Finding 'that' load

E5B · Post by **E5B** » Mon Jan 07, 2013 6:15 am

I have a CZ 527 American topped with a VXIII 3.5-10x40 that I've been working loads for.

Started with 39 gr SBK's and Benchmark (Hornady Brass, CCI and seated 2.940"). Five shot groups were no better than 1.5" - that's from min load working all the way up to max.

Moved on to H4895 with same bullet. Same result.

There is no crown damage, all scope mounts are tight and I'm shooting from a good rest. I decided to move on to 32 gr Nosler BTs with Benchmark and will post back after the range.

Anyone with a CZ have issues stabilizing the 39 gr SBK's?

HoundofSC · Post by **HoundofSC** » Mon Jan 07, 2013 10:03 am

post the ladder you used, along with the COL, group size, primer etc. Could be your barrel might not like them, every barrel is different. If you were using large jumps ( .5) grain go back and do a set using .2 jumps in the middle of the load range spanning 1.0 - 1.4 grains. If you find something there that groups .5 or so do a set .1 grains on either side. I had to try 3 different powders before I found one that my barrel liked

E5B · Post by **E5B** » Mon Jan 07, 2013 10:09 am

Ladder: min to max in half grain increments.

Seated: 1.940"

Group size: all were 1.5" or worse, spread out all over

Primer: CCI small rifle

We shall see what these 32 grainers do.

Anyone else have issues with a 1-12 twist stabilizing a 39-40 grain bullet?

HoundofSC · Post by **HoundofSC** » Mon Jan 07, 2013 10:13 am

E5B wrote:Ladder: min to max in half grain increments.

Seated: 1.940"

Group size: all were 1.5" or worse, spread out all over

Primer: CCI small rifle

We shall see what these 32 grainers do.

.5 grain increment jumps is the problem. you could have jumped 2 or 3 nodes and never saw them , look at the ladder I did on the 34 grain dogtown thread. a difference of .2 grains can make the difference between a 2 inch group that was all over the paper and a .5 inch group

My buddy who shoots BR does his workups, min to max using .1 increments, I am not that patient.

RAMOS · Post by **RAMOS** » Mon Jan 07, 2013 11:29 am

Yep, you could have easily jumped right over the node by using .5 grain increments. The 39gr SBK's seem to have exceptional accuracy in most 12 twist barrels, as long as the rest of the load and components are "correct". I will go out on a limb here and say that your Hornaday brass may be messing with you as well. Does not seem to be very consistent and a bit hard to work with. Whatever is going on, I REALLY doubt that it is the bullet.

magnum · Post by **magnum** » Mon Jan 07, 2013 3:23 pm

E5B wrote:I have a CZ 527 American topped with a VXIII 3.5-10x40 that I've been working loads for.

Started with 39 gr SBK's and Benchmark (Hornady Brass, CCI and seated 2.940"). Five shot groups were no better than 1.5" - that's from min load working all the way up to max.

Moved on to H4895 with same bullet. Same result.

There is no crown damage, all scope mounts are tight and I'm shooting from a good rest. I decided to move on to 32 gr Nosler BTs with Benchmark and will post back after the range.

Anyone with a CZ have issues stabilizing the 39 gr SBK's?

i to found it hard to get 39 bks to group as i was taking my loads up (i found that taking up to far

)past that sweet spot i all most gave up on them but some of lads told me i was taking up to much 0.5 and to go up in 0.2 of a grain (h4895) and that took it from a 3" grouping down to a 0.5" which fine for whot i use it for

iamdan · Post by **iamdan** » Mon Jan 07, 2013 8:24 pm

Hi guys, I'm new to this but I thought I'd chime in... I've been having nothing but better luck since I went from 32gr to 40gr vmax. Same components, but with similar to better groups. 1:12 twist savage model 12.

broper · Post by **broper** » Tue Jan 08, 2013 6:02 am

I have a 700 Rem. VLS .204. I have really had good luck with the Nosler 32 gr. Varmageddon, BLC(2) powder, Win brass, and Rem. 71/2 primers. Started with 28 gr. powder, worked up to 30 gr. At 29 gr. I shot a .169 group. My biggest group was .718. I would really reccomend the Varmageddon. Gun writer, John Barsness, reccomended them to me and I'm very happy with them. They're super accurate and very reasonably priced.
Bob

Jim White · Post by **Jim White** » Tue Jan 08, 2013 11:21 pm

E5B wrote:I have a CZ 527 American topped with a VXIII 3.5-10x40 that I've been working loads for.

Started with 39 gr SBK's and Benchmark (Hornady Brass, CCI and seated 2.940"). Five shot groups were no better than 1.5" - that's from min load working all the way up to max.

Moved on to H4895 with same bullet. Same result.

There is no crown damage, all scope mounts are tight and I'm shooting from a good rest. I decided to move on to 32 gr Nosler BTs with Benchmark and will post back after the range.

Anyone with a CZ have issues stabilizing the 39 gr SBK's?

With my CZ527 American I never had any problem stabalizing a 39 SBK or a 40 H-VMAX but the 39 SBK was the more accurate of the two for me. However I did have the following issues with it;

- Mine was neither beaded or free-floated. The groups were so-so but afterwards this little guy turned into a hammer. With consistent components this little thing will shoot consistent 1/4" groups @ 200 yards (presuming the

behind the trigger does his). Try the dollar bill test with both a warm & cold barrel. If it fails get that fixed.

- FWIW, a CZ-527 American has a thin barrel and from my experirnce with mine, it doesn't take to many shots to get it warmed up and only a few more before it gets toasty. This will alter your groupings, so be aware.

- There are other subtle things that will impact your groups. One of them is a round in a warm/hot chamber any longer than a few seconds, even with Hodgdon's EXTREME powder line, although not quite as bad. Also, if you're seing even a smidgen of mirage in your scope (barrel) let it cool.

HTH,

bow shot · Post by **bow shot** » Wed Jan 09, 2013 10:02 am

Jim.. you just nailed something, made the light come on big time for me

... the thing about letting rounds sit in a hot chamber. Very much an "AHA!!" moment for me. Can't wait to do a little experiment...

Thanks!

iamdan · Post by **iamdan** » Sat Jan 12, 2013 11:36 am

I shoot all my loads at 300yds. I haven't put my current load through any high volume testing but the last 5 loads I tried, 0.1 gr increments from 26.4gr to 26.8 gr, starting from lower to higher in 3shot groups, shooting pretty much as fast as i could load without any cooling time or having empty cartridges in the chamber for more than a few seconds and went 2.1, 1.8, 1.325,1.275, and 0.4. Yes 0.4". Seems a bit lucky so I have another 30 rounds waiting to prove to myself I'm not crazy, and eliminate some of the variables. Also noted a fairly louder report and more recoil in the three hotter loads. No sign of pressure that I can detect though. 40gr VMax, Win brass, h335, federal 205 pr. Savage Model12 BVTS

I've heard it mentioned that H335 is not known for its temperature resistance and I would change to something else in a heartbeat if I could prove it, as I have no plans to develop different loads for different seasons if not necessary. Do any of you use H335 in the 204?

Jim White · Post by **Jim White** » Sun Jan 13, 2013 11:46 pm

bow shot wrote:Jim.. you just nailed something, made the light come on big time for me ... the thing about letting rounds sit in a hot chamber. Very much an "AHA!!" moment for me. Can't wait to do a little experiment...

Thanks!

I stumbled across an article a while back that really caught my eye on the subject. Wile the temperature insensitive rounds were better, they too had significant varancies.

Darkker · Post by **Darkker** » Mon Jan 14, 2013 10:14 pm

As a little bit of clarity on the "Extreme" powders:
ADI builds those extruded powders with a SPECIFIC cartridge/case in mind. Those properties are NOT a universal trait. In most instances, the "difference" is not statistically valid anyway. Take the 22-250, "Extreme" won by a blistering 6 fps.....Pretty cool huh?
Dr. Denton Bramwell has done some testing on the "extreme" powders in "other than designed for" cases. There generally seems to be something to same parent cases, but it doesn't translate into others. Varget for example(built for 308) retains some virtues in the 243, but is a steaming pile in the 223.

If you use extruded powder and think you will "miss a node" without measuring in 0.1gr increments: First you better not be using an affordable electronic scale. The better ones are only accurate to .1gr. meaning you could be off by .2. You also might want to get the allowable BR/BD variation in writing. Because the swing is larger than that. If you are shooting for consistency with extruded, you gotta start using volume; not weight.
Another possibility for your issues could well be from Hard Carbon. Another side effect of ADI's Extreme Extruded powders.

IamDan,
H335 & Win 748 are essentially the same powder, individual lots may vary of course. Barrel heat will be the biggest cause of what you perceive as "sensitivity" to heat. That powder will be fine in most situations, even if it is a little grey around the edges.