A Trip to the Range

Greetings,
I got to the range yesterday to do some testing and sighting in for some of the rifles for this seasons F class. I think I have posted before about selecting the 60 grain VMax for my 1 in 12" twist .223. BM8208 had been selected as it was a little faster and denser than AR2206H. The rifle, a VSSF will be used at 300 yards. Three sets of data were selected which could not have been more different.
For the 60 grain projectile Hodgdon listed a max of 23.6 grains for 3,057 fps, Hornady listed a max of 25.3 grains for 3,000 fps and Brian Pearce in his Pet Loads series listed a max of 25.4 grains for 3,148 fps. Not all that helpful. The quoted pressure for the Hodgdon load was only 51,700 PSI.
Anyway some test cartridges were loaded with 23.6 grains of BM8208, 60 grain VMax projectiles in S&B cases with Federal primers. These chronographed 2,950 fps or 100 fps less than the Hodgdons data in spite of the extra 2" of barrel and the much heavier case. This speed was a better match for the Pearce data. A load of 25 grains of AR2206H (1 grain under max) was also chronographed with the 60 grain in SBMC cases (average weight) which delivered 3,140 fps.
For comparison Hodgdon claimed 3,057 fps from 23.6 grain, Pearce claimed 2,911 fps from 23.5 grains and Hornady claimed 2,800 fps from 23.7 grains all of BM8202 (IMR8208XBR). Hodgdon and Pearce used Winchester and Hornady cases respectively and 24 and 22 inch barrels. Looks like something in the 24 to 25 grain range will be the goods so will keep you posted.
My Sendero 7mm SAUM also made the trip to the range for a rough sighting in with its new scope. Load testing continues.
Regards Grandpamac.

Hey you can't get away without posting the accuracy results as well. I took the 6mm ARC I'm working up (Hornady 103s with 28.1 of 8208 in Starline brass with Fed 205s) and fired 3 shots at 100M for a 15mm group. Went back to 300Y and fired 3 more for a 55mm group. It was as windy as all hell but I wanted to get an idea on actual drop (2709 fps actual versus the 2745 the chrony had been telling me). Cheers

Greetings @Tentman,
The main aim for the day was to get a rough sight in for both rifles and try to make more sense of the varying load data so no actual groups were shot. Those will come later. I am using a 35P chronograph with a 4 foot screen spacing so am comfortable with the readings. The proof channel helps
GPM.

Greetings All,
Had a good look at the load data today. Brian Pearce's results are closest to my chronographed data so it seems reasonable to use that as a base. I can't be bothered with endless ladder tests so have selected 25 grains of BM8208 as a probable maximum and that with 24.5 grains have been loaded for a quick test tomorrow weather permitting. Expected velocities are around 3,060 fps for 24.5 grains and 3,120 fps for 25 grains. Looking at the data it appears that the Hodgdons barrel is much tighter than Brian's and mine and the Hornady barrel may be much shorter.
A quick count revealed that there are no less than six rifles in the cupboard that are candidates for F Class of which only two have been used so far. I could probably just shoot with one but where is the fun in that?
Regards Grandpamac.

Greetings All,
A reasonably calm day here so time for a little testing.
Attachment 233757
The target is made up using the predicted trajectory above the target centre at 200 metres with the rifle zeroed at 275 metres (300 yards). There was a variable left to right breeze blowing and the target shows it. The target was set at 200 metres and no attempt was made to aim off for the breeze. The rifle is my Remington VSSFII with a Mk4 4.5-14 scope lent by my son. It has some sort of fancy minute based scope reticle which I am still getting my head around. I prefer to make up a target like this rather than dialling and use the system for zeroing F class rifles at both 300 and 600 yards. I settled on the 25 grain load which still needs to be chronographed but should be a little over 3,100 fps
One down and one to go plus several stragglers of course.
Regard Grandpamac.

Greetings All,
300 yard shoot yesterday and I hadn't loaded anything for the VSSF so the bog standard T3 Lite in .223 I used last year was taken. The scope is a fixed 10 power Bushnell with a mil dot reticle and the loads use the 69 grain Sierra HPMK projectile. It was quite windy and 3 minutes left was needed to get the shots in the middle. My score was 53.01 shooting from my mini bench rest with a front rest and rear bag. The little T3 looked a bit out of place amoung the other hardware but I might have to keep it for the windy days at 300. There is a box of 75 grain ELDM projectiles here that might have to be loaded when the Sierra's run out.
Regards Grandpamac.