HEADSPACE

[Col]

Hi guys, I have been reloading for my Remington 700 .308 and my P14 for about 3 years,I have never yet had any bad experiences
but lately I have been reading about others who have experienced problems due to the headspace condition.
I own and shoot two rifles suited for the 308,(although one is 7.62). I keep the fired cases seperate in marked boxes
and lately I have been neck sizing only. The question I would like answered if you would be so kind is, Due to the cases being fire formed would this prevent the issue of headspace problems

[Tower75]

I've never heard of it being a problem.

If you neck size only, and if you use the cartridges that were fire-formed in the chamber of the rifle you are using, then you wont have a problem.

Regards
T

[DaveT]

You MAY eventually get cartridges that become hard to chamber and need a thou or so shoulder 'setback' at some stage depending on how much pressure your charges are creating... THEN you may create a headspace issue if you over-do the shoulder setback.... plenty of stuff on the internet or the better reloading books on this technique.

[ovenpaa]

You should not see any significant head space issues with a Rem700 or even a P14 as they are both front lockers, so as long as they are in good condition you should be OK. The SMLE which is a rear locker is slightly different and had numbered replacement bolt heads to counteract this. You can buy No-Go gauges to check.

As Col says, neck sizing can eventually allow the head to shoulder length to grow to such a point that the bolt is hard to close and at this point you need to set the neck back by .0015" ish or just full length size. My 7,62x51 is on neck sized brass that is anywhere from 10 to 14 shots and is fine. My P14, well although I only neck size I tend to only use the brass for a handful of shots as I am wary of case head separation with the S&B brass. For some unknown reason I have never been happy with using the same brass in a .303 for more than 2-4 shots despite having read of people getting 20-30 shots from one .303 case.

I made a bump gauge insert that fits in a Hornady comparator holder for measuring how far the neck needs setting back for my 7mm. If you use the Hornady comparators let me know and I can pop a bump gauge insert in the post for you, I have a couple spare and they work for anything up to 8mm from memory.

[DaveT]

Ovenpaa... would you mind elaborating on your bump gauge please? Using the Hornady gauges and comparators I take unfired case measures of headspace and record these then measure again after first firing and finally after around 5 or so firings to 'track' incremental case growth. Dependant upon what I find I will at some point setback shoulders to somewhere around first-fired length or a little longer (this usually coincides with .001 / .002 thou)

HOW DOES YOUR METHOD DIFFER?

[ovenpaa]

My process is similar in principle, I wrote this for something else a while ago.

Shoulder Bump Gauge - I need to set the shoulders back on my 7mm from time to time, the problem was how to measure it reliably. I built an insert for the Hornady comparator base (The red bit) so it could be used in a digital vernier. The measuring is based on a precise register on the inside of the neck of the insert. Great, however when you are measuring a change of .001" the slightest misalignment of the case to the insert will lead to incorrect readings so I added a second insert that holds the cartridge head in place and finally a dowel precisely machined to fit inside two comparator bases.

To use, join the two bases together with the dowel and lock the grub screws, now attach it to the vernier. Remove the dowel and replace with the comparator insert and cartridge head insert, lock the grub screws up and off you go, perfectly measured shoulder bump every time.

I really should take a couple more pictures but this is enough to show the components.

EDIT - I will take a picture of the inside of the bump insert itself so you can see what it looks like.

[DaveT]

Now that is bloody clever!

I am always a little wary of variances in the reading of headspace using the Hornady tool so take multiple repeats to make sure that I get reasonable consistency... and that takes time.

You should market some of your ideas.

DaveT

[ovenpaa]

Such things are mostly me tinkering away in the shed, I do make things for other people from time to time but it is still mostly me just playing around with ideas. Next on the list is a small bench top Mill, ideally something old with some character, maybe in the new year

[Dougan]

Hi guys, I have been reloading for my Remington 700 .308 and my P14 for about 3 years,I have never yet had any bad experiences
but lately I have been reading about others who have experienced problems due to the headspace condition.
I own and shoot two rifles suited for the 308,(although one is 7.62). I keep the fired cases seperate in marked boxes
and lately I have been neck sizing only. The question I would like answered if you would be so kind is, Due to the cases being fire formed would this prevent the issue of headspace problems

Hi Col,

I can't advise you on the specific question - but I do know that depending on your action, then 308 and 7.62 aren't always perfectly intechangable - I have an Enfield action on my TR, and when I changed from the NATO 7.62 (RG) to the Win .308 (RUAG) round...I had to get the bolt head changed, allowing 0.006" more headspace, so that the bolt would close correctly.

[dromia]

It was the No 4 that had the numbered bolt heads not the No 1 (SMLE). They were made up as necessary usually with a "U" marking denoting a difference in specification.