Uh oh.....should I worry?

[3006guns]

I finally got the two 91/30's I ordered some time ago, both hand picked from AIM. I slugged the bores and both are .314 on the nose.....okay, I have a supply of already cast .314 170 gr. rnfp ready to go. Full lenth resized the brass in standard dies, then loaded about 40 rounds with 9 gr. of Trail Boss (this is a plain base boolit) and ventured out to the ranch to make it go boom.

I fired the first shot...negligible recoil, like a .32-20. I compared the fired case neck to one of the unfired rounds by trying to push a boolit nose into the fired case. Very tight....tight enough that I doubt it will need to be neck sized at all. When I got home I grabbed a micrometer and found:

O.D. of UNFIRED case neck: .314 (neck tension must have compressed the boolit)

O.D. of FIRED case neck: .312-.313 !!!!

Allowing for brass spring back, either I'm at the limit of what this chamber will accept or I have the world's only Norma "shrinking brass". I was hoping to use a larger boolit in the future.

Most of the rounds chambered a little tight (whack the bolt handle) due to the shoulder, but were easy to extract after firing, having been fire formed. They'll be trimmed and neck sized only from this point on.

At any rate, the rifle seems to be at least "minute of dirt clod" and might be a winner, but the tight neck worries me a bit. Opinions? Advice?

[clearwater]

I finally got the two 91/30's I ordered some time ago, both hand picked from AIM. I slugged the bores and both are .314 on the nose.....okay, I have a supply of already cast .314 170 gr. rnfp ready to go. Full lenth resized the brass in standard dies, then loaded about 40 rounds with 9 gr. of Trail Boss (this is a plain base boolit) and ventured out to the ranch to make it go boom.

I fired the first shot...negligible recoil, like a .32-20. I compared the fired case neck to one of the unfired rounds by trying to push a boolit nose into the fired case. Very tight....tight enough that I doubt it will need to be neck sized at all. When I got home I grabbed a micrometer and found:

O.D. of UNFIRED case neck: .314 (neck tension must have compressed the boolit)

O.D. of FIRED case neck: .312-.313 !!!!

Allowing for brass spring back, either I'm at the limit of what this chamber will accept or I have the world's only Norma "shrinking brass". I was hoping to use a larger boolit in the future.

Most of the rounds chambered a little tight (whack the bolt handle) due to the shoulder, but were easy to extract after firing, having been fire formed. They'll be trimmed and neck sized only from this point on.

At any rate, the rifle seems to be at least "minute of dirt clod" and might be a winner, but the tight neck worries me a bit. Opinions? Advice?

What are the min and max loads with trailboss for that rifle?

[felix]

Use magic marker on loaded round. Center round into chamber gently and lock the bolt for firing. Extract the loaded round, gently, gently, gently. If you see a scraping on all sides of the neck, then you are too tight. Reduce a half thousands at a time by neck turning (only if gun is worth it), otherwise a full thousands at a time by sizing the boolit. Make sure the chamber is dirty, as if after firing a few, before any measurements. ... felix

[3006guns]

The 9 gr. Trail Boss load is from a milsurp website and has worked very well in my .303's and 8mm Mauser. Some folks are loading up to 12 grs.

Thanks Felix......of course I just cleaned the rifle and discovered LEAD, but with a good lube "star" at the muzzle. I know the reason for this though, salvaged soft metal.....should have used straight wheel weights.

I have the one unfired round I brought back. Even though I cleaned the rifle I'll try the marker trick. At least it will give a ball park idea of where I am.

[StarMetal]

Another way using a fired case is to flare the mouth of the case enough so that's larger then the neck portion of the chamber. Then load the case into the chamber. You'll have to force it closed to to size down that flare. Extract and mic very carefully. Agreed even with this there will be some spring back but not as much as a fired case. I use this for a quick check. The way to get absolute is mic the neck chamber area which requires a good pound cast or cerosafe.

[3006guns]

Thanks StarMetal.....I just tried the permanent marker trick and aside from one minor scrape from dropping the round in, no sign of the ink being disturbed. Since I have to flare the necks slightly anyway I'll try that next.

It also occured to me that I have a small hole gauge out in the shop that I've never used for anything. The handle's a bit short, but with a little luck I might get an accurate measurement that way too.

I may be way overboard worrying about this, but I like to know everything about all of my rifles. The leading mystified me at first, but I think my alloy was very soft so I'll a healthy dollop (technical term) of lino to the next pot and test before casting.

[Multigunner]

I was getting elevated pressures with a .303 years ago, and found it was due to a baked hard deposit of sealant,atomized lead, graphite, and carbon fouling in the chamber neck.
A chamber brush did nothing the deposit was set too hard for solvents to penetrate.
I did keep the chamber wetted with solvents for awhile to try to soften it, then made a scraper from a piece of brass tubing.

I had a proper diameter tube, slightly smaller than the chamber neck. I cut two angled slots in the body to carry away debris, and filed saw teeth around the edge.
The brass was not going to cut steel but could cut into the hardened fouling.
I turned it carefully by hand.

On the first pass, black stuff the consistency of a LP record disc began to peel out in hair fine strips.
I had to bell the mouth of the tube at every pass to maintain any cutting pressure.

After several passes the black stuff stopped and I hit a gray layer that cut away like pencil lead
Soaking in solvent again to soften that layer I started again and soon the brass teeth began to slide smoothly over the steel of the chamber neck surface.
I then finished up with a Garand Chamber brush with the rotator gear cut off and the wire shaft threaded to fit an old section of cleaning rod, this in a hand cranked drill. Soon the chamber was throughly clean and happily not scratched or corroded under the deposit.

Result, no more pressure signs with the same loads.

Soviet 7.62X54R that I've pulled bullets from showed the same aspaltum sealant I've found in POF .303 ammo, and the added red laquer water proofing.
The powder in those was a fine silvery ball powder, I suspect the silvery look came from graphite added to the powder mix.
Old Mosin Nagant bores I've cleaned up had a thick black deposit in the grooves, so its likely your chamber neck has a deposit.

These deposits look no different on the surface than polished steel, so its hard to spot them by eye.

The foam cleaners seem to work fairly well in breaking up hard to reach deposits in the shoulder and neck. First time I used a foam cleaner in a bore that appeared perfectly clean the bore proved to be spotless but a clot of black crud came out of the shoulder and neck area.

[3006guns]

Now THAT makes some sense! I found it strange that, in a rifle known for somewhat "loose" tolerances, the neck area could be so "match quality".

I just finished bell mouthing a case and forcing it into the chamber. When I pulled it, the neck was straight and smooth....the flare had been ironed down to match the rest of the fired neck.

I'll try the tubular brass tool idea and see what happens. If nothing is removed I'm having thoughts about lapping the neck area a bit to loosen it up a touch.

[swheeler]

06; I think you made a mistake on OD of loaded round and fired round, .334 OD sounds more like neck diameter of a loaded round, thats what mine are(.335")and fired case neck OD measures .336using Graf brass. Felix gave you good advice on blackening the neck and carefully chambering, then even more carefully extracting, if you have a problem you will see full circumference rubs.

[3006guns]

I don't know why I didn't think of it before, but I've got several hundred rounds of surplus 7.62 x 54.......all I had to do was measure the O.D. of a "factory round" and find out where I stood.

I'm sure my measurements were right, because I didn't believe them myself...so I measured several times to be sure. I've used a mic for years so feel comfortable with them. Although at this point I'm beginning to suspect my FL sizing die might have something to do with it. I'll tell you this...those boolits were a little tough to seat, more than a "normal" cast round, so something affected my case neck size.

When in doubt, start over! You never give up in this hobby!:mrgreen:

Thanks everyone for your help and advice.

MAJOR EDIT: Forget everything you read in this post.........it was all a bad dream! Group hysteria! O.K......I goofed. Despite what I just said, after measuring a military round it is indeed .337-.339 O.D. neck diameter. So where did the strange measurement come from? Overconfidence, that's where! I've used precision instruments most of my life but it's become obvious that I need better light over my reloading bench. The mic had rotated PAST the .025 mark and stopped on .014. I think the fired case necks simply didn't expand much because of the light charge. In other words, I created a problem that never existed. Major red face here!

[StarMetal]

I don't know why I didn't think of it before, but I've got several hundred rounds of surplus 7.62 x 54.......all I had to do was measure the O.D. of a "factory round" and find out where I stood.

I'm sure my measurements were right, because I didn't believe them myself...so I measured several times to be sure. I've used a mic for years so feel comfortable with them. Although at this point I'm beginning to suspect my FL sizing die might have something to do with it. I'll tell you this...those boolits were a little tough to seat, more than a "normal" cast round, so something affected my case neck size.

When in doubt, start over! You never give up in this hobby!:mrgreen:

Thanks everyone for your help and advice.

I do believe your measurements were incorrect also. I was concentrating on giving you an alternate chamber neck measuring means and didn't look at the figures. Here are case dimensions for the 7.62x54R:

http://stevespages.com/jpg/cd762x54rrussian.jpg

If chambering the flared case sized that flare even with the rest of the neck then the marker pen should have picked up some marks.

[3006guns]

Thanks StarMetal.......please see embarrassing post above.:roll:

[StarMetal]

Thanks StarMetal.......please see embarrassing post above.:roll:


No problem there. Happens to many of us. You won't get and hassling about it from me, but I sure got my **** reamed out for a mic mistake in a 6.5 Swede thread. [smilie=s:

[MtGun44]

My first thought was this HAS to be ID not OD.

Believe that we all have made similar mistakes. So far I haven't done quite so bad in
public if you don't count the "6 yd group" comment . . . . . . :roll:

Bill

[303Guy]

Ha ha. Aren't we all just human?;-) However, there have been ground breaking discoveries made from mistakes!:drinks:

[3006guns]

Well, I don't want to drag this thread (and my embarrassment) any further, but I had to share some really good news......

I've been using a 170 mold, I think designed for the 32-40 Winchester, and squeezing down to .314 in order to use the boolits in my 7.7 Jap and .303's. It actually performs amazingly well considering the lube grooves end up looking like pencil lines.

I started rummaging through my mold box and found one that I'd inherited years ago, a three hole Hensley and Gibbs. There were three oiled bullets in the cavities, so I dropped and measured them....in good light this time! Holy yamagucci Batman....they measure .315, are a round nose flat point of at least 180 grains with nice BIG grooves. It didn't take long to get the Saeco pot going and I've already cast about 100+ as the mold drops 'em right out.

Thank you Lord..............................:bigsmyl2:

[Maven]

"I've been using a 170 mold, I think designed for the 32-40 Winchester, and squeezing down to .314 in order to use the boolits in my 7.7 Jap and .303's. It actually performs amazingly well considering the lube grooves end up looking like pencil lines."

3006guns, The trick is to fill the lube grooves (with lube) prior to radical resizing. That way the grooves are supported and won't end up as yours did.

[madsenshooter]

What's a LP record disc, doe it have something to do with propane? I've heard Hank Hill mention LP.

[Multigunner]

What's a LP record disc, doe it have something to do with propane? I've heard Hank Hill mention LP.

LP stands for Leopard Pelt. In the old days we cut a round section from a Leopard hide and put it on the new invention the Wheel. Using a stout thorn wedged in a mamoth femur and lashed to a hollow log we could record drum beats to play back during the eclipse ceremony to scare away the black panthers that were eating the sun.

Seriously old military ammo was once sold to manufacturers of laquers and glues. The powders broken down and recycled to make furniture finish and large diameter 78 rpm records. Later on records were made with vinyl.
The high strength glues made from these recycled materials are still in use.

The earlier large diameter records were 78 revolutions per minute, the LP was 38 RPM. not sure when the switch came about. Most if not all LP records are likely vinyl.
The 12 inch 78 RPM aren't really LP, just longer play than the ten inch records.
I've accidently broken large diameter record station discs, and found a fiberous layer under the brittle surface.

Antique furniture restorers like to buy up old broken 78 RPM records and dissolve them in alcohol to make a furniture finish that matches the original formulas made from the same recycled materials as the records.

[3006guns]

Maven.....thanks for the tip. I actually thought that might work, but hadn't asked anyone yet.

LP records......LP records..........Oh, yeah! Those things that look like oversize CD's, but black! Got a ton of them (and 78's) stored away until I can find a turntable that's still in decent shape. No, I'm NOT going to turn them into furniture finish!

[Multigunner]

The 78 rpm connection just gave me an idea, of all the solvents I've tried I haven't tried simple PGA, pure grain alcohol.
Some substances will respond quickly to one type of solvent but be completely unaffected by others that would be considered much stronger.

The Records surface layer was made from a nitrocellulose shellaque, very tuff stuff and durable. There recycled propellants containing nitrocellulose to make that stuff.

I'd run across the use of recycled nitrocellulose in making high strength glues only recently.

Could be the really stubborn deposits in grooves and chamber shoulder and necks are a similar material, baked hard and compressed in the bargin.

[twotrees]

:hijack:

For all you Other GOF's that still have 78's 33's and 45's take a look at this turntable.
It hooks to your usb port and lets you turn them into CD's !!!8-)

USB turn table (http://www.ithomeproducts.com/product/usb-turntable)

The software that comes with it sucks, big time. So....


Audio Cleaning Lab (http://magix.com)

That lets you get rid of most of the hiss and noise and even saves tham as MP3's!!

See some of us have other hobbies besides Boolits.

Oh Oh Did I just blaspheme?[smilie=1:

[StarMetal]

:hijack:

For all you Other GOF's that still have 78's 33's and 45's take a look at this turntable.
It hooks to your usb port and lets you turn them into CD's !!!8-)

USB turn table (http://www.ithomeproducts.com/product/usb-turntable)

The software that comes with it sucks, big time. So....


Audio Cleaning Lab (http://magix.com)

That lets you get rid of most of the hiss and noise and even saves tham as MP3's!!

See some of us have other hobbies besides Boolits.

Oh Oh Did I just blaspheme?[smilie=1:

I've been looking for something like that, thanks. Wonder how much that turntable costs? Too back there's not an adaptor to plug my turn table into my pc. I have a bunch of records and cassettes I want to burn onto DVD's.

[twotrees]

Mine cost the wife $99 at Christmas. I have seen them for about $70.

They work really well.

[swamp]

starmetal,

Office Max sells outfit that lets you plug turntable into pc to transfer onto harddrive.
They go for 25-50 $ I think. Haven't checked on them recently.

swamp

[StarMetal]

Thanks guys.

[303Guy]

Guys, guys, guys! You have just made Cast Boolits history with a new record.:drinks:
Never before to my knowledge has there ever been a shooting topic go this far off topic:!:
Tee hee!:mrgreen:
Now tell me more about this turntable business. It's exactly what I'm looking for!:bigsmyl2:
:drinks:
:drinks: