carcano & cruise missile

[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.



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.