.300 Whisper Accuracy or lack of!

[Bill G]

Hi Guy's

I've just built myself a .300 Whisper, or whatever you want to call it. I asked for a .300 whisper barrel from a barrel maker, CH tool company .300 Whisper dies & .221 fireball brass. I built it on a Brno Fox 2 (no semi-auto's allowed where I come from). I've gone out and shot it twice now, and can't get it to shoot at all. My worst group at 100 yards is 6 inches. I've used 240gn SMK's, 180gn SGK's & 160gn Hornady FTX's, all with varying powder weights and still to no avail. Any ideas? the last group of 240gn SMK's shot a verticle 6" group, most other groups were all over the show. All powder charges were very carefully weighed an a balance scale, and the powder was AR2205, which I believe is an equivilent of H110. Some of the loads are compressed. Can someone tell me exactly what effect compressed loads have, and what is too compressed? My 240gn SMK's have to be seated way out to reach the lands 2.3" And any shorter than this they are compressed too much I believe. I may be missing something big time, so any help would be appreciated.

[d-mon]

Hi Bill G,
I live across the pond.
I have built my whisper on the same action.
And have had sometime similar problems.
!st: what is the twist on your barrel?
2nd: Was your brno in 222 or 223 originally?
3rd: what powder are you using?

Yes ,the 240 smk are crushing the powder, that is normal, specially if you use a 222 magazine in your rifle which is shorter than a 223 mag.

I went to the range today and tried the 208 amax, right in the land, with 8,7 gr of vita n110. I got a nice cluster at a 100yards. The only problem is that i had to single load each round because they were to long for my mag.

consistency in you reloading is important (I turn my necks, weight each charge to 0.1 grain), weight my cases.
And consistency in your shooting is important as well:
a rear bag below the but is a must when shooting of a bipod or a front bag.

If your rifle is heavy it helps as well to control it when that slow bullet is still traveling down the barrel under recoil...

ND

[Alleycat]

+1 on VV N110

[Bill G]

Originally Posted by d-mon

Hi Bill G,
I live across the pond.
I have built my whisper on the same action.
And have had sometime similar problems.
!st: what is the twist on your barrel?
2nd: Was your brno in 222 or 223 originally?
3rd: what powder are you using?

Yes ,the 240 smk are crushing the powder, that is normal, specially if you use a 222 magazine in your rifle which is shorter than a 223 mag.

I went to the range today and tried the 208 amax, right in the land, with 8,7 gr of vita n110. I got a nice cluster at a 100yards. The only problem is that i had to single load each round because they were to long for my mag.

consistency in you reloading is important (I turn my necks, weight each charge to 0.1 grain), weight my cases.
And consistency in your shooting is important as well:
a rear bag below the but is a must when shooting of a bipod or a front bag.

If your rifle is heavy it helps as well to control it when that slow bullet is still traveling down the barrel under recoil...

ND

G'day D-mon,

I was only over your way a month ago, spent 4 weeks on the South Island. We got both of those polar blasts that came through, I've never seen so much snow. Bit of luck and I'll be over there for the roar next year.

I've been using AR2205, with very little success, similar to H110. I've now ordered some N110 after yours and Alley cats advise. I shoot off a bench with tripod and rear bag so all good there and I'm using a 16 x scope for load development to try and eliminate any physical influence.

The barrel is a TSE 1:8 at 18 1/2 inches and mid weight, my Brno was originally a .222.

When the powder and prodgies turn up i'll seat them right out to the lands and post back here. Cheers heaps for the advice.

P.S. Go the Walabies

[Bill G]

Cheer Guys, I will give the N110 a try and see how we go. D-mon I was just over your way a month ago, spent an awesome month on the South Island. might get over for the roar down the Hollyford next year with a bit of luck. I will post the next lot of results next time I get a chance to go out.
P.S. go the Walabies

[d-mon]

It looks like the wallabies have not done so great, a bit like the French tonight.
And the warrior won as well!

ND

[Colohunter]

I feel your pain, I haven't been real satisfied with my Whisper groups either, but they have settled around 1.5" with 150gr Hornady FMJs (which is mainly what I shoot to save money, loaded subsonic with 1680). I still would like to get a new free float tube to see if that helps a little, but that wouldn't help you since you aren't using an AR15 platform.

Since you are getting vertical stringing I would check your scope mount to make sure it isn't moving around at all. I had that problem with one of my rifles, though it led to two distinct groups in my 5-shot strings.

[Bill G]

It took a while but I got to shoot the Whisper again, maybe I need to get a less intrusive job.

Vhit. N110 was the answer the velocity has stabilised and the groups are now around an inch, with the 240gn SMK all but touching the lands. Unfortunately this round does not fit in the magazine by .100", so the next step will be to get it to fit the magazine and see how it shoots.

[Hoser]

I have the worst luck with the 240s. Very finicky. 220s for me.

[Trikstr]

SSK upper w/16.25" 1:8 twist Shilen bbl. SSK reflex style suppressor.
Up until today I have been using Rem. 7 1/2 primers exclusively. Best groups have been around and inch. Had a load today that will be retested soon.
200 grn Sierra MK
8.6 grn N110
CCI 400
OAL 2.200"
reformed 221 brass
1-1070 fps
2-1027 fps
3-1029 fps
4-1025 fps
5-1020 fps
Es-50
Avg-1034
Sd-20
If the 1st shot is edited from above the results are
Es-9
Avg-1025
Sd-4
1st shot of the string velocity is always high and consequently land higher(2.1") in this case for a group 2.335" c2c.
Shots 2,3,4 were in one hole(.127"c2c),5th touching 2,3,4 low(.334" c2c)
Fired next test load fairly close together. Same load above except WSR primer. OA group was 1.42" c2c.
Next load was
208 grn A-max
8.6 grn N110
CCI400
OAL 2.210"
+1074 fps
-1049 fps
Es-25
Avg-1062
Sd-9
Fairly round group .932" c2c
Last load same as above except WSR primer.
+1084
-1075
Es-9
Avg-1079
Sd-3
Group size 3" c2c
Appearantly my gun prefers the CCI 400 primer(over 20yrs old).
Don't be afraid to try different component combinations. I also have some Fed 205M I had better try.