've had VERY good results with them, and the neat thing is they allow tinkering with the choking to get exactly the pattern you want.
Ignore the markings on the Polychoke body, and with your selected shot charges, start patterning, then just remember or jot down what the marking is for the load and desired pattern. Sometimes the performance is NOT what the marking indicates, which, actually, is true about screw-in tubes, also.
With slugs we just opened it all the way up which I THINK is the proper solution. IIRC, back in the '70's, slugs were said to be a no-no with a Polychoke, then that was wholly debunked and merely cranking the thing to CYL makes it all safe.
If I can find a cheap Ithaca barrel for my old 87, I want to cut it to 18 and have a soupcan installed. I really like them. With the screw-in tube barrel, I always seem to forget to install the right tube, and then compound the problem by forgetting to bring the spares...
Anyway, just another thought/option.