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Has anyone tried the Berger 90's versus the SMK 80's in .224? Holding the two side by side the Berger looks rather nice, I am interested in how the Berger performs at around the 990m/sec mark.

Hopefully,

Laurie Holland will pick up on this one.

Cheers
Vince

ovenpaa,

certainly don't think of using the 90gn SMK for what you have in mind. Sierra developed this bullet for 20-inch barrel .223 Rem AR15s and the US Hi-Power XTC 600yd slow-fire stage as a higher-BC alternative to the existing 80gn SMK. It was not a success in this role as the drop in MVs largely negated the improved BC at safe pressures.

Moreover, Sierra recommends a too-fast 1-6.5" twist rate and the chamber form adopted saw accuracy drop right off at under 1,000 rounds down the barrel. If driven too fast - over 2,700 fps or so - the 90gn SMK acquired a bad reputation for blowing up in flight, unusual for SMKs which normally employ thick jackets. There is a theory around that the SMK's problems are down to internal design that sees the core move under maximum .223R pressures. In any event, this bullet did great harm to the use of 90s in the calibre and created the widely held view that they simply don't work probably through being over long in relation to their diameter, also that barrel condition is critical and accuracy goes sour at low round counts.

That leaves the JLK VLD and two Berger designs. I haven't heard of any outside of the US experience with the former. A correspondent in Florida says it shoots very well in .223R, but suffers in flight break-up too. But that is in a 1-6.5" twist barrel.

The Berger 90s have a very good reputation. Both (BT L-R and VLD) are well made and stay in one piece at .223R MVs, and can be driven as hard as the cartridge will take. G7 BCs are 0.262 and 0.281 which bracket a good 6mm 105gn VLD (Berger is 0.272) and the VLD is only just shy of the Lapua 139gn 6.5mm Scenar (but well behind the highest BC 6.5s).

You need a 1-7" twist rate, possibly even a little slower. at your planned MV you might get away with 1-7.5". I shoot the VLD at a little under 2,900 fps in .223 Rem and it has performed very well to date with around a 1,300 round-count. There are still warnings around of the effects of throat wear though, so you'd have to bear them in mind. The other thing to bear in mind is that the two Bergers produce very different pressures for reasons that aren't obvious (ie bearing surface lengths are near identical). I suspect the BT L-R has a thicker jacket and/or harder core than the VLD. In any event I have to drop my .223R long-range Re15 load by 0.6gn for this bullet, a lot in this cartridge, and even then primer pockets loosen faster than with the VLD. So maximum MVs are lower for the BT model.

These are very long bullets (1.263" for the VLD), so a lot of freebore is essential irrespective of cartridge design employed. With the .223R throat that the custom PT&G reamer cuts for the dummy 90gn VLD round Vince & I used in the spec, 80s could just be used when the barrel was new with minimal depth seating. 1,000 odd rounds and 0.020" throat erosion, I might still be able to barely seat the 80gn A-Max or Berger VLD into the lands, but it has to be marginal. So, you are committing yourself to a chambering built around a near single loading of whatever cartridge is being employed.

I have asked the question (on behalf of others as I only punch paper) on US forums whether these bullets are of any use for varmint shooting and the asnswer is a deifinite 'No!'. Unlike some other Berger VLDs they don't expand even at .22BR type velocities.

Thanks for your reply Laurie. I thought I clicked submit to my reply to this a couple of days ago

The plan was to try the 90's in Christel's 22-6.5x47. The SMK80's work nicely to 1200 but improvement is never a bad thing. Currently the 80's have an MV of around 3250fps and could go slightly faster but need to be kept range legal hence the desire to try something a tad heavier and pointier if only for wind bucking. Her rifle has a 1:8 twist so the Berger 82 grain would certainly fit but I do wonder what extra advantage it would give over the SMK80 again the reason to look at the 90's. However if pushing them hard results in failures and if the stabilisation is marginal then the change is probably best avoided.

The alternative could be to look at bullet pointing I guess