I need some Serious Help (advice), Here !!

Started by Thumper, July 08, 2012, 08:09:56 PM

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Thumper

I got that Winchester 73' in 32-20 mechanically up and runnin', I hope for the next 100 years.....but my targets look like I was shooting a scattergun (pic below). The barrel has some faint lands and grooves all the way through, the bore is well pitted. When I bought it, it was suggested I might want to reline it for accuracy sake. After 25+ rounds at 25yds, and site adjustment, only up and down, not laterally, the last 2 shots (middle target, one is hard to see cause it actually hit the center) went straight. I'm thinking that the fouling got thick enough that the bullet was finally centered as it left the tube???!! I'm using a 96g slug over over a full load of goex fff (approx 18-20g). My thought is that a hollow based bullet might work like it did in the old 58 minies to flare out and engage the rifling and a friend (SG), suggested I lighten my load by putting a lube pill or two under the slug to slow the velocity. Anybody have anyother suggestions....I'm willing to try them all. Thanx

Pettifogger

Quote from: Thumper on July 08, 2012, 08:09:56 PM
I got that Winchester 73' in 32-20 mechanically up and runnin', I hope for the next 100 years.....but my targets look like I was shooting a scattergun (pic below). The barrel has some faint lands and grooves all the way through, the bore is well pitted. When I bought it, it was suggested I might want to reline it for accuracy sake. After 25+ rounds at 25yds, and site adjustment, only up and down, not laterally, the last 2 shots (middle target, one is hard to see cause it actually hit the center) went straight. I'm thinking that the fouling got thick enough that the bullet was finally centered as it left the tube???!! I'm using a 96g slug over over a full load of goex fff (approx 18-20g). My thought is that a hollow based bullet might work like it did in the old 58 minies to flare out and engage the rifling and a friend (SG), suggested I lighten my load by putting a lube pill or two under the slug to slow the velocity. Anybody have anyother suggestions....I'm willing to try them all. Thanx


I guess the key is what you mean by "faint lands and grooves."  If that is truly the case and they are indeed faint and the bore is heavily pitted it won't matter if you use a hollow base bullet (if you can find one in .32) as there is simply nothing for the bullet to engage.  If the bore is really that crappy, then you should consider the reline option.  I have several and they all have some pits.  But the lands and grooves are still sharp and they shoot fine.  The other thing to check is the actual bore diameter.  Have you slugged the bore?  Do it and find out the actual bore size.  This will also tell you if there is enough left of the old bore to inscribe the bullet with land and groove marks.  If your bore is worn and you are shooting a hard cast bullet it might not be expanding enough to fill the lands and grooves.

w44wcf

Thumper,
It appears that the bullets are yawing a bit which would indicate that they may be undersized which also leads to inaccuracy.
What diameter are the bullets?
Have you slugged the barrel to determine the groove diameter?

Early '73 barrels can vary a bit in dimension. In the 32 W.C.F., I have heard of barrels as large as .316" dia. in the groove.

In my experience, if the bullet fits the barrel well, even old, worn, pitted barrels can shoot remarkably well. Using some PSB (Poly Shot Buffer) under even an undersized bullet will = accurate shooting since the PSB acts as a gas check keeping the powder gases behind the bullet allowing it to transverse the barrel undisturbed by gas getting by, destroying accuracy.

Typically, with Goex BP even in a smooth barrel, unless the bullet is carrying enough lube (or using a lube cookie) accuracy will start to deteriorate after a dozen rounds or so as hard fouling builds up in the barrel.

If you send me a PM, I would be happy to send you some PSB and some other 32-20 bullets to try.

w44wcf  
aka Jack Christian SASS 11993 "I can do all things through Christ who strengthens me." Philippians 4:13
aka John Kort
aka w30wcf (smokeless)
NRA Life Member
.22 W.C.F., .30 W.C.F., .44 W.C.F., .45 Colt Cartridge Historian

Thumper

W44CF..,.as the saying goes' Huston we have a problem (I think). My bullet is .3115 fresh, after slugging, I get between .3102 and .3085. However, at one point on the muzzel of the barrel I get a reading of .3115 !!! Think the bullet is a tad small. Sound right? Please explain "PSB", I'm using a tallow, paraffin and beeswax as a grease ring seal.

w44wcf

Thumper,

Based on your barrel dimensions, the .3115" diameter bullet is being sized down to about .309" average (Is there a possibiliy that there is leading forward of the chamber which is making the barrel smaller there?) at the start.  As the barrel gets a bit larger toward the muzzle, gas will get by the now undersized bullet which will cause it to be much less accurate and explains the scuffing at the target (partial keyhole).  

Since the bullet is .3115" diameter and the muzzle is not sizing it down, there is a possibility that the dimension at the muzzle could actually be a bit larger than that.

If the rifle was cleaned quite a bit over the years, a bit of cleaning rod wear at and toward the muzzle is possible which could make it a bit larger there.

Ideally, it is much better that the smallest diameter be at the muzzle.

In lower velocity cartridges, shallow rifiling works just fine.

A couple of fixes.....
1.) Use soft bullets (lead or no harder than 50/1 lead /tin / commercial bullets are much harder)  that will be more "plastic"  which will conform much better to the various dimensions in the barrel.

2.) Use PSB (Poly Shot Buffer) which has a consistancy similar to corn meal but is plastic.  It will keep the gas behind the bullet, thus  enhancing accuracy in less than perfect barrels. To use, allow enough room between the powder and the bullet so when compressed,  there is a minimum of 1/8" of space for the PSB. Compress the PSB at least 1/3, meaning that at 1/8" space between the powder and bullet, put at least 3/16" of PSB over the powder.

Do not use PSB over smokeless powders quicker than 2400.  B.p. ok.

In straight walled cases, a .06" thich LDPE wads can also keep the gas behind the bullet and improve accuracy.

3.) Lap the barrel so that the dimension is close to the same for the entire length. That can be done by "fire lapping" which means that bullets with fine lapping compound are fired through the barrel at very low velocity.

I would be happy to send you some PSB and other bullets to try......

Do you plan on using smokeless as well?

w44wcf




aka Jack Christian SASS 11993 "I can do all things through Christ who strengthens me." Philippians 4:13
aka John Kort
aka w30wcf (smokeless)
NRA Life Member
.22 W.C.F., .30 W.C.F., .44 W.C.F., .45 Colt Cartridge Historian

wildman1

NECO Industries is a good place ta get some quality lapping compound. They have a kit made specifically for fire lapping and will send bullits with the kit for your rifle. WM
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Pappy Myles

Heres a thought.  Hollow base bullets.
I know the only commerically available in 32-20 (32 pistol) is a 90 98 grain wad cutter. Speer, Horniday.  Maybe get a box of then, load them up and see how they perform.  If they do well, maybe contace accurate molds in Salt Lake City and see if he can build you a hollow base mold in 32-20?

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KirkD

In my experience, w344wcf's suggestion to use the polyfiller is probably the one that will give you success. I have not used polyfiller but I have used other filler, such as cotton and toilet paper. The filler acts as a variable gas check. As the bullet approaches the wider groove diameter near the bore, the high pressure gases push the filler into the tiny gap around the bullet, sealing off the high pressure gases. Polyfiller is probably the best at this due to the design of the filler, but if you absolutely cannot find any, then you could try a small pinch of cotton between the powder and the bullet. As w44wcf says, do not use filler with powders with a burn rate faster than 2400. Also make sure you have enough filler to fill the space between the bullet and the powder. I have shot quite a few old guns, some with outrageously awful bores, and filler always tightened up the groups considerably.

Thumper

I just figured out how to take reasonable pics of my bore. I use a fiber optic attachment (I just purchased) on a Mini Mag flashlight and tape the flashlight to the receiver. For your consideration, here they are. Notice in the 1st one there is a grooved circled in the barrel from someone doing something (there's a couple more also). Is this bbl saveable or not worth the effort? I've been working closely with w30wcf on this project and am in no way questioning his knowledge or expertise!! Just looking for more input from someone with perhaps a loosely guarded secret (Heh-Heh).




Lefty Dude

I would start with a serious cleaning job. My 1894 Springfield 30-40 Krag looked about like your 73 before I got it to shoot.
You must be patient and consistant with the cleaning. It may take a couple of Weeks of soaking and such to get the krud out of that sewer pipe of a bore. I use a mixture of 50% Hoppes and 50% Kroil, applied with a bore mop. This I do twice a day followed by a nylon bristle bore brush with a tight patch. I rotate the piece in my cleaning Rifle station 180 degrees after each soak .
Once I begin to get a clean patch, no grey color, only solution color. Then I use JB bore paste for the last step.

After cleaning you must slug the bore. This will determine what bullet size to use. My 30-40 slugs out at .3115", I shoot a 303 Brit. bullet sized at .313". I also use a gas checked bullet, this reduces leading with the rough bore.

If you have any Rifling, even a little it will shoot. Not as accurate as a prestine new bore.

Your other option is a re-line job, good Luck. ;)

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