870 SM choke opinions

[SCDieselDawg]

Recently shot my 870 SM (23 or 24 inch barrel) with 3.5" hevi#6s through a .660 JH. While it patterned fairly decent I'm still not 100% impressed. I'm wondering if I went a little more open on the choke if the pattern would get better?  Say maybe a .665 JH or IC maybe even the .670 Haymaker?   

[Jbird22]

Hmmm..well since the JH didn't shoot well I'm not sure what to tell you. I get great patterns out of my 870 SM 23" using a JH .665. I have no experience with them but from all the things I've read about em I believe an Indian Creek would be your next best bet.

[SKFOOTER]

Try the 3" Hevi 6's thru that .660 JH.

[allaboutshooting]

Recently shot my 870 SM (23 or 24 inch barrel) with 3.5" hevi#6s through a .660 JH. While it patterned fairly decent I'm still not 100% impressed. I'm wondering if I went a little more open on the choke if the pattern would get better?  Say maybe a .665 JH or IC maybe even the .670 Haymaker?   

I don't know how your patterns look but I would look for good even coverage, with no 1 1/2" or more gaps, in your pattern. I use a 1 3/8" circle and don't want to see gaps larger than that, from hit to hit. I consider any 2" or more gaps unacceptable. The numbers in the pattern are really much less important than coverage.

Normally, when you want a more dense pattern in a short-barrelled gun, you need to go a bit tighter in a choke. Exit diameter however is only one part of the chokes geometry but all things being equal, you might want to look at a tighter choke tube.

I'd also "deep clean" the bore. It can really help with patterning.

Lastly, if you're experiencing a "scattered" pattern, I'd make sure that the magazine cap is tight, tighten as tight as possible by hand and then 3 "clicks" with some padded pliers. That cap is all that holds your barrel in the receiver and if it's just a bit loose, it can cause the barrel to move when its shot, causing erratic patterns.

Thanks,
Clark

[nyhunter]

What are your numbers? and what is the lot number on that box of shell? I have some that will only put 135 in a ten. And i have others that will put over 200 in a ten.

[VaTuRkStOmPeR]

What is "decent"?

Sumtoy .660 or .650 are good starting points.

Rhino .660 is a more expensive but high performance option, too.

[Gooserbat]

What is "decent"?

Sumtoy .660 or .650 are good starting points.

Rhino .660 is a more expensive but high performance option, too.

I got a .658 Sumtoy listed in the classifieds.

[Longshanks]

Rem 870 SM , Ventilator .655, hevi 3/2/7's

I had the same experience with JH .665. So so patterns. POA/POI went way off.
I found this choke for 12.00 plus shipping. Dead on POA/POI..If it doesn't do what you want with HTL. It is a killer with all of the Win Pb 6's. my patterns were good then I sent the gun to my gunsmith and had it professionally polished for 30.00. Gun shoots lead so good I stopped shooting HTL out of it.

170's in a 10 @ 40  Pb 6's

280's in a 10 @ 40. Hevi 7's

[SCDieselDawg]

First off let me say that I lack the ability to leave good enough alone. This setup shot high 170s. While my Moss. 935 (also with a JH) went in the 200s out of the same box of shells. This left me wondering if a different choke could improve the numbers. The pattern for this 870 sm is posted in the pattern forum but here it is

[VaTuRkStOmPeR]

That is a poor pattern considering the load you're shooting.

Have you polished your barrel? If not, I'd highly recommend that enhancement.

There is no reason you can't get that gun up over 200 (I would consider that decent; anything over 220 great, and 240+ exceptional). 

My 870 loves a Sumtoy with that same load.  You can't go wrong with a Sumtoy .660-.650, rhino .660, or IC .665 out of your gun.

Best of luck with finding the right choke/load combination for it.

[SCDieselDawg]

Haven't had a chance to polish yet.  But it is on my list.  I'm new to a lot of this patterning stuff this year so I'm learning as I go.

[taylorjones20]

I recently posted almost the same question on here.  These guys gave me some great advice and I ended up with a pattern that completely blew my mind.  870 SM .660 JH  3 1/2 Hevi #7's  336 hits in 10" circle at 40 yards.