.303 British Primer Protrusion

[Marnoot]

I'm a bit of a novice reloader, and my .30-06, 7.62 Nagant, .303 savage, and other loads have been working out well, but I'm having some problems with my .303 British. After firing, the primer protudes out .020" to .031". No signs of over-pressure: extraction was easy, no bulging or splits. Is this possibly an under pressure situation? Regretfully, I misplaced the data on this load when I recently moved, but I pulled a few, and they're loaded with 37.6-38 grs. of IMR 3031, behind (don't have the box the bullets came from and my scale doesn't go past 100 gr.) I believe 150 gr sp spitzers; new remington brass. I didn't think to look for fouling around the neck area before I cleaned them, so I didn't see if that was the case.
Are these loaded too light? I'm just a bit confused as I haven't had this happen to me with any of my other calibers I've loaded. Any tips?

Thanks,
Greg

 

[RON in PA]

If you were loading to too low a pressure you would see soot on the outside of the cases, more likely you are seeing signs of excess headspace.

 

[Marnoot]

The shoulder on the fired cases is pushed upward towards the mouth roughly .040" in contrast to the unfired, full-length sized brass. Is this something normal that neck-sizing-only the fired brass will take care of from this point on, or do I need to have a gunsmith fix a headspace problem?

 

[pbhome71]

I checked my manual and 38gr of IMR 3031 with a 150gr SP is definitely not a high pressure load.

My Speer Vol 13 does not have IMR 3031. But running QuickLoad, an estimate pressure for 38gr with Sierra 150gr SP yields around 34K PSI (for comparison, SAAMI spec is max 49K PSI)

Regarding Neck-only sizing, I think you are doing fine, as long as you don't mix brass from different rifles. I have 2 Enfields, I bought a winchester brass for one, and a RP brass for another. I also Neck-only sizing.

-Pat

 

[RON in PA]

303 military rifles were made with loose chambers to accommidate corroded ammo (remember the British Empire was all over the world, esp. in hot, humid places). Upon firing 303 factory ammo or full length resized ammo typically exhibits expanded shoulders. More importantly, from the reloaders point-of-view, is case-head separation that often happens on the 3rd or 4th reload. Cases often show incipient separation after one firing. You can check this with a straighted paper clip that has a right-angle hook on one end. Stick the clip into the case and feel for the separation at the botom of the case. The Lee-Enfield, excellent battle rifle that it is, was never designed for the reloader.

You are doing what is recommended to extend the life of 303 brass, neck sizing and reduced loading. If you have a #4 rifle interchangeable bolt heads are available to change head space, but they won't eliminate the chamber dimension problem.

 

[DarthBubba]

You can also try a heavier bullet.
Try a 180 grn bullet with 39 grns. Of IMR4320 should give about 2170 fps at muzzle.
If you have an earlier model rifle it was made to shoot at least a 174 grn. Round the original load was a 215 grn. military round and it will like the heavier loads better.
You can also try the load that I have had the best luck with which is between 42 and 46 grains of IMR4350 with a 180 grn. Hornady BTSP .311 size.
The over all length of the cartridge is slightly longer than the 150 grn. Rounds and that can take up some of the slop in the chamber. Also you can try RON in PA advice if it is a number 4 rifle.

DarthBubba

 

[Marnoot]

It is a No.4. I think I'll try heavier bullets in the future and stick with neck-sizing. I have a hundred or so 174 gr. bullets I pulled from a bunch of Pakistani ammo I bought before I knew how terrible the stuff was. I'll try those in this next batch of neck-sized-only ammo and see how it goes.

Is the primer protrusion a side-effect then, of the full-length sized brass being fired in a chamber with slightly different shoulder specifications? Thanks for all the input!

Edited to add: I'm using Federal large rifle primers.

 

[The Bushmaster]

Just an off hand note. I was having the same problem with my .30-30 Winchester (an old one at that). My gunsmith said that I was experiencing a worn chamber and the head space was out of tolerence, but nowhere near dangerous. He suggested that I fire form the cases and full length size them short of .030. Anotherwords set the resizing die with a feeler gauge the distance that the primers protrude off of the shell holder rather then to set the die touching the shell holder. On the second firing you will see a difference if your problem is excessive head space. What happens is that you will move the shoulder forward so it takes up the space better. The trick worked on my Winchester 94. Good luck....

 

[rbernie]

Is the primer protrusion a side-effect then, of the full-length sized brass being fired in a chamber with slightly different shoulder specifications?

In a nutshell - sorta. The shoulder moving forward is a side effect of the chamber being cut large at the factory to allow dirty ammo to be chambered. While the oversize chamber is great if you're a grunt in the mud of the trenches, it'll tend to allow SAAMI-sized brass to grow a fair bit. On the other hand, the primer backing out a bit is usually a sign of mildly excessive headspace or too-light a load. Since 38gr of 3031 is a normal load for 150gr .311 bullets in the 303R, I'd suspect a wee bit 'o extra headspace.

Neck-sizing will cure the first issue (shoulder moving) since that'll allow the brass to grow to fill the extra chamber space. It probably won't cure the headspace issue since the case headspaces on the rim - you can either live with it, find brass with a thicker rim (not as hard as you'd think), or get a next-size-up bolt head (also not hard).

 

[Marnoot]

I've got two brands of brass, Winchester and Remington, both of which have rim thicknesses of exactly .063". My rifle currently has a #2 bolt head on it. Any ideas of brass brands with slightly thicker rims, or sources for a #3 bolt head? I've found alot of places that list it, but they're all out of stock.
If/when I get a size 3 bolt head, I understand they require some fitting. Is it a part I can fit myself or would I need a gunsmith to do it? In the meanwhile, is there any negative effect to primer protrusion that would cause me to not want to fire the weapon until I get things fixed? Thanks!

 

[rbernie]

Any ideas of brass brands with slightly thicker rims, or sources for a #3 bolt head? I've found alot of places that list it, but they're all out of stock.

Sometimes you'll find PMC brass to have thicker rims. PMP brass also tends to the thicker side of life, at least in the lots that I've gotten. I got my #3 bolt head from eBay - it cost me about $30.

Frankly, I'm not sure that it's a problem worth messing with. Given that there are no signs of over-pressure, I can't see how having the primer back out a wee bit is going to cause any harm.

 

[Vic303]

Gunparts Corp (Numrich) should have all sizes of Enfield bolt heads I would imagine.

 

[rbernie]

Gunparts Corp (Numrich) should have all sizes of Enfield bolt heads I would imagine.

Nope - been there, done that. The #3 bolt heads are rarer than hens teeth. As far as I've seen, none of the traditional gun parts or mil-surp suppliers have had any in stock for the last several years. AuctionArms or eBay are your best bets....

 

[Vic303]

Didn't realise Numrich was out. Try this link for a list of other possible suppliers.

http://www.webpages.uidaho.edu/~stratton/parts.htm

Looks Like Lawrance in Australia has #3 boltheads available.
http://www.lawranceordnance.com/new/acces-gunspares.html

 

[Archie]

To avoid excess headspace problems...

Load new brass with bullets seated out far enough to engage the rifling. This will insure the case head is up against the bolt face and the case can't stretch; it'll just blow out against the chamber walls and 'fireform' itself.

When you do this, use a basic starting load. The extra pressure from putting the bullet in the lands won't spike pressure far enough to worry.

You can also use a charge of fast burning powder (2400 works well) and a wax plug or cap; but you have to figure a way to keep the case back against the boltface. Squeezing the case mouth out of round may work, but you can't distort it too much or the case won't chamber.

Once fired, neck size only and reload normally. The cases should last a good while.

By the way, this will work with any rifle with excess headspace. You just don't want to sell it to someone else without them knowing about it. Factory ammo can be unpleasant with extra headspace.

I don't have a SMLE. I probably should.