Loading 308 HBC's - seat depth

[Barry Davies]

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Barry

[macguru]

The important thing is accuracy, not just velocity. I have a load thats 42.5 gr of 2208 that shoots sub 0.5 moa. It works at 900 yards just fine (have not tried 1000) , with most shots going in the 6 ring and about half in the x ring in MILD conditions. Velocity is about 2800fps with the bullets seated deep in the case as my factory savage rifle has a short chamber.

The thing is, when the wind blows , those that have the same accuracy at the hotter sweet spot, say 3000fps (30 inch barrel) will get the better scores.......
I have not found that load yet but i will keep looking Whenever i try a hotter load i get fliers. I may need to rechamber or even rebarrel to get this result.

Good Luck

[Seddo]

Whenever i try a hotter load i get fliers. I may need to rechamber or even rebarrel to get this result.Good Luck

you can always get the throat lengthened before going to a new barrel.

[Deano 29]

Stuart,

As im new to the sport this question may be redundant but, your group @ 100m was 0.119" centre to centre ( what does that mean ). I ask because with a new barrel with 10 rounds in total my 5 shot group @ 100m was 0.364" minus projectile width outside to outside at its greatest width. Just curious...

Deano

[stu_bear2002]

Just to clarify a few things about my loads, I changed from winchester cases to lapua's and kept the load the same(46.1), which we thought should give a little higher velocity given the smaller capacity of the lap's but something strange happend a loss of 100fps , So i up'd the load as far as 47.1 with very erratic velocity spreads(upto 65fps) and my 100m groups went out to nearly 2" not to mention its a pretty hot load for an omark with a 26" barrel.
So then it was back to basics and i loaded 5 rounds at 6 different weights starting at 44.5 and going up to 46.5. It was obvious what was working so i've chosen to stick with it untill i can afford a new 30" barrel and its getting pretty decent results at my local range(werribee) although i haven't ran these ones over a chrony yet if i get a chance friday i will.
I will be using it at castlemaine this saturday and will see how it goes there.
Deano, i have a program on my pc that does all the calculations after you scan the target. If your group was 0.364 from the furthermost edges then your center/center would be 0.056 which is pretty much a one hole group, however if it was just over half an inch (0.672) before subtracting the .308 projectile to get the result of 0.364 then its still sub moa which you should be very happy with straight out of the box.

Cheers Stuey

[Seddo]

I did my first lot of testing with some BHC's on monday. I dont have a bullet length guage so i seated them to just touch the lands, very slight graze on the projie when closing the bolt. Started at 46.8 and went to 47.4gr 2208, the best group was with 47.4 and they were all touching at 100m. I havent run them over a chrono but will get it done this week sometime.

i fired 5 shots over the chrono today (lunch break) with an average of 3010fps. The oal is 2.920. I think i have a 25" barrel, what ever the standard barrel length was less the cut for the front sight (didnt like the look of the step in the barrel profile).

[AlanF]

Seddo,

From the figures you've given, I'd be surprised if you're not having to compress the load a little, and you could also be getting pressure signs?

Alan

[stu_bear2002]

I managed to get a few rounds over the chrony friday arvo for an average around 2715-2720, and my overall length is 2.884,
Load details are dyer hbc, 45gr 2208, lapua cases and cci primers, this is out of a 26" barrel hence the lower velocity than the 30" guys.
Stuey

[Seddo]

Alan,

It is compressed a bit, powder comes up to just below the neck. The adi guide lists 47gr as a compressed load but that will be with a shorter oal so i dont think it will be too far over the top. I run 47.5gr of 2208 with 155gr nosler custom comps (winchestre brass) in my LTR and it gets 2750 out of a 20" barrel. The primers are not flattening but the firing pin indent (on primer) is starting to show the signs of flow but i put that down to a oversized firing pin hole.

[Barry T]

Hello ,i hope this might help.my 308 load for fclass is 155 nosler comp projectile,46.8 grains of ar2208 in a remington case and cci primers and o.a.l is 73.0 mm.
i use this load right out to 1000 yards no problems with a savage 1 in 10 twist s/steel 26 inch barrel.

happy shooting in fclass and many super six's