Unburned powder
 

Not so much a RELOADING question, but I thought this might be the best thing. I took my 12g 1880 grade 2 lifter with 32" barrels down to the club today and shot a round of skeet with it. First time shooting it much. I was shooting RST lite 1oz loads of 7 shot. Factory loads. I noticed a lot of unburned powder in the bores. What might cause that?

Possibly the ambient temperature and how the powder and/or primer were affected by it?

I had the same problem shooting 16ga RST lite shells at the Vintage Cup last year. I had powder build up in the latch to the point I couldn't close the gun. I had to us my pocket knife to get the powder out before I could continue to shoot. The weather was nice, so I don't think it had anything to do with the powder not burning?

Our friends at RST make a great shell but they do burn a bit dirty. Cold weather will make this a bit worse.

I have not really noticed this issue as bad in other guns. I doubt that the gun would have anything to do with it. It could be the weather. It was colder yesterday.

An oversize bore could contribute. This is not uncommon in old guns that have honed bores. A larger bore allows gas blow-by, reduces burn confinement, and leaves residue... especially with some powders like Red Dot or Clay Dot.

John's answer would be my choice. RST low pressure loads, together with the large bores, (.750 on some Parkers), contributes to less complete burning of the powder coating. I doubt that the incomplete burning extends to the explosive components of the powder. Call Alex and ask.

I have also noticed this with my early parkers with oversized bores. So I will assume the bore size is a major factor.

Good answers. To some degree some unburned powder is the small price you pay with low P loads, especially in the cold. When you shoot in extreme cold keep your shells inside your coat somehow and don't pile your extras on a table. My bbls are a disaster when I shoot up here at -25deg - they look just like black powder burn. I try to put a factory target load through each bbl as my last shot to clean them out.

Mr. Flanders has hit the nail on the primer. The low pressure loads don't burn as efficiently as their counterparts.