Loaded up some rounds for my K31 and used straight up brand new brass but did so before hearing that it's best to actually run the brass through dies first. Anyways went to the range with my reloads and got absolutely awful accuracy with plenty of flyers and even a few keyholes. Wondering could these results be due to not sizing the brass? The once fired brass will now be neck sized only as they should be properly fire formed to the chamber. Will probably have to get that bullet puller now since there's no point wasting the remaining rounds. Wondering also if I could pull the bullets, empty the powder and just neck size to ensure a good grip on the bullet without having to remove live primers? Any thoughts fellas? I'm all ears.
using new brass unsized
- Thread starter jongun
- Start date
If the rounds fit your rifle, resizing wouldn't have done anything besides maybe rounding out a dented neck. If you are getting bullets that keyhole, I think you have bigger problems that your brass. Lapua and Norma brass you should be able to start loading without doing anything to it. Bulk brass I would run through the resizing die.
Barrel slugged out to 307 so I used Prvi 150gn FMJBT 308 bullets,40gn H4895,CCI LR primer and OAL of 2.9". It's my great grandfathers rifle that hasn't been shot in years and barrel and rifling looked to be pretty darn minty. Not sure what else to say.
I'm using Prvi brass
That is a pretty light load, maybe try upping the charge to see if the accuracy improves. I am shooting the same bullet (same brass and primers, too) with 44.4gr of IMR4064 and get 3"-5" groups at 100yds with the issue sights on my K-31. My OAL is 2.960" with that bullet, you may be too far off the lands and getting accuracy issues with that big jump. I can't say why you would get keyholing with that bullet, though.
Edit - I just re-read OP and see he is using a boat tail bullet, I am using the 150gr FMJ PRVI, but flat based. Not that this difference should be the end of the world, but the OAL may not be the same with the different bullets.
Mark
I'm not sure what your shooting, every Prvi bullet I have seen were boat tails. If the muzzle is worn a boat tail bullet can be pushed sideways as it exits the bore. A worn barrel will like flat base bullets much better and be less effected by muzzle blast.
The .303 Enfield rifle used flat base bullets and cordite powder, machine guns used boat tail bullets and single base powders. The accuracy with the Mk.8z single base powder in machine guns lasted longer because of less bore erosion.
Interesting article I found on crown damage and effects on accuracy. Give it a read, it's quite informative...
h ttp://www.longrangehunting.com/articles/rifle-crown-1.php
Also I doubt it's to do with unsized brass...I only run my brass through enough to round out the case mouth if it looks overly deformed. Other than that I just chamfer, prime, add powder, stuff in a bullet and I'm good to go, even bulk Remington and Win brass.
h ttp://www.longrangehunting.com/articles/rifle-crown-1.php
Also I doubt it's to do with unsized brass...I only run my brass through enough to round out the case mouth if it looks overly deformed. Other than that I just chamfer, prime, add powder, stuff in a bullet and I'm good to go, even bulk Remington and Win brass.
No need to size virgin brass. But, it is standard procedure to champfer the mouth of new cases so as to not scrape and scratch bullets when seating.
To champfer the case mouth, it needs to be nice and round, so I run the FL or neck sizer over the case neck mouth, to uniform them, prior to champfering.
Your inaccuracy has nothing to do with sizing. I agree your load is mild. Try hotter loads in 1 gr increments.
To champfer the case mouth, it needs to be nice and round, so I run the FL or neck sizer over the case neck mouth, to uniform them, prior to champfering.
Your inaccuracy has nothing to do with sizing. I agree your load is mild. Try hotter loads in 1 gr increments.
I think the magic word is "PRIVI", meaning anything can happen.
I have a box of factory loaded Privi, 7x57, marked 140 gr. The onlly headstamp marking, besides the calibre, is what looks like, "nnY," only all letters were the same size.
I fired three cartridgess under ideal conditions, in an accurate Mauser and they grouped 4 inches at 100 metres.
After reading this thread, in particular where the bullets may be boat tailed, I pulled the bullet on a factory loaded Privi, to check.
For starters, the case wouldn't fit in the proper shell holder! I tried two different shell holders, one being a RCBS. The groove was just too small to go in the shell holder. I finally used a piece of wood as a punch and hammered a case into the shell holder.
The bullet was flat base, BUT, the portion that was in the case was noticeably smaller than the portion that protruded from the case! The forward portion measured about .287", but what was in the case measured .282 to 2835. There was a step in the bullet, where the mouth of the rim had been, but it didn't appear to be a cannalure, as from this step rearward, the bullet was just smaller diameter. It gave the appearnace of having had the entire neck so squeezed down, as to reduce the size of the bullet.
I have a box of factory loaded Privi, 7x57, marked 140 gr. The onlly headstamp marking, besides the calibre, is what looks like, "nnY," only all letters were the same size.
I fired three cartridgess under ideal conditions, in an accurate Mauser and they grouped 4 inches at 100 metres.
After reading this thread, in particular where the bullets may be boat tailed, I pulled the bullet on a factory loaded Privi, to check.
For starters, the case wouldn't fit in the proper shell holder! I tried two different shell holders, one being a RCBS. The groove was just too small to go in the shell holder. I finally used a piece of wood as a punch and hammered a case into the shell holder.
The bullet was flat base, BUT, the portion that was in the case was noticeably smaller than the portion that protruded from the case! The forward portion measured about .287", but what was in the case measured .282 to 2835. There was a step in the bullet, where the mouth of the rim had been, but it didn't appear to be a cannalure, as from this step rearward, the bullet was just smaller diameter. It gave the appearnace of having had the entire neck so squeezed down, as to reduce the size of the bullet.
Bullets are like a football. Not enough speed and spin they will wobble and keyhole. The rate of twist in your barrel will have alot to do with the weight of bullet that will work best. Most gun makers have a middle of the road twist that stabilize most popular bullet weights.With your K-31 I am sure there is a standard load and bullet weight.Find the sweet spot. I used to have this trouble in old rifles particularly old Winchesters and lead bullets. If the bores weren't completely worn out usually a increase in powder cured the keyholing. I increased the powder in very small increments until things straightened out or pressure signs started to show that I had gone far enough. I also had trouble with the old 98 mausers trying to send a 220 grn bullet down range. They would also key hole and when I started to have extraction issues with increased powder increments it was time to go back to a lighter bullet. I have never went beyond maximum loads listed in the manuals. I resize all new brass. No surprises that way.
