Ammo Testing in the Club
OK, so it is not Eley with a 50m
indoor range and a clamp that weighs tons, but it will give you an idea
if you can select ammo that does decent groups from your barrel.
You need
- 2 people - 1 to do, 1 to help,
- Duncan Murrays patent rifle holder
- to hold the rifle,
- FP4 - it has been drilled to take
the rifle holder,
- 2 clamps - to hold the rear of the
rifle holder solid,
- The plastic risers and some tops
off eley boxes - to give height under the bench leg,
- 2-3 consectutive details,
- 2-3 blank cards put on OLD
backing cards. The first card has a spotter taped in the middle,
- A pen and paper,
- Oh and at least 10 rounds of
each type of ammo you need to test.
The Plan
- Be methodical,
- Be slow,
- Warm the barrel,
- Shoot groups of 10 with each ammo, move the rifle clamp after
each group,
- Document,
- Select any particularly good or bad ammo and retest,
- Document everthing.
Some more Detail
- You need 2-3 consectutive details to do a decent job. You
NEED to be on FP4,
- Put up 3 BLANK cards for your details. On the first card
put a single black target in the middle. Dont use good backer
cards, use scrap ones.
- Fit the rifle clamp to FP4 - which has a hole drilled for the
pivot point. The rear is held in place with the two wood clamps.
- Put your normal sights on the rifle (you wont use them but they may will effect the
groups), but remove the handstop and dont put the bolt in to start with.
- Clamp up the rifle, and with the bolt removed have a go at
bore-sighting on your single aiming mark. DONT use the screw leg
on the bench to give height - it shakes too much in use - use the wee
black plastic risers under the leg. 1 Eley top of a box (about
1mm) under the leg will rise you about 1" on target.
- Warm the barrel on the black mark, use a scope to make sure you
are on target
Now we start
- Move the rifle to (say) the
bottom left of the card by guessing how little to move the bench.
- Shoot 10 shots and document
which ammo yo uused and where it landed.
- Make sure you ONLY touch the
trigger. Dont lean on the bench, dont press on the rifle, dont
rest on the rifle clamp.
- Move the rifle clamp by
about 1 mm at the rear to move the group an inch (see marks on the
table for a clue).
- Shoot another 10 shots and
redocument. 40-50 shots in a 15 minute details is probably
right. THINK ABOUT BARREL HEAT.
- Dont leave the bolt open
with air cooling the barrel at any time. Load and close the bolt,
OR put a breech flag in.
- If you can aim the clamp
properly you can use 1 card for about 10-15 different ammo types.
If not you may need to use the cards you put up for the successive
details.
- That is it. When you
think you are finished, reshoot the best and the worst grouping ammo to
get an idea if it was you, or is the ammo.
- Be consisiderate of the folk
shooting comp cards round about you.