How to reduce free bore in No1 Mlll*

[buffdog]

125 grn sierra pro hunter projectiles. The problem i have with this projectile is the loss of velocity caused by the amount of freebore and gas bypassing the projectile before it can engage in the rifling. The reloading data in the manual im using suggests I should be getting around 2900 fps but I estimate im only getting between 2000-2200 fps.

A velocity loss of 700 FPS in less than half an inch is hard to imagine. Your manual suggests 2900 FPS but you ESTIMATE that you are getting 2000 FPS to 2200 FPS. First of all, a Manual is only a generalized guide and the velocity reading will vary depending upon firearm used, barrel diameter, barrel wear, primers, cartridge case, and other factors.

You should run some of your reloads through a Chronograph and get some true readings before you do anything else. How did you come up with your ESTIMATED velocity? I would fire and chronograph your loads in at least two other .303 rifles to get a good idea of what is happening.

Next. What is the actual diameter of your 125 grain projectiles. Are you using .308 inch diameter projectiles designed for the 30 calibre bores such as 30-06, .308, etc. or are you using .312 inch diameter bullets designed for the .303 British?

What is your accuracy? It does no good to have something going like a bat out of hell if you can not hit anything with it. I have used 123 grain Remington bulk bullets designed for the 7.62x39 Russian cartridge out to 600 yards with good results.

What is your actual load? Powder, charge weight, case, primer, overall length?

I believe you should do some more factual testing before you try to fix a problem that may not exist.
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