Horizontal stringing with cast only

[texassako]

I am kind of stumped with this one since there is no horizontal stringing with factory ammunition. Hi-Point 3895 carbine in .380, Lee 356-102-1r boolit sized .357" with 45/45/10 TL, loaded at .960". Groups horizontally string with every powder I tried today. The slower the powder the less it strings, and Vectan AO was the best with a 1" high by 3" wide group at 50 yards with my starting load of 3.2 grains. My chrony was acting up; so no speed data. I believe today was the first time I have ever seen multiple 1" tall x 6" wide groups when factory Remington and Federal FMJ shoot 4"x4" at 50 yards. I am going to load up some more Vectan A0, try some slower Blue Dot, and see just how far out the chamber will let me seat the Lee's (plenty of room in the mags). Hints, possibilities, other things to try? I wanted a challenge, and now I got it.

[Dusty Bannister]

Mixed head stamps? Possible powder measure having trouble with small charges? Everything tight with the sighting system? Gun clean and well lubed?

[Bzcraig]

My first thought is different bullets/loads.

[OS OK]

Iron sights...right? Then I'm guessing sight picture, it wouldn't take much side to side misalignment for a 3" string at 50 yards.

[texassako]

Here is some additional info I should have included. All Remington brass, all charges were weighed, used Hornady dies, good 2-1/2 power scope (old Texan) in Nikon rings, the best loads were the Lee but I also shot a Saeco 371 105 gr TC that did worse, gun was cleaned and lubed after the previous session, shots were 3-4 seconds apart, 10 shot groups, barrel is 1:10 twist, 10-12 BHN lead, and no sign of leading. I just find it strange that factory jacketed does not string this way, even shot up a couple of partial boxes right after the test loads.

[runfiverun]

try a different primer.
the AO is basically a shot shell powder.

[texassako]

Interestingly enough I haven't used one of the high point carbines, but I have heard that some folks do better when they use .358 diameter cast bullets in high points or khars.


try a different primer.
the AO is basically a shot shell powder.

Thanks, both easy suggestions to try. My Lee mold just barely hits .358" and I have a couple of other primers tucked away.

[Tripplebeards]

I had vertical strings last month. Scope came loose and ended up failing. I'd check all the your mounting screws to eliminate one unknown issue and blue loctite them. I lapped my rings as well. Also check your action screws. Probably not your problem but start with the simple things first.

[texassako]

How about an extremely long throat and very short bullets? I did the old backwards bullet trick and the lands are wayyy out there. I can seat a 124 gr commercial cast RN bullet to 1.16", 9mm length basically, and be just off the lands. Good thing they fit in the magazine and feed. I guess I have Weatherby style freebore in a pistol carbine.

[Yodogsandman]

If you run that across a chronograph, you'll most likely find erratic velocities from inconsistent ignition. Can be powder or primer but, I'd go with a new primer where you've tried different powders.

[Digital Dan]

If you want to give your loads a chance slow down the cadence of your shooting. Sounds a lot to me like your barrel is heating up and wandering a bit.

[texassako]

Update: problem solved. It was the huge jump to the lands. It is finicky about what powders are accurate (Bluedot and Vectan A0), but no stringing today loading the Ranchdog 100 gr out to 1" OAL. I only had a couple Lee 124 gr RN, and it shot even better loaded all the way out to 1.15".