My Boolits Too Big?? Advice Needed...Pics!!

[juanvaldez]

Thinking these are a tad too big but fairly new to shooting cast. Recovered these from the sand berm behind my target stand. They were shot from a 12.7x44r swede rolling block. Boolit was cast from WW's in a Lee 430 grain .515 mold. Load was 28 grains of H 4198 pushing boolit to about 1200 FPS. Looking or some advice please.

Cheers

http://img.photobucket.com/albums/v76/juano2001/100_1757.jpg

[hiram]

Some people will say slug the bore and use 1-2 thousandths over that. Others will say use the largest bullet, which when seated in the case, will still fit the chamber.

[MtGun44]

Looks like they may be a bit small if anything. The part of the boolit that
is in the grooves does not seem to show any marks from reaching the bottom
of the grooves.

Did you get any leading of the bore? If not, there is certainly plenty of
rifling engagement. How were the groups?

Have you slugged the bore? You generally (as said previously) want about
1 or 2 thousandths of an inch larger than the groove diameter. Softer slugs
will likely bump up to a larger diameter on firing, harder ones will not.

These look like they were pretty hard boolits, not a lot of impact damage.

Bill

[juanvaldez]

Little more info...these bullets were sized to .510 with a LEE sizer. The reason I was thinking too big is the back of the bullet is cup shaped after firing and I have a hard time chambering unless I give the loaded round a small roll crimp. The seated bullet seems to expand the case to the point that chambering is difficult unless I crimp. Have not slugged the bore but measuring the recovered bullets I get from .505 -.508. The load is extremely accurate. I have shot 3 shot cloverleafs at 100 yards from the bench with very crappy iron sights. I get no leading. I'm just worried about the integrity of an almost 150 year old action. Is it possible to exceed the safe pressure limits if my boolit is way oversized. Which is safer (ie less pressure for a given load) a soft lead alloy or a harder one. The ww I used make a very hard bullet as seen by the photo above. Thanks for the help.

Cheers

[Bigjohn]

If the cartridges will not chamber unless crimped, could mean your cases are too long or tere is crud in the very end of the chamber.

If your getting that sort of accuracy, I would not complain.

Also, as someone here has said already; 'Slug the bore', that is about the only way to confirm what size boolit you need. A boolit recovered from the earth berm has had other forces acting upon it to deform it enough to give false sizes.

For the cartridge you are loading, I would try a softer metal than straight wheel weights. 30 to 1 maybe and BP.

As to the base cupping you describe, I've checked out your photo and IMO, it is nothing worth worrying about. Your rear end would be seriously cupped if you had as big a boot placed there with that amount of force. I have seem the same thing to varying degrees in WW boolits form smokeless loads in my .45/70.

John.

[juanvaldez]

Bigjohn...I did check for crud a the end of the chamber and it was fine. An empty sized case will chamber fine, it is only when a boolit is seated that I have problems.

[Bigjohn]

Paint the neck of a case, with a boolit seated in normal position, with texta/ marker pen and chamber it. Any high spots should scrape away the marker.

Do the same to the ogive of the boolit and the will show you if it is engaging with the rifling.

John.

[juanvaldez]

The pics below show the marks on the case where the chamber gets tight. It only effects the last 1/8" of the case and as I mentioned only when a boolit is seated.

http://img.photobucket.com/albums/v76/juano2001/100_1758.jpg
http://img.photobucket.com/albums/v76/juano2001/100_1760.jpg

[Bigjohn]

Juan paint the neck and boolit ogive with a marker pen then chamber the cartridge. Any contact points should show up very easily.

I have a Enfield Martini rebarreled to .45/70 in which the entire full diameter section must be inside the case, otherwise it will not chamber the cartridge.

John

[Bigjohn]

Juan, that picture to me indicates that there is something wrong in the chamber. You may need to chamber cast and measure the area.

John

[Bigjohn]

Juan, I am currently checking my library for information on the cartridge. Nonte does not list it in his book on cartridge conversions.

Barnes book Cartridges of the World 8th. Edition on page 373 lists a 12.17 x 44Rmm Remington M67

They state bullet diameter is .502", weight 345/360 grains (Lyman 509134) 75 grains Fg black powder or 32 grs IMR 4198

Their listed measurements are:- Neck Diam. = .544"; Base diam. = .546"; Rim diam. = .624"; Case length = 1.73" and Cartridge length = 2.13"
The bores on most rifles were a little generous to allow for fouling from the powder. With smokeless, fouling is not a problem and boolits can fill the bore without problems, if you can load them.

Hope this helps,

John.

[hiram]

You might have a short chamber as was suggested. With the case empty, there is give (spring-weakness) in the case mouth. A seated bullet supports the case mouth and the give is absent.

[Buckshot]

..............Juan, welcome to the board!

Those boolits look just great to me! They're obviously sealing the barrel as I see no gas cutting. Trust me, if the high pressure gas behind them could get past, it will. In the process it will cut and erode the boolit in it's passage like a stream of water.

The base will look a bit concave as those Swede RB's have tall lands. When they engrave the lead HAS to go somewhere, and that's toward the back. If you'll look where the lands engrave there on the base, you'll see that that is the area sticking out beyond the base the most.

..............Buckshot

[Bret4207]

In the first pic the boolit lying on it's side looks as though the top lube groove is bottomed out, but the upright boolit shows nothing like that. If this seems to be the case check for run out in your loaded cartridge. That could cause some chambering problems. If that seems okay you should try a softer alloy. That will shrink your boolit a tiny bit and allow for a little more ductility which *might* lead to less spring back and chambering problems. If you stil have problems you could consider removing the decapping pin from you FL Sizer die and gently running the loaded round in a certain depth. If the boolit is causing a bulge that'll iron it out. The other option is to shorten your brass.

As you can see there are a few options to consider.

[juanvaldez]

Thanks for all the replies.

Is their any negatives to shortening my brass? That was the first thing I had considered doing.

I checked some of my fired brass. The ones I had crimped do not show the marks on the last 1/8th of an inch and and they slipped right in. I got better accuracy without the crimp though. Under 3 inches with some spectacular 3 shot groups (I chickened out on the last 2 shots). The crimp opens them up a bit. Surprisingly, bullet seating depth did not seem to greatly impact accuracy.

Cheers

[juanvaldez]

Here is a better pic of one of my boolits

http://img.photobucket.com/albums/v76/juano2001/100_1761.jpg

[eka]

You can shorten your brass a reasonable amount with no problems. I, as well as a lot of other people, use blown out 30WCF brass in the 38-55 Winchester which ends up being quiet a bit shorter than the trim to length of the factory produced 38-55 brass. If you are crimping into that top groove, you'll of course be shortening your cartridge overall length and encroaching on your powder space. Who knows where that will take your accuracy. May not make much difference. It's worth a try.
Keep at it, with cloverleafs at 100, you're definitely on the right track. Just need some fine tuning.

Keith

[runfiverun]

i would trim the brass back. you have plenty of neck tension so you really don't need the crimp.
try 6 and shoot.
your brass looks like you have a rough chamber right up there.

[Wayne Smith]

I would want a cerrosafe cast of your chamber and throat area. This will tell you how long your chamber is. That one piece of brass does look as if the brass is impinging into the throat, but that's pure guess at this time. A chamber cast will remove all doubt.

Cerrosafe is available from Brownells. It is not expensive and is reusuable. It melts barely above water boiling temps.

[Bigjohn]

Juan, from looking at your latest picture; NOW that is engraving! Still no sign of marks on the outer edge of the boolit (where the metal is in the grooves).

A few have suggested having the chamber cast made to check the end of the chamber and start of the rifling. IMHO, this step would be very revealing.

You did not mention how your case length compares to the published details, can you post that for us?

You obviously have a shooter if you can get it to print clover leaf groups at 100. Best of luck with it,

John

[juanvaldez]

So I took a sulphur chamber cast...here are the pics. There appears to be a definately line corresponding to the brass trim length after which the chamber begins to taper in and gets pretty rough for about 200 thous, then the rifling begins. Is this what I should be seeing?

http://img.photobucket.com/albums/v76/juano2001/100_1763.jpg
http://img.photobucket.com/albums/v76/juano2001/100_1764.jpg
http://img.photobucket.com/albums/v76/juano2001/100_1765.jpg
http://img.photobucket.com/albums/v76/juano2001/100_1766.jpg
http://img.photobucket.com/albums/v76/juano2001/100_1767.jpg
http://img.photobucket.com/albums/v76/juano2001/100_1768.jpg

[TAWILDCATT]

the fired case looks rough.is the chamber smooth. also did you take out the flare,
because it works when you crimp.a lot of 45 shooters have had trouble for not taking out the flair.:brokenima:coffeecom[smilie=1:

[leftiye]

Check your case mouth flare on the rounds with the boolit seated, and uncrimped. Make sure that the flare has been straightened out.

Check also the case mouth measurement on fired brass and see if it gets more than a little smaller right at the mouth (your boolits might be getting sized down by the chamber mouth/case neck). Another way is to cast the chamber as was mentioned. This will tell you both what size the chamber is, and if it is tapered at the mouth of the neck area. With a single shot, you may (should) be able to seat boolits with thumb pressure in unsized or marginally sized cases. See if such a cartridge will chamber. If not, your chamber neck may be undersized.

Sum a them cartridges made for paper patched boolits and Black powder used way undersized boolits that fit inside the rifling (in the bore) after being patched. The idea was that they would bump up from the shock wave the Black powder produces and fill the rifling when fired. These often also had undersize chamber necks due to this consideration ( paper patched boolits with small diameters) - like the 38-55 often is still made today.

I didn't see your chamber casts when I wrote this above. From the pictures, it looks like your freebore is almost the same diameter as the chamber neck area is (european tapered freebore). Also it appears that the chamber area is just a hair shorter than your brass is, so your assessment was right, the cases only fit when crimped. This cahmber would then be sizing your boolits when they fired. So, shorten your brass some, seat the boolits out against the rifling, and maybe your accuracy will improve some. What diameter is the freebore? You could, if you wanted, ream out the chamber to remove the freebore, and go to longer brass, but with accuracy as good as you're getting, I'd guess that the freebore isn't causing much distortion of the boolit, and not do that.

[Buckshot]

............There are no bad issues with trimming to fit the chamber, and that's what they SHOULD do anyway. Fit the chamber, that is. That's one of the problems with getting a .577 Snider to shoot. Thier chambers were cut for the old Boxer foil cartridge. Using those and with BP fouling in mind, the chambers for use with today's drawn brass is a bit, "Casual" shall we say :-) With a land diameter of .577", the cartridge was loaded with a Minie' of .564" OD.

..............Buckshot

[juanvaldez]

On the casting...measuring the diameter at the case neck I get .524" just after the case neck ends and before the rifling begins I get .516" I slugged the bore and get .508-.509" My bullets are sized to .510". The freebore just seems taper into the rifling. Is this normal? Is some of this the result of erosion of the throat on a 130+ year old gun?

Trim length on the brass I was using was 1.720" I measure a chamber of 1.695" on the casting but it is difficult to tell because of the tapered free-bore.

I guess my main concern was safety with this old gun. As I mentioned accuracy is phenomenal and very consistent. I've shot a couple cloverleafs and am always in 2-3 inches. It seems the limiting factor is the nut behind the wheel. I haven't tried loading all the way out yet because I haven't really had a need to.

[Bigjohn]

Juan, Please bear with me; sometimes it is difficult trying to help someone, who has a problem such as your when there is such a large distance between us. I am a hands on problem solver and find it hard when I have to ask you to do all the things I would do automatically.

I use all of natures supplied measuring equipment first then resort to the manmade equipment.

Can you check the following measurements for me and post the results?

A cartridge case Fired in this chamber at the case mouth =

The chamber casing at the same point =

A cartridge case with a boolit seated as you have been seating them BUT no crimp =

A cartridge case with a boolit seated as you have been seating them, crimped =

Some of the information you have posted indicates where I think your problem might be and I need these measurements to confirm or discount it.

Also can you post the length of your cases?

With out personal inspection the last photo of the chamber casting shows a bulge on the right hand side at approximately the case mouth position. Is there a bulge there or is it an effect of the lighting?

John

[Bigjohn]

On the casting...measuring the diameter at the case neck I get .524" just after the case neck ends and before the rifling begins I get .516" I slugged the bore and get .508-.509" My bullets are sized to .510". The freebore just seems taper into the rifling. Is this normal? Is some of this the result of erosion of the throat on a 130+ year old gun?

Trim length on the brass I was using was 1.720" I measure a chamber of 1.695" on the casting but it is difficult to tell because of the tapered free-bore.

I guess my main concern was safety with this old gun. As I mentioned accuracy is phenomenal and very consistent. I've shot a couple cloverleafs and am always in 2-3 inches. It seems the limiting factor is the nut behind the wheel. I haven't tried loading all the way out yet because I haven't really had a need to.

Juan, The idiosyncies of the computors and when they refresh the info they have. :brokenima

Two things out of this ammended posting; take three cases from your supply and trim them back to 1.700" and try them (load and shoot). If they still require a crimp to chamber properly then try them at 1.690".

Regarding the chamber; no it is not unusual; the .310 Cadet Rifles have a simular chamber.

Let us know how you go,
John.

[juanvaldez]

Fired cartridge at case mouth = .530" this case is slightly shorter, it is formed brass from baco trimmed to 1.708. Mine were trimmed to 1.720
Same point on casting = .527-.530" seems slightly out of round

With crimp = .526"

With no crimp= no cases left all loaded with crimp

Bulge is just the lighting not really there.

Starting to make sense now. The baco case trim length is definately closer to what I need

[Buckshot]

On the casting...measuring the diameter at the case neck I get .524" just after the case neck ends and before the rifling begins I get .516" I slugged the bore and get .508-.509" the freebore just seems taper into the rifling. Is this normal? Is some of this the result of erosion of the throat on a 130+ year old gun?

..............Seems just fine to me. You have to remember that back when they were making these things it was all new. There just wasn't years of previous work done with cartridges. Those guys weren't dummies and I'm sure they had some pretty good idea of what would deliver the best accuracy. However, bear in mind that these were military rifles and the only propellant was BP. The rifles were made to be reliable shooters first of all.

Gilt edged accuracy would have been desireable also, but if you develop a rifle that is match grade for 5 rounds and then you can't load it, you'll have some pissed off soldaten. I'm reminded of the Ross rifle in WW1 (superbly made, and very accurate) and also it seems some of Custer's troopers had some problems (with copper cases/fouling).

http://www.fototime.com/D64F7C66B9D4C78/standard.jpg http://www.fototime.com/A54FEE2E10D6415/standard.jpg

Check out THIS chamber cast!:veryconfu LEFT PHOTOThere is ZERO neck area. It's from a 1874 Comblain carbine made for the Brazilian government. It was made and delivered as one of the last batch in 1892. The cartridge was labeled as the 11.2x42R, and the rifles originally took a foil constructed case like the British Snider and 577-450. RIGHT photo Here are a couple 'Mangled to shape' altered 32 ga brass shotshells I used to shoot the carbine. I probably used 5-6 different dies, from 45 Colt to .43 Spanish to get them to the point where they'd chamber.

It's quite obvious that the neck (with rather a blind eye to any uniformity) will blow out and disappear upon firing. I've since made up some dies to form the brass, BELOW:

http://www.fototime.com/FEB48295FDD2804/standard.jpghttp://www.fototime.com/7C6776752B29618/standard.jpg

The dies were made from some front shock strut rods from an '87 Chevy Celebrity. One the right are the 3 stages of forming. The size die still sizes part of the case body a bit too much and it could be larger in OD. However it is a LOT faster then trying to swap out 5 or 6 dies and end up with something that is REALLY not right, and darn ugly to boot! So far these have been fired maybe 5 times apiece and are still trooping along.

http://www.fototime.com/8F2D7613C6820E4/standard.jpg

This was the carbine's 2nd range outing. This was at 50 yards, and except for the load of Blue Dot were all 10 shot groups. I used some of the Blue Dot loads to get on the paper. It sure liked SR4759, didn't it? :drinks: At the chamber end the grooves are .465" and the lands are .433". At the muzzle the groove is .451" and the lands remain the same, so it has a progressively shallower groove.

http://www.fototime.com/A28505379A30A69/standard.jpg

Here's the little rascal. One final oddity is the twist, considering it's age. Today, 45 cal rifles sport a quick twist of 16 - 18" to help stabilize the long heavy lead boolits for long range shooting. Since this was a carbine and utilized an abbreviated cartridge (like the Trapdoor's rifle and carbine ammo) I suspect the boolit probably weighed well less then 400 grains. However they gave this carbine a 16" twist :shock:

For the shooting above I used a Group Buy 45 cal FN slug weighing 353 grs in WW alloy, fired unsized at .460". Considering the chamber shape, the brass I was using, the undersized boolit, 209 shotshell primed brass (to replace the Berdan primer) I was tickled to have the boolits even HIT the target let alone want to group.

..................Buckshot

[Bigjohn]

In the era which your rifle was built, the Quality Control (QC) was not up to what it is today (tho sometimes I think we have slipped back a bit). Something like a chamber reamer was difficult to mass produce without variations. The factories even had them re-sharpened until they were cutting chambers at the low end of their tolerences. The same applied to barrel reamers and riflers; hence the variations we see.

With regard the age of the rifle, we all should hope to be in as good a condition as it is when we reach 130+, we just need to watch carefully what we feed it in it's ammunition.

I know this may sound like a silly question but, you are turning the case mouth flare back flat along the boolit on the uncrimped rounds?

In the standards of the day 1.730" case length would be about the maximum a chamber should accept. I you are getting a reading of 1.695"; it indicates to me that you need to trim a little off your cases. But just three for now, no point in doing them all at this time.

John

[juanvaldez]

The 4759 is definately your powder for that one. Very nice!! Am heading out to experiment with shorter brass tommorow. Will try and post pics if she performs well in accuracy. Always regret posting groups sizes then having to live up to em. Here's hopin. Thanks for all you help, this was a very frustrating problem but I think I see the direction I need to go.

Yes getting rid of the flare.

Cheers

[juanvaldez]

In the era which your rifle was built, the Quality Control (QC) was not up to what it is today (tho sometimes I think we have slipped back a bit). Something like a chamber reamer was difficult to mass produce without variations. The factories even had them re-sharpened until they were cutting chambers at the low end of their tolerences. The same applied to barrel reamers and riflers; hence the variations we see.

John


This gun has a few oddities. The rim of a 50/70 brass fits without trimming. Unheard of from my reading. The bore is 3-5 thous smaller then others I have compared to.

[Bigjohn]

Good luck and good shooting;

John

[Blammer]

brass is too long