Is this a sign of blowback?

[Blood Trail]

I recovered wads from my Lee key slugs (1oz)and they are all grey. The wads are PT1205 which fit them like sabots. Is this blowback? How does it affect ballistics and how do I stop it?

Check out these shot cup bases: (???)

[Reloader270]

Shotgun wads is never a tight seal. I think it is impossible to eliminate all blow back past the wad.

[longbow]

That seems a little excessive to me.

I have had a few gas seal blow out but the only leakage I have experienced that was even close to that is when I decided to use up some shotcups I had cut gas seal off and used two nitro card wads then a fiber wad under the shotcup with a wad slug in it. Well, those nitro card wads don't seal nearly as well as a plastic gas seal! I had several shotcups with shredded petals and most had gas cuts in them. However, nothing as bad as yours.

I have to think you either have an overbore barrel or that is an over pressure load.

Longbow

[300winmag]

Are you shooting them out of a rifled barrel? If so that would be your answer.
300

[longbow]

Rifled barrel or not they shouldn't look that bad.

[Blood Trail]

Longbow, my barrel, in fact, is overbore and rifled.

[longbow]

You might try some other wads to see if different gas seals work better, or possibly get some BPI gas seals and put one of them over the powder then the wad on top of that... except you might have to go with a shorter cushion section to fit it all in.

It seems to me that BPI has wads/gas seals for overbore/backbored barrels but you would have to check on that.

How is your barrel overbore and rifled? Is it commercial?

Longbow

[Vinne]

Also, you may want to check your powder charge is correct!!

[longbow]

Good point. What charge, slug and components are you using?

Another thing I should have mentioned is wad/slug fit to bore. In a rifled barrel it should be pretty tight as the shotcup has to transmit the rifling rotation to the slug and to be honest I am not sure how practical or possible it is to push a proper fitting wad/slug combination through a rifled gun.

What I can say though is that if the wad/slug combination slides through relatively easily then it is too loose.

Look for Ajay's (VDOmemorie) old posts on slug/wad fit. I know he had a lot of information on smoothbores but he also post some for rifled guns.

Longbow

[Blood Trail]

You might try some other wads to see if different gas seals work better, or possibly get some BPI gas seals and put one of them over the powder then the wad on top of that... except you might have to go with a shorter cushion section to fit it all in.

It seems to me that BPI has wads/gas seals for overbore/backbored barrels but you would have to check on that.

How is your barrel overbore and rifled? Is it commercial?

Longbow

Sorry longbow, two of my three barrels are back bored (28" field barrel and 20" turkey barrel). My rifled barrel is not back bored. My gun is mossberg 835.

[longbow]

Nonetheless, your wads shouldn't get chewed up like that. It must be an overpressure load... at least for those wads.