Confused!

[CntrlPA]

I've never been real big into patterning my gun but am dabbling a bit more as of late. I'm using a 3" 870 with a 21" barrel shooting 3" 2oz 7 hevi 13. On a warm day we had last week I decided to compare my remington xtra full choke(.687) and a Ventilator choke(.655) again. I have a TRS-25 red dot on it that i love so far. Our back stop is ranged at 39yds from the end of the barrel. Hevi shot is expensive so after experimenting with some lead loads I only shot one hevi shell from each choke. I know one shell is not the most scientific way of getting accurate numbers but it will do for me. The xtra full choke put 177 in a 10" circle (162 the last time when it was 41 degrees outside). The ventilator surprised the crap out of me, it put 251 in 10" compared to 156 when it was 41 degrees outside. What could explain almost a 100 pellet increase? And no I did not clean the gun since the last time i shot the hevi shot.

[ILIKEHEVI-13]

I have been telling folks about the Rem Ventilator .655 choke for some time now.  I can honestly say I have shot a lot of choke tubes over the years.  And for the money, I can 100% say that it's the best shooting choke I have tried in the 870 shooting Hevi-13 loads.  It shoots the 5's, 6's, and 7's very well.  And that is odd for a .655 choke.  Typically that is getting pretty tight to shoot some loads well.  But it does.  I can't take credit for discovering this choke.  Reloader on here was the guy that told me about it.  So I will give him full credit for telling me about it.  He pretty much talked me into buying one when he posted a pattern he shot I believe with his reloads.  And he says it shoots very well with lead loads.  One of the best chokes he has tried shooting lead was what I believe he told me.  And it shoots great with Hevi-13 loads from what I have seen.  I have put 282 in a 10" at a tape measured 40yds with Hevi-13 3" 2oz #7's.  Now for a $23 shipped choke, you can't beat that.  My Pure Gold .670 or Indian Creek .669 I had never did that good.  

[runngun]

ILikeHevi13 what about the difference in the two patterns, same shell same choke only difference is the temp???

[ILIKEHEVI-13]

Get em while you still can.  It will work in most Rem guns I do believe.  Shoots as good in my buddy's sons 28" 870 as it does in mine I do believe.

http://www.cdnninvestments.com/re8712exratu.html

Here's some proof to back what I have said. 

Here's the backside of that pattern that had 282 shot in the 10" at 40yds.



Here was the turkey target 11" x 11" that was taped to the front of this cardboard.  You can't hit it much better than this with only a 2oz #7 load.



And here's one more I shot with only a 3" 1.75oz load of Hevi-13 #6.  Again a tape measured 40yds.
 

[ILIKEHEVI-13]

And notice that last target was shot on a cool 45 degree day. 

[ILIKEHEVI-13]

And to answer your question about the shot difference on cooler day vs the warmer day, all I will say is I have seen my great shooting Star Dot choke shoot just mediocre patterns on 45 degree days.  And the same will go for a lot of chokes and great shooting loads.  70 degrees is a huge difference in what you will see in the patterns vs say 45 degrees.  But yes some chokes will be a more cold weather choke.  Why that is is really unexplainable.  But it happens. 

[CntrlPA]

Thanks for the info. I never though temp had such an effect on different chokes.

[tha bugman]

been looking for a choke for my new Remington 870...just ordered it!!!

[deerslayer357]

Temperatures, barrel fouling, wind, and chokes could all affect the patterning of a single gun with the same shells.

My guess would be choke if both were tried on the same day, one after the other with time for the barrel to cool in between shots.