carcano & cruise missile

[bkbville]

I cast up some of these "cruise missiles" this morning (just got the Midsouth package yesterday) - they dropped .270 and around 175gn WW. I hand fit gas checks, and pan lubed in NRA formula.

I loaded them over 15 grain of 2400, and went to the range with a Vetterli, which is gain twist like the M91's.

The results I could almost call a group, but all the bullets went through sideways. Clearly a stability problem.

Anyone have wisdom or suggestions on this?

[jonk]

I've had the same issue with the same bullet and same load. I'm thinking that you may need (as do I) to UP the velocity..... Hmmmm..... sounds like a good project for the weekend.

[SierraWhiskeyMC]

What is the length of the boolits?

Do you know what the barrel twist rate is as the muzzle?

[geargnasher]

Ask 45 2.1, Buckshot, or a few others, they'll tell ya!

Gear

[bkbville]

The Cruise Missile is 1.256" long; at .270 caliber applying Greenhill's formula I come up with 1:8.7 as optimal twist.

Italian issue carcano bullets are 1.19" and 160grain. This would work to 1:9.

That includes the whole length of the bullet, olgive and all.

I read the Carcano M91 gain-twist starts 1:19 at the breech and ends 1:8 at the muzzle. My assumption is this is the same, but I can't accurately measure the gain twist using a cleaning rod.

So, none of this looks out of scope. In fact there are a few notes in the forum about folks getting this mould for the Carcano.

My thinking is I will try a more powerful charge of 2400, as per Jonk. (Jonk, let us know if got to this.)

I'll also try a slower burning powder, maybe 4895, with the idea of a more steady pressure through the tighter twist. It's suggest with the Vetterli to not use high-pressure loads, so I am limited in how far I can take that.

I've gathered bits and pieces of the RPM theory, but haven't found a post that explains it fully, so it's like listening into someone elses conversation.

I'd like to hear from 45 2.1 or Buckshot on their thoughts?

[Buckshot]

................Did you say what model Carcano you were using? The M91/24 carbines were made by shortening the 1891's so the barrel lost the fastest part of the twist.

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

[bkbville]

It's a Vetterli 70/87/15, full length barrel.

Definitely a big difference in the twist from the breech to the bore - very visably noticable.

Given the lack of detailed information (at least in English) on the Vetterli, I'm assuming the gain twist rates of the M91 barrel applies to the Vetterli liners for the same cartridge.

[StarMetal]

http://translate.google.com/translate?hl=en&sl=it&u=http://www.andreaturchi.org/vetterli70-87-15.html&ei=aZjSSpiVFY2xtgefjM2DBA&sa=X&oi=translate&resnum=6&ct=result&ved=0CBcQ7gEwBTgK&prev=/search%3Fq%3DVetterli%2B70/87/15%26hl%3Den%26sa%3DN%26start%3D10

Joe

[SierraWhiskeyMC]

I plugged some numbers into Don Miller's stability calculation Excel spreadsheet, available for download from this page:
http://accurateshooter.wordpress.com/2008/06/03/calculating-bullet-rpm-spin-rates-and-stability/

Caliber: 0.263 Inches
Bullet Weight: 175 Grains
Bullet Length: 1.256 Inches
Barrel Twist: 9 Inches/turn
Muzzle velocity: 1200 fps
Temperature: 20 degrees Fahrenheit (59 is standard)
Pressure: 29.92 inches of mercury (29.92 is standard)

Sg = 1.51 (needs to be 1.5 or higher to be fully stabilized)
RPM = 96000

I have zero experience with those rifles. However, I think that the groove diameter is supposed to be around .264 maximum. Isn't the bore diameter supposed to be around .256"? In that case, it would be reasonable to re-do the stability calculations using .260", the average of the two.

Temperature and altitude also have a large effect on stability. Rounds stable at high altitudes and/or temperature can become unstable at lower altitudes/temperatures; it's a function of air density.

I have Lyman's 45th edition reloading guide. It suggests that there are wide variations in groove diameters which exist in these surplus military rifles, we suggest that you proceed with caution. Slug your bore to determine the correct bullet diameter for your rifle. If your groove diameter is larger than .264", you could experience gas blow-by when using the listed starting loads with the standard bullet size. They also suggest using cast bullets sized to the exact groove diameter of your particular rifle.

The heaviest J-word bullet they have load data for is 160 grains.
The heaviest boolit is 143 gr Lyman #266469 w/GC; it's a Loverin RN design w/ 6 loob grooves; comes out of the mold @ .267"

I'm just guessing that you were getting around 1200 fps muzzle velocity using 15gr of 2400 but I think using more could be risky.

As Buckshot says, the carbines were made by lopping off the barrels.

Even if it isn't a carbine, it's possible that someone shortened the barrel to get rid of a worn bore at the muzzle.

Arguably, the safest thing to do would be to try out a shorter boolit.

H4895 is safe to use down to 60% of maximum loads, according to Hodgdon's website. I don't have any load data for a lead boolit that heavy. In any case, I don't think I'd go above 31gr of H4895 at that boolit weight without a chrony.

[bkbville]

I checked and the barrel is not cut - 33-1/2" - which is the correct length for the Vetterli Carcano.

I did Chrono these cruise missile shots - Avg 1542 fps (1515-1566 fps). This would work to about 139K RPM. Using the spreadsheet above Sg=2.33 (Seems like they should be stabalized.)

For reference I also shot PRVI .264 FMJ 139 gn. These were stable and about 100fps faster, but did not group well: I think from being undersized. From examing a squib I found they are not touching the bore - which is what I expected from everything Carcano folks tell me - these bores are typiclly .268 or larger.

160gn is the weight of the Italian military round used for Carcano's; 175 doesn't seem that far off.

The Cruise Missile ("6.5 Swed") is mentioned herein by several posts for use in Carcanos with "good results". In fact, I shied away from the the Lyman Moulds on what I've read in here about those dropping narrow for carcanos.

[StarMetal]

It's not the weight of the bullet you want to look at, it's the length. That cruise missile is very long. It's longer then the military 160 for the caliber.

As an aside I have a 260 Remington. It was playing with some cruise missile that a former member Oldfeller had given me. I was seeing where they would destabilize in my rifle and found it to be below 1400 fps. My twist is a 9.

I do believe you may be better served with the Kurtz group buy bullet or the Lyman 266469 if you can find a mould that drops them fat enough. The Kurtz will but the newer Lyman's won't.

Joe

[TAWILDCATT]

I think you need more speed but you may need another powder.I use red dot in all my military but not yet in 6.5 jap or carcano.as I think I may have to drop the charge some for those two.
lyman lists 18 grs 2400 for 1783 for 143 gr bullet.castbullet lyman
in the jap they give for 4198 26 gr for 143 gr " at 2159 castbullet lyman
in 6.5 jap =156 bullet=27..3 gr of 4064 at 1985=33,200 NRA hand book

[SierraWhiskeyMC]

OK, I'm not sure what to suggest other than trying to slug your barrel to find out how worn it is at various points. I'm suspecting that the muzzle is worn so much from cleaning that you have more like a blunderbuss than a rifle. My hunch is that the boolit is disengaging from the rifling as it gets near the muzzle.

I'm moderately surprised that you're clocking that 175gr round at 1,542fps; the starting load for the 143gr boolit in Lyman #45 is 15.0gr 2400 @ 1,545fps, max 18gr @ 1763.

In other words, you're getting the same velocity for a 175gr boolit as Lyman reported with a 143gr boolit with the exact same powder charge. The difference is that Lyman used a 21" barrel on an Italian service carbine with gain twist.

That would also explain why they used lighter (shorter) boolits in their loads.

[bary]

Would the Universal 16/2400 load be a good place to start with an M91?

[303Guy]

Have you checked the straightness of the boolits themselves? I have found long boolits that were bent inside the mold! I have heard from these forums that a boolit can bend after a while after being cast. Easy to check. Just roll them on a flat surface.

Oh, a projectile needs more twist rate closer to mac 1, so below 1400 it would need more but below 1000 or so, a little less - to do with air flow over the projectile as it approaches the sound barrier. (A projectile that is slowing down already has a higher spin when it slows to mac 1).

[bkbville]

303Guy - I took a dozen or so of these boolits and rolled them on table - they roll fine and show no day light. I water-dropped these into a towel drapped in a bucket of H2O.

SierraWiskey - I agree - the velocity seems high - higher than I expected for the heavy 175gn boolit given 16gn 2400 on the 139 FMJ gave me 1610fps (1581-1665fps)

Perhaps the gas checks came loose, effecting the chrono, but I didn't find any (I actually looked because this is the first time I hand seated GC's.)

I used CCI mil LR primers though - and I understand these to be magnum, or at least hot. As I had a couple of rounds that needed to be struck twice, I'll use my dwindling supply of Win LR primers.

Later I'll attempt to re-verify the velocity for the 15gn A2400.

First though I've already loaded 22.5-25gn H4895 with hopes slower burn gives these pressure as they run the tighter twist on the long barrel.

As for the rifling - its distinct throughout - some muzzle ware, but not terrible. This is a decent bore overall, no visable pitting, and I used electrolosis to clean out a lot of copper.

TAWILDCAT - red dot goes the other way

[dromia]

You really need to slug your barrel. Pust a soft lead slug through to find the smallest bore/ groove diameter and them slug the muzzle.

If the muzzle slugs larger than another point on the barrel then thats your problem.

If you slug then you'll know either way.

Its the first thing anyone should do when shooting cast boolits in a particular gun, it will save a lot of grief, wellbeing, powder and components.

[semtav]

what is the consensus on gas checks? 264 or use 277. I need to order some and wonder if the 264 will defeat the purpose of the bigger 268 or 269 bullet?
thanks

[leadhead]

I use the cruise bullet in just about every type carcano made and they
shoot just fine in all of them. Even the 91/24 that has been cut down
from M91's will shoot half dollar groups at 50 yds. I settled on 14.5 to
15 grs of 2400. I size in a .270 dia die.
Denny

[bkbville]

You really need to slug your barrel. Pust a soft lead slug through to find the smallest bore/ groove diameter and them slug the muzzle.

If the muzzle slugs larger than another point on the barrel then thats your problem.

If you slug then you'll know either way.

Its the first thing anyone should do when shooting cast boolits in a particular gun, it will save a lot of grief, wellbeing, powder and components.

Dromia - I've sort of been down this road.

When I try to slug this rifle the progressive twist takes it's toll on the engraving - the changing pitch removing the engraving - so by the time I get the slug out the other end I have no indication of the actual groove side.

I have to wonder how that works on an actual shot.

Slugging the muzzle (if I recall correctly - I'll have to dig up the slug to verify) I get a tight .266 on the grooves, and .258 on the lands. So, I don't think it's shot out.

None the less I'll give slugging it another try.

BTW: the H4895 loads - both keyholed - 24.2 at 1614fps and 25.2 at 1853fps (velocity based on only 3 shots each)

[Buckshot]

[QUOTE=bkbville;691802]Dromia - I've sort of been down this road.

When I try to slug this rifle the progressive twist takes it's toll on the engraving - the changing pitch removing the engraving - so by the time I get the slug out the other end I have no indication of the actual groove side.

QUOTE]

..............JUst drive a slug part way into the breech. Enough to guarantee engraving. Then drive one into the muzzle.

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

[bkbville]

I gave 9.0 and 11.0 gn of Unique a try - figuring if going faster wasn't helping I'd try slower.

A couple of the 11.0 gn were not stable, but most were.

All (7) of the 9.0 gn Unique were stable and even grouped reasonably well. These chrono'ed at 1235 fps. I'll work up more of these 9.0 gn and check them out to 100yds, then work up a load in that range.

I'll try and slug it tonight.

[Shooter6br]

Shoot my 6.5 Jap with the missle. I used 4759 and Universal Clays 14g and 9.2 respectively.The UC had flyers (goood at 7.5 G) The 4759 shot well The rifle has a 2.5 power scope. It always shot "minute of Deer" I think 47 59 is the powder for me 13 to 15grain. Velocity with 14 g out of a 16 in barrel is estabmated to be 1550 fps

[Boz330]

Shot my Carcano yesterday with the Cruise Missile. Tried 18 and 20gr of 4759. The 18 gr load had 2 out of 6 hit the target sideways and all holes were oval. 20gr had 4 of 6 hit sideways, the other 2 went away and this was on a 4'X4' backboard. Obviously more powder is the wrong way.
I'll have to try Shooter6br's load and see what happens. 4759 has become my go to cast boolit powder and I was was really bummed out by the first results. The up side is that the fixed sights seemed dead on POA at a 100yd for the boolits that went through semi-straight.

Bob

[bkbville]

Per Buckshot's recommendation I slugged the Vetterli Carcano muzzle and breech-end:

Muzzle: .265-.266
Lead: .269-.270

I also passed a slightly harder slug through the length at .268; more of the engraving remained than in my previous attempts.

Boz330 - OK - thought I was the only one seeing this.

[dromia]

Try sizing to .270", remember to only change one thing at a time because if you get success you won't know what to attribute it to.

Good luck.

I've just got a really nice 91/28 in and was looking forward to playing with it but it seems I have a customer for it already.

[MilSurpFan]

bkbville,

Thanks for the report on the light Unique loads. I was having the same troubles with my 91/38 Cav. Carbine and 2400, but now I have something else to try.

If I can get repeatable 2" groups at 50 yards, I'll be happy. I get decent results with the jacketed 160gr Hornadys, but the cost makes plinking with the Carcanos less fun than they could be.

[closey]

Try sizing to .270", remember to only change one thing at a time because if you get success you won't know what to attribute it to.

Good luck.

I've just got a really nice 91/28 in and was looking forward to playing with it but it seems I have a customer for it already.

Looking forward to seeing that really nice 91/28.

Closey;-)

[bkbville]

[QUOTE=dromia;697248]Try sizing to .270", remember to only change one thing at a time because if you get success you won't know what to attribute it to.
QUOTE]


Dromia - do mean size them even if they drop .270?

[dromia]

If thats what they are dropping leave them at that.

[Boz330]

OK I took the Carcano out yesterday again. Tried 13gr of 4759 and 12gr of 2400. The gun is really trying to group with these loads but the boolits are still unstable. The powder charge is REALLY small, maybe 1/4 case density. I hate to go lighter but slower seems to be the sweet spot. Does anybody see any problems with going lighter. My other thought is maybe trying 5744 for more case density but I don't have a clue where to start. Any thoughts?????? The Carcano action while being bad mouthed as being weak has shown itself to be pretty strong, but I don't want to be the test case.

Bob

[StarMetal]

OK I took the Carcano out yesterday again. Tried 13gr of 4759 and 12gr of 2400. The gun is really trying to group with these loads but the boolits are still unstable.That doesn't make sense The powder charge is REALLY small, maybe 1/4 case density. I hate to go lighter but slower seems to be the sweet spot. Does anybody see any problems with going lighter. My other thought is maybe trying 5744 for more case density but I don't have a clue where to start. Any thoughts?????? The Carcano action while being bad mouthed as being weak has shown itself to be pretty strong, but I don't want to be the test case.

Bob

Bob,

That's like saying "I got a couple good punches in on Mohammad Ali but he still knocked me out". I guess there are degrees of unstableness huh?:roll:

Joe

[Boz330]

Joe, I agree but the holes are oval and grouping in the 3 to 5 inch area at a 100yds. At 16gr 4759 some of them are hitting sideways.

Bob

[StarMetal]

Joe, I agree but the holes are oval and grouping in the 3 to 5 inch area at a 100yds. At 16gr 4759 some of them are hitting sideways.

Bob

Bob,

Try some Unique.

Joe

[Crash_Corrigan]

Drop the powder charge a couple of grains and after you charge the case fill the remainder with some dacron. This will give you a consistent and even burn of the powder and also increase the pressure some with the added weight.

I was having problems with less than full cases of powder when loading for my Garand. Larry Gibson gave me some great advise regarding dacron tufts and such and my results are excellent.

[StarMetal]

Drop the powder charge a couple of grains and after you charge the case fill the remainder with some dacron. This will give you a consistent and even burn of the powder and also increase the pressure some with the added weight.

I was having problems with less than full cases of powder when loading for my Garand. Larry Gibson gave me some great advise regarding dacron tufts and such and my results are excellent.

Crash,

Well I'm glad you got help with your loads and they are shooting better. Since 45 2.1 taught me "the technique" my Dacron is gathering quite an accumulation of dust in the shop. I don't use it anymore.

Joe

[semtav]

I don't know if this will translate over to the heavier Cruise Missile, but I've gotten excellent results so far with 14 gr IMR 4227 and the Kurtz bullet.

I think my cruise missile mold is on the way, so I'll try same load with it for starters.

[Boz330]

Crash,

Well I'm glad you got help with your loads and they are shooting better. Since 45 2.1 taught me "the technique" my Dacron is gathering quite an accumulation of dust in the shop. I don't use it anymore.

Joe

So Joe, share the secret of the technique!!!!!
I tried 8gr of Unique and that was in the same area or slightly larger as the 4759 and 2400 as far as group size and the holes were oval as well. I'm thinking that if the groups are in the 3 MOA area with wallowing boolits this gun could shine with the right powder combination.
I have used Dacron in the past and never had a problem but having heard of potential problems, I am more than a little leery. I have also used Kapok as a filler but the accuracy always seemed to suffer.

Bob

[bkbville]

I had the Vetterli out again today and shot about a 3" group @50y of 9 shots; the 10th was about 4"-5" higher and *sideways* - all through a chrono and that didn't show anything odd any shot.

(BTW: 1251fps avg for 9.4gn Unique)

I'm frustrated with the CM. :(

[Boz330]

I had the Vetterli out again today and shot about a 3" group @50y of 9 shots; the 10th was about 4"-5" higher and *sideways* - all through a chrono and that didn't show anything odd any shot.

(BTW: 1251fps avg for 9.4gn Unique)

I'm frustrated with the CM. :(

Join the club!!!!!!!!!!

Bob

[atr]

Bob,,,,
I have a Mauser 93 which is tumbling the boolits and my best "grouping" is something like
12"......I checked the free-bore and it was almost 7/8 of an inch,,,which means that my boolit is having to jump this gap before it hits the rifling. I think in my case this excessive free-bore is what is causing the tumbling and inaccuracy. Just a thought to pass our way.

[JIMinPHX]

Are you able to recover the fired boolits intact? If so, does the rifling engraving look to be torn off the boolit?

You might want to try a softer boolit, that will more easily bend as the twist rate changes going down the barrel.

Once you have a gas check on the back of the boolit, you really don't need much hardness on the rest of it, especially for something with as much bearing surface as the boolit you have. I would try something around 10 or 12 BNH & see what happens.

[Boz330]

I don't have an easy way to catch a boolit, but the brinell should be in that area. The mix is ACWWs. I have a bunch of different loads put together, just need a break in the bad weather to give them a try.

Bob

[swheeler]

I had the Vetterli out again today and shot about a 3" group @50y of 9 shots; the 10th was about 4"-5" higher and *sideways* - all through a chrono and that didn't show anything odd any shot.

(BTW: 1251fps avg for 9.4gn Unique)

I'm frustrated with the CM. :(

You have not said what dies you are loading with? I believe most manufactures use an expander for .264 bullets, Lee uses one for .268 bullets. Even my 6.5x55 dies from Lee needed an expander rod for the 6.5 Carcano to keep boolits seating concentric(this is what your 10th shot flier sounds like to me, or an undersized bullet that slipped through inspection) A std twist Carcano will shoot these loads just fine-91/41

170CM-23.0 I4895+DAC@2.910"-1754FPS and 2"@ 50 yds for 6 rounds
170 CM-16.0 A 5744 @ 2.895"- 1495fps- 1.3" A 50 yds for 5 shots

As for Unique(this is old Hercules) the groups grew to almost double from 10 to 11 grs, 10- 1317fps and 1.9", 11-1404 fps and 3.5" and 10 was most accurate from 9-12.
I also tried the real slow mil-surps(860-872-T5020-5070-870) some with PSB some without, mostly shotgun patterns so far.
I have been using a 270 mold of about 125 grains more recently. Your ten shot group with 9 in and 1 out tells me that one round had something wrong with it, let your bullets age up before lube and sizing. .02

[Boz330]

Well got out in the 18* cold yesterday and tried out 8 different powders with the CM from the Carcano Carbine. The results were somewhat surprising, none of the holes were round but the closest to round was 16gr of 4198 with a 8"HX5.5"W group. The 2 best groups were with 5744, 3.25"H X 3.5"W, and 9.1 Of Trail Boss at 2.5"H X 3.25"W. Considering the sights I was pleased with the these groups. The other powders used had groups from 5" to almost 10" and these were all shot at 100yd.
I'm going to try increasing the powder on all of the above loads and see where that goes. I'm also going to try a case full of slow powder and see if that might be a direction to go. The powders that are giving the best case density seem to be what is shooting the best group, regardless of boolit stability. Doesn't make much sense does it????????
BTW all groups were 6 rounds since that is what the enblock clips hold.

Bob

[swheeler]

"The 2 best groups were with 5744, 3.25"H X 3.5"W"

Boz you don't say at what loading but that is 100 yd hunting accuracy by anyones book.

[bkbville]

Although the light Unique loads put the CM's in straight holes, the low speed hasn't been conducive to grouping, even at the 50yds I've been testing it at.

I've tried varous powders and fills to try and get these to stablize at a faster speed, but anything too fast (say 1300fps - I'd have to go over my notes for the actual numbers) and they keyhole.

Lacking 6.5 kurtz boolits, I took a dozen CM's and *cut* them down to just after the first lube ring, (making them PB), so they are around 145gr (from 175gr at full length.)

I loaded these up for about 1750fps, and I'm waiting for weather to test these (at the current rate, it may be a long wait.)

[Boz330]

"The 2 best groups were with 5744, 3.25"H X 3.5"W"

Boz you don't say at what loading but that is 100 yd hunting accuracy by anyones book.

I'm sorry Scot, it was 12gr of 5744. I upped that load to 14gr and 10gr on the Trail boss. I also loaded some AA8700 just to see what that does. Yes it is and it would probably do some horrific damage since the boolit would probably tumble as soon as it hit anything. I have other guns that I hunt with though and this is just a plinker and project so to speak. Cast in a 6.5 for deer is not something I have a lot of faith in. Especially in low velocity loads.
I had intentions of cutting some fence posts yesterday and then shooting the above loads, but after going out to get gas I decided that I would stay inside and cast and load, then watch some football. Even the dog didn't stay out long.
bk, how did you go about cutting those boolits down? Unique didn't work at all for me.

Bob

[twotoescharlie]

please be careful with the Italian vetterli. they have a black powder action and were bored and relined to 6.5 cal. doubt if they will handle hot loads.

TTC

[swheeler]

Bob; I've got Trail Boss too but haven't got around to trying it yet. I tried PSB filler with surplus ball(8700 speed or close) without much luck also. Looking at notes 16 gr 5744 was most accurate for me, by 17.0 grs -1600- groups were 3.5". I only shoot open sights at 50 yds, I've got a choice, see the sights or see the target, but not both. Now I do plug away at the gong with open sights sometimes, visions of M Quigley in my head! Scot

[bkbville]

Although the light Unique loads put the CM's in straight holes, the low speed hasn't been conducive to grouping, even at the 50yds I've been testing it at.

I've tried varous powders and fills to try and get these to stablize at a faster speed, but anything too fast (say 1300fps - I'd have to go over my notes for the actual numbers) and they keyhole.

Lacking 6.5 kurtz boolits, I took a dozen CM's and *cut* them down to just after the first lube ring, (making them PB), so they are around 145gr (from 175gr at full length.)

I loaded these up for about 1750fps, and I'm waiting for weather to test these (at the current rate, it may be a long wait.)

Last Friday I had time to get to the range with this experiment.

As a control group I shot 7 full length cruise missles (170gn) on 16.0 gn Alliant 2400 - they all keyholed and grouped wide - say > 6" at 50Y. These were avg 1580fps.

I then shot the cut-down cruise missles (about 145gn, no GC) - identical charge of A2400 - they went in straght - no keyhole, and also closer to POA - a good 4" lower, group about the same size. These were avg 1740fps.

I then shot an identical A2400 load with some 139gr FMJ's for a 3" group, closer again to POA. These were avg 1616fps.

I haven't made sense of it, but figured I'd report to folks - I keep seeing posts from folks shooting Cruise missles in various rifles and having them going sideways...

[geargnasher]

Last Friday I had time to get to the range with this experiment.

As a control group I shot 7 full length cruise missles (170gn) on 16.0 gn Alliant 2400 - they all keyholed and grouped wide - say > 6" at 50Y. These were avg 1580fps.

I then shot the cut-down cruise missles (about 145gn, no GC) - identical charge of A2400 - they went in straght - no keyhole, and also closer to POA - a good 4" lower, group about the same size. These were avg 1740fps.

I then shot an identical A2400 load with some 139gr FMJ's for a 3" group, closer again to POA. These were avg 1616fps.

I haven't made sense of it, but figured I'd report to folks - I keep seeing posts from folks shooting Cruise missles in various rifles and having them going sideways...

BK, if you like that shorter Cruise Missile, check out my post here http://castboolits.gunloads.com/showthread.php?t=73781, if you like the way the nose fits the gun you can chop the back off any length you want to have pb or gc remaining.

I've been trying to get my Swedish Mausers to shoot straight, and I'm having the same problems everyone has: Keyholing and "patterning" rather than grouping, also some really incredible fliers, off a 4x8 backstop at 25 yards happened twice. This is a sub MOA gun at 100 and 200 yards with good J-word handloads. I wish you luck with your quest, and I think you ought to keep a close eye on Larry Gibson's HV Swede tests in the special projects section, seems the "technique" Starmetal and .45 2.1 refer to is the careful use of an exact amount of a compacting, granular filler together with an undercharge of slow-for-cartridge, single-based powder. And benchrest fitting and loading techniques, too. Check out the "milk jug 300 yard swede" thread, about page 6 at 20/pg, 45 2.1 explains it for the swede pretty well.

Gear

[bkbville]

Geargnasher,

Thanks for the suggestions -

I didn't realize "the technique" was being revieled.

I'm currently hardening some of the full-length CM's to test the technique JiminNZ posted in his carcano thread.

But I may end-up modifying my mold as you did - if I can trust myself with a hacksaw (none of my shortened CM's had flat bases.)

[bkbville]

Finally, I got to the range to test hardened CM's (full-length).

I fired a control lot using an identical load (16.0 gn A2400) but with non-hardened 174gr Cruise Missles.

- The boolits were 10/10 unstable,
- as experienced before, (that's why I use control groups)
- 1580 fps.

I then fired the test group, 16.0 gn A2400 using "hardened" 174 Cruise Missles.

- These were 8/10 STABLE,
- 1562 fps,
- grouping 1-1/2" at 50yd (2 tumblers a bit out of this group)
- (not spectacular but I wasn't using the best benchrest technique.)

A third smaller batch - hardened CM's over 17.0gr A2400 were then tested.

- these were 5/5 unstable.
- 1637 fps
- wider group than even the control lot
- I suspect this is a bit hot for the Vetterli anyway.

Notes:

I'm refering to the first batch as "non-hardened" when in fact I did water-drop these when cast. I don't have the best tempo with this mould, so possibly they just don't get dropped fast enough to adequately harden.

Additionally, I had temperature issues with my oven, so I probably didn't leave the "hardened" boolits in much more than 15 minutes before quenching - perhaps that's why I had 2 tumble.

These were hardened 4 weeks ago for age.

I have another batch where I more closely monitored the temp and soaked for 45 minutes - these are currently aging.

I'm postulating the softer boolits are pushed past the rifling without imparting sufficient spin, while the harder boolits tolerate the pressure and more adequately engrave. (I have no mechanism to recover the boolits to confirm.)

I think this effect is aggrevated by the progressive rifling of this rifle.

Where to go:

I'm thinking of trying some slower powders targeting the same velocity; I have 4895 and 4831.
(I had 1854 fps from 25.2 gn of H4895 - I would need to cut this down, just not sure where to start.)

The goal is to have a tighter group, fully stabalized, between 1500-1650fps.

Anyone have thoughts or suggestions?

[JeffinNZ]

bkbville: What is your definition of "unstable"?

The following is a 100m/110y target of mine pushing the CM out of my Carcano at 1750fps over 25gr H4350 topped with 8gr of BPI shotshell buffer.

http://img.photobucket.com/albums/v505/JeffinNZ/Shooting%20stuff/SC3522157010030214370.jpg

The high shot is when the light changed so I discounted. The other 5 measure less than 2 inches. You can see the yaw of the oval holes. I don't consider my bullets "unstable" however. Yes, the back end is swinging but if they were not stable they sure would not group like this.

I believe the Carcano throat requires a bullet of full length bearing eg: Loverin style with a flat nose. Maximum engagement of bullet in throat. Without this IMHO I feel the bullets with undersized noses (CM) can cant/skew in the throat on launch.

I size to .269 to match the throat. The bolt takes a little effort to turn down as the SNUG bullet engages in the throat. Thing is though that one the first driving band and half of the second band engage. The nose is floating and when the case neck 'gives' so is the back end of the bullet. I believe the engaging bands then become a pivot point and the bullet skews in the throat. On exit the nose trues up but the base swings out wide.

Bottom line is 2 MOA from a milsurp shooting cast bullets over iron sights is more than I could hope for so what is a little fish tailing?

[bkbville]

Jeff,

I'd take the skew; what kind of backing is the target on? maybe they are turning in deceleration on impact.

What I'm seeing is boat shapes right through the OSB backing, with random orientations. I wouldn't want to be hit by one...

All three lots above were seated to the same length; on the thrid grease groove from the bottom of the CM.

I previously did try seating them as far in as I could (they didn't fit in the mannlicher clip) but that didn't stabalize them.

My CM's drop about .002 larger than my bore so I haven't sized them.

Did you measure the 21 BHN?

(I guess I should really buy a hardness tester.)

[JeffinNZ]

Yeap, measured 21 BHN. Target is photocopy paper on layered paper backing.

[bkbville]

I returned to the range with my Vetterli carcano today.

After the last trip I wanted to try a slower powder. I intended on putting together a baseline with H4831SC, the slowest powder I have.

I loaded up oven-hardened 170gn cruise missles over 21gn of 4831SC. I (erroneously) came on this number looking at the H4895 number I had from last fall. I loaded half without fill, and added 1.0gr of poly to the other half. I have no 4831 experience, so I was being conservative.

Once done, I looked at further information and realized I probably really wanted to be around 28-30gr of 4831 to get 1500-ish FPS. (Hogdon has 1891 fps on 160 gr RN Jacketed behind 37.0 gr of H4831.)

Rather than tearing these apart I figured I shoot them. I didn't have time to load more with a larger charge.

I shot my control group - (16.0 gr A2400 over a hardened CM) 1.25" wide x 6" high - It had a lot of vertical stringing but they were no signs of instability. 1558 fps

I shot the H4831SC loads without fill - they were 6" low of POA and grouped 2-1/4" at 50yd, 1165fps.

The pleasent surprise was the same load with poly fill - still 6" low, but grouped 0.8" - all stable, and showing promise. 1185fps. The fill really helped tighten this load.

Note again, I'm not using much benchrest shooting technique here - I use my range bag as my rest, and I don't cool or clean between shots, so 2MOA looks good to me (of course then I start thinking 1MOA...)

I'll load some more with more 4831, targeting greater velocity (I'm looking around 1500fps) - hopefully the groups don't widen before then.

I'm also going to use poly fill on the A2400 load to see if that eliminates my vertical stringing with those.

If I can gather a few phone books I may attempt boolit recovery of the instable load to see if cutting is the cause, or if seems to mush the rifling on the progressive barrel.

[Boz330]

By poly do you mean Dacron or the beads?
The vertical stringing sounds like velocity differences and I can see where that would be a problem with 4831 in light loads.
I have some Kapok and might give that a try as a filler.

Bob

[bkbville]

I used Dacron here, out of my guest room pillow.

The vertical stringing was with the A2400. About 1" wide and 6" high.

Up to now I've attributed it to projectile instability. With the oven hardened CM's the bullets fly straight, the group width tightened, and the vertical skew shows up more clearly.

The H4831-SC - even without filler - did not exhibit stringing. (And I was relaxed on measuring this powder compared to the A2400, where I trickled.)

I don't have much experience with 4831 but the other stick powders I use seem to work well with light loads, especially H4895.

[StarMetal]

I used Dacron here, out of my guest room pillow.

The vertical stringing was with the A2400. About 1" wide and 6" high.

Up to now I've attributed it to projectile instability. With the oven hardened CM's the bullets fly straight, the group width tightened, and the vertical skew shows up more clearly.

The H4831-SC - even without filler - did not exhibit stringing. (And I was relaxed on measuring this powder compared to the A2400, where I trickled.)

I don't have much experience with 4831 but the other stick powders I use seem to work well with light loads, especially H4895.

Is there a reason you have to use the CM? I can understand the velocity range you are wanting, but why not use a lighter shorter bullet?

[Boz330]

Is there a reason you have to use the CM? I can understand the velocity range you are wanting, but why not use a lighter shorter bullet?

Not sure about bkbville but it is the only thing with enough diameter for the Carcano. The current lot casts at .272. Mine is .269. The NEI boolits that I have from a mold I sold some time back are only .266.
I'm thinking of cutting my CM mold down and see how it does. It is pretty cheap so no loss if it doesn't work.

Bob

[StarMetal]

Not sure about bkbville but it is the only thing with enough diameter for the Carcano. The current lot casts at .272. Mine is .269. The NEI boolits that I have from a mold I sold some time back are only .266.
I'm thinking of cutting my CM mold down and see how it does. It is pretty cheap so no loss if it doesn't work.

Bob

Would .268 work for you Bob?

[bkbville]

Joe,

I went with the CM to fill the bore (its droping .270) (like Boz330)

I thought the 170 gr would be a little better to move this out to 500 yds.

I could not find a kurz mould, though it would have been my first choice - 145gr if I recall.

I didn't think I could beagle a lyman 226469 enough.

Back a page or so I hack-sawed a dozen CM's to 140 gr. These shot well.

I can't bring myself to shorten the mould - it seems like it would be difficult to cut straight.

Also, I hope to pick up a swede at some point. Then again, at .270 this is fat for a swede.

What's the deal with the CM? Older posts brag about it, newer posts are all keyhole...

[Boz330]

Joe, I just reread my post and it sounds like my mold is .269 but the barrel on my Carcano is .2685 to .269. The mold is .272 and I don't size them at all. To answer your question, I don't know if they would work. I would think that there might be some leading. The grooves on the Carcanos are pretty deep compared to other milsurps.

Bob

[StarMetal]

BaBores remake of the Kurtz drops a little over .268 with 50/50 alloy. That and the original Kurtz is what I'm shooting in the Swede and as you know the Swede has as deep or deeper rifling grooves then the Carcano and to boot a fast twist...although I'm not positive what the fast part of the Carcanos gain twist is. What I'm getting at is I've shot bullets not big enough in the Swede (then finally getting the right sizer and bullets) with no leading and I'm pushing them as your probably know. Most are just AC which is not a real hard bullet, some are water dropped.

If you have a bullet that just barely makes groove size, or slightly under, with the right powder, the right loading, if you whack it hard enough it will bump up and work. I know lot of things have to be right there, but it does work.

It certainly wouldn't hurt to try some of BaBores Kurtz and he remake of the 469 Lyman too.

[bkbville]

Sounds like a good idea but I don't see the kurtz on BaBores cast pics site - actually nothing in 6.5 - ??any idea on this??

IIRC the gain twist on the Carcano M91 Fucile barrel (and the vetterli barrel liners) starts 1:19 down to 1:8. (which Greenhill-wise works for a 170gr)

I can't push the Vetterli action too fast - it started out as a BP design. I even get concerned over 17gr of A2400.

I think what the hardening did was to prevent the gain twist from mushing the engraving.

My theory being by the time the (softer) boolit got to the 1:8 end of the barrel it was riding the lands, the rifling imparting no further spin; hence never achiving a stable rotational velocity. I haven't been able to do any bullet recovery to verify this.

[Boz330]

Sounds like a good idea but I don't see the kurtz on BaBores cast pics site - actually nothing in 6.5 - ??any idea on this??

IIRC the gain twist on the Carcano M91 Fucile barrel (and the vetterli barrel liners) starts 1:19 down to 1:8. (which Greenhill-wise works for a 170gr)

I can't push the Vetterli action too fast - it started out as a BP design. I even get concerned over 17gr of A2400.

I think what the hardening did was to prevent the gain twist from mushing the engraving.

My theory being by the time the (softer) boolit got to the 1:8 end of the barrel it was riding the lands, the rifling imparting no further spin; hence never achiving a stable rotational velocity. I haven't been able to do any bullet recovery to verify this.

I never thought of that. With the length of the driving section on the CM the gain twist could be stripping by the time it gets to the fast twist portion where as in the Swede the twist is constant all of the way. By going to a shorter driving section the change in twist rate is not quite as detrimental to the engagement.
I tried a 129gr boolit in my Swede years ago and it shot quite well, but it is a hunting rifle so I shoot jacketed in it. Actually I don't shoot it much anymore but it is a great rifle to break in young shooters to a high powered rifle and deer hunting. All of my deer hunting is done with a BPCR now. I just enjoy the challenge of doing it the old way, I guess because I'm old now.
bkbville if I get mine cut down anytime soon I'll send you a few to try. I have a milling machine here at the shop so it shouldn't be a big deal and the mold isn't that expensive.

Bob

[StarMetal]

Sounds like a good idea but I don't see the kurtz on BaBores cast pics site - actually nothing in 6.5 - ??any idea on this??

IIRC the gain twist on the Carcano M91 Fucile barrel (and the vetterli barrel liners) starts 1:19 down to 1:8. (which Greenhill-wise works for a 170gr)

I can't push the Vetterli action too fast - it started out as a BP design. I even get concerned over 17gr of A2400.

I think what the hardening did was to prevent the gain twist from mushing the engraving.

My theory being by the time the (softer) boolit got to the 1:8 end of the barrel it was riding the lands, the rifling imparting no further spin; hence never achiving a stable rotational velocity. I haven't been able to do any bullet recovery to verify this.

Send Babore a pm as he has both the remakes of group buy 6.5 Kurtz and the Lyman 266469. I have one of each.

[bkbville]

I never thought of that. With the length of the driving section on the CM the gain twist could be stripping by the time it gets to the fast twist portion where as in the Swede the twist is constant all of the way. By going to a shorter driving section the change in twist rate is not quite as detrimental to the engagement.

The shorter the bullet, the slower the turn required to stabalize - it's more the length of the bullet than the weight, IIRC the greenhill formula. So even if the shorter soft CM is being forced past the 1:8, it can still be stable.

Well, that's the theory...

[Boz330]

The shorter the bullet, the slower the turn required to stabalize - it's more the length of the bullet than the weight, IIRC the greenhill formula. So even if the shorter soft CM is being forced past the 1:8, it can still be stable.

Well, that's the theory...

I agree but why is the boolit not reaching the proper spin velocity for the length. That boolit should stabilize with the twist rate at the exit but it's not. A shorter engagement area and more bore riding section might have a better chance of getting the boolit up to the proper rotational velocity with out stripping. Maybe I'm wrong about this but it seems to make sense in my mind. By shortening the CM mold from the back you are working on both problems at the same time.
For me the Carcano is a fun project not a must do thing. I have as much in the reloading stuff as I paid for the rifle probably a little more.:shock: Somehow I just can't turn down a $60 rifle. And if all else fails I can unfold the bayonet and gig frogs with it.:lol:

Bob

[barnetmill]

How well does the rifle shoot with commercial ammo?
Many military rifles get damage about the end of the muzzle from cleaning. I would not think it would cause tumbling, more like inaccuracy. Another possibility is a bulge or ring in the barrel that might cause tumbling. Did you test this gun with a shorter bullet to prove that the barrel is good? Long thread so I did not read every post. You can detect a ring in the barrel with a tight patch on a cleaning rod. The barrel may also be badly corroded at the throat.

[bkbville]

Boz,

I'm saying that somewhere on the transition from 1:19 down to 1:8 the change in angle of the engraving (regardless of the length of engagement area) isn't tracked by a soft boolit - the engraving gets smoothed over.

A 1.26" CM wouldn't stabalize until it runs at least 1:8.5 twist.

When the alloy is soft and the pressure sufficient the engraving is gone before it reaches the final 1:8 section. It has no further grip on the changing gain. It's running at twist rate where it lost traction. It's not rotating fast enough to stabalize flight.

I lower the velocity of the longer "soft" CM to 1300fps and there isn't sufficient force to mush the engraving, so the long bullet tracks and runs the 1:8 terminal twist of the carcano. It's rotating fast enough and flight stabalizes.

A shorter 1.0" CM needs to run only 1:11 twist to stabalize.

The "soft" shorter CM doesn't need to run the 1:8 twist to stabalize. Even at the same 1650fps pressure it is already stable when it's engraving is mushed. Even if its riding lands with no grip it's already rotating fast enough to stabalize flight.

I harden the full length CM boolit and raise the pressure and velocity back to 1650fps. The harder boolit tracks the rifling and doesn't get mushed, keeps it's engraving, and runs the 1:8 twist. It rotates fast enough to stabalize in flight.

Of course, I could be completely wrong. But this is my attempt to make sense of the data and observations I have.

Boolit recovery would help here.


Barnetmill,

I've shot 140 gr "cut" cruise missles and Prvi 139gr FMJs. Both were stable.

The Prvi's were .264 as well - under groove size, but still grouped well.

The throat/barrel/crown are in good shape.

[Boz330]

We are thinking in the same vein. My boolits were ACWWs and the best groups were at slower velocity's. Just over 2MOA with 3MOA sights but they are fishtailing going through the target.
I have some Lino type or could water drop to see if that makes a difference after all it is the chase that's fun.
The barrel on my Carcano looks damn near new. It was late war production and appears to be a bring home although I don't know that for sure. Probably been in a closet for 50 years.

Bob

[Boz330]

Well tried a WW linotype mix yesterday in the Carcano to see if the harder boolit would take the rifling without stripping. These were hard enough that you could mark them with your finger nail but not actually scratch them. Didn't work either, not even a good shotgun pattern.
Next try will be cutting the mold down to see if a shorter boolit is the answer. After that the whole kit & caboodle goes up for sale.
Had another problem yesterday as well, the firing pin was striking weakly and I was getting failure to fire. When I checked protrusion it seemed sufficient. Anybody know how the bolt comes apart so I can clean it or maybe replace the spring.

Bob

[swheeler]

Well tried a WW linotype mix yesterday in the Carcano to see if the harder boolit would take the rifling without stripping. These were hard enough that you could mark them with your finger nail but not actually scratch them. Didn't work either, not even a good shotgun pattern.
Next try will be cutting the mold down to see if a shorter boolit is the answer. After that the whole kit & caboodle goes up for sale.
Had another problem yesterday as well, the firing pin was striking weakly and I was getting failure to fire. When I checked protrusion it seemed sufficient. Anybody know how the bolt comes apart so I can clean it or maybe replace the spring.

Bob

http://www.surplusrifle.com/carcano9138/boltdisassembly/index.asp- Bob go here, step by step with pictures.

[bkbville]

Boz,

Here are carcano bolt disassembly instructions:

M91/38:
http://www.surplusrifle.com/carcano9138/boltdisassembly/index.asp

M91/41
http://www.surplusrifle.com/carcano9141/boltdisassembly/index.asp

You mention yours was a late war production; is it progressive gain? I didn't think any past '41 or so were progressive gain.

Have you slugged it? (or tried factory in yours?)

This reminds me - I was talking to a guy at the range; a few years ago he had been shooting a carcano with poor results. He finally discovered it was 7.35; he was firing 6.5 ammo. (At least it wasn't the other way around.)

I tried to recover some boolits last week to see if I could figure out what gives with the keyholing.

I had 3 thick wet phone books; I thought at 1600fps three would be sufficient (about 8".) It wasn't. They passed right through and lodged deeply in the 4x4 target stand behind them.

I'm on the look out for a few more phone books.

[Boz330]

Boz,

Here are carcano bolt disassembly instructions:

M91/38:
http://www.surplusrifle.com/carcano9138/boltdisassembly/index.asp

M91/41
http://www.surplusrifle.com/carcano9141/boltdisassembly/index.asp

You mention yours was a late war production; is it progressive gain? I didn't think any past '41 or so were progressive gain.

Have you slugged it? (or tried factory in yours?)

This reminds me - I was talking to a guy at the range; a few years ago he had been shooting a carcano with poor results. He finally discovered it was 7.35; he was firing 6.5 ammo. (At least it wasn't the other way around.)

I tried to recover some boolits last week to see if I could figure out what gives with the keyholing.

I had 3 thick wet phone books; I thought at 1600fps three would be sufficient (about 8".) It wasn't. They passed right through and lodged deeply in the 4x4 target stand behind them.

I'm on the look out for a few more phone books.

Thanks for the links.
It is definitely a 6.5 and gain twist. You can really tell the difference in the twist looking from the different ends. It slugs at .269 and the lino mix boolits are .273, a little bigger than the WWs. I was hoping to find a boolit in the berm but no luck. I still think that the long driving area is stripping and cutting the boolit length will help. It sure can't hurt.
No I haven't tried any jacketed and don't really want to. I have lots of different 6.5 bullets in stock, all .264. One of my first HP rifles was a Vanguard in 264 Mag and also a Swede so I'm stocked well. In fact I probably have more 6.5 jacketed than anything else.

Bob