Dyer HBC's.

[IanP]

Thanks Brad, good info!

Ian

[Malcolm Hill]

Brad Y
Any time you want to part with those batch 15 HBC"s let me know, they were by far the best that I used. Not a single elevation shot with any of them. Later batches even before the manufacturing problems are not as good with the odd vertical up or down sneaking into the 5 ring for no apparent reason.
Regards Malcolm.

[Woody_rod]

Interesting to note the comments about using illegal projectiles. I can pick a Berger 155.5 from a fair distance, as they look nothing like a HBC, and are much more streamlined than the SMK 2155. The Lapua Scenar 155 on the other hand looks quite similar to the HBC and would be very hard to pick on the shooting line from 5 meters away.

If people are willing to cheat (not that they are necessarily), then what else might they be doing? VV powder, increased case dimensions from the original etc etc.

The only way to make sure would be to check everyone's ammo - picked from their box, while they are getting ready to shoot - so they dont give the RO a "fixed" round.

[Brad Y]

Hi Malcolm

I know these bullets would better serve a shooter who is more competitive than myself but I need all the help I can get!

Rod

If you compate a 155HBC and 155VLD they are pretty similar too.

We have been trying a few things out just in the club shoots. Im sure someone will get a box of 155 hybrids or 155.5 fullbores to try soon.

[Woody_rod]

Rod

If you compate a 155HBC and 155VLD they are pretty similar too.

We have been trying a few things out just in the club shoots. Im sure someone will get a box of 155 hybrids or 155.5 fullbores to try soon.

Hey mate, true enough for the VLD's, which are almost identical to the Lapua Scenar. We have all sorts of projectiles now from our FTR testing...from ancient Lapua D46's to the latest stuff from Berger.

[Brad Y]

Im very keen to try the 155 hybrid and 155.5 fullbore in the 308 as well. Though I probably need to start stocking up on 6.5mm 140 hybrids too.

[Woody_rod]

Im very keen to try the 155 hybrid and 155.5 fullbore in the 308 as well. Though I probably need to start stocking up on 6.5mm 140 hybrids too.

If you ask Linda (Southcape on here) nicely, she might lend you a few 155.5 FBBTs

[Brad Y]

Thats alright, Im going to do the rounds in perth to see what might be up there. Hopefully Dave Kerr or Claremont Firearms might have some there.

[Brad Y]

Well I managed to get a bag of 100 of the latest HBC's to try out. Still have plenty of my others to get through anyway.

From measurements, I found the ogive to be about 8 thou further forward than my current lot. I dont know why that is but it sure had me confused for a while. I found the over all length to be a whisker shorter- not by much. The bases are very flat and square and the boat tail has a pressure ring around them as well- definitely cant say they havent been seated into the jacket properly!

I know my current load is working well so Im just going to adjust the seating die to maintain the jam and stick with the same powder charge and try some 100m groups.

[richmac]

Hi Brad
looking forward to your findings,quite a lot of shooters still have the old type and I have not had any feedback,we could all of a sudden get a flow of information as the old one run out
Cheers Rich

[aaronraad]

Here are some comments/recommendations I passed onto a club member based on a dozen samples of the current HBC's he supplied to me following some accuracy concerns. At the time I was unaware that there were a number of shooters with similar accuracy issues so I have made some additonal comments. The shooter is considering going to the Sierra MK, so I'm putting my differences aside in the hope he sticks with a local manufacturer. I'm not an expert yet but an avid admirer at least. Not sure if this should go under a new thread?

From front to back;

Meplat

75% good but 25% badly truncated at approx. 30 to 45 deg.
Flat is preferable but smooth is not necesary.

Ogive

Very secant. Secant ogives can be extremely seating depth sensitive but not always.

Shank

Extremely parrallel with no detectable taper in either direction.
Very close to .30800" average, so definitely not thick or thin in diameter.
Bearing surface possibly a bit long considering short ogive and adequate length boat tail

Base

Angle and length seem in proportion and are obviously adequate to stay supersonic out to 1000y.

Overal the current Dyers seem to be very consistent. If the meplat issue is also consistent (and not batch related) then this can be discounted as an accuracy issue for thos 'struggling' to get the HBC's to work. The 155gr projectile is a tricky design to get right in the .308 calibre using lead/lead alloy and gilding metal.

I would be looking at seating depth as a factor of case alignment and neck tension in the chamber, when being presented by the bolt. The design of the HBC might be consistent but it doesn't make it chamber friendly.

Part of the reason I believe that shooters have success with a jammed seating depth for secant projectile designs is that it guarantees projectile alignment in the bore. If there is significant misalignment when the projectile is being jammed into the lands, there is more of an opportunity to inconsistently launch the projectile with the same pressures. In the event of misalignment this can be compensated or compounded by the shank design and jacket/core hardness. Other secant designs I have observed at are not so severe, and there is definitely some taper in the shank with a maximum diameter closest to the base.

So what could the shooter do? I would suggest to start by comparing the alignment/concentricity of load ammunition against that of a chambered cartridge. This would have to be done on a range as you need to leave the firing pin in place to get the same tension on the bolt. You might even want to check the alignment in a warm chamber after firing half a dozen rounds? I assume the Winchester NRAA loaded factory ammunition with the HBC is still available and could be used for loaded ammunition concentricity. It might be a good standard to compare against your handloaded ammunition?

How do gunsmiths approach improving alignment issues from the boltface to the rifling? Lead angles, ejector tension, case head squareness etc. ? Gunsmith feedback would be useful.

...did anyone actually understand that?

[RAVEN]

Another issue that can cause misalignment is that the tip contacts the top of the seater the seater must bare on the ogive.
I think most modern reloading die seaters allow for this but how many old ones out there.
Just don't for get the basics ppl
RB

[aaronraad]

I knew I wasn't going completely nuts...unless Lijla are too..damm

http://www.riflebarrels.com/articles/bullets_ballastics/throat_angles.htm

[Brad Y]

Thought I had put up a reply to this but obviously not.

The newer lot HBC's shot every bit as well as the older ones I have. I used them prior to the WA queens at a local club shoot at 300m. Will try them out again this weekend at 600m but thumbs up so far.

[saum2]

I had batch 15 & they shot VERY well. Now another batch with new batch numbering, have had to sort them into various weights etc. Now I have an alignment issue. I have read another thread about this issue of 'run out" & I have some doubts that misalignment shouldn't cause accuracy problems. I have done a lot of testing lately, with .025" jump, runout is causing accuracy issues. When the projectiles are straight they work quite well. Maybe the new HBC's pointing or mispointing is causing seating problems. I've nearly torn my hair out over many weeks trying to sort out SB/Dies, press & seating dies with very little improvemnent. Although, my seating depth has changed from .008" to .025" with a change in HBC's and barrel. ( some brillant scores/groups with straight bullets & poor groups with misaligned bullets with this barrel) Maybe this new barrel is very seating depth sensitive.
I'm now seriously looking at FTR with 185gn Bergers as an option after watching what Alan Seaman did with them at SARA queens. I have a 1-11 twist barrel with the same chamber specs as Alan. I'm hoping the Bergers are more consistant.
my 2 cents worth.
cheers
Geoff