Home Forums Hunting & Shooting Hunting Rifles R.O.T question-bullets are keyholing

Took out an old Vanguard .308 today to test some 130gr TSX and TTSX. Suffice to say it was a dismal failure. Had mounted a new scope so took one shot at 50yd which looked perfect. Went to about 125 and fired 3, only 1 landed. Figured I was shooting high since I saw no splash, so held low and got a hit that was clearly keyholed. This was a TSX with full case of Varget.

Tried the TTSX with the same load, only 2 hit paper at 100 and both also keyholed. I'm guessing the ROT is just too slow. I tried measuring and it seems to be 1 in 11, close as I can measure. According to the Barnes site that should be fine. Any idea what is going on here? This was going to be my elk rifle this year, but looks like its going to be either the .375 or .243 instead.

Marlin had problems with the gilded bullets in their micro-rifling barrels. The lands would load up and bullets would not have any spin at all. I sent pics of my targets to Hornady with some of the most perfect keyholes I have ever seen. You might have the same sort of problem, I would give the barrel an extreme cleaning and see if that helps.
BTW I shot some Fed. 150' & 170's at the same distance (35 yds) & same time and the bullets were touching with the same old Marlin 30-30.

I took a look down the tube and it looks clean and sharp. I gave it a good cleaning before shooting the Barnes, as I heard they did not like being shot over top of other types of copper.
I just loaded up some 150gr BT's over 46gr of Varget, and its doing the same thing. Fired 3, 2 of which landed sideways. I'm kinda baffled.

Whatever is going on isn't because of an 11" twist.

^^^^^^

How does the crown look?

Crown looks ok, I recrowned it a few years back because I initially thought that was the problem with the poor accuracy it was plagued by. It didn't help, but didn't seem to hurt either. I removed the bedding and rebedded it this year, and it showed the best accuracy I've seen from it in a long time. Earlier this year I loaded up a few 130gr Speers to test after bedding it, and it shot pretty decent with those. That gave me enough encouragement to go ahead and get these Barnes bullets, thinking it would be good enough at least for a couple hundred yards on elk.

Who did the recrown job?? Also have you tried heavier bullets Ie 180's??

slug the bore and mic the bullets...

Current of a 1-10" twist, no telling what the older do, but as mentioned, 1-11" ain't the problem.

What did the target backing look like? If you staple your targets to a backing that's all shot up and full of holes, you get some funny-looking bullet holes. Shoot with a solid backing and see if they look the same.

Update-took it out this morning with some 150gr Winchester Powermax. No stability problems at all, nice round holes. So, the one common denominator in all this is the can of Varget I used to load the TSX,TTSX and BT's. The TSX's I loaded previously with CFE223 did not tumble, but I had only shot 3 so thought it mighta been a fluke or something.

Also, I was shooting a full foot low at 100 this morning with the factory stuff. Was shooting way high yesterday but I had only fired the previous 3 rounds of TSX's with the new scope before so didn't think much of it. Going to load some with CFE again today and maybe some 4064 as well, see what happens.

True keyholing is a stability problem. Different powder wouldn't cause it unless your velocity was extremely low.

OK, I will take a WAG here.

Since the TTSX is a monolithic and it is harder than most cup and core jackets it has driving bands. Which are basically just voids to reduce the surface engaging the rifling at any given time and thus reduce the amount of pressure needed to get the bullet out the barrel.

Has the rifling become too shallow or worn to the point that it is not engaging the harder surface of the TTSX but can grip the softer jacket on the 150 grain Winchesters?

Ok,another update..loaded up a few rounds with the TTSX and 4064. I cleaned the barrel again after trying the factory stuff, so fired 1 at 50 and it looked good. Fired a 6 shot group at 100, and turned out to be the best the rifle has shot in years. Blowing like mad out there and my little fold up table was less than ideal but still got all six in around 1.5". Almost no vertical differences, just some horizontal stringing. Going to try the CFE223 again but if it doesn't produce then the 4064 will work.

I'm wondering if the Varget was too heavily compressed for proper ignition, as I ended up with the case pretty well full. I've shot compressed loads before without problems but not as compressed as these. Perhaps with the CCI primer it just wasn't lighting off correctly? Although I must say todays 4064 loads certainly felt much milder than the Varget I shot yesterday.

Any chance you were hitting low to begin with and by holding lower you were seeing ricochets hitting paper?

The thought did cross my mind, but I wasn't see any splash and the paper was completely clean except for the bullet holes. I also got a couple nice side profiles of the bullets going through, and particularly with the 150 BT I didn't think it likely that would have happened had it hit the ground first.

Whenever I obtain a new or new to me rifle I try to eliminate some variables by shooting factory stuff. You did that and proved it wasn't the barrel. You loaded another powder and bullet combination, proving you knowhow to reload. Having a secondary hit from a hard back stop was an interesting notice; I'll have to remember that one.

You said the load was compressed which does offer up some of its own variables. What load are you using?

If it were me, I would call Hodgdon's (Pete) and Barnes (Ty) and get their opinion. I would also make a third call, with a tiny white lie, to the Sierra bullet smiths. I would replace the word TTSX with Game King, just to see what they would say.

NOTE:
If you work for Sierra and frequent these boards, by real name is Sally.

Miss Sally..

Ha! No worries, not an employee of Sierra or any other bullet manufacture, although with the lack of bullet selection here I wish I was.

The Varget load was 50gr with the 130gr and 46.5 with the 150gr BT. I wanted to go up to the 52gr the Barnes site listed as max but there was just no room.

I tried some CFE223 this afternoon and it didn't shoot too well, although no tumbling issue's arose with it. The 4064 is the clear winner in the accuracy department and I think I'll use it this year and then boot the gun down the road after this elk season.