leading with lino.

[mto7464]

My loads today in my K31 were 31.5 and 32.5 grains 4895 (from Bartlet) under a lyman 165 sillywet, GCed, cast with Lino, lubed with 50/50 sized .308. Accuracy from a clean barrel was good, 2" at 100 yards. The problem I am having with my lino boolits is that it is leaving some fouling in the barrel that I know will lead to accuracy dropping off after 30 rounds or so. I only fired 12 rounds tonight and pushed a tight patch thru it when I got home as it has traces of lead. Should I switch lubes? Try different alloy? what?

[Shiloh]

I used the 50/50 untill I switched to Larsen's Lube http://www.lsstuff.com/lube/index.html
Never had leading with it.

I have used his 2500 and now use the BAC I had no problems with WW boolits up to 2200 FPS, as fast as I went. I find my best accuracy at about 1650 or less with the '03 and Krag. Both have 1:10 twist. I currently had a batch at 17.5 gr of SR4759 clone that gave spot on 1550 fps in the '03, with about 25 rounds of the 50 fired. going into about a 3" circle. The rest were close to it. I get a trace of lead, but I think that it is shavings from the throat area as there is nothing in the bore, and I get a lube star at the muzzle.

Shiloh

[jhalcott]

Hard boolets often do NOT expand to fill the bore properly. This can lead to leading. A softer alloy MIGHT help in this case. Another remedy could be a faster powder OR a stiffer charge(with in reason) to aid in the expansion factor. Shiloh may have a point in his post. WHERE in the bore are you finding the leading?

[cbrick]

Sized .308" but what is the slugged groove diameter? What velocity are you getting?

Rick

[docone31]

Yeah, I am looking at the .308 sizing.
I wonder if .309 might be the trick.
The 7.5 vs 7.62, .308 might be a little lean.
Have you sized it?

[mto7464]

slugged .3065. didn't chrono these today but I 'd gess around 2000. I can't see the leading but it is there.

[Lloyd Smale]

I dont understand your statement that you cant see the leading but its there. If its only a gray wash in your barrel i wouldnt even be conserned with it. If your load is shoot well and the lead is not building up to the point it is effecting accuracy what are your worried about?

[mto7464]

If you read my above post you will see that I say I lose accuracy. The bore just looks shiney to me. I may not have a good eye to see the lead. I think I will try a different lube or size to 309.

[Lloyd Smale]

reading your post it looks to me like your assuming that the accuracy will fall off. Most times guns will get a little lead coating and it doesnt get any worse. That kind of leading is no big deal and surely nothing to worry about.

[mto7464]

I am not assuming, "I know" it will happen. It already has with past shoots.

I think maybe jhalcott may be on to something since I didn't get this with WW's.

[hyoder]

If your groove diameter is indeed .3065 then going to .309 make make the leading worse. You may be getting swaging, or shaving, in the throat and this may be the source of leading. It may then be getting partially vaporized and blown down the barrel.

[jhalcott]

Could you post a picture of the "slug"? That will answer a LOT of the ??'s with out a lot of back and forth guessing. I can get 2000FPS using ACWW and felix lubed/gas checked .30 caliber in several guns. I get minimal IF ANY leading. Bullets are sized for the individual bore.

[Lloyd Smale]

If your comparing it to leading youve seen with softer alloys theres a difference. High antimony alloys like lineotype will put a light gray wash in your barrel. It is hard to get out but the good thing is that it doesnt have to come out. Most times what happens is in a few shots you will have this gray wash and it wont get any worse. It isnt a bad thing. Weve even noticed increased velocitys when its pressent so its probably lubeing the bullets to some degree. i do agree with the others that your sizing to small though. Id size at least 309 and probably 310 in your case.

[dardascastbullets]

If your comparing it to leading youve seen with softer alloys theres a difference. High antimony alloys like lineotype will put a light gray wash in your barrel. It is hard to get out but the good thing is that it doesnt have to come out. Most times what happens is in a few shots you will have this gray wash and it wont get any worse. It isnt a bad thing. Weve even noticed increased velocitys when its pressent so its probably lubeing the bullets to some degree. i do agree with the others that your sizing to small though. Id size at least 309 and probably 310 in your case.

Back in the old days when Saginaw Steering Gear machine gun barrels were available, we would put them on our Springfield actions and they were highly regarded for their accuracy! Especially with the Lyman 311466. Those barrels (if memory serves me correctly I went through five of them) slugged at 0.3065. We sized our 311466's to 0.310 (actual linotype we purchased from the print shop) and had zero leading and sub X constant groups at 200 yards. I actually won the highpower state championship one year using the cast bullets for the 200 yard offhand stage. Everyone was asking me what I had loaded and what that funny white powder was that was shooting out the barrel (dacron filler).

My point is......I believe that the poster is sizing too small also. The general rule that I was brought up on was always size 0.003" over slug diameter. It always worked for me.

Matt

[Lloyd Smale]

personaly ive rarely seen where softer lead would outshoot harder lead if the dimentions were proper in the gun. Softer lead can be a crutch for a pooly built gun but thats about it.

[runfiverun]

a improperly sized hard boolit will lead a bbl much faster then an correctly or oversized soft one will.
btw with a 18 bhn boolit my k-31 likes a 310 size. right near 2000
haven't even looked for leading as it has never changed it's accuracy level.
and this is over 600 rounds as far as i can remember.