Rifle Shooter – July 2019

http://www.rifleshootermagazine.co.uk 85

Accuracy and load performance with Matthew Cameron FEATURE

»

A QUESTION

OF TIMING

Matthew Cameron explores the impact of cleaning and shooting speed on group

size – and ends up with with some interesting results

I

n this article, I will address two simple questions. First,

will the first projectile out of a cold, clean barrel print out

of a subsequent group? And second, will the group size

vary depending on the speed at which the group is shot?

The real problem is, why are there aberrations in both

velocity and group size with ammunition that is handloaded

with some care, in particular with factory rifles? Many

hundreds of thousands of words in relation to these

variations have permeated the world’s gun writings for many

years, perhaps ignored by many because of the complexity of

the subject matter. Of course, it is patently obvious that the

rifles are almost certainly capable of shooting groups better

than what we achieve, providing they are fed with good

ammunition, but when all of the components (including the

trigger man) come together, there is an absolute limit as to

what the combination is capable of.

You can purchase a varmint rifle that will be guaranteed to

shoot 0.25 MOA groups. A good benchrest rifle is capable of

better accuracy – but I would suggest that the ability of the

man behind the butt and the outdoor environment play a

major part in the whole equation and affect the final result. In

addition, modern factory rifles have a much better accuracy

profile than those in the past.

As a minimum suggestion, the rifles need to be shot with

at least a bipod, preferably off a permanent or portable

bench; in this case, a rear sandbag should also be used.

The next step up is a forward rest, complete with both front

and rear sandbags similar to those used in benchrest. You

also need to ensure that the rifle sling studs do not catch on

the bags, and the bench needs to be stable. Personally, I

would trade speed for accuracy in any rifle, but you might not

agree. Overall, there has to be a balance.

There is no laid down process that specifies just how you

should test loads for the best results. In addition, there are

the items that affect the process itself and the results

obtained, such as increasing barrel fouling and heat from all

shots. But the question must be asked, is barrel fouling the

major cause of flyers? Let us not forget that some barrels

foul more readily than others. In addition, what is the role of

increasing heat?

BELOW: All the

loads were shot

off this bench