Printable View
I slugged my savage model 10 .308 win today and what i found interesting was the first 1/2 of the process from the breach to the muzzle it took taps on the brass rod to push the slug through. about 1/2 or so it go so easy i could push it by hand and got easier as i went towards the muzzle. is this normal? thanks
rrh
If you started with a dry bore, you might have left some lead behind at the breach end, meaning you would be pushing a smaller slug the rest of the way. Don't ask me how I know this..... :x
I suspect if you repeat the process from the muzzle end you'll see the same thing.
On the other hand you may have a bore looser at the muzzle which would not be a good thing.
Have you shot it yet?
Would suggest some a light coat of oil for the lenght of the barrel before running the dry lead down. Have slugged a few Savage and others and they pretty much all start out with resistance and once to size it is nice going. Go slow once the slug is to size to detect and tight spots or heavy burrs in the barrel. Not that I have the skills to deal with barrel defects but good information as to the quality of the barrel maker. Carefully clean the slug with a clean cloth and then take a good look for heavy or deep scratches. The slug can tell you a lot about the barrel.
Re: Slugging a Savage.....not legal here in Canada.
Normal? I suspect so. Desireable? No, definitely not. The first thread I ever started on this forum was over the EXACT same issue. I do not know for certain, but I suspect you could slug 100 .30 Savage barrels and find the same issue in nearly, if not every one.Quote:
Originally Posted by redriverhunter
I can only guess that the reason this continues is because the majority of shooters will NEVER slug their barrel, and most will buy a box or 2 or 3 shells, go to the public range and shoot 10 or 15 times, have 3 or 4 within an inch and blame the rest of it on wind, distractions, scope adjustments, inexperience, or whatever and proceed to go online and brag about their sub-MOA rifle they bought for $4 Ben Franklins. [smilie=b:
You know what you saw. Poke a slug in the chamber end, knock it back out and measure it. Do the same at the muzzle end. BE CAREFUL.
I'm guessing the muzzle end slug will measure about .0015" larger than the chamber end. No, this is not a condition that will result in decent J-word groups, let alone desirable cast groups.
Welcome to the reality of cheap factory rifles. What you do next is up to you.
The whole problem is getting wrapped around the axle of slugging the bore in the first place. Make a pound cast (search the forum for Goodsteel's thread on a good way to accomplish this) and size your bullets based on the throat entrance diameter.
Savage barrels are soft and if yours happens to have a reverse taper (doubtful) it will correct itself in a few hundred rounds.
Gear
How does slugging a barrel to measure groove and bore diameter amount to getting 'wrapped around the axle'? These are basic barrel dimensions, no more, no less.Quote:
Originally Posted by geargnasher
If one makes a pound cast as you suggest, and sizes their cast bullets to match the throat entrance, then one of two things are going to happen : either your pound cast will give you a dimension matching your groove diameter, and therefore you will size the same as you would if using your barrel slug, or your pound cast will give you a dimension greater than your groove diameter, in which case your bullet will be swaged down to the groove diameter when fired, just like using your slug measurement. All this is presuming the barrel bore/groove diameter is not tapered, correct?
And Savage barrels are soft? As compared to what? Remington barrels? Winchester barrels? Jacketed bullets? I do not follow . . . .
I do the pound chamber cast and never look back. Record the dimensions, mark the cast for reference and fill the 1 time fired casing in neck and try get the rest to be close to chamber slug and shoot with a grin! It really isn't hard at all.
I have slugged several hundred firearms and found that the barrel need to be cleaned down to bare metal for the best results. Also if the barrel has many bullets/boolits down it the throat area may be rough. This could be why the lead slug the OP used got easier to push as it went down the barrel. I have polished the throat area on several rifles that had rough throats and it did help accuracy with boolits.
I usually push a slug in the chamber end and back out, and the same for the muzzle. Another all the way thru to check for tight or loose spots. Sometimes a barrel with a gas hole in it may make the slug catch a little bit. Hope to get a bore scope down one of these barrels to see the condition of the gas hole.
I use a patch with motor oil on it to lube the bore and the slug, some use grease, just don't do it with a dry bore or slug.
When you slug the barrel by pushing a slug the full length of the barrel, it only shows the smallest dimensions.
A pound cast of the chamber and first bit of rifling will show the size where the boolit enters the rifling. This is the dimension you should try to match. If the boolit matches this dimension it will leave the case and enter the rifling as straight as it can. If you size to match the full length slug then it may be a bit small in the chamber. This could lead to the boolit not being as straight in the barrel as it could.
Leo
True. However, the bullet is still going to get swedged to the smallest bore/groove diameter. If these dimensions do not remain consistent along the barrel, and even worse if they increase along the barrel, much wasted time and frustration is upon the shooter's horizon.Quote:
Originally Posted by 44magLeo
It could be metallic fouling, but I doubt it, right in the first half-inch of rifling. I'd expect this to be further down the barrel, where the relative motion of lead or gilding metal and steel is faster. Also the powder gases are much more erosive in that first half-inch than elsewhere, and there are more part-burned grains mixed up with it. I believe if they will erode steel they are likely to scour away anything softer.
There are two pieces of good news. If there really is tightness of the bore itself, it is likely to correct itself in a few hundred shots. The other is that the bullet may, at that point, be capable of expanding to seal the remainder of the bore. It is much better than a tight spot produced in an area of reduced pressure, by a heavy and over-tight soldered barrel band.
Tightness so located can't be the result of unwise rolling of the barrel threads. Does anybody know for sure how Savage rifle barrels? I would think they button rifle a reamed bore. In this case it could be a tightness of either the grooves or the lands, while the other is the same as it is all along its length. This would make sealing a possible problem, but without letting the bullet fall out of concentricity with the bore axis.
I'd try a slug from the muzzle, and see if it tightens up where you think it will. If it does, I believe I would lap it with a long lap cast with Cerrosafe alloy, so that it will be long enough to never come out at the breech.