PP Firelapping load for .303

[no34570]

Hi Fella's
Have a Martini Enfield MKII,with a very dark bore,thinking of firing some unlubed pp slugs down her to help clean it up,it is chambered for the great o'l .303 British.

Any ideas?
Have these powders on hand:
ADI AR2205 (H4227/H110)
ADI AS30N (Clays Bullseye)
Win231
Bullseye
Unique
W296

These are left over from my revolver & pistol days,wish I still had em,sorry off topic there.
Also have most rifle powders too

I'll be using a 180gr pp boolit?

Thanks in advance

[gerrycan]

Hi I,m from Oz also and have had similar work on my big MH.
I kept up cleaning with steelwool and Brasso until I finally resorted to PP and valve-lapping paste.
I,m loading Trailboss at moment but any of your pistol powders will do[up to 16 grs, so I,ve heard].Keep away from ball powders [like 296 etc] they don,t like reduced loads.
All the best to you Gerry.

[docone31]

Simple,
Size to .308, wrap with two wraps of notebook paper, then size to .314.
Take valve lapping compound and lightly smear it on the loaded patch.
After about 20rds, the bore looks great.
My load is minimum start load data for 180gn jacketeds for paper patch.
Great results.

[303Guy]

A 'dark' 303 Brit bore cand be really 'dark'! I have cleaned out a bore that had been 'lapped' by a gunsmith and I was able to expose the grooves - he only 'polished' the bore.

I've done the same with my own rifles. I can get rust out of the deep pits in a bore.

Here's how I do it.


The bit on the nose (L/H side) is there as a bore guide to make sure the 'working surfaces' traverse the bore true - especially the throat and leade.

The grooves that seat inside the case neck get filled with valve grinding paste. There is a bit that seats past the neck shoulder (the first groove - stays free of paste). This keeps all grit out of the chamber. The bands are actually over groove diameter so as to force the grit into the corners. I used AR2205. Enough powder is needed to make sure the 'fire-lapping bullet' goes all the way through.

A fired one.



Then proceed with normal fire-lapping using patched boolits followed by normal patched boolits.

In my opinion, a 303 Brit is a good candidate for paper patching (and even plain cast) because of the oversize throat they came out with and the shallow leade angle coupled with the hot and erosive cordite propellant used. One ends up with a tapered bore that can accept a way oversize boolit.

[no34570]

Thanks fella's
I'm going to do what you suggest,all good info.
Will stay away from ball powders gerrycan.

[no34570]

A 'dark' 303 Brit bore cand be really 'dark'! I have cleaned out a bore that had been 'lapped' by a gunsmith and I was able to expose the grooves - he only 'polished' the bore.

I've done the same with my own rifles. I can get rust out of the deep pits in a bore.

Here's how I do it.


The bit on the nose (L/H side) is there as a bore guide to make sure the 'working surfaces' traverse the bore true - especially the throat and leade.

The grooves that seat inside the case neck get filled with valve grinding paste. There is a bit that seats past the neck shoulder (the first groove - stays free of paste). This keeps all grit out of the chamber. The bands are actually over groove diameter so as to force the grit into the corners. I used AR2205. Enough powder is needed to make sure the 'fire-lapping bullet' goes all the way through.

A fired one.



Then proceed with normal fire-lapping using patched boolits followed by normal patched boolits.

In my opinion, a 303 Brit is a good candidate for paper patching (and even plain cast) because of the oversize throat they came out with and the shallow leade angle coupled with the hot and erosive cordite propellant used. One ends up with a tapered bore that can accept a way oversize boolit.

303guy
What the heck are those in the pics,?look cool they do

[303Guy]

Those are brass 'fire-lapping bullets'. I machined them up. They were sized to only just enter the throat and the 'nose' piece rode the bore with slight contact. They get all the rust out a bore prior to the paper patch fire-lapping treatment.

The problem with rust is that it bites back reducing the effectiveness of fire-lapping further down the bore. Not with these things!

[no34570]

Those are brass 'fire-lapping bullets'. I machined them up. They were sized to only just enter the throat and the 'nose' piece rode the bore with slight contact. They get all the rust out a bore prior to the paper patch fire-lapping treatment.

The problem with rust is that it bites back reducing the effectiveness of fire-lapping further down the bore. Not with these things!

I suppose you could use oversize brass rod,would that still do the job?.
Or brass bolts?,I have no way of making those
Any other ideas I could use like that?
Bloody cool though mate,I like them,makes me want to get myself a lathe now(thats all I need,no where to put it)

[no34570]

Is it true that when you firelap a barrel,don't you have to have the speed around 600fps?
I seem to have heard that somewhere,might have been on this forum.

I was thinking of using 4.0- 5.0grs of Bullseye behind the 180gr boolit hoping to get around that speed,for I know that 7.0grs will give me around 1050fps???

Comments?

[barrabruce]

I'd use a bit of dacron to fill the case up with the bulleye.
Or tip the barrell up.
I haven't tried that powder yet so I really don't know but I think thats what they do.
Good luck with it
Barra
One day if someone wants to give me one I'll shoot the milatary shoot with PP bullets.

[303Guy]

I'd suggest trying paper patched boolits with imbedded grit as a first measure, as per docone31's suggestion. Only if a few of those do not get subborn rust out would I consider the 'fire-lapping bullet'. Use a soft-ish lead and a stiff-ish powder charge i.e. a normal starting load. The lead core will obturate, forcing the grit against the bore.

Or brass bolts?

Brass bolts could work. definately not solid brass rod - it's jam in the throat and anyway, it needs grooves to hold the abrasive and ribs to push the abrasive into the grooves. And somewhere for the displaced brass to go.

If you are going to try brass bolts, I would suggest filing down the diameter of a bit to fit the muzzle neatly so that there is a bit of a guide. Only apply the abrasive in the threads that are covered by the neck and let the filed down bit stick out like a bullet.

P.S. I did manage to get a few jammed in the throat. That was caused by the 'lapping bullet' moving on chambering and getting grit into the throat where it was unable to 'jump-start' down the bore. That and the fact that those were too long with too many grooves. It's a hell of a job getting the things out! They cannot be knocked out from the muzzle end with a rod. They have to be drilled out. I made a special tool for that purpose.

[no34570]

I'd suggest trying paper patched boolits with imbedded grit as a first measure, as per docone31's suggestion. Only if a few of those do not get subborn rust out would I consider the 'fire-lapping bullet'. Use a soft-ish lead and a stiff-ish powder charge i.e. a normal starting load. The lead core will obturate, forcing the grit against the bore.

Brass bolts could work. definately not solid brass rod - it's jam in the throat and anyway, it needs grooves to hold the abrasive and ribs to push the abrasive into the grooves. And somewhere for the displaced brass to go.

If you are going to try brass bolts, I would suggest filing down the diameter of a bit to fit the muzzle neatly so that there is a bit of a guide. Only apply the abrasive in the threads that are covered by the neck and let the filed down bit stick out like a bullet.

P.S. I did manage to get a few jammed in the throat. That was caused by the 'lapping bullet' moving on chambering and getting grit into the throat where it was unable to 'jump-start' down the bore. That and the fact that those were too long with too many grooves. It's a hell of a job getting the things out! They cannot be knocked out from the muzzle end with a rod. They have to be drilled out. I made a special tool for that purpose.

Sounds wise to go with the PP boolits first I think
I would not like to get a brass bolt stuck in the bore.
I have lapping compound here so will use that,make up 10,fire 5,clean,then soak with bore foam,clean and if needs be more firelapping,thanks mate and to all.