Need help interpreting target

[MilSurpFan]

Hi folks,

I've been lurking for about a year now and I decided to sign up.

I recently bought the Lee 6.5 170 gr. mould from Midsouth. I cast a few samples to try out in one of my Carcanos. I used Hornady gas checks seated by lightly pushing the bases into a RCBS .265 sizer. Unfortunately, the checks never did crimp tightly to the shank even when the band above the GC began to just touch the sizer. Not wanting to size the checks or bullet any further, I left them slightly loose (I could spin them on the base, but they would not pop off.).

Looking at the bullets I have not loaded, the shanks are slightly tapered with the base end @ .249" The gas checks are a hair above .270" unsized and I need the bullets to stay at the unsized diameter of .268. That only leaves me with .002" to crimp the check with.

I loaded up 20 samples in new Graf's cases. Lubed with Lee LLA and loaded over 13 gr. of 2400 I got the following results at 50 yds. (see pic)

I was shooting in 30 degree weather with 30+ mph wind gusts, so I didn't expect any great results, but I am puzzled by the impact holes on the target. It looks like the bullets punched nice round holes followed by something else that makes another impact but not so round. My first thought was the bullets are beginning to tumble, but the round "primary" holes make this seem unlikely. Such a long projectile should make a very pronounced oval hole if it is anything but straight, correct?

Is it possible that the gas checks are coming off close to 50 yards and making secondary holes in the target? If so, how should I go forward from here? Glue the checks on and call it a day, or hone the shank area on the mould to fit the gas checks better? The bullets cast at .268, so I don't want to size the entire bullet if I can get around it somehow.

Thanks,
MSF

[Shiloh]

Gas checks can and do come off of the slugs. It normally happens at shorter ranges but I suppose they could come anytime. I have seen chronographs peppered with dislodged gas checks, and have read on the gun boards about the digital screen being damaged by them.

Because yours aren't on real tight and are apparently not being swaged on by the bore,
I supposed that thats what could be scarring up the target, or they are starting to tumble. Have you slugged your bore to see what the actual bore size is??

Shiloh :castmine:

[mooman76]

I can't speak for myself but I have heard of some glueing on the checks. Another option would be soft checks or a filler instead of a gas check that would sort of act as a check. What you stated is true in the fact that gas checks do come off some times and another thing is the bullet you are useing is extreamly long my not be too stable for your gun as it was designed for the Swedish Mauser. I'm not saying it won't or isn't working for your rifle and from looks of the target it is working or at least at 50y.

[Whaump 'em]

I'm no expert but if the gas checks (even Lyman) won't crimp on I think your alloy is too soft, shrinking in the mold. What alloy are you using?
Try backing your targets with cardboard to see if you can stop a gascheck.
Lee Liquid Alox has been used by others to glue on the check.

[Thumbcocker]

Looks like a .268 sizer die is in you future.

[MilSurpFan]

Thanks for the help everybody.

I slugged the bore a while back and the groove is right at .267 The bullets as-cast are .268.

I'm not sure about the alloy I was using. My father gave me about 20 lbs of some mystery alloy that was already in Lyman ingots. It is very hard and the air-cooled bullets can barely be scratched with a thumbnail, and even then, it's more of a shiny spot than a dent or scratch. This batch of metal has worked well for the Lee 312 160 gr TL bullet in a variety of calibers.

I'm definitely getting a .268 or .269 sizer soon. I keep putting it off because I'll have to get it straight from Lee. I have a Swede too, so the .265 sizer will be put to good use soon.

It sounds like it is at least possible that the gas checks were causing the shadow impacts on the target. I'll try to glue the next batch on and see how they work in more ideal conditions and at longer ranges. The day I tested this load the wind was blowing hard enough to knock over the trash can at the range and send the lid nearly 100 yards into the corn field behind the firing line.

[405]

Actually that target looks like unstable bullets to me. Not tumbling but yawing around the bullet axis. It seems that if the GCs were coming off they wouldn't all come off at the same range and follow the bullet like that. If they were coming off seems like once in a while one might hit the target somewhere in a random fashion. Looking at Carcano specs seems originals may have a gain twist or about a 1-8" designed for the 160 gr. JBullet at 2500 +/- fps. If your target velocity/pressure is 1400-1500 fps I'd sure try an alloy down around 12-15BHN or maybe a little harder, with a GC bullet sized to .268-269 in the 120-140 grain range. Ohhh the challenges of getting the oldsters to behave:mrgreen:

[garandsrus]

MilSurpFan,

I would suggest shooting a few boolits without the gas check to see what the target looks like...

John

[405]

I posted earlier that it looked like unstable bullets yawing around the axis. I really studied the photo more closely on a clearer screen and now may have to say not so sure. It does look like the bullets are entering the paper in a stable attitude but something else is going on. Still doubt the GCs are coming off all at the same range and following the bullets in. Almost looks like a piece of the bullet base or part of the GC, still attached to the bullet, is making that extra impression in the paper. I've seen all sorts of different debris associated with bullets holes in targets like bits of lube or particles of lead that are spewing out, pieces of wad at shorter ranges, etc, even the super high vel molten lead comet tail..... but nothing like what shows in the photo. It would really be interesting to find out for sure! Anyway, you might still try a shorter, GCd bullet sized to correct diameter at maybe a slightly softer BHN and at a modest pressure and velocity.

[Nelsdou44]

MilSurpFan,

I've shot the "Cruise Missile" through my Carcano with fairly good results w/o gas checks and 10 grains of Unique. I have the M91/38 short rifle with approximately 8 1/2 standard twist (not gain twist). Next step for me is to cast some more, gas-check w/ Lee sizer and heat treat. Just got my sizer from Lee; took about three weeks on a phone order.

My cartridge OAL is limited by magazine length, so the the GC ends up a bit below the case neck. I'd recommend having the GCs crimped on securely.

Nels

[Buckshot]

................I'm sure 405 had it right the first time. Your slugs are yawing.
What model Carcano are you shooting?
If you have fired jacketed in it how did they do?
Since you've slugged the barrel, did you also slug the throat?
It's a very long boolit, but does it engrave in your rifle?

I just went out and miked the ones I have and they're cast at 15.4 bhn. They measure .267". If your alloy is close to linotype then mine at .267" with a 15 bhn very well could drop one at or close to .268" with a similar alloy as what you're using.

If we knew the throat ID and where that slug engraves I very well might have some 6.5mm slugs you could try to see what happens by fitting the throat.

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

[MilSurpFan]

The rifle is a 91/38 Cavalry Carbine with the folding bayonet. It performs well with the Hornady 160 gr. .268 jacketed bullets, stays around 3-4" at 100 yards.

I haven't slugged the throat yet. I did seat the bullets out until they began to engrave. The throat is very long on this one and I had to seat the bullets about 1/4" in the neck. I single-loaded them by placing the case on the follower arm, then using a wood dowel to push the rim under the extractor. Very slow going, but gentle on the bullets.

I will try shooting a few with glued on checks and some with no checks and Unique like Nelsdou44 suggests. If neither of those works, then I may accept the offer for some other bullets to try.

[Larry Gibson]

Your bullets are yawing or pitching. You are not losing the GCs and gluing them on would not show any improvement more than likely. In other words the bullets just are not very stable. Your Italian carbine should have a gain twist made for the 162 gr service bullet at probably 2000 fps. Your 13 gr load of 2400 is not driving the 170 gr bullet fast enough to stabilize it. It is probably in the 1300-1400 fps range. I'd suggest trying 4895 starting at 24 gr and working up to 28 gr in 1 gr increments. You should find an accurate load in the 1700-1850 fps range.

Larry Gibson

[MtGun44]

Seems like I read somewhere that some of the Carcano carbines were
made from cutdown long rifles, and the fast portion of the gain twist
was cut off, leaving the bullets inadequately stabilized.

Can anybody correct me if I'm wrong and maybe identify which models
had this problem.

Could this be the issue?

Bill

[Buckshot]

Seems like I read somewhere that some of the Carcano carbines were
made from cutdown long rifles, and the fast portion of the gain twist
was cut off, leaving the bullets inadequately stabilized.

Can anybody correct me if I'm wrong and maybe identify which models
had this problem.

Could this be the issue?

Bill

............These models had gain twist:

M91 Fucile 6.5x52 (long infantry rifle)
M91 Cav. 6.5x52 (cavalry carb which had an attached folding bayonet)
M91 T.S. 6.5x52 (Special troops {Truppe Speciali} with detachable bayonet)
M91/24 T.S. 6.5x52 (another Special troops carbine with detachable bayonet) This is the one made by shortening the M91 Fucile
M91/28 T.S (detachable bayonet)
M91/38 Cav. 6.5x52 (Cavalry carbine, attached folding bayonet)
M91/38 T.S. 6.5x52 (Special Troops carbine, detachable bayonet)

These models had a fixed twist:

M38 Fucile Corto 7.35x51(detachable-folding bayonet)
M38 Cav. 7.35x51 (Attached-folding bayonet)
M38 T.S. 7.35x51 Carcano (Detachable bayonet)
M91/38 Fucile Corto 6.5x52 (Fixed-folding bayonet) the JFK Rifle
M41 Fucile 6.5x52 (detachable)

From: http://personal.stevens.edu/~gliberat/carcano/models.html

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