[1944]

I have a box of CCI Gold Dot 50 gr HP ammo. I decided to try them today. I was using an almost new Marlin 25MN rifle. They clocked at a rather lame average 1450 fps. After firing 10 rounds, I went and retreived the target that I had placed at 47 yards. The large HP made perfect circle holes, BUT the rest of the hole had a definite oval shape with rifling stripes on one side. It appears that the bullets are trying to "keyhole." I believe that Marlin uses a 16" twist in their magnum barrels. It looks like a 16" twist may not be enough to properly stabilize the 50 gr bullets. Has anyone else had this problem with this ammo?

 

[1494]

I have had problems shooting this stuff in my Marlin 882SSV. I went to look at the target and I didn't even hit the 8"x13" sheet of paper that I had my target on. I went and got a sheet of cardboard and found that it was shooting way to the left and low. The holes looked like the bullets had hit it sideways instead of the perfect holes that should have been there. I still have a box of them so I will try them again sometime.

 

[Chum]

The greenhill formula for 50 grain .22 bullets is a 14:1 twist. The 50s also have quite a bit of drop. The bullet hits the target at the same angle it left the gun. This will cause a verticlely oval hole. The farther the range the more oval it should be because of the higher upwards angle of the bore.

.22 Bullets with a length of .49" to .51" = 14:1 according to this app

http://www.z-hat.com/twistrate.htm

 

[1944]

I do not think that bullet drop was the problem. Most were diagonal ovals. Most with the nose to the lower right. Some with the nose to the upper left. I still think it is a stability problem.

 

[899]

Although, I've never noticed any signs of "key-holeing" from either of my Magnums.....

The "Gold Dots" just never performed well.

IMHO, Too heavy for such a small cartridge!!

50grns! That's getting into .223 centerfire stuff.

 

[899]

I tried them again, today.......

It's been awhile since I tried the "Gold Dots", so....

Volquartsen Custom Magnum, SS Barrel w/comp.

25 yds & 100yds

No sign of "key-holing". BUT!

They would not be my choice of ammo, where "shot placement" was critical.

Ya might "scare" the varmint, to death, when the bullet slams into something behind it.

 

[1747]

...
Ya might "scare" the varmint, to death, when the bullet slams into something behind it.

How true, they do produce quite the "thwap"
I've shot them with the 25mn and they do ok 50-75 yards. After that the gold-dots tend to drop and wander. (twist rate 1:16)
Anyone tried their luck with the Federal 50 gr's?

 

[B Coyote]

This is an excellent thread. I've just scoped my Marlin 882 and I have 100 rounds of .22WMR GDHP for testing. I'll definately have to watch for this problem.

Thanks guys. Once again, Rimfirecentral comes through.:t

Jeremy