Thread: Loose projectile

Originally Posted by Happy Jack

Its possible as I didn't have any ammo carriers available so had them loose.

Greetings @Happy Jack,
Looks like the cavalry in the form of dannyb galloping over the horizon is a little delayed so here is something you can try yourself. I am pretty sure that your problem is seating the projectile too deep although other things may also be involved. You can check the maximum cartridge length quite easily. You need a cleaning rod, some callipers and a bit of tape. Set your rifle up in a vice nice and steady with the bolt in and cocked. Your cleaning rod needs to have a flat tip. I use my old Parker Hale rods but if you have a later type with the female threads you will need a spear point jag with the front filed flat. Run the cleaning rod down the barrel until it touches the bolt face. Put the bit of tape on the rod flush with the muzzle. Next pull the rod back a bit and slide a projectile point first into the start of the rifling. This is a bit tricky with an action with front lugs. I usually hold the rifle muzzle down and drop the projectile in. Hold the projectile in place with another rod and slide the cleaning rod in to touch the projectile tip. Now without bumping anything measure the distance between the tape and the muzzle. This is your cartridge overall length with the projectile touching the lands. Deduct 1mm (0.040) from this measurement and you have a good place to start. dannyb will do this in his own and likely more precise way plus check all the other items when he arrives but this should get you started.
Regards Grandpamac.

Then measure you max mag length and compare with your touching the lands minus 40 thou length. The mag length may be your determiner.

if you seat a projectile really long,use that dummy round in chamber held by hand/finger when you insert cleaning rod...stops it falling or not sitting in throat properly.

Originally Posted by Micky Duck

if you seat a projectile really long,use that dummy round in chamber held by hand/finger when you insert cleaning rod...stops it falling or not sitting in throat properly.

Nice tip Micky. Easier than a second cleaning rod.
GPM.

Right, so with time on my hands part of today I started to look at this again.

I googled seating depth to see what sort of baselines there might be and from my reading lots of results said depth = calibre. I know this is very subjective but it gave me somewhere to start.


So cases are 48.4mm and projectiles are 26mm and so at 6mm calibre this theoretically would give a seating depth resulting in a max length of 68.4mm.

I made up a dummy round and seated it to that and although it did feed the bolt was very stiff. I reduced it to 67mm and its still very stiff.

Tomorrow I'm hoping to do the cleaning rod thing. I ran out of time today.

On a side not I could seat a projectile 40mm and it would still fit in the magazine those things are huge.

More work Friday methinks and hopefully some pictures too.

Im guessing you meant to type 70mm????
try colouring projectile with vivid felt pen and do the chambering thing again,open and shut bolt a few times ,lift and close bolt handle so projectile will rub felt off if is touching rifling...

Originally Posted by Micky Duck

Im guessing you meant to type 70mm????
try colouring projectile with vivid felt pen and do the chambering thing again,open and shut bolt a few times ,lift and close bolt handle so projectile will rub felt off if is touching rifling...

Will do.

Go and do a Youtube search for the Alex Wheeler method of finding the seating depth .

Thanks @zimmer dannyb did describe that but it was good to see it demonstrated on Youtube

The continuing saga of my quest.

Spent a couple of hours in the shed this afternoon and did some measuring with a cleaning rod and a couple of rounds one a factory PPU round and one a seated long 63mm Sierra round.

From what I could determine using this method (bear in mind I was measuring to a bit of tape) it came to 60-60.78mm.



Factory PPU round


Factory round in magazine


Comparison of rounds the black one has been cycled twice and no marks seen.


In my post yesterday I made a typo, I recalibrated my calipers with e new battery today and the following measurements were recorded along with the 60mm chamber measurement noted above.

Resized case 48.58mm
Sierra 1455 projectile 21mm

Seated 6mm into the case gives me 63.5mm which is really tight to close the bolt. I reduced down to 62mm and its still tight so I'm guessing at this point due to a mistake on my part in damaging the case of my dummy that the 60mm is going to be pretty close and the 59.4 of factory rounds is good but seats the projectile quite deep at 9mm approx.

I'm going to stop for now as its getting confusing and will hope all this lockdown nonsense is over soon.

soon as I can I'll come out mate will make all of this a lot simpler

have you trimmed overall length of case back to spec????
if case is tight to chamber....and projectile ISNT rubbing......something else is touching...NOT the projectile

Originally Posted by Micky Duck

have you trimmed overall length of case back to spec????
if case is tight to chamber....and projectile ISNT rubbing......something else is touching...NOT the projectile

Yep pretty sure that is what my mistake was hence why I stopped. But I do have a better understanding of a few things after today so at least I learnt something.

I'm not going to do anymore until such times as I can catch up with dannyb

Big shout out to @r87mm for calling in today on his way back from the Molesworth and helping me to measure my chamber and set up my sizing die properly. Thanks mate and good to meet another member of this great place.

Don't ask me the numbers its all written in my book which is out in the shed.