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Old August 23, 2012, 02:47 PM   #1
Major Dave (retired)
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Need "trigger job"...

on a Rem 870, to get good slug patterns?

Early this week I shot Federal Truball slugs thru my Rem 870 Wingmaster, using a 20 (?) inch smooth bore "Slugster" barrel. The 870 and the "Slugster" barrel are mid-70's vintage, so the barrel is a fixed choke, Open Cylinder, 2 3/4 inch chamber.

After zeroing the scope (a Bushnell Magnum Phantom 1.3 X pistol scope - long eye relief), I was very pleased with the 3 round groups at 50 yards, but not so much at 100 yards.

At both distances, the windage was only 1/2 inch off center, with only 1/2 inch deviation in windage for the 3 shots.

The elevation, however, was about 2 inches high at 50 yards, with too much dispersion at 100 yards ( 8 inches from highest hit to lowest hit) to come to a valid conclusion as to the "zero", from an elevation standpoint. However, the high shot was 4 inches above center, the low one 4 inches below center, and the "middle" shot was only one inch high of the bullseye.

So, my question is, "How do I tighten up the vertical dispersion"?

My "guess" is that the trigger, which is a standard trigger for a shotgun used primarily for birds/waterfowl, is not conducive to accuracy when trying to get rifle like performance.

Shotgun trigger is too heavy - about 5 lbs, perhaps; and doesn't "break like glass".

Am I right?

Do I need to have a gunsmith polish the sear and try to lighten the pull weight? Can that be done to a factory 870 trigger, or is it possible/neccesary to put an after market trigger (like Timney or Canjar) in it?

I'm looking for advice/opinion/experience input from the Firing Line Forums community.

Thanks, in advance for your response(s).
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Old August 23, 2012, 02:59 PM   #2
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Someone with experience will come along. As I have only fired a few slugs for familiarization, I may be all wrong, but I suspect the problem is too much choke. From what I have read that others say, everyone needs to pattern and experiment with what shoots best for them, but my recollection is that most do best with a modified or an ic.

Also, from what I have heard paying for a trigger job on an 870 is a waste of money.
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Old August 23, 2012, 03:03 PM   #3
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I had a shotgun as well as a rifle trigger group.

Quote:
Shotgun trigger is too heavy - about 5 lbs, perhaps; and doesn't "break like glass". Am I right?
Major, if you see the need, then you are right. Not to say that you can't do without but you are suggesting is realistic. Let me share what I have done.

I had and 1100 that I felt could be improved. I used it for upland hunting and during the deer season, used the slug barrel. I bought an extra trigger group and reworked it myself. Got the pull down and smooth and yes, my groups improved. Some would say it was a waste of time but I like tinkering anyway. I'm sure you could do the same on the 870 as I know they drop out, just like the 1100. ...

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Old August 23, 2012, 04:47 PM   #4
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Klawman...

The "Slugster" barrel has no choke constriction at all. It is "open cylinder", from the factory. That's the way they made them in the Mid-70's.

You may be right when you said getting a trigger job on an 870 is a waste of money. That's exactly MY question!

Pahoo, I don't know how to tinker with trigger groups, so I will have to pay a gunsmith - if I become convinced that it is worth the money. Just how much did your groups improve?
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Old August 23, 2012, 06:19 PM   #5
Virginian-in-LA
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I would try at a minimum 4 or 5 different factory slug loadss before I even thought about messing with the gun. Vertical dispersion due to trigger should be the same as horizontal dispersion.
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Old August 23, 2012, 06:47 PM   #6
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Ghosts of the past.

Quote:
Just how much did your groups improve?
It's been a long time since I was there but seems to me that I went from about 5" to 3" at 50yds. There were other factors as well as I was also going from a smooth bore to rifled bore. Also various slugs to accomodate each barrel. There was a big difference in handling as it actually felt like a rifle; smooth and crisp. Might add that the 5-Lbs. pull you listed, is not all that bad. ....

Quote:
don't know how to tinker with trigger groups, so I will have to pay a gunsmith
Sorry for taking too much for granted as I think most gun-guys, like to tinker.
I did the work myself and it went fairly well and wasn't all that difficult. I doubt that I would have paid someone to do it. I'm a conservative so that means I'm cheap ...

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Old August 23, 2012, 06:48 PM   #7
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Doh, somehow I read fixed choke, open cylinder as "full choke, open cylinder". I should have realized my error as I was wondering what the heck you were talking about as there is no such animal - coupled with the fact you seem to know more than a trifle about weapons - but you were an officer.
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Old August 24, 2012, 01:51 PM   #8
Dave McC
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First, let me say that IMO, the average shotgunner should not do trigger work, just like the average driver shouldn't do brake work.

The stakes are too high.

Remington says the parameters from the factory are 3.5-6 lbs. Things being what they are these days, betcha there's more 6 pounders than not.

And that's too heavy and probably way too nasty for good slug work.

I had the trigger done on my Slug 870 some decades past. The poundage dropped a little, but more importantly the break cleaned up. Now, it's crisp and just under 4 lbs, IIRC. Groups run about 4 inches at 100 yards with the rifled tube in.

FYI, the trigger on Number 1 is close to that and hasn't been touched since it left Ilion in 1950.

Frankenstein is also unmodified and runs about the same. Number 6 runs 4.25 lbs or so and the 20 gauge runs 5.

The 870TB trap gun I had went 3.75, and was truly sweet.

A light, clean trigger makes a huge difference.

However, the vertical dispersion may be due to another factor or factors.

Possibilities include, but are not limited to.....

Loose scope, mounts or barrel.

Incompatibility of barrel and that make of slug.

Less than perfect bench technique.

And,sorry to say, flinching. Benching slugs can hurt.

Besides all that, my experience is a LOT of slugs start destabilizing around 100 yards out. The groups mentioned above were tight, but showed keyholing.

HTH....
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Old August 24, 2012, 02:27 PM   #9
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I would say, after further reflection,

that your statement about a lot of slugs beginning to destabilize at about 100 yards is probably true in my situation.

I say that, based on the fact that my slugs cut clean, perfectly round holes in the 50 yard target, but cut ragged, out of round holes in the 100 yard targets. The contrast between the two targets was conspicuous, and I made the comment to a range buddy that I thought the slugs were tumbling at 100 yards.

Still, the POI for windage at 100 yards was very consistent, with hardly 1/2 inch of windage dispersion.

I haven't priced a gunsmith installed rifle-style trigger group for an 870 yet, but if it was around $75 or more, I would pay that. Mainly because the current trigger required a rather lengthy, slow squeeze for each shot. I doubt that a buck is going to stand still, broadside, for the 30 to 45 seconds of trigger pull required to touch off a precise shot with the current trigger.
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Old August 24, 2012, 02:42 PM   #10
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Update...

Just talked to a gunsmith.

He said: They don't make after market trigger groups for 870.

He can smooth/polish/clean up the factory trigger, reducing the pull by a pound or so, and making it break "clean", without creep.

$65

Sounds like a winner, to me. I intend to dedicate this 870 to deer hunting with slugs, and turkey hunting, so a smooth, clean breaking trigger is what I need.
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Old August 24, 2012, 02:49 PM   #11
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My experience has shown a modified choke sends slugs with the most accuracy, from a smooth bore barrel.
But definitely experiment with different slugs.
They all fly differently.
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Old August 24, 2012, 03:04 PM   #12
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g.willikers, I got the op's question confused. His barrel has a fixed open cylinder. I wonder if he would do better to look around for a barrel with a fixed modified or spend the money on having his machined to accept tubes?

Last edited by TheKlawMan; August 24, 2012 at 03:14 PM.
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Old August 24, 2012, 03:33 PM   #13
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cleaning up the trigger is a smart choice in my view.....it'll help a lot in terms of how well you can execute the shot ...and that will tighten up your groups / at least up to the accuracy level of the gun ammo combination you choose.
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Old August 24, 2012, 07:31 PM   #14
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Sounds like a plan !!

Quote:
He can smooth/polish/clean up the factory trigger, reducing the pull by a pound or so, and making it break "clean", without creep. .... $65
Wow, that's not bad and sounds like he has been there before. Understand that it is going to feel different but after a time, you won't notice. ...

Also forgot to mention that I installed a SpeedFeed monte Carlo stock on mine. ....

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Old August 25, 2012, 12:07 AM   #15
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Pahoo...

I have a detachable leather Monte Carlo stock on mine. It laces on with a shoe string. It is a necessity because the scope is mounted high, and I can't line up my eye in the scope and get a good cheek weld without it. With it, I can close both eyes, mount the gun to my shoulder with a good cheek weld, and then open my eyes to find that my eye is already centered to the scope eyepiece. Works like a charm.
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Old August 25, 2012, 10:03 PM   #16
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I used a Timney Trigger Fix kit for my 870 slug gun and am extremely happy with it. It lightened the pull to about 3 pounds with the lightest spring in the kit and definitely got rid of the creep. instructions in the kit are clear and easy to follow. Recommend it for slug guns.
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Old August 26, 2012, 06:58 AM   #17
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My Benelli went from 8.5 lbs to 5 ! that's by just polishing with a fine stone all the contact surfaces .

DO NOT use a dremel, change angles or round off contact surfaces .
Just polish !
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Old August 26, 2012, 10:18 AM   #18
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Definetly under-rated !!

Quote:
My Benelli went from 8.5 lbs to 5 ! that's by just polishing with a fine stone all the contact surfaces .
Personally I find this to be very true on just about all firearms. It's a great First-Pass ...


Trust yourself and;
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