different brass making keyholes?

[04JRB]

I recently picked up at the range some really nice LC 07 brass that I decrimped and FL sized and went against my better judgement and used the same recipe (24.5gr H335-CCI 400-55gr Hornady V-Max- Win brass) as I normally do with winchester brass I use. I got keyholes and strays in my target at 100yds. I have never had anything less than great accuracy out of this savage 12fv. the only thing changed was the brass.

Maybee I got the barrel to hot, even though I only shot 50 rds in 1 hr?

The first 30 rds were normal recipe with winchester brass, and it was right where it normally is on the target. as the session progressed, it went from great accuracy to wondering why I was a couple inches off, to flat out strays and keyholes .

I didnt think brass would make that much difference, but Ill go back to my tried and true load and eliminate any variables. the only other thing was the barrell seemed warmer than normal. I shot many more rounds than this in a day during the fall, winter, spring and didnt have heat issues though.


Any thoughts? I know I did wrong by not working up a new load by switching componants, but did learn a valuable lesson from it.

 

[308win]

The LC brass may hold less volume and your pressures and velocity will go up; your barrel may not stabilize the bullet you are shooting at higher velocity.

 

[Grandpa Shooter]

Biggest mistake was going from on headstamp to another and assuming your load would work. It will at lower loadings with negligible differences, but if you were close to max with your other brass you may be well over with LC. The only time I have had keyholing I also had smeared, or flattened, primers. Have you looked at the primers in the brass where you got keyholing?

 

[04JRB]

308win- I think you are right. How much less volume is the LC brass out of curiosity?

Grandpa shooter- The primers were fine, at least when I looked at them at the range, I certainly will check them again. I should have known that this was not only going to result in an unaccurate load, but reckless and dangerous. It isnt like me at all to even try new things, let alone let a significant known fact like the brass volume pass instead of working up a new load. One good thing from this is that I certainly wont be doing it again.

On a side note, how long does it take to warm up a barrell too much? I usually check targets at 15min intervals and let the gun cool and fire another 30 rounds. I havent noticed my groups opening up at all until this last trip.

 

[rcmodel]

According to the Hornady #6 manual, you were already over max before you changed to GI brass.

They show 23.2 grains H-335 as Max Load with the 55 grain V-Max bullet.

You were 1.3 grains over max before changing to GI brass with less capacity.

Regardless, it seems unlikely you were over-driving them at too high a velocity.
They work great in a 220 Swift at 3,800 FPS!

You might want to check your bore for copper fouling. That could cause key-holing if severe enough.

If you burnt out your barrel, there won't be any rifling left right in front of the chamber for an inch or so. It will look like orange peel.

rcmodel

 

[USSR]

Case capacity between commercial and military .223 brass doesn't vary greatly the way 7.62x51 and .308 does.

Don

 

[04JRB]

rcmodel- I just recently bought the hornady book, but the other books I own (sierra,lee, and nosler) show the max to be over 25gr if I remember without looking it up(Im supposed to be working right now,lol). I very thoroughly cleaned the gun before this trip. I use Hoppes copper solvent and bore scrubber to clean and hoppes elite oil and two dry patches after oiling. If I look down the bore from the muzzle, I do see orange stipes but can see where the black of the rifling is too. I guess Im confused by this as I have only put around 1k rounds through this gun. I have only had it since last fall.

I am certainly going to check that hornady book again, but Im pretty sure that my load was around middle of the road when I was going by the sierra book.

 

[BeJaRa]

I just started reloading for 223 and I weighed several examples of all available headstamps. I know this does not give me the volume of the case, but it does give some insight into the cases construction. Winchester and PMC brass averaged the heaviest, around 3 grains heavier than Remington or Lake city brass. Unlike my 30-06 were LC brass is alot heavier than commercial brass, I would say the LC 223/5.556 does not need to be reduced by 10% like other LC calibers, but as always start slow and work your way up.

-Just my opinion based on my observations

 

[rcmodel]

but Im pretty sure that my load was around middle of the road when I was going by the sierra book.

What's the Sierra book got to do with anything?

You said you were shooting Hornady V-Max bullets, not Sierra.

V-Max bullets are shaped very differently then Sierra bullets, and have more bearing surface to create friction in the bore.

We also don't know if the jacket material is even close to the same hardness or alloy.

rcmodel

 

[04JRB]

Well, after some good advice from you all, I will go back to my stash of loaded tried and true ammo and see if anything unusual happens. Im confident that it will be fine. Like I said before, I knew I did something I shouldnt have but learned something from my experience. I just wanted conformation that what I did could cause a keyhole.

Ill post back after the weekend with a range report.

 

[04JRB]

Wasnt the brass after all

I took 20 of the suspected LC loads, 20 of the normal winchester brass loads that I shoot all the time, and 20 of the CT ballistic tip load I have that hasshot very well in the past.

It turns out that it wasnt the brass, powder, or projectile at all. The target had all loads right on target, no elevation changes at all. The LC loads shot exactly as the same load with winchester cases. I took the rifle to a friend who had the technology to look further in the bore than I have at home. Holy copper fouling batman! I was using Hoppes benchrest copper solvent until it came out with no green color. I thought I was doing a thourough job, but I wasnt as the fouling has built up over time. I was removing some of the fouling at a time, but not all.
I will not be using theHoppes again as it doesnt seem to work. I bought some Barnes cleaner that smells wicked and awful, but got the bore clean in several passes with a saturated patch and nylon brush combo. This stuff worked great, I did have to open a few windows in the shop though.

I thank everyone for their responses and suggestions. case closed. I will be re-developing this load however. Based on this event, I will start over from minimum and see what happens.