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Thread: 308 Fire lap Question

  1. #1
    Boolit Master
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    308 Fire lap Question

    Need a recommended start charge for a fire lap load

    Been working on this all summer ...... I though it was me but Now i think it is this barrel

    M1 Garand 308 barrel made by Citadel ( yes the cheep one- out of business )

    its a new barrel less than 500 rounds of cast through it with some jacketed thrown in

    I just bore scoped it and think it needs firelaping
    I have seen worse and I have seen lots betterClick image for larger version. 

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    1 to smooth out the bore / rifling
    2 to increase throat dia a tiny bit if it was 301, i could use any bullet

    groups with it are not great cleaning it not bad (not leading with cast Water Droped)

    any bullet with a nose over 301 will not chamber

    311299 & the 30 xcb will not fit chamber with out pushing it back in the case or sticking a bullet

    so have been using rcbs 165 sil or rcbs 150g fn .300 nose and that is border line tight

    thanks

  2. #2
    Boolit Grand Master

    Winger Ed.'s Avatar
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    I'm a big 311299 fan and have used it in Springfield 03A3, and a M1A.
    My mold is a old one from before they changed it from that Coke bottle shape to the new one that looks like a bore rider.

    A little bit of chamber resistance is OK if you can chamber a round, pull it back out and see
    Some engraving from the rifling on the nose. In a lot of cases, it will improve accuracy.
    One of the Lyman books, I think it was the orange cover one that had a several page article about this.
    That little bit of engraving on a Lead boolit's nose won't come anywhere close to causing a dangerous pressure spike.

    You should still end up with the bolt being able to fully cycle, close, and lock from one round to the next.
    If you're getting a push back into the case neck, ya might need a bit more (roll) crimp.


    Everyone was all ga-ga about fire lapping back in the 80s-early 90s.
    I'd go easy with it. People who got a little aggressive doing it trashed a lot of barrels.
    Last edited by Winger Ed.; 08-06-2022 at 03:56 PM.
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  3. #3
    Boolit Master
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    I did a friends brand new Remington .308 that would not hit a pie plate at 100yards. Used jacketed ammo with "Flitz" impregnated into the jacket. Took 15 / 20 rounds but brought it around to a MOA shooter.

  4. #4
    Boolit Master
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    Do you know anyone with or are close to the tools to remove barrel? Being in the Garand receiver makes it kind of tough push through anything, pull through could be done maybe with muzzle guide but gets difficult at the end. What about if barrel removal is out go with making lead or epoxy lap set up avoiding the uncontrollable hard to monitor throat attack.
    Maybe a couple hundred pulls with JB paste would get you where you are at least almost happy.

  5. #5
    Boolit Master
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    Not really sure about removing the barrel for what you have described. Hand lapping or fire lapping will work. Fire lap a couple and see how it goes. You can always finish up with some hand lapping. It really does do a good job of smoothing out a contrary barrel.

  6. #6
    Boolit Master
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    That barrel looks a lot better than my Savage and it shoots 1/2MOA with the right jacketed loads, close to 1MOA with cast. It also would not chamber 311299's without a lot of force. Like yours the RCBS 165SIL was a very good bullet. Now days I use a nose sizer from NOE to get the proper fit for the nose ride bullets. I like a slight resistance when chambering.

    Also like yours the throat on mine makes the XCB seat deep into the case. The bullets still shoot very well, but, a crimp on gas check is a must.

    If you feel you must lap it then be very careful. As mentioned above, many have ruined a decent barrel by fire lapping. If I were lapping I'd set it up for a hand lap instead.

  7. #7
    Boolit Buddy
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    I have seen to many barels ruined. The last one shot did it in> shoot and clenne with borteck ilimator. Will break in, in 50 too 100 rounds. Just use a plastic or aluninum jag. Bortec will desolive a brass one in no time>>

  8. #8
    Boolit Master
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    Well I started to fire lapp it
    started with 5 rounds of the fine grit only
    4.2 g of unique with a gc rcbs 150g fn .... I think i could see the bullet go down range App 4 ft of drop at 100

    took it home and cleaned and bore scoped it ... maybe a very small change but it does look better

    will try another 5 rounds of Fine next trip

  9. #9
    Boolit Master Hannibal's Avatar
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    Before you spend too much time with it I would suggest that you slug the barrel to make sure it's not loose at the muzzle compared to the chamber. I had a Savage that would shoot jacketed bullets at 1 1/2" @ 100 yds but cast was 4" plus. Slugged the barrel and it was .002" larger at the muzzle than at the chamber end. The slug would be tight at the chamber, begin to push easy about a third of the way down and fall out with gravity at about 2/3rds of the way down. Returned it to Savage twice and they never did fix the issue so I got tired of messing with it and sold the rifle. The second time I got a message saying it met their accuracy expectations but they never sent a target back with it.

    Might save you some time and frustration if your barrel is similar. Hopefully that's not the case. There are several threads and stickies on barrel slugging on the forum if you've never done it.

    Edit to add : While you're in there with your borescope, check to make sure your throat is concentric with the rifling all the way around. If the throat/leade is not concentric to the bore you'll likely never get a cast load to shoot with satisfactory accuracy.
    Last edited by Hannibal; 08-15-2022 at 01:46 PM.

  10. #10
    Boolit Master
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    Update
    Well I started with 5 rounds of the fine grit only (Wheeler barrel lapping kit)
    Hard to see any change 4.2 g of unique with a gc rcbs 150g fn .... I think i could see the bullet go down range App 4 ft of drop at 100
    shot 5 over a chono ..... 850/ 900 fps

    Next did 5 plus five rounds of Med grit =(10) and then cleaned and bore scoped a bit better also notices it had a bit of cleaning patch lint caught on a sharp edge at the gas port hole

    next outing did 5 plus five rounds of course grit =(10)

    So Have a total of 25 fire lapp rounds down the barrel and going to stop here, maybe a very small change but it does look better

    I will repeat it here this 308 Barrel was not made very well, company that made barrel went out of business many years ago
    it has some (still) ugly reamer marks that you can see with a bore scope

    this rifle was to be my rainy day / take to the club / Hunt & shoot it and not worry rifle , Club level 100 yard fun shoot, etc
    that i Do not care how many rounds go down the pipe, Cast just make it more affordable and 308 make it just a bit cheaper to shoot
    parts were not the best looking and has no collector value, other than it a Garand, that I put together for my self.

    I do have a another garand that I would not take out of the safe on a rainy day, that I like to shoot too that has a criterion barrel in it
    that when you bore scope it looks way way better

  11. #11
    Boolit Master


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    Fine first, then medium, followed by course? sounds like the order is reversed to me.
    With regard to the trajectory, it was my impression that any charge that got the bullet out the barrel was adequate.
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  12. #12
    Boolit Master
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    Well, that 's a lot of fire lapping. have you shot it for score since the lapping? Any change?

  13. #13
    Boolit Grand Master

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    Traditionally- metal removal is done with the coarse first, then medium, and the fine is done last as a polishing.
    In school: We learn lessons, and are given tests.
    In life: We are given tests, and learn lessons.


    OK People. Enough of this idle chit-chat.
    This ain't your Grandma's sewing circle.
    EVERYONE!
    Back to your oars. The Captain wants to waterski.

  14. #14
    Boolit Master
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    the Wheeler kit i have coarse grit is 220.

    I am going to shoot it a bit and see what happens .. I can always use some fine grit in the future
    Going to do a work up load using the 311299 . Was using the rcbs 165 sil as that was the only bullet that came close to fitting and extracting with out being pulled out of the case

    Click image for larger version. 

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    This is a pic of the gas port , before barrel was put on

    It shaved lead and snaged cleaning patches
    it Does not do this now

    I put some jacketed down barrel first the some cast/ then more cast then tried the lapping compound

  15. #15
    Boolit Master
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    Quote Originally Posted by Winger Ed. View Post

    Everyone was all ga-ga about fire lapping back in the 80s-early 90s.
    I'd go easy with it. People who got a little aggressive doing it trashed a lot of barrels.
    I've done a little of it and I'd advise the same thing; go easy with it.
    Instead of the conventional abrasives, maybe try some JB Compound. It's less aggressive and non-embedding, so there's a reduced chance of ruining anything.
    Warning: I know Judo. If you force me to prove it I'll shoot you.

  16. #16
    Boolit Master Rapier's Avatar
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    Nothing like upside down and backwards. Another customer in the works.

    First thing about cast bullet shooting, bore, all of it, must be clean and smooth for the best results. Fire Lapping; Very, very slow velocity, just make it out the muzzle type slow, 5 shots then clean, examine. Course to finest in steps, no skipping steps. You must remove the crud with the course. Once all the crud is removed, and it is polished with the fine, slug the barrel again, start load development again. I have done literally hundreds of barrels.
    Do you know what is used to finish fire lapping a 22 LR competition barrel? Pine rosin. That is a fine finish.
    Good shooting.
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Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check