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View Full Version : Firelapping, what velocity?



geargnasher
06-07-2010, 03:19 PM
I've done some reading on the subject here and elsewhere, but keep finding conflicting information and am trying to sort facts from "opinions", hope someone here can help.

The patient is a late-fifties 336 in .30-30 with the Micro-groove rifling. Chamber is perfect, but the bore has a few patches of rust, mostly in the grooves, causing leading and accuracy degradation after a 10-15 rounds. The gun is a great shooter when clean, and I've been trying to get the rust just polished down so it will quit grabbing lead. It only leads in three or four of the grooves (same ones each time) and I'm convinced I have good boolit fit and the usual suspects sorted out, including a thorough alternating delead/decopper electro-chemical treatment, and I've sworn off shooting J-words through it unless I have no other choice.

So far I've fired four series of five Loverin boolits imbedded with 320 grit Clover compound through it, with a cleaning/deleading and a box of regular cast between each lapping series. This has helped, but not much seems to be improving at the muzzle end. The firelapping loads are 23 grains 748 for about (est.) 15-1600 fps. Is this too fast, or is the grit just dead by the time it gets to the muzzle? Any better ideas on how to clean up this old carbine? Any help would be appreciated.

Gear

BABore
06-07-2010, 03:45 PM
Yes! Waaaaaay to fast. You want 500-600 fps.

I try to use a boolit with alot of bearing surface and preferrably not a bore ride type. A GC boolit, sans GC, is fine. Use a 11-13 bhn boolit cast from straight WW's as cast. Coat the boolit with a gob of Clover 320 grit and roll between plates til it is embedded good. The bands should look black. It should take you 2-3 minutes to coat one boolit. fill the lube grooves with compound. Clover brand lapping compound is silicon carbide suspended in a heavy grease. It breaks down into smaller grits as it goes down the bore. The ACWW boolit will get sized down as it passes under a constriction and wears it away. The lapping process works progressively from breech to muzzle.

Use unsize cases that were fired in your gun. Extend out the decapping pin and deprime them, then reprime. Use about 2 grains of something like Red Dot and put in a tuft of Dacron to keep the powder close to the coals. Gently seat the boolit and try to not drop it in the case. Try one and make sure it exits the bbl. Shoot 5 and clean completely, then repeat. I initially clean the gun and inspect the grooves at the muzzle from an angle. Take a pic if necessary. You need to know what the tooling marks and rifling look like. When the lapping proceeds to just, and I mean just, start to abraid on those marks, STOP. I have found that most all the rifles and pistol I've done take between 25 and 35 lapping rounds total.

Now, clean the bore well. Then, take an old bronze bore brush and wrap it with a long strip of cotton. I use an old pair of skivvies and cut a 1/2" wide strip from below the waist band. Wrap the brush til it is a very tight fit. Coat it well with lapping compound and push it from breech to muzzle and don't leave it come out either end once it's in the bbl. This back and forth is one stroke. Do 99 more in rapid succession. When done the bbl will be warm. Clean it one last time and you will freak at how smooth it is. I then break it in as you would a new gun

I've done many guns like this as well as having shown others. I've never had it fail to improve accuracy. Usually drastically. Everything I've stated here is as I've digested it from the Beartooth Bullets manual. LBT's instructions are similar.

Doc Highwall
06-07-2010, 03:47 PM
I had to fire-lap a muzzle loader and I put some lapping compound on the bullet and loaded it then put some lapping compound on a patch and coated the bore with it. I used 800 grit compound.

rhbrink
06-07-2010, 03:58 PM
Maybe try some of the you know what, copper patched, just a passing fancy, type bullits. Might be hard enough to iron out those rough spots. I did a firelap job last week with paperpatch, 400 grit, took about 10 shots greatly improved a old rusty Mosin. The first couple that I did I couldn't get the lapping compound to stick on the paperpatch, everywhere else but not where I wanted it. Had some JB bore cleaning compound with me so wiped some on a boolit and lightly rubbed lapping compound on that and it worked. Something that I noticed is that everytime that I fired one and then cleaned the barrel I pulled out lead. Wasn't happy with that but went ahead anyway. Finally shot up my special lapping loads and decided what the heck fired off a few paperpatch rounds and shot the best group ever with that rifle with cast and no lead. So guess it works can't wait to get back to the range to try some more.

357maximum
06-07-2010, 04:31 PM
Gear.......My advice is to do it the way BaBore says, he knows what he is doing...............hope his hat still fits after that statement.:kidding:

He took my 35Whelen from shooting decent pyramid shaped groups into a barrel that now shoots tiiiiiiight round groups. 3 grains of reddot was the charge used in the 35whelen case and your 30/30 would likely work with 1.5 to 2 grains of reddot.

geargnasher
06-08-2010, 12:19 AM
WOW. Thank you Mr. Brandt! The lightbulb is on now, all I had to do is ask, that's what I love about this place!

I was using some Loverin boolits that WilJen sent me just for the purpose since I didn't have a firelap-suitable mould in .30 caliber. Also, I wasn't embedding them with enough grit. I was afraid to roll the boolits too much and make them undersized, although they were about the right bhn. I'll try again.

Gear

largom
06-08-2010, 07:25 AM
I have fire-lapped many dozens of barrels very similar to BaBores method only I use a finer grit compound and finish up with JB. I put duct tape over the muzzle to prevent pushing thru which would damage the crown. I also use a one caliber under nylon bore brush wrapped with cotton cloth for the JB treatment.

The fire-lap will probably lengthen your throat slightly which is a very good thing for your 30-30. I have never had a barrel that was not improved by fire-lapping and do this automatically to all of my own personel guns.

Larry

Molly
06-09-2010, 02:45 PM
Maybe try some of the you know what, copper patched, just a passing fancy, type bullits. Might be hard enough to iron out those rough spots. I did a firelap job last week with paperpatch, 400 grit, took about 10 shots greatly improved a old rusty Mosin. The first couple that I did I couldn't get the lapping compound to stick on the paperpatch, everywhere else but not where I wanted it. Had some JB bore cleaning compound with me so wiped some on a boolit and lightly rubbed lapping compound on that and it worked. Something that I noticed is that everytime that I fired one and then cleaned the barrel I pulled out lead. Wasn't happy with that but went ahead anyway. Finally shot up my special lapping loads and decided what the heck fired off a few paperpatch rounds and shot the best group ever with that rifle with cast and no lead. So guess it works can't wait to get back to the range to try some more.

I've had great success using jacketed bullets with half normal loads. Takes about six shots. I know of others who have done this with similar success. Leaves a bore mirror bright, with - at least in my case - no measurable bore wear.

geargnasher
07-04-2010, 05:09 PM
Ok update!

After firing four sets of five embedded boolits with three grains of Titegroup and about a grain of Dacron with deep cleanings between each set I finally started to see little scratches on the lands near the muzzzle. I figured I'd stop right there, do the tight-patch routine, and see how she does. I can always do more later.

Finally got the gun completely clean and properly lubed, went out this afternoon and shot two, five-shot 50-yard groups just under two inches and put the last 13 in the box into 1-3/4", and this was with my fading eyes, poor light, shade over the target, and an old barrel and towell used for a rest (shooting bench is the next projet for my home range now that I've cleared brush out to 50 yards and built a berm there). I'm REALLY happy with that, I thought this barrel was a goner when I pulled it out of storage and found the rust. I did find some 50-yard targets from 15 or more years ago that I shot with this gun and J-words, it would only shoot 2" then.

All that with no leading that I can see. Some of the rust patches are still there, but they must be below level since the bore is super-smooth and no grey streaks following the rust.

Thanks again for all the help, I'm going to load some more and post pics if I get any consistent groups that are better than these.

Gear