Accuracy and Velocity.

[muffett.2008]

I've had a couple of queries in relation to comments I have posted on the need to check the velocity of your Milsurp when Accuracy is in question or problems are encountered when zeroing.

As an old school Armourer and avid tinkerer, I check and record the velocities and groups of all my rifles with both the Milsurp ammo and my reloads.
This gives me a baseline which enables any problem regarding accuracy, to be quickly determined and remedied.

As most of the old school know, the relationship between Accuracy with our LE's depends on several factors, barrel wear, throat erosion, muzzle condition and correct/undamaged fitment of timber.

The constant comments regarding failure to perform with other than flat based projectiles, fails to take into account the subjective barrel and throat condition created by the Milspec. Ammo of the day, hence the constant and often irritating discussions regarding the rifles ability to use anything else.

These comments usually are in error, a simple recognition of the need to either change out a worn barrel, or adjust the load to suit would save the likes of us old hands bruising our foreheads or losing more hair than we can grow back.

The need to know your milsurp baseline is required to keep these old girls near their peak and capable of putting up a good fight, if you do your bit.

Muzzle Velocity varies from firearm to firearm, maybe only a few FPS with new firearms, but the odds that any brand will produce the same MV is next to none.

Knowing your Milsurp MV compared to your Reloads will help to overcome any variation in both accuracy and zeroing and will help you get the best out of your old klunker over much longer ranges than you probably shoot now.

What we must try to maintain, is a velocity range that allows accuracy with out stressing the firearm, we know what twist, what baseline velocity the milsurp round should maintain and the minimum acceptable levels of accuracy required, all we need to do is adjust our loads to maintain our velocity within the paremeters and we should be good to go.
If you cannot achieve a velocity range within these boundaries, it's time to think new barrel.

So we know the 303 Mk.7 pushes out at aprox. 2450fps, these are factory Specs, based on charge and twist rate, but will(and often do) vary from batch to batch and country of origin.
Maintaining your MV within a range from 2150 fps to 2450 fps will ensure no keyholeing when zeroing and keep everyone happy. (Whilst the Mk.6 round can drop as low as 1850 fps from 2250 fps)

Just to show the variation with Milspec over reloads, here are four rifles I checked yesterday, the Milsurp is flat base, the reloads are boattail.

1922 Lithgow Range Pattern, H barrel.........MV Milspec.2463, Reloads 2432
Attachment 84701Attachment 84692Attachment 84691

1936 Lithgow light barrel, worn........MV Milspec.2432, Reloads 2322
Attachment 84699Attachment 84695Attachment 84693

1937 Lithgow light barrel, worn........MV Milspec. 2431, Reloads 2361
Attachment 84700Attachment 84696Attachment 84694

1918 Enfield, Target Rifle configuration.......my baseline testing rifle.Milspec. 2429, reloads 2424
Attachment 84698Attachment 84697Attachment 84690



........and just to quell any comment about variable Milsurp ammo, the ones I use are all from a batch I have tested and found to be the best.........no, not Brit. or OZ, but Indian.
Five round test, 2384, 2379, 2382, 2382, 2383.
Lo. 2379, Hi. 2384, Av. 2382, ES. 5.62, SD. 1.73.
Most reloaders would sell their first born for those spec's.

Information

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[browningautorifle]

Good written piece, all one need is a chronograph and they're good...those are cheaper now than they've ever been.

[30Three]

Thanks for taking the time to share your experience Muffet. Your target spec rifle looks well sorted!
I have been using a chronograph when testing my reloads; especially when trying out new powder etc.
My No1MkIII* seems to have better accuracy at around 2320 feet per second. Where as my No4 rifle is better at close to the mil spec load at around 2440 feet per second.
I would love to get my reloads within 5 feet per second! (in my dreams)