303 reloads

[ovenpaa]

I neck size .303 after the first firing and I also build them as long as possible as well. The important part is consistency, they need to be as close to identical as you can make them, if a bullet feels tight when seated then pop it to one side for plinking or as a fouler and keep the good ones for when they are needed.

I assume you mean short seating with a low neck tension so that the bullet is pushed into the neck when the bolt is closed? This would leave the bullet 'jammed' and is not something I would ever do with one of my .303's but I am not an expert on the cartridge and other may disagree.

EDIT - By building long I mean I build them to a few thou off the lands if possible so the bullet has less distance to travel before it engages the rifling.

[Steve]

Building long is what i meant,but didnt know why.Thanks for clearing that up.

[Steve]

Tested more reloads this morning.This time they were full length sized and slightly more powder (35grns instead of 34.5).

Not as tight as before,but this might have been me rather than ammunition.


I'll have a stab at the Mauser next.

[ovenpaa]

They are still good groups, did you build them any longer this time? What you need to do is find the maximum cartridge overall length (COAL) you can build is and then back it off say 30 thou (.020") to start with

You can use proper tools for this however an easy way is to take a case fired in your rifle and neck size it then cut a couple of slots in from the mouth to just in front of the shoulder, then de-burr and clean it up, then take a bullet and give it a wipe of case lube and push a bullet in so that it is just engaged, them chamber the case and bullet slowly, with luck the bullet will move back in the neck because of the slots allowing the neck to open slightly.

Open the bolt carefully and measure the COAL. Repeat the process.

Now have the look at the bullet, if it is heavily grooved from the rifling the neck tension is too tight and you need to tweak it carefully so it has less grip on the bullet. I use a permanent black market to mark the bullet so I can see where it engaged in to the rifling.

Once you have your COAL build an empty bullet to your chosen length make sure it still fits the magazine.

[Dougan]

They are still good groups, did you build them any longer this time? What you need to do is find the maximum cartridge overall length (COAL) you can build is and then back it off say 30 thou (.020") to start with

You can use proper tools for this however an easy way is to take a case fired in your rifle and neck size it then cut a couple of slots in from the mouth to just in front of the shoulder, then de-burr and clean it up, then take a bullet and give it a wipe of case lube and push a bullet in so that it is just engaged, them chamber the case and bullet slowly, with luck the bullet will move back in the neck because of the slots allowing the neck to open slightly.

Open the bolt carefully and measure the COAL. Repeat the process.

Now have the look at the bullet, if it is heavily grooved from the rifling the neck tension is too tight and you need to tweak it carefully so it has less grip on the bullet. I use a permanent black market to mark the bullet so I can see where it engaged in to the rifling.

Once you have your COAL build an empty bullet to your chosen length make sure it still fits the magazine.

For my first .303s I copied the COAL of the PPU I've been using....one of my next questions, was going to be, 'how to find the perfect COAL for my rifle'? ...Nice one

Steve: don't forget that if you're using cases that have already been fired in the rifle you intend to use, then neck sizing gives you the advantage of the case fitting your chamber better - if you 'full length' resize..you lose that advantage....

[Steve]

Thanks for the tips.I'll have a go at that tomorrow.Other than a little more powder i did decrease the neck size a bit so it gripped the bullet more firmly to see it that makes any difference,but i think i tried too many things at one time so unsure of the results.

[Steve]

Steve: don't forget that if you're using cases that have already been fired in the rifle you intend to use, then neck sizing gives you the advantage of the case fitting your chamber better - if you 'full length' resize..you lose that advantage....

I was given this brass by other club members a while back Dougan and just wondered if full length resizing made any accuracy difference compared to neck only.Rest of the brass has been fired in my rifle so is alright for neck size only.

[Steve E]

As for sorting the COL out it depends on what .303 you are loading for. If it is a No4 or a SMLE, you may find that it is impossible to load the bullets long enough to reach the lands and then back off 20 thou' and still have enough bullet (if any) left in the case. I know this is the case with the No4 that I have and the SMLE's that I have owned. No4s and SMLE's were chambered long specifically to allow for dirt, mud and other detritus not to effect the loading of round in a combat situation. My Winchester made P14 on the other hand has a chamber that is as near to Saami specs as you can get in a .303 so I am able to load to a COL of 3'' using Sierra 174 Match kings. Having a tight chamber in the P14 also means that the shoulders dont get bumped forward like they do in a N04 or SMLE. If I do my part the P14 will shoot to about 2 1/2 MOA which is very good for a .303 whilst my No4 shoots about 3 MOA. I hope to improve my No4's ability this year when I put a new barrel on it that will be cut with a match chamber and have the stock glass bedded. I know that it will then not be eligible in any classic/historic matches but I have other competitions in mind for it.


Steve E

[Dougan]

Steve: don't forget that if you're using cases that have already been fired in the rifle you intend to use, then neck sizing gives you the advantage of the case fitting your chamber better - if you 'full length' resize..you lose that advantage....

I was given this brass by other club members a while back Dougan and just wondered if full length resizing made any accuracy difference compared to neck only.Rest of the brass has been fired in my rifle so is alright for neck size only.

Arr, ok sorry mate - if the cases were shot in someone elses rifle, then yes - full sizing. You might get better results from them on the next reload...?

[Dougan]

Having a tight chamber in the P14 also means that the shoulders dont get bumped forward like they do in a N04 or SMLE

I've definatlly seen this in the cases fired in my SMLE - but it's more the shape of the shoulder, than the position of it (though they have moved forward a few thou).