Fellas, i have noticed with the Hogdon H322 in my .38-55 i get a bit of unburnt powder in my barrel. After i fire a fouling shot, my accuracy is quite respectable for my lever action with 1" groups at 100 yards. However, once i get to about shot 15 or so, my accuracy drops off. Is this from unburnt powder in my barrel or from not letting my barrel cool enough??

Mark
Could be the barrel heating up. Some other considerations would be lead bullets vs jacketed, lead or copper build up in barrel. Could simply be a combination of bullet, powder fouling.
Maybe shooters fatigue from a long string of shots.
I've got two lever actions an 1886 in 45-70 and a Rossie 1892 in 45 Colt. Both shoot very accurately when I do my part. I've never seen any indication of groups growing when I've shot long strings off the bench or off hand, due to barrel heat. Shooter's screw ups, shooter's not paying attention, in my experience it's seldom the rifle and most times it's the shooter.
Now I will say my 25-06 is the exception to this and makes a liar out of me. This rifle has two different groups 3/4 of an inch a part. There is slow fire warm barrel group and the rapid fire hot barrel group.
So for what's worth.
Jim

Thank you Jim. That helps.

Shooting to fast will take it's toll on group size. If your rifle bore is more than luke warm to your touch your shooting to fast. The rifle is telling you to slow down or that it needs cleaned after fifteen rounds down the bore. Hunting weight barrels heat up very quickly in warm temperatures and need more time to cool between shots. Few game animals get more than three rounds fired at them under hunting conditions. Hunting groups only rquire three rounds from a stone cold bore. Target rifle shooters will fire as many as twenty rounds to post a five shot group in seven minutes and must have heavy barrels to maintain accuracy.

A method I found that really helps to eliminate
barrel overheating is to take more than one rifle
with you to the bench. Shoot three rounds through
the first rifle and lay it aside to cool while
firing three rounds through the second rifle. This will help reduce throat errosion and increase
the barrel life. Hot Core's suggestions are great
too along with the other's here. I've learned more
about shooting and reloading on this forum than
anywhere else I've gone. Good shootin & loadin!BLR7

Just noticed the same,I have been working on a 45-70 cast load for a week. Lots of shooting.I have found the load,just confirming it...

I was not sure what�s up either,could not make good ten shot groups.

The three shot groups were often like this at 50 yards:



I wanted to get ten shot groups at 75 yds... nope,decided to do five shot groups instead.

The first five shot group (after fouling shots) was always much better than the second one. But chrono shows no difference. Then,if I grab a shotgun, walk 100 yds and shoot claybirds for ten minutes,walk back and shoot another 45-70 group it is back to the "normal" size.

It is a combination of barrel heating and shooter fatigue,mostly the latter in my case at the moment. Taking another rifle or a shotgun whatever helps with both problems.

Here,two five shot groups fired without a significant break at 75 yds.I adjusted the POI to the right between the groups. Then after a claybird break it is back to the better size again.



The 405 grainers going 1950 fps, recovered from sand and wet phonebooks,penetration is 32 inches in phonebooks,with a piece of 1/2" plywood being pierced too between the rotting books.

80% wheelweights,20% linotype. Marlin 1895.

Almost out of topic... take two guns and see if it helps.It may be the shooter after all.

Another suggestion to speed up barrel cooling. It is the season for the politicians to be beating the bushes for votes.
With two politicians, on the hottest of days, give the motor mouths a topic such the effect of Social Security reforms on invest strategy for deep water wells in the Oklahoma panhandle vs the electric power grid in New South Wales. There will be air movement to cool the barrel, you will learn to judge the wind dispersion effect nearby stumps and VWs, the heat wave will be blown out to sea, and the EPA will declare an alert, ban politicians from speaking with out a permit.
Life is good your problems are solved and life as we know it continues.
Jim

A good one!

Thanks guys. great points!!!

Mark,

Quickload program estimates powder burned, so I ran the 38-55 with 26" barrel, Barnes 255g FNSP,30g H322 for 90% loading density and got 1700fps with 15% of the powder unburned and this was better than most powders. Interesting cartridge.

steve

What you are seeing is what is termed 'all-burnt'. Steve505 touched on this when he posted the results from QuickLOAD. All-burnt is a highly scientific term ( ) used by ballistitions to describe the amount of powder that will be burned for a given case/barrel length etc. Once all-burnt is reached, no more powder will be burned. Essentially then, the unburned powder is filler.

Some powders have a higher all-burn level than others, but none will give you a 100% burn. Don't worry about it and good shooting.

Turok

Thanks again fellas. This helps alot.