Need Advice about inconsistent patterns with 870 & 21" barrel

[nyhunter]

Well i got a new 21" barrel for my 870 , I polished it friday and got out to pattern it sunday. using the sumtoy 562-5, 3" Fed HW #7.   I feel my numbers aren't very consistent . what are you guys running this same combo getting from 1 shot to the next as far as numbers in the 10 at 40.  Patterns were very even
here's what i got . These were all the same lot number also

1) 157
2) 117
3) 107
4) 138

[Greg Massey]

After polishing the barrel did you dry the barrel or leave it oily?

[gophert]

It is something that can happen with factory shells but you don't tend to see it as much within the same lot#.  Not sure if you did this or not, but I run a dry bore snake 3X between shots so I know the conditions are consistent.  Perhaps your gun just likes a real clean barrel. 

[Greg Massey]

I don't care for polishing the barrel on turkey guns. Try running about 10 or 12 cheap shells thru the gun then wipe the barrel out and try it again with a turkey load for pattern. Leave the barrel dry.

[nyhunter]

after polishing the barrel i deep cleaned it then used denatured alcohol and then dry patches. I did not clean or boresnake the barrel between shots.

[Greg Massey]

Was the tube ported or did you ask them for a non- ported tube. I just don't care for ported tubes.

[VaTuRkStOmPeR]

You need to boresnake between shots to have a consistent platform of comparison.

It is not at all surprising that your first shot had the highest numbers of the 4 in the data sample.

[gophert]

You need to boresnake between shots to have a consistent platform of comparison.

It is not at all surprising that your first shot had the highest numbers of the 4 in the data sample.

Yep this^^^^  Sounds like your gun doesn't like to be dirty.  157 is smoking!

[nyhunter]

Thanks guys I bought a bore snake today