Went to the range today and had something strange happen.

Was shooting 30-06 with 22" barrel. Also shooting 300 win.

5 loads for the 30-06 shot in this order;

168 TSX RL22 62.5
168 TSX RL22 63
200 TSX RL22 58.5
200 TSX RL22 59
200 ACCUBOND RL22 58.5

The 2 loading of 168 grainers went fine

The 200 grain TSX were all over the target and were keyholing. Velocity averaged 2522 for the 58.5 grain load and 2532 for the 59 grain load.

The Accubonds averaged 2581 with the 58.5 grain RL22 load and shot 1 1/4" pattern.

Was it the twist of the barrel not stabilizing the long flat base TSX? The Accubonds are not as long and are boat tailed so there is less bearing surface.

All these cartridges were loaded at the same time and with the same methods. Never had keyholing before.

Near as I can figure I have a 1 in 12.5 twist.


Without guns we are subjects, with guns we are citizens

Seeing as no one else has answered, I'll have a go, even though I don't know much.
It seems to me the keyholeing bullets were too long to be stabilised in your twist. (The length is very critical.)
Most likely reason I reckon.
John L.

hmm,
go to
www.realguns.com and use the twist calc.

copper bullets are very very very long, and that's one of the three reasons you can get keyholing
1- over sized bore
2- undersized bullet
3 - twist WRONG

jeffe

Was the .30-06 a Sako, Blaser or other European rifle?? Quite a few of those - including the 2 mentioned above - use a 1-11" twist rate for their .30-06 barrels, in contrast to the 1-10" commonly used in the US. Most 200 grs bullets will probably stabilize just fine in a 1-11", but as stated above, the TSXs are VERY long bullets so maybe...

- mike

It's a Sauer lightweight with a 22" barrel.


Without guns we are subjects, with guns we are citizens

Hello there
just read your mail re- key holeing of the TSX bullet.

I too experienced this for the first time 2 weeks ago in my .270 winchester, following the data supplied in the box I loaded rounds backed off from those listed in the Barnes #3 manual and ended the test with rounds 1 grain over the maximum stated for the 140 X bullet. This information was confirmed to me by return e-mail from Barnes technical staff.

The group at 100 yards starting with the reduced load of H414 and working up to 1 grain above max revealed a 6 inch spread but with evidence of sideway entry into the target (paper targets)

No other round has shown the same propensity to do this, the issue of bearing surface/ length of bullet may be of relevance, although the bullet is of course a boat tail with a steep ogive and lateral grooves, so bearing surface per se is probably no longer than that of other conventional bullets.

At least these are my own observations for what they are worth, but I would be glad of further thoughts as to why this phenomonen should occur.

Jonathan Tomlinson

Yorks
England

I abuilt up a 6.5x308 one time with a twist of 1 in 9 shot heavy (long ) bullets fine, wouldent shoot 85 gr bullets they keyholed, changed the barrel to a 1 in 11 1/2 in twist. this shot 85 and 100 gr bullets fine but wouldent shoot the heavy long bulltes. Now the long bullets keyholed. I believe that the twist is directly dependent on the velocity of the bullet. If I could have gotten the velocity of the long bullet equal to the velocity of the lighter short bullets I think that they would have shot fine.
Mike